- Email: [email protected]
Traffic at residential address, respiratory health, and atopy in adults: the National German Health Survey 1998
ARTICLE IN PRESS
Environmental Research 98 (2005) 240–249 www.elsevier.com/locate/envres
Traffic at residential address, respiratory health, and atopy in adults: the National German Health Survey 1998 Joachim Heinricha,, Rebekka Toppa, Ulrike Gehringa,b, Wolfgang Thefeldc a
GSF-National Research Center for Environment and Health, Institute of Epidemiology, Ingolsta¨dter LandstraX e 1, D-85764 Neuherberg, Germany b Ludwig-Maximilians University (LMU)-IBE, Chair of Epidemiology, Munich, Germany c Robert-Koch-Institut, Berlin, Germany Received 4 May 2004; received in revised form 30 July 2004; accepted 10 August 2004 Available online 27 September 2004
Abstract Motor vehicle traffic contributes to more than 50% of PM10 in Europe and might have far reaching impacts on human health. We investigated the relationship between residential street type as a surrogate for traffic intensity and the prevalence of respiratory symptoms, atopic diseases, and allergic sensitization in adults. Data from 6896 subjects of the German Health Survey 1998 with complete information on residential street type were used. Multiple logistic regression analyses were applied to model associations between street type categories, and respiratory and atopic outcomes were assessed by screening questionnaire of The European Respiratory Health Survey and specific IgE measurements. Living at extremely or considerably busy roads (23.9% of total study population) compared to roads with no or rare traffic (64.5%) was statistically significantly associated with chronic bronchitis (aOR 1.36 (95% CI) (1.01–1.83)) while nocturnal coughing attacks (past 12 months) (1.24 (0.98–1.57)), wheeze during the past 12 months (1.21 (0.93–57)), and hay fever (1.16 (0.94–1.42)) were marginally increased after adjustment for several potential confounders and for multiple testing. No increased risks were found for asthma (0.97 (0.67–1.42)) and allergic sensitization (1.05 (0.91–1.20)). We conclude that exposure to traffic-related air pollutants increases the risk of nonallergic respiratory symptoms and to a lesser degree the risk of hay fever and allergic sensitization but not the risk of asthma in adults. r 2004 Elsevier Inc. All rights reserved. Keywords: Traffic intensity; Respiratory symptoms; Allergic sensitisation; Adults; Germany
1. Introduction Traffic is a major source of air pollutants in urban areas. In Europe, exhaust from motor vehicle traffic is considered to contribute more than 50% of PM10 (Fillinger et al., 1999; Kunzli et al., 2000). Several surrogates have been used to assess exposure to traffic-related pollutants: self-reported residence on specific street types, which may be different with regard to traffic intensity, or self-assessment of traffic intensity or distance to major roads (Nitta et al., 1993; Weiland et al., 1994; Duhme et al., 1996; Ehrenstein et al., 1999; van Vliet et al., 1997; Ciccone et al., 1998), investigatorCorresponding author. Fax: +49-89-3187-3380.
E-mail address: [email protected] (J. Heinrich). 0013-9351/$ - see front matter r 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.envres.2004.08.004
based assessment of distance to a major road including usage of GIS data (van Vliet et al., 1997; Brunekreef et al., 1997; Venn et al., 2000; Janssen et al., 2003; Carr et al., 2002; Nicolai et al., 2003), data on traffic counts at residential address (Wjst et al., 1993; Wyler et al., 2000; Zmirou et al., 2004), measurements of NO2 and/or particle mass in communities (Studnicka et al., 1997; Braun-Fahrla¨nder et al., 1992; Guo et al., 1999; de Marco et al., 2002), in schools (van Vliet et al., 1997; Brunekreef et al., 1997), or at residential address or areas (Kra¨mer et al., 2000; Hirsch et al., 1999; Forsberg et al., 1997; Lee et al., 2003; Guo et al., 1999), and finally sophisticated exposure models using GIS data at residential address and measurements of traffic-related air pollutants (Brauer et al., 2002; Bellander et al., 2001; Gehring et al., 2002; Carr et al., 2002; Nicolai et al.,
ARTICLE IN PRESS J. Heinrich et al. / Environmental Research 98 (2005) 240–249
2003; Briggs et al., 1997, 2000; Oosterlee et al., 1996). Most of these studies were cross-sectional studies (Wjst et al., 1993; Oosterlee et al., 1996; Nitta et al., 1993; Nakatsuka et al., 1991; Weiland et al., 1994; Studnicka et al., 1997; Braun-Fahrla¨nder et al., 1992; English et al., 1999; Hirsch et al., 1999; van Vliet et al., 1997; Brunekreef et al., 1997; Duhme et al., 1996; Guo et al., 1999; Kra¨mer et al., 2000; Carr et al., 2002; Nicolai et al., 2003), but recently exposure to traffic-related pollutants has been also evaluated by cohort study designs (Brauer et al., 2002; Gehring et al., 2002). Of these studies only a few evaluated potential respiratory health impacts in adults (Oosterlee et al., 1996; Wyler et al., 2000; Nitta et al., 1993; Lercher et al., 1995). The cross-sectional studies have consistently found the prevalence of nonallergic respiratory symptoms to be elevated in subjects living in more polluted communities or close to major roads (Oosterlee et al., 1996; Nitta et al., 1993; Nakatsuka et al., 1991; Braun-Fahrla¨nder et al., 1992; Weiland et al., 1994; Duhme et al., 1996; Hirsch et al., 1999; English et al., 1999; Nicolai et al., 2003; Kra¨mer et al., 2000) with the exception of a few studies (Wjst et al., 1993; Carr et al., 2002; Lercher et al., 1995). Several studies showed even stronger associations with respiratory symptoms if truck traffic intensity was used as the traffic exposure surrogate (Brunekreef et al., 1997; Weiland et al., 1994; Ciccone et al., 1998). With regard to the prevalence of asthma, nonspecific allergies, hay fever, and allergic sensitization, the results are diverse. One of the two large German ISAAC studies in Munich found statistically significant associations between trafficrelated air pollution and current wheeze and eczema (Nicolai et al., 2003), whereas the other ISAAC study conducted in Dresden did not (Hirsch et al., 1999). Both studies did not find any association between traffic-related pollution and allergic sensitization. The Dutch ISAAC II study found more respiratory symptoms near motorways with high truck but not high car traffic counts (Janssen et al., 2003). Lung function and bronchial hyperreactivity were not related to air pollution. Pollen sensitization was increased in relation to truck but not car traffic counts (Janssen et al., 2003). The reasons for these heterogeneous study results are unclear. Self-reported traffic intensity is presumably a subjective measure, which leads to misclassification, in particular, if the study area comprises rural and urban areas. Studies which analyzed a combination of urban and rural areas failed to show effects of traffic (Ciccone et al., 1998; Kra¨mer et al., 2000), while analyses stratified for rural and metropolitan areas showed effects for the urban areas (Ciccone et al., 1998; Kra¨mer et al., 2000). However, if nonurban areas were considered, one Austrian study reported strong statistically significant associations between asthma and annual average of NO2 concentrations (Studnicka et al., 1997) and a Swiss study did not (Braun-Fahrla¨nder et al.,
241
1992) although similar methods were used. Another reason for the heterogeneity might be residual confounding by socioeconomic factors. Finally, several of these studies had only a small sample size and found effects on allergic sensitization in even smaller subgroups with a long duration of living at current address or only for pollen sensitization (Wyler et al., 2000; Janssen et al., 2003). Here, we analyze the relationship between traffic intensity at residential address using residential street type as a surrogate and prevalence of respiratory symptoms such as bronchitis and cough, asthma, hay fever, and IgE antibodies in serum against common aeroallergens using data from adults in the German Health Survey 1998.
2. Methods 2.1. Study design This is a cross-sectional study which investigates questionnaire-derived data on street type at the home address in relation to respiratory health and atopy assessed by blood tests using data from the German Health Survey 1998. 2.2. Study population Between October 1997 and March 1999 the National Health Survey investigated 7124 subjects (response rate 61%) aged 18–79 years from a population-based sample, which is representative with regard to age, gender, and community size with an oversampling to the general population of the East German area. Methods and population selection are described in detail elsewhere (Bellach et al., 1998; Thefeld et al., 1999). Data on traffic intensity were not available from 228 of the 7124 participating subjects. These participants were therefore excluded from the present analyses. Thus, the study population consisted of 6896 subjects (97% of the study participants). 2.3. Data collection Self-administered questionnaire-based data were used from the public use file BGS98 which was provided by the Robert-Koch-Institute, Berlin, Germany. Moreover, a screening test for allergic sensitization against common aeroallergens (SX1) was performed in subjects’ sera (details are mentioned below). 2.4. Traffic intensity questions To assess traffic intensity we used the question: Is your home located at an extremely busy road,
ARTICLE IN PRESS 242
J. Heinrich et al. / Environmental Research 98 (2005) 240–249
considerably busy side street, not busy side street, or on a street with no or very rare traffic? The first two and the last two categories were combined and so three categories representing low, moderate, and high traffic intensity were created. Furthermore, data about annoyance by street traffic noise were derived from the following question: How much do you feel annoyed, also during nights, by noise caused by street traffic? The answering categories were very strong, medium, not strong. 2.5. Questionnaire on respiratory health The German version of the screening questionnaire of the European Community Respiratory Health Survey (ECRHS) was used in the 1998 German National Health Survey (Burney et al., 1994; Heinrich et al., 2002). For our analyses we used only data from this questionnaire for wheeze and nocturnal attacks of coughing during the past 12 months. According to the screening questionnaire and the ECRHS methodology, asthma was defined as having an asthma attack during the past 12 months or current use of asthma medication (Burney et al., 1994). In addition, we defined atopic asthma as subjects having current asthma and a positive test result to SX1 and nonatopic asthma as subjects having had asthma but a negative SX1 test. Atopic wheeze and nonatopic wheeze were defined analogously. For the assessment of presence of hay fever the ECRHS question ‘‘Do you currently have nasal allergy including hay fever?’’ was used. For the assessment of chronic bronchitis we used data from the question ‘‘Which of the following diseases have you ever had?’’ The answering category was chronic bronchitis, e.g., coughing during the night without cold and phlegm in the morning most of the days for at least 3 months per year in 2 successive years. Furthermore, the highest educational level was recorded and categorized as low (less than 10 grades), medium (10 grades), and high (more than 11 grades). Smoking history was reported in detail and the numbers of pack-years were calculated using the methods by Junge and Nagel (1999), which also included smoking of cigars and tobacco smoking in pipes. 2.6. Allergic sensitization Allergic sensitization was assessed by measuring specific IgE to common inhalant allergens in serum, using the Pharmacia SX1 test (Pharmacia, Uppsala, Sweden). The SX1 is a screening assay to identify specific allergic sensitization against mite, cat, dog, Cladosporium herbarum, and pollen allergens (timothy, grass, rye, birch, and mugwort). The SX1 test is a qualitative test. The categorization of the assay results as positive or
negative was based on the recommendations of the test manufacturer. 2.7. Statistical analyses To check whether the characteristics of the study population differed between the three traffic exposure categories we applied the Jonckheere–Terpstra trend test for ordinal variables (Pirie, 1983) and used a linear regression analysis for trend testing with continuous variables. To assess the association between respiratory health outcomes and traffic exposure we applied single and multiple linear logistic regression models. As we tested various health outcomes on our data set we corrected the level of significance for multiple testing using the formula of Tippelt–Holmes (ai=1(1a)(1/ (ni+1)) ). All analyses were carried out using SAS V8 (SAS Institute, Cary, NC).
3. Results Data on traffic intensity at residential address was available for 6896 of the 7124 adults (96.8%). Table 1 shows characteristics of the study population. According to the type of road at residential address, 23.9% of the subjects were highly exposed to traffic-related air pollutants and 64.5% to low or no traffic exhaust at their home address (Table 2). Table 2 also shows the prevalence rates for the respiratory outcomes and allergic sensitization. In addition prevalence rates for atopic asthma and atopic wheeze are provided. The association between traffic exposure at home address and participants’ characteristics is shown in Table 3. All of these characteristics were significantly different between the three traffic exposure categories. Table 4 shows nonadjusted and adjusted odds ratios (OR) for traffic exposure at home address and respiratory health outcomes and allergic sensitization. After adjustment for age, gender, education, community size, and packyears, the risk of chronic bronchitis remained significantly elevated for the highest traffic category (Table 4). The elevated crude OR for nocturnal attacks of coughing did not reach the level of statistical significance after confounder adjustment (Table 4). A marginally nonsignificant increased OR was found for hay fever, while no associations were found for asthma and prevalence of allergic sensitization (Table 4). In addition, the subdivision into atopic and nonatopic asthma and atopic and nonatopic wheeze did not show statistically significant effect estimates. Moreover, the results for nonatopic asthma and wheeze are even inconsistent. While the effect size estimate increased for nonatopic asthma compared to that of atopic asthma, the effect size estimate decreased for nonatopic wheeze compared to that of atopic wheeze (Table 4).
ARTICLE IN PRESS J. Heinrich et al. / Environmental Research 98 (2005) 240–249 Table 1 Characteristics of the study population (N ¼ 6896) n/N
243
Table 2 Description of exposure and health variables of the study population (N ¼ 6896) % n/N
%
Type of road at residence with Low traffic Moderate traffic High traffic
4448/6896 797/6896 1651/6896
64.5 11.6 23.9
Annoyance level from traffic noise low moderate high
680/2199 1169/2199 350/2199
30.9 53.2 15.9
Respiratory health: Chronic bronchitis (ever) Nocturnal attacks of coughing (past 12 months)
543/6692 939/6798
8.1 13.8
66.0 34.0
Asthmaa (past12 months) Atopic asthmab Nonatopic asthmab
301/6896 162/6896 128/6876
4.4 2.4 1.9
2223/6896 1071/6896 1191/6896 2411/6896
32.2 15.5 17.3 35.0
Wheeze (past 12 months) Atopic wheezec Nonatopic wheezec Hay fever Allergic Sensitizationd
721/6870 302/6896 393/6896 886/6783 1963/6518
10.5 4.4 5.7 13.1 30.1
Smoking status Never smokers Former smokers Current, daily smokers
3148/6338 1349/6338 1841/6338
49.7 21.3 29.1
Pack years 0 (0–5) (5–10) (10–20) X20
3148/6583 883/6583 519/6583 841/6583 1192/6583
47.8 13.4 7.9 12.8 18.1
Duration of living at current address (year) o1 173/6896 1–5 1908/6896 6–9 949/6896 X10 3866/6896
2.5 27.7 13.7 56.1
Gender Female Male
3538/6896 3358/6896
51.3 48.7
Age group 17–29 30–39 40–59 60–79
1254/6896 1513/6896 2592/6896 1537/6896
18.2 21.9 37.6 22.3
Education o10 years 10 years 410 years
2914/6696 2256/6696 1526/6696
43.5 33.7 22.8
Region West Germany East Germany
4554/6896 2342/6896
Community size o20,000 20,000–100,000 100,000–500,000 4500,000
a
Asthma attack or medication during past 12 months. Atopic asthma was defined as current asthma and positive SX1 test; nonatopic asthma was defined as current asthma and negative SX1 test. c Atopic wheeze was defined as current wheeze and positive SX1 test; nonatopic wheeze was defined as current wheeze and negative SX1 test. d Positive SX1 test. b
3.1. Gender Adjusted models with the full set of confounding variables from Table 4, with the exception of gender, showed similar effect estimates for men and women (data not shown). 3.2. Age group
Adjustments changed the effect estimates only marginally. While the risk for bronchitis was statistically significantly increased and the risks for nocturnal cough, wheeze, and hay fever were marginally increased for the highest traffic category (living on an extremely or considerably busy road; 23.9% of the total population), no increase in corresponding risks were seen for the moderate traffic category (living on a not busy side street; 11.6% of the total population). In addition to the fully adjusted models presented in Table 4, stratified analyses were performed to identify susceptible subpopulations and to reevaluate traffic-related effect estimates by residential region (West Germany versus East Germany) and community size.
Stratified analyses for the younger subjects aged 18–39 years and the older subpopulation aged 40 years or more did not change the effect estimates substantially (data not shown). 3.3. Residential area The traffic-related effect estimates on respiratory outcomes listed in Table 4 were similar when analyses were stratified for East and West German residential addresses (data not shown). 3.4. Community size Since the proportions of the high traffic categories ranged only marginally (21–26%) in the four commu-
ARTICLE IN PRESS J. Heinrich et al. / Environmental Research 98 (2005) 240–249
244
Table 3 Description of the study population by traffic exposure categories (N ¼ 6896) p value
Traffic exposure at home address Low (N ¼ 4448)
Moderate (N ¼ 797)
High (N ¼ 1651)
n
%
n
%
n
%
60.3 15.7 2.6
100 277 26
14.7 23.7 7.4
170 709 315
25.0 60.7 90.0
o0.0001a
445 352 47.7 [16.3]
12.6 10.5
889 762 45.2 [15.8]
25.1 22.7
0.0001a
Annoyance level from traffic noise, N ¼ 2199 Low 410 Moderate 183 High 9 Gender, N ¼ 6896 Female Male Age (mean [sd]), N ¼ 6896
2204 2244 45.3 [15.8]
62.3 66.8
Education, N ¼ 6696 o10 years 10 years 410 years
1855 1432 1035
63.7 63.5 67.8
327 264 184
11.2 11.7 12.1
732 560 307
25.1 24.8 20.1
0.0034a
Residential region, N ¼ 6896 West Germany East Germany
3084 1364
67.7 58.2
474 323
10.4 13.8
996 655
21.9 28.0
o0.0001a
Community size, N ¼ 6896 o20,000 20,000–100,000 100,000–500,000 4500,000
1497 702 760 1489
67.3 65.6 63.8 61.8
214 141 148 294
9.6 13.2 12.4 12.2
512 228 283 628
23.0 21.3 23.8 26.1
o0.0001a
Smoking status, N ¼ 6338 Never smokers Former smokers Current, daily smokers
2060 896 1137
65.4 66.4 61.8
388 161 191
12.3 11.9 10.4
700 292 513
22.2 21.7 27.9
0.0018a
Pack years, N ¼ 6583 0 1–5 6–9 10–19 X20
2060 569 346 507 757
65.4 64.4 66.7 60.3 63.5
388 104 52 93 135
12.3 11.8 10.0 11.1 11.3
700 210 121 241 300
22.2 23.8 23.3 28.7 25.2
0.0085a
a
0.0003b
Testing for trend using the Jonckheere–Terpstra test. Testing for trend using a linear regression model.
b
nity size categories (see Table 3), sensitivity analyses stratified for community size might be valuable. Fig. 1 shows adjusted estimates for high traffic exposure (home located on extremely or considerably busy road) versus low traffic exposure (home located on a street with no or very rare traffic) for respiratory outcomes and allergic sensitization by community size classes. The strongest and most significant effects on chronic bronchitis, nocturnal coughing attacks, and wheeze were found within the metropolitan areas (more than 500,000 inhabitants), while the effect estimates within the small (less than 20,000 inhabitants), medium (20,000–100,000 inhabitants), and large (100,000–500,000 inhabitants) community size classes did not show any statistically significant results. For the allergic outcomes asthma, hay fever, and allergic sensitization, no statistically
significant associations were found with traffic intensity within each of the four community size classes, except for hay fever and medium community size. 3.5. Moving According to the cross-sectional study design of this analysis, exposure was estimated on the basis of current residential address. Although most of the outcomes reflect the preceding 12 months and few had moved within the past 12 months (n ¼ 173; 2.5%), exposure prior to the past 12 months might also cause irreversible adverse respiratory health effects. Therefore, an additional analysis for the subpopulation that lived 2 or more years at the current address was performed. The crude effect estimates for bronchitis, coughing, and
ARTICLE IN PRESS J. Heinrich et al. / Environmental Research 98 (2005) 240–249
245
Table 4 Association between traffic and respiratory health and allergic sensitization Traffic exposure at home address Low (N ¼ 4448)
Moderate (N ¼ 797)
High (N ¼ 1651)
1 1
1.02 [0.68,1.55] 0.94 [0.60,1.46]
1.41 [1.06,1.87]b 1.36 [1.01,1.83]b
Nocturnal attacks of coughing (past 12 months) OR 1 Adjusteda OR 1
1.07 [0.79,1.46] 1.05 [0.76,1.45]
1.30 [1.04,1.62]b 1.24 [0.98,1.57]
Wheeze (past 12 months) OR Adjusteda OR Atopic wheezec OR aOR Nonatopic wheezec OR aOR
1 1 1 1 1 1
1.02 0.95 0.93 0.86 1.07 1.05
[0.72,1.44] [0.66,1.38] [0.54,1.59] [0.47,1.54] [0.69,1.64] [0.67,1.64]
1.22 1.21 1.40 1.43 1.09 1.05
[0.95,1.57] [0.93,1.57] [0.98,1.99] [0.99,2.07] [0.79,1.50] [0.75,1.48]
Asthmad (past 12 months) OR Adjusteda OR Atopic asthmae OR aOR Nonatopic asthmae OR aOR
1 1 1 1 1 1
0.78 0.74 0.60 0.52 0.89 0.87
[0.46,1.33] [0.43,1.28] [0.28,1.29] [0.23,1.20] [0.44,1.84] [0.42,1.82]
1.02 0.97 0.98 0.87 1.13 1.15
[0.72,1.46] [0.67,1.42] [0.62, 1.56] [0.52,1.44] [0.69,1.86] [0.69,1.93]
Hay fever (past 12 months) OR Adjusteda OR
1 1
1.06 [0.82,1.36] 1.10 [0.84,1.44]
1.12 [0.93,1.36] 1.16 [0.94,1.42]
Allergic sensitizationf OR Adjusteda OR
1 1
0.98 [0.83,1.16] 1.06 [0.88,1.27]
1.03 [0.91,1.17] 1.05 [0.91,1.20]
Chronic bronchitis (ever) OR Adjusteda OR
a
Adjusted for age, gender, education, community size, and pack years. Statistically significant after adjustment for multiple testing. c Atopic wheeze was defined as current wheeze and positive SX1 test; nonatopic wheeze was defined as current wheeze and negative SX1 test. d Asthma attack or medication in past 12 months. e Atopic asthma was defined as current asthma and positive SX1 test; nonatopic asthma was defined as current asthma and negative SX1 test. f Positive SX1 test. b
wheeze were not increased. No increased effect estimates could be identified for asthma, hay fever, and allergic sensitization (data not shown). 3.6. Nationality/ethnicity When subjects who were not born in Germany (n ¼ 645; 9.38%) were excluded from analyses, the effect estimates changed only marginally (data not shown). 3.7. Socioeconomic status (SES) Stratified analyses by educational level as surrogate for SES did not show consistent effect modification of exposure to traffic-related pollutants by SES (data not shown).
3.8. Smoking Stratified analyses for never and ever smokers did not show substantially different effect estimates on the outcomes listed in Table 4 (data not shown).
4. Discussion In this large national sample of adults we have found a statistically significant positive association between chronic bronchitis and traffic-related air pollutants using type of street at current home address as a surrogate measure. The positive associations between traffic intensity and nocturnal coughing attacks, current wheeze, and hay fever were not statistically significant. Statistically nonsignificant associations were observed with asthma and allergic sensitization. The statistically
ARTICLE IN PRESS 246
J. Heinrich et al. / Environmental Research 98 (2005) 240–249
Fig. 1. Traffic intensity (high versus low) and respiratory outcomes and allergic sensitization by community size after adjustment for age, gender, education, and smoking. Data from The National German Health Survey 1998, 6896 adults aged 18–79 years.
significant and the nonsignificant effect estimates were generally robust, did not change after multiple adjustments for potential confounders, and were similar in several subgroups. No single subgroup that might be considered to have a stronger susceptibility than others was identified. Even for the low socioeconomic status, where exposure to traffic is slightly higher, all effect estimates were similar to those of the other SES strata. Results of the present study on adults are in good agreement with the results of other studies on the effects of exposure to traffic-related pollutants and prevalence rates of bronchitis in children (Hirsch et al., 1999; Braun-Fahrla¨nder et al., 1992; Studnicka et al., 1997) and adults (Nitta et al., 1993), cough in children (Hirsch et al., 1999; Brunekreef et al., 1997; van Vliet et al., 1997; Braun-Fahrla¨nder et al., 1992; Ciccone et al., 1998; Gehring et al., 2002; Nicolai et al., 2003) and adults (Nitta et al., 1993), and wheeze in children (Wjst et al., 1993; Oosterlee et al., 1996; van Vliet et al., 1997; Ciccone et al., 1998; Nicolai et al., 2003; Brunekreef et al., 1997; Duhme et al., 1996) and adults. For reported asthma the results are less clear. However, the effects on nonallergic respiratory outcomes are more consistent in children than in adults. The wheezing effects are not consistent in adults and in children. While some studies found increased reporting of asthma (van Vliet et al., 1997; Studnicka et al., 1997; Guo et al., 1999; Duhme et al., 1996; Zmirou et al., 2004; Nicolai et al., 2003), others found no increased prevalence rates
(Braun-Fahrla¨nder et al., 1992; Hirsch et al., 1999; Wyler et al., 2000; Brauer et al., 2002; Janssen et al., 2003; Oosterlee et al., 1996; Lercher et al., 1995). The few studies that explicitly analyzed associations with hay fever also showed diverse results. Increased reporting of hay fever in relation to high exposure to traffic-related pollutants was found in studies in metropolitan areas (Weiland et al., 1994; Duhme et al., 1996; Lercher et al., 1995; Hirsch et al., 1999; Lee et al., 2003) or when the analysis was restricted to the urban/metropolitan areas (Ciccone et al., 1998; Kra¨mer et al., 2000), however, several other studies, also conducted in large communities, reported no statistically significant associations for hay fever (Wyler et al., 2000; Nicolai et al., 2003). When assessment of allergic sensitization by skin prick testing or blood test was implemented in studies on traffic-related health effect, some studies failed to show statistically significant positive associations in the total study population (Hirsch et al., 1999; Kra¨mer et al., 2000; Wyler et al., 2000; Nicolai et al., 2003), but others could find positive associations if the analyses were restricted to urban areas (Ciccone et al., 1998; Kra¨mer et al., 2000) or if only pollen sensitization was considered (Wyler et al., 2000; Janssen et al., 2003). It should be noted that most of these traffic-related studies exclusively investigated children and that most of these studies were conducted in Europe. The studies that include both children and adults found stronger associations between adverse respiratory health and traffic exposure in children than in adults (Lercher et al., 1995) and concluded that children might be more susceptible than adults (Oosterlee et al., 1996). Furthermore, children with hyperreactive airways and/or sensitization to common allergens were considered sensitive subgroup, since traffic-related increased respiratory health risks were restricted to them (Janssen et al., 2003). This study used the type of residential address street as a simple surrogate for exposure to traffic-related air pollutants. This might be in particular a major limitation if the study area is very heterogeneous with respect to population density and consequently traffic density. With increased population density or community sizes it seems plausible to assume more traffic and consequently increased ambient concentrations of exposure to trafficrelated air pollutants. However, the relative frequencies of the high traffic exposure category only slightly increase with increasing community size (Table 3). A similarly weak association was also seen between community size and traffic annoyance (Table 3). Therefore, an adjustment for community size and a sensitivity analysis for subjects living in areas of different community sizes are crucial. Indeed, analyses stratified by community size showed that the total effect estimates for chronic bronchitis, cough, and wheeze were mainly caused by the effect estimates for the metropolitan
ARTICLE IN PRESS J. Heinrich et al. / Environmental Research 98 (2005) 240–249
areas. We speculate that exposure misclassification in the smaller communities might be larger due to a lower heterogeneity in traffic-related exposures, within each of the community size strata. We might therefore speculatively conclude that exposure misclassification is different between community size classes. The subjective assessment of exposure to traffic-related pollutants by living at a specific type of street was validated by air pollution measurements (Oglesby et al., 2000a; Kuhlisch et al., 2002; Forsberg et al., 1997). However, these comparative studies on subjective versus objective assessment of exposure to traffic-related air pollution were mostly performed in homogeneous settings. When the study was heterogeneous as in the Swiss SAPALDIA study, the authors concluded that population mean score (subjective) rather than individual scores may serve as a simple tool for grading air quality within an area (Oglesby et al., 2000a, b). Another possible explanation for the observed affect in the largest communities (4500,000 inhabitants, see Fig. 1) might be that the entire exposure distribution is shifted toward sufficiently high concentrations where effects are detected. Although subjects living on a busy road are obviously exposed to higher levels of traffic-related pollutants than those living on a side street in areas with mostly low or even no traffic, several other factors such as lower active ventilation to avoid exposure to traffic noise need to be considered. Consequently indoor pollutants that have strong indoor sources such as tobacco smoke might be increased. In addition, buildings on busy streets might be different from those in quiet residential areas with regard to age, size, and height. Finally, subjects who were categorized according to their address street type might differ in many aspects other than the exposure of interest. Although we found only a weak association between type of street and SES, we could not exclude that using classifications other than educational level might lead to stronger associations. We cannot exclude residual confounding by SES, which is in agreement with the study of Nicolai et al. (2003), which also did not find any effect modification by SES. Low SES, even in the affluent society of Germany with no major social deprivation, is a strong predictor for poor health with the few exceptions of atopic dermitis and hay fever (Heinrich et al., 2000). The higher prevalence rates of hay fever and mild asthma in higher-social-class subjects and the supposed lower exposure to several environmental pollutants including traffic-related air pollutants might mask the association between traffic intensity and atopic outcomes even after adjustment for SES. In addition, several lifestyle-related factors such as diet, living characteristics, and smoking are known to be different among different socioeconomic strata (Heinrich et al., 2000). Thus, one might also speculate that the observed adverse effects of living
247
close to a busy freeway in Holland, which was seen only in low- to medium-SES children (van Vliet et al., 1997) might be related to the lower coping capability of lowsocial-class children. In addition, the cross-sectional design of this study did not allow for the evaluation of whether subjects with respiratory illness prefer not to live along busy traffic streets. Selective migration might be in particular a problem if the association between traffic-related air pollution exposure and asthma is assessed by crosssectional studies. A further limitation is related to the validity of selfreported respiratory health outcomes. Particular attention has to be paid to self-reported wheeze in adult studies and to using the German language, where no corresponding word is available. Whether wheeze is specific for asthma in the German language is still questionable. In adults, the wheeze symptom in particular is also associated with bronchitis. Even atopic wheeze was highly associated with chronic bronchitis in this study (16.6% versus 3.1% in subjects with and without chronic bronchitis). Thus, we are hesitant to evaluate the reported association between traffic intensity and wheeze exclusively as a major symptom of asthma. We could not exclude that perception of traffic intensity is equally distributed between diseased and nondiseased groups. So the effect estimates could be biased. However, no increased risk for attacks of asthma in relation to traffic-related exposures was found, although there is a common belief in the public that ambient air pollution causes asthma and strong evidence that ambient air pollutants might exacerbate asthma. Therefore, we would not consider our positive findings between exposure to traffic-related pollutants and respiratory health strongly biased by differential exposure misclassification, but we could not exclude bias for sure.
5. Conclusion Exposure to traffic-related air pollutants increased the risk of nonallergic respiratory symptoms such as chronic bronchitis but not the risk of atopic disorders or in particular the prevalence of allergic sensitization in adults.
Acknowledgments The authors thank Dr. Heribert Stolze (RKI, Berlin), who provided support to use the public use file, Hubert Schneller who designed the figures, and Regina Gillig for cautiously writing and editing the manuscript.
ARTICLE IN PRESS 248
J. Heinrich et al. / Environmental Research 98 (2005) 240–249
References Bellach, B.M., Knopf, H., Thefeld, W., 1998. The German Health Survey. 1997/98. Gesundheitswesen 60 (Suppl 2), S59–S68. Bellander, T., Berglind, N., Gustavsson, P., Jonson, T., Nyberg, F., Pershagen, G., Jarup, L., 2001. Using geographic information systems to assess individual historical exposure to air pollution from traffic and house heating in Stockholm. Environ. Health Perspect. 109 (6), 633–639. Brauer, M., Hoek, G., Van Vliet, P., Meliefste, K., Fischer, P.H., Wijga, A., Koopman, L.P., Neijens, H.J., Gerritsen, J., Kerkhof, M., Heinrich, J., Bellander, T., Brunekreef, B., 2002. Air pollution from traffic and the development of respiratory infections and asthmatic and allergic symptoms in children. Am. J. Respir. Crit. Care. Med. 166, 1092–1098. Braun-Fahrla¨nder, C., Ackermann-Liebrich, U., Schwartz, J., Gnehm, H.P., Rutishauser, M., Wanner, H.U., 1992. Air pollution and respiratory symptoms in preschool children. Am. Rev. Respir. Dis. 145, 42–47. Briggs, D., Collins, S., Elliott, P., Fischer, P., Kingham, S., Lebret, E., Pryl, K., van Reeuwijk, H., Smallbone, K., van der Veen, A., 1997. Mapping urban air pollution using GIS: a regression-based approach. Int. J. Geogr. Information Sci. 11, 699–718. Briggs, D.J., de Hoogh, C., Gulliver, J., Wills, J., Elliott, P., Kingham, S., Smallbone, K., 2000. A regression-based method for mapping traffic-related air pollution: application and testing in four contrasting urban environments. Sci. Total Environ. 253, 151–167. Brunekreef, B., Janssen, N.A., de Hartog, J., Harssema, H., Knape, M., van Vliet, P., 1997. Air pollution from truck traffic and lung function in children living near motorways. Epidemiology 8, 298–303. Burney, P.G., Luczynska, C., Chinn, S., Jarvis, D., 1994. The European Community Respiratory Health Survey. Eur. Respir. J. 7 (5), 954–960. Carr, D., von Ehrenstein, O., Weiland, S., Wagner, C., Wellie, O., Nicolai, T., von Mutius, E., 2002. Modeling annual benzene, toluene, NO2, and soot concentrations on the basis of road traffic characteristics. Environ. Res. 90 (2), 111–118. Ciccone, G., Forastiere, F., Agabiti, N., Biggeri, A., Bisanti, L., Chellini, E., Corbo, G., Dell’Orco, V., Dalmasso, P., Volante, T.F., Galassi, C., Piffer, S., Renzoni, E., Rusconi, F., Sestini, P., Viegi, G., 1998. Road traffic and adverse respiratory effects in children. SIDRIA Collaborative Group. Occup. Environ. Med. 55, 771–778. de Marco, R., Poli, A., Ferrari, M., Accordini, S., Giammanco, G., Bugiani, M., Villani, S., Ponzio, M., Bono, R., Carrozzi, L., Cavallini, R., Cazzoletti, L., Dallari, R., Ginesu, F., Lauriola, P., Mandrioli, P., Perfetti, L., Pignato, S., Pirina, P., Struzzo, P., 2002. ISAYA study group. Italian Study on Asthma in Young Adults. The impact of climate and traffic-related NO2 on the prevalence of asthma and allergic rhinitis in Italy. Clin. Exp. Allergy 32 (10), 1405–1412. Duhme, H., Weiland, S.K., Keil, U., Kraemer, B., Schmid, M., Stender, M., Chambless, L., 1996. The association between selfreported symptoms of asthma and allergic rhinitis and self-reported traffic density on street of residence in adolescents. Epidemiology 7, 578–582. Ehrenstein, O.S.V., Mutius, E.v., Nicolai, T., et al., 1999. Prevalence of asthma, BHR and atopy in children reporting increased exposure to traffic jam in Munich. Epidemiology 10, S171. English, P., Neutra, R., Scalf, R., Sullivan, M., Waller, L., Zhu, L., 1999. Examining associations between childhood asthma and traffic flow using a geographic information system. Environ. Health Perspect. 107, 761–767. Fillinger, P., Puybonnieux-Texier, V., Schneider, J., 1999. PM10 Population Exposure Technical Report on air pollution. Health Costs due to Road Traffic-related Air Pollution. An Impact
assessment project of Austria, France and Switzerland. Prepared for the Third WHO Ministerial Conference of Environment & Health, London, Bern, Paris, Wien. Forsberg, B., Stjernberg, N., Wall, S., 1997. People can detect poor air quality well below guideline concentrations: a prevalence study of annoyance reactions and air pollution from traffic. Occup. Environ. Med. 54 (1), 44–48. Gehring, U., Cyrys, J., Sedlmeir, G., Brunekreef, B., Bellander, T., Fischer, P., Bauer, C.P., Reinhardt, D., Wichmann, H.E., Heinrich, J., 2002. Traffic-related air pollution and respiratory health during the first 2 years of life. Eur. Respir. J. 19 (4), 690–698. Guo, Y.L., Lin, Y.C., Sung, F.C., Huang, S.L., Ko, Y.C., Lai, J.S., Su, H.J., Shaw, C.K., Lin, R.S., Dockery, D.W., 1999. Climate, trafficrelated air pollutants, and asthma prevalence in middle-school children in taiwan. Environ. Health Perspect. 107, 1001–1006. Heinrich, J., Mielck, A., Schafer, I., Mey, W., 2000. Social inequality and environmentally related diseases in Germany: review of empirical results. Soz. Praventivmed. 45 (3), 106–118. Heinrich, J., Richter, K., Frye, C., Meyer, I., Wo¨lke, G., Wjst, M., Nowak, D., Magnussen, H., Wichmann, H.E., 2002. Die Europa¨ische Studie zu Atemwegserkrankungen bei Erwachsenen (ECRHS). Pneumologie 56, 297–303. Hirsch, T., Weiland, S.K., von Mutius, E., Safeca, A.F., Grafe, H., Csaplovics, E., Duhme, H., Keil, U., Leupold, W., 1999. Inner city air pollution and respiratory health and atopy in children. Eur. Respir. J. 14, 669–677. Janssen, N.A., Brunekreef, B., van Vliet, P., Aarts, F., Meliefste, K., Harssema, H., Fischer, P., 2003. The relationship between air pollution from heavy traffic and allergic sensitization, bronchial hyperresponsiveness, and respiratory symptoms in Dutch schoolchildren. Environ. Health Perspect. 111 (12), 1512–1518. Junge, B., Nagel, M., 1999. Smoking behavior in Germany. Gesundheitswesen 61 (Dec), S121–S125. Kra¨mer, U., Koch, T., Ranft, U., Ring, J., Behrendt, H., 2000. Trafficrelated Air Pollution is associated with atopy in children living in urban areas. Epidemiology 11, 64–70. Kuhlisch, W., Hirsch, T., Olunczek, U., Vollheim, B., Gross, B., During, I., Weiland, S.K., Leupold, W., 2002. Validierung von subjektiven Angaben zur Verkehrsexposition durch Verkehrsza¨hlungen, NO2-Ausbreitungsmodellierungen und NO2-Immissionsmes-sungen. Soz. Praventivmed. 47 (2), 116–123. Kunzli, N., Kaiser, R., Medina, S., Studnicka, M., Chanel, O., Filliger, P., Herry, M., Horak, F., Puybonnieux-Texier, V., Quenel, P., Schneider, J., Seethaler, R., Vergnaud, J.C., Sommer, H., 2000. Public-health impact of outdoor and traffic-related air pollution: a European assessment. Lancet 356, 795–801. Lee, Y.L., Shaw, C.K., Su, H.J., Lai, J.S., Ko, Y.C., Huang, S.L., Sung, F.C., Guo, Y.L., 2003. Climate, traffic-related air pollutants and allergic rhinitis prevalence in middle-school children in Taiwan. Eur. Respir. J. 21 (6), 964–970. Lercher, P., Schmitzberger, R., Kofler, W., 1995. Perceived traffic air pollution, associated behavior and health in an alpine area. Sci. Total Environ. 169 (1–3), 71–74. Nakatsuka, H., Watanabe, T., Ikeda, M., Hisamichi, S., Shimizu, H., Fujisaka, S., Ichinowatari, Y., Konno, J., Kuroda, S., Ida, Y., et al., 1991. Comparison of the health effects between indoor and outdoor air pollution in Northeastern Japan. Environ. Int. 17, 956–963. Nicolai, T., Carr, D., Weiland, S.K., Duhme, H., von Ehrenstein, O., Wagner, C., von Mutius, E., 2003. Urban traffic and pollutant exposure related to respiratory outcomes and atopy in a large sample of children. Eur. Respir. J. 21 (6), 956–963. Nitta, H., Sato, T., Nakai, S., Maeda, K., Aoki, S., Ono, M., 1993. Respiratory health associated with exposure to automobile exhaust. I. Results of cross-sectional studies in 1979, 1982, and 1983. Arch. Environ. Health. 48, 53–58.
ARTICLE IN PRESS J. Heinrich et al. / Environmental Research 98 (2005) 240–249 Oglesby, L., Kunzli, N., Monn, C., Schindler, C., AckermannLiebrich, U., Leuenberger, P., 2000a. Validity of annoyance scores for estimation of long term air pollution exposure in epidemiologic studies: the Swiss Study on Air Pollution and Lung Diseases in Adults (SAPALDIA). Am. J. Epidemiol. 152 (1), 75–83. Oglesby, L., Kunzli, N., Roosli, M., Braun-Fahrlander, C., Mathys, P., Stern, W., Jantunen, M., Kousa, A., 2000b. Validity of ambient levels of fine particles as surrogate for personal exposure to outdoor air pollution—results of the European EXPOLIS-EAS Study (Swiss Center Basel). J Air. Waste. Manage. Assoc. 50 (7), 1251–1261. Oosterlee, A., Drijver, M., Lebret, E., Brunekreef, B., 1996. Chronic respiratory symptoms in children and adults living along streets with high traffic density. Occup. Environ. Med. 53, 241–247. Pirie, W., 1983. Jonckheere tests for ordered alternatives. In: Kotz, S., Johnson, N.L. (Eds.), Encyclopedia of Statistical Sciences, vol. 4. Wiley, New York, pp. 315–318. Studnicka, M., Hackl, E., Pischinger, J., Fangmeyer, C., Haschke, N., Kuhr, J., Urbanek, R., Neumann, M., Frischer, T., 1997. Trafficrelated NO2 and the prevalence of asthma and respiratory symptoms in seven year olds. Eur. Respir. J. 10, 2275–2278. Thefeld, W., Stolzenberg, H., Bellach, B.M., 1999. The Federal Health Survey: response, composition of participants and non-responder analysis. Gesundheitswesen 61, S57–S61. van Vliet, P., Knape, M., de Hartog, J., Janssen, N., Harssema, H., Brunekreef, B., 1997. Motor vehicle exhaust and chronic respira-
249
tory symptoms in children living near freeways. Environ. Res. 74, 122–132. Venn, A., Lewis, S., Cooper, M., Hubbard, R., Hill, I., Boddy, R., Bell, M., Britton, J., 2000. Local road traffic activity and the prevalence, severity, and persistence of wheeze in school children: combined cross sectional and longitudinal study. Occup. Environ. Med. 57 (3), 152–158. Weiland, S.K., Mundt, K.A., Ruckmann, A., Keil, U., 1994. Selfreported wheezing and allergic rhinitis in children and traffic density on street of residence. Ann. Epidemiol. 4, 243–247. Wjst, M., Reitmeir, P., Dold, S., Wulff, A., Nicolai, T., LoeffelholzColberg, E.F., von Mutius, E., 1993. Road traffic and adverse effects on respiratory health in children. Br. Med. J. 307, 596–600. Wyler, C., Braun-Fahrla¨nder, C., Ku¨nzli, N., Schindler, C., Ackermann-Liebrich, U., Perruchoud, A.P., Leuenberger, P., Wu¨thrich, B., and the Swiss Study on Air Pollution and Lung Diseases in Adults (SAPALDIA) Team, 2000. Exposure to Motor Vehicle Traffic and Allergic Sensitization. Epidemiology 11(4), 450–456. Zmirou, D.S., Gauvin, Pin, I., Momas, I., Sahraoui, F., Just, J., Le Moullec, Y., Reungoat, P., Bremont, F., Cassadou, S., Albertini, M., Lauvergne, N., Chiron, M., Labbe, A., 2004. Traffic-related air pollution and incidence of childhood asthma: results of the VESTA case control study. J. Epidemiol. Commun. Health 58 (1), 18–23.
Environmental Research 98 (2005) 240–249 www.elsevier.com/locate/envres
Traffic at residential address, respiratory health, and atopy in adults: the National German Health Survey 1998 Joachim Heinricha,, Rebekka Toppa, Ulrike Gehringa,b, Wolfgang Thefeldc a
GSF-National Research Center for Environment and Health, Institute of Epidemiology, Ingolsta¨dter LandstraX e 1, D-85764 Neuherberg, Germany b Ludwig-Maximilians University (LMU)-IBE, Chair of Epidemiology, Munich, Germany c Robert-Koch-Institut, Berlin, Germany Received 4 May 2004; received in revised form 30 July 2004; accepted 10 August 2004 Available online 27 September 2004
Abstract Motor vehicle traffic contributes to more than 50% of PM10 in Europe and might have far reaching impacts on human health. We investigated the relationship between residential street type as a surrogate for traffic intensity and the prevalence of respiratory symptoms, atopic diseases, and allergic sensitization in adults. Data from 6896 subjects of the German Health Survey 1998 with complete information on residential street type were used. Multiple logistic regression analyses were applied to model associations between street type categories, and respiratory and atopic outcomes were assessed by screening questionnaire of The European Respiratory Health Survey and specific IgE measurements. Living at extremely or considerably busy roads (23.9% of total study population) compared to roads with no or rare traffic (64.5%) was statistically significantly associated with chronic bronchitis (aOR 1.36 (95% CI) (1.01–1.83)) while nocturnal coughing attacks (past 12 months) (1.24 (0.98–1.57)), wheeze during the past 12 months (1.21 (0.93–57)), and hay fever (1.16 (0.94–1.42)) were marginally increased after adjustment for several potential confounders and for multiple testing. No increased risks were found for asthma (0.97 (0.67–1.42)) and allergic sensitization (1.05 (0.91–1.20)). We conclude that exposure to traffic-related air pollutants increases the risk of nonallergic respiratory symptoms and to a lesser degree the risk of hay fever and allergic sensitization but not the risk of asthma in adults. r 2004 Elsevier Inc. All rights reserved. Keywords: Traffic intensity; Respiratory symptoms; Allergic sensitisation; Adults; Germany
1. Introduction Traffic is a major source of air pollutants in urban areas. In Europe, exhaust from motor vehicle traffic is considered to contribute more than 50% of PM10 (Fillinger et al., 1999; Kunzli et al., 2000). Several surrogates have been used to assess exposure to traffic-related pollutants: self-reported residence on specific street types, which may be different with regard to traffic intensity, or self-assessment of traffic intensity or distance to major roads (Nitta et al., 1993; Weiland et al., 1994; Duhme et al., 1996; Ehrenstein et al., 1999; van Vliet et al., 1997; Ciccone et al., 1998), investigatorCorresponding author. Fax: +49-89-3187-3380.
E-mail address: [email protected] (J. Heinrich). 0013-9351/$ - see front matter r 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.envres.2004.08.004
based assessment of distance to a major road including usage of GIS data (van Vliet et al., 1997; Brunekreef et al., 1997; Venn et al., 2000; Janssen et al., 2003; Carr et al., 2002; Nicolai et al., 2003), data on traffic counts at residential address (Wjst et al., 1993; Wyler et al., 2000; Zmirou et al., 2004), measurements of NO2 and/or particle mass in communities (Studnicka et al., 1997; Braun-Fahrla¨nder et al., 1992; Guo et al., 1999; de Marco et al., 2002), in schools (van Vliet et al., 1997; Brunekreef et al., 1997), or at residential address or areas (Kra¨mer et al., 2000; Hirsch et al., 1999; Forsberg et al., 1997; Lee et al., 2003; Guo et al., 1999), and finally sophisticated exposure models using GIS data at residential address and measurements of traffic-related air pollutants (Brauer et al., 2002; Bellander et al., 2001; Gehring et al., 2002; Carr et al., 2002; Nicolai et al.,
ARTICLE IN PRESS J. Heinrich et al. / Environmental Research 98 (2005) 240–249
2003; Briggs et al., 1997, 2000; Oosterlee et al., 1996). Most of these studies were cross-sectional studies (Wjst et al., 1993; Oosterlee et al., 1996; Nitta et al., 1993; Nakatsuka et al., 1991; Weiland et al., 1994; Studnicka et al., 1997; Braun-Fahrla¨nder et al., 1992; English et al., 1999; Hirsch et al., 1999; van Vliet et al., 1997; Brunekreef et al., 1997; Duhme et al., 1996; Guo et al., 1999; Kra¨mer et al., 2000; Carr et al., 2002; Nicolai et al., 2003), but recently exposure to traffic-related pollutants has been also evaluated by cohort study designs (Brauer et al., 2002; Gehring et al., 2002). Of these studies only a few evaluated potential respiratory health impacts in adults (Oosterlee et al., 1996; Wyler et al., 2000; Nitta et al., 1993; Lercher et al., 1995). The cross-sectional studies have consistently found the prevalence of nonallergic respiratory symptoms to be elevated in subjects living in more polluted communities or close to major roads (Oosterlee et al., 1996; Nitta et al., 1993; Nakatsuka et al., 1991; Braun-Fahrla¨nder et al., 1992; Weiland et al., 1994; Duhme et al., 1996; Hirsch et al., 1999; English et al., 1999; Nicolai et al., 2003; Kra¨mer et al., 2000) with the exception of a few studies (Wjst et al., 1993; Carr et al., 2002; Lercher et al., 1995). Several studies showed even stronger associations with respiratory symptoms if truck traffic intensity was used as the traffic exposure surrogate (Brunekreef et al., 1997; Weiland et al., 1994; Ciccone et al., 1998). With regard to the prevalence of asthma, nonspecific allergies, hay fever, and allergic sensitization, the results are diverse. One of the two large German ISAAC studies in Munich found statistically significant associations between trafficrelated air pollution and current wheeze and eczema (Nicolai et al., 2003), whereas the other ISAAC study conducted in Dresden did not (Hirsch et al., 1999). Both studies did not find any association between traffic-related pollution and allergic sensitization. The Dutch ISAAC II study found more respiratory symptoms near motorways with high truck but not high car traffic counts (Janssen et al., 2003). Lung function and bronchial hyperreactivity were not related to air pollution. Pollen sensitization was increased in relation to truck but not car traffic counts (Janssen et al., 2003). The reasons for these heterogeneous study results are unclear. Self-reported traffic intensity is presumably a subjective measure, which leads to misclassification, in particular, if the study area comprises rural and urban areas. Studies which analyzed a combination of urban and rural areas failed to show effects of traffic (Ciccone et al., 1998; Kra¨mer et al., 2000), while analyses stratified for rural and metropolitan areas showed effects for the urban areas (Ciccone et al., 1998; Kra¨mer et al., 2000). However, if nonurban areas were considered, one Austrian study reported strong statistically significant associations between asthma and annual average of NO2 concentrations (Studnicka et al., 1997) and a Swiss study did not (Braun-Fahrla¨nder et al.,
241
1992) although similar methods were used. Another reason for the heterogeneity might be residual confounding by socioeconomic factors. Finally, several of these studies had only a small sample size and found effects on allergic sensitization in even smaller subgroups with a long duration of living at current address or only for pollen sensitization (Wyler et al., 2000; Janssen et al., 2003). Here, we analyze the relationship between traffic intensity at residential address using residential street type as a surrogate and prevalence of respiratory symptoms such as bronchitis and cough, asthma, hay fever, and IgE antibodies in serum against common aeroallergens using data from adults in the German Health Survey 1998.
2. Methods 2.1. Study design This is a cross-sectional study which investigates questionnaire-derived data on street type at the home address in relation to respiratory health and atopy assessed by blood tests using data from the German Health Survey 1998. 2.2. Study population Between October 1997 and March 1999 the National Health Survey investigated 7124 subjects (response rate 61%) aged 18–79 years from a population-based sample, which is representative with regard to age, gender, and community size with an oversampling to the general population of the East German area. Methods and population selection are described in detail elsewhere (Bellach et al., 1998; Thefeld et al., 1999). Data on traffic intensity were not available from 228 of the 7124 participating subjects. These participants were therefore excluded from the present analyses. Thus, the study population consisted of 6896 subjects (97% of the study participants). 2.3. Data collection Self-administered questionnaire-based data were used from the public use file BGS98 which was provided by the Robert-Koch-Institute, Berlin, Germany. Moreover, a screening test for allergic sensitization against common aeroallergens (SX1) was performed in subjects’ sera (details are mentioned below). 2.4. Traffic intensity questions To assess traffic intensity we used the question: Is your home located at an extremely busy road,
ARTICLE IN PRESS 242
J. Heinrich et al. / Environmental Research 98 (2005) 240–249
considerably busy side street, not busy side street, or on a street with no or very rare traffic? The first two and the last two categories were combined and so three categories representing low, moderate, and high traffic intensity were created. Furthermore, data about annoyance by street traffic noise were derived from the following question: How much do you feel annoyed, also during nights, by noise caused by street traffic? The answering categories were very strong, medium, not strong. 2.5. Questionnaire on respiratory health The German version of the screening questionnaire of the European Community Respiratory Health Survey (ECRHS) was used in the 1998 German National Health Survey (Burney et al., 1994; Heinrich et al., 2002). For our analyses we used only data from this questionnaire for wheeze and nocturnal attacks of coughing during the past 12 months. According to the screening questionnaire and the ECRHS methodology, asthma was defined as having an asthma attack during the past 12 months or current use of asthma medication (Burney et al., 1994). In addition, we defined atopic asthma as subjects having current asthma and a positive test result to SX1 and nonatopic asthma as subjects having had asthma but a negative SX1 test. Atopic wheeze and nonatopic wheeze were defined analogously. For the assessment of presence of hay fever the ECRHS question ‘‘Do you currently have nasal allergy including hay fever?’’ was used. For the assessment of chronic bronchitis we used data from the question ‘‘Which of the following diseases have you ever had?’’ The answering category was chronic bronchitis, e.g., coughing during the night without cold and phlegm in the morning most of the days for at least 3 months per year in 2 successive years. Furthermore, the highest educational level was recorded and categorized as low (less than 10 grades), medium (10 grades), and high (more than 11 grades). Smoking history was reported in detail and the numbers of pack-years were calculated using the methods by Junge and Nagel (1999), which also included smoking of cigars and tobacco smoking in pipes. 2.6. Allergic sensitization Allergic sensitization was assessed by measuring specific IgE to common inhalant allergens in serum, using the Pharmacia SX1 test (Pharmacia, Uppsala, Sweden). The SX1 is a screening assay to identify specific allergic sensitization against mite, cat, dog, Cladosporium herbarum, and pollen allergens (timothy, grass, rye, birch, and mugwort). The SX1 test is a qualitative test. The categorization of the assay results as positive or
negative was based on the recommendations of the test manufacturer. 2.7. Statistical analyses To check whether the characteristics of the study population differed between the three traffic exposure categories we applied the Jonckheere–Terpstra trend test for ordinal variables (Pirie, 1983) and used a linear regression analysis for trend testing with continuous variables. To assess the association between respiratory health outcomes and traffic exposure we applied single and multiple linear logistic regression models. As we tested various health outcomes on our data set we corrected the level of significance for multiple testing using the formula of Tippelt–Holmes (ai=1(1a)(1/ (ni+1)) ). All analyses were carried out using SAS V8 (SAS Institute, Cary, NC).
3. Results Data on traffic intensity at residential address was available for 6896 of the 7124 adults (96.8%). Table 1 shows characteristics of the study population. According to the type of road at residential address, 23.9% of the subjects were highly exposed to traffic-related air pollutants and 64.5% to low or no traffic exhaust at their home address (Table 2). Table 2 also shows the prevalence rates for the respiratory outcomes and allergic sensitization. In addition prevalence rates for atopic asthma and atopic wheeze are provided. The association between traffic exposure at home address and participants’ characteristics is shown in Table 3. All of these characteristics were significantly different between the three traffic exposure categories. Table 4 shows nonadjusted and adjusted odds ratios (OR) for traffic exposure at home address and respiratory health outcomes and allergic sensitization. After adjustment for age, gender, education, community size, and packyears, the risk of chronic bronchitis remained significantly elevated for the highest traffic category (Table 4). The elevated crude OR for nocturnal attacks of coughing did not reach the level of statistical significance after confounder adjustment (Table 4). A marginally nonsignificant increased OR was found for hay fever, while no associations were found for asthma and prevalence of allergic sensitization (Table 4). In addition, the subdivision into atopic and nonatopic asthma and atopic and nonatopic wheeze did not show statistically significant effect estimates. Moreover, the results for nonatopic asthma and wheeze are even inconsistent. While the effect size estimate increased for nonatopic asthma compared to that of atopic asthma, the effect size estimate decreased for nonatopic wheeze compared to that of atopic wheeze (Table 4).
ARTICLE IN PRESS J. Heinrich et al. / Environmental Research 98 (2005) 240–249 Table 1 Characteristics of the study population (N ¼ 6896) n/N
243
Table 2 Description of exposure and health variables of the study population (N ¼ 6896) % n/N
%
Type of road at residence with Low traffic Moderate traffic High traffic
4448/6896 797/6896 1651/6896
64.5 11.6 23.9
Annoyance level from traffic noise low moderate high
680/2199 1169/2199 350/2199
30.9 53.2 15.9
Respiratory health: Chronic bronchitis (ever) Nocturnal attacks of coughing (past 12 months)
543/6692 939/6798
8.1 13.8
66.0 34.0
Asthmaa (past12 months) Atopic asthmab Nonatopic asthmab
301/6896 162/6896 128/6876
4.4 2.4 1.9
2223/6896 1071/6896 1191/6896 2411/6896
32.2 15.5 17.3 35.0
Wheeze (past 12 months) Atopic wheezec Nonatopic wheezec Hay fever Allergic Sensitizationd
721/6870 302/6896 393/6896 886/6783 1963/6518
10.5 4.4 5.7 13.1 30.1
Smoking status Never smokers Former smokers Current, daily smokers
3148/6338 1349/6338 1841/6338
49.7 21.3 29.1
Pack years 0 (0–5) (5–10) (10–20) X20
3148/6583 883/6583 519/6583 841/6583 1192/6583
47.8 13.4 7.9 12.8 18.1
Duration of living at current address (year) o1 173/6896 1–5 1908/6896 6–9 949/6896 X10 3866/6896
2.5 27.7 13.7 56.1
Gender Female Male
3538/6896 3358/6896
51.3 48.7
Age group 17–29 30–39 40–59 60–79
1254/6896 1513/6896 2592/6896 1537/6896
18.2 21.9 37.6 22.3
Education o10 years 10 years 410 years
2914/6696 2256/6696 1526/6696
43.5 33.7 22.8
Region West Germany East Germany
4554/6896 2342/6896
Community size o20,000 20,000–100,000 100,000–500,000 4500,000
a
Asthma attack or medication during past 12 months. Atopic asthma was defined as current asthma and positive SX1 test; nonatopic asthma was defined as current asthma and negative SX1 test. c Atopic wheeze was defined as current wheeze and positive SX1 test; nonatopic wheeze was defined as current wheeze and negative SX1 test. d Positive SX1 test. b
3.1. Gender Adjusted models with the full set of confounding variables from Table 4, with the exception of gender, showed similar effect estimates for men and women (data not shown). 3.2. Age group
Adjustments changed the effect estimates only marginally. While the risk for bronchitis was statistically significantly increased and the risks for nocturnal cough, wheeze, and hay fever were marginally increased for the highest traffic category (living on an extremely or considerably busy road; 23.9% of the total population), no increase in corresponding risks were seen for the moderate traffic category (living on a not busy side street; 11.6% of the total population). In addition to the fully adjusted models presented in Table 4, stratified analyses were performed to identify susceptible subpopulations and to reevaluate traffic-related effect estimates by residential region (West Germany versus East Germany) and community size.
Stratified analyses for the younger subjects aged 18–39 years and the older subpopulation aged 40 years or more did not change the effect estimates substantially (data not shown). 3.3. Residential area The traffic-related effect estimates on respiratory outcomes listed in Table 4 were similar when analyses were stratified for East and West German residential addresses (data not shown). 3.4. Community size Since the proportions of the high traffic categories ranged only marginally (21–26%) in the four commu-
ARTICLE IN PRESS J. Heinrich et al. / Environmental Research 98 (2005) 240–249
244
Table 3 Description of the study population by traffic exposure categories (N ¼ 6896) p value
Traffic exposure at home address Low (N ¼ 4448)
Moderate (N ¼ 797)
High (N ¼ 1651)
n
%
n
%
n
%
60.3 15.7 2.6
100 277 26
14.7 23.7 7.4
170 709 315
25.0 60.7 90.0
o0.0001a
445 352 47.7 [16.3]
12.6 10.5
889 762 45.2 [15.8]
25.1 22.7
0.0001a
Annoyance level from traffic noise, N ¼ 2199 Low 410 Moderate 183 High 9 Gender, N ¼ 6896 Female Male Age (mean [sd]), N ¼ 6896
2204 2244 45.3 [15.8]
62.3 66.8
Education, N ¼ 6696 o10 years 10 years 410 years
1855 1432 1035
63.7 63.5 67.8
327 264 184
11.2 11.7 12.1
732 560 307
25.1 24.8 20.1
0.0034a
Residential region, N ¼ 6896 West Germany East Germany
3084 1364
67.7 58.2
474 323
10.4 13.8
996 655
21.9 28.0
o0.0001a
Community size, N ¼ 6896 o20,000 20,000–100,000 100,000–500,000 4500,000
1497 702 760 1489
67.3 65.6 63.8 61.8
214 141 148 294
9.6 13.2 12.4 12.2
512 228 283 628
23.0 21.3 23.8 26.1
o0.0001a
Smoking status, N ¼ 6338 Never smokers Former smokers Current, daily smokers
2060 896 1137
65.4 66.4 61.8
388 161 191
12.3 11.9 10.4
700 292 513
22.2 21.7 27.9
0.0018a
Pack years, N ¼ 6583 0 1–5 6–9 10–19 X20
2060 569 346 507 757
65.4 64.4 66.7 60.3 63.5
388 104 52 93 135
12.3 11.8 10.0 11.1 11.3
700 210 121 241 300
22.2 23.8 23.3 28.7 25.2
0.0085a
a
0.0003b
Testing for trend using the Jonckheere–Terpstra test. Testing for trend using a linear regression model.
b
nity size categories (see Table 3), sensitivity analyses stratified for community size might be valuable. Fig. 1 shows adjusted estimates for high traffic exposure (home located on extremely or considerably busy road) versus low traffic exposure (home located on a street with no or very rare traffic) for respiratory outcomes and allergic sensitization by community size classes. The strongest and most significant effects on chronic bronchitis, nocturnal coughing attacks, and wheeze were found within the metropolitan areas (more than 500,000 inhabitants), while the effect estimates within the small (less than 20,000 inhabitants), medium (20,000–100,000 inhabitants), and large (100,000–500,000 inhabitants) community size classes did not show any statistically significant results. For the allergic outcomes asthma, hay fever, and allergic sensitization, no statistically
significant associations were found with traffic intensity within each of the four community size classes, except for hay fever and medium community size. 3.5. Moving According to the cross-sectional study design of this analysis, exposure was estimated on the basis of current residential address. Although most of the outcomes reflect the preceding 12 months and few had moved within the past 12 months (n ¼ 173; 2.5%), exposure prior to the past 12 months might also cause irreversible adverse respiratory health effects. Therefore, an additional analysis for the subpopulation that lived 2 or more years at the current address was performed. The crude effect estimates for bronchitis, coughing, and
ARTICLE IN PRESS J. Heinrich et al. / Environmental Research 98 (2005) 240–249
245
Table 4 Association between traffic and respiratory health and allergic sensitization Traffic exposure at home address Low (N ¼ 4448)
Moderate (N ¼ 797)
High (N ¼ 1651)
1 1
1.02 [0.68,1.55] 0.94 [0.60,1.46]
1.41 [1.06,1.87]b 1.36 [1.01,1.83]b
Nocturnal attacks of coughing (past 12 months) OR 1 Adjusteda OR 1
1.07 [0.79,1.46] 1.05 [0.76,1.45]
1.30 [1.04,1.62]b 1.24 [0.98,1.57]
Wheeze (past 12 months) OR Adjusteda OR Atopic wheezec OR aOR Nonatopic wheezec OR aOR
1 1 1 1 1 1
1.02 0.95 0.93 0.86 1.07 1.05
[0.72,1.44] [0.66,1.38] [0.54,1.59] [0.47,1.54] [0.69,1.64] [0.67,1.64]
1.22 1.21 1.40 1.43 1.09 1.05
[0.95,1.57] [0.93,1.57] [0.98,1.99] [0.99,2.07] [0.79,1.50] [0.75,1.48]
Asthmad (past 12 months) OR Adjusteda OR Atopic asthmae OR aOR Nonatopic asthmae OR aOR
1 1 1 1 1 1
0.78 0.74 0.60 0.52 0.89 0.87
[0.46,1.33] [0.43,1.28] [0.28,1.29] [0.23,1.20] [0.44,1.84] [0.42,1.82]
1.02 0.97 0.98 0.87 1.13 1.15
[0.72,1.46] [0.67,1.42] [0.62, 1.56] [0.52,1.44] [0.69,1.86] [0.69,1.93]
Hay fever (past 12 months) OR Adjusteda OR
1 1
1.06 [0.82,1.36] 1.10 [0.84,1.44]
1.12 [0.93,1.36] 1.16 [0.94,1.42]
Allergic sensitizationf OR Adjusteda OR
1 1
0.98 [0.83,1.16] 1.06 [0.88,1.27]
1.03 [0.91,1.17] 1.05 [0.91,1.20]
Chronic bronchitis (ever) OR Adjusteda OR
a
Adjusted for age, gender, education, community size, and pack years. Statistically significant after adjustment for multiple testing. c Atopic wheeze was defined as current wheeze and positive SX1 test; nonatopic wheeze was defined as current wheeze and negative SX1 test. d Asthma attack or medication in past 12 months. e Atopic asthma was defined as current asthma and positive SX1 test; nonatopic asthma was defined as current asthma and negative SX1 test. f Positive SX1 test. b
wheeze were not increased. No increased effect estimates could be identified for asthma, hay fever, and allergic sensitization (data not shown). 3.6. Nationality/ethnicity When subjects who were not born in Germany (n ¼ 645; 9.38%) were excluded from analyses, the effect estimates changed only marginally (data not shown). 3.7. Socioeconomic status (SES) Stratified analyses by educational level as surrogate for SES did not show consistent effect modification of exposure to traffic-related pollutants by SES (data not shown).
3.8. Smoking Stratified analyses for never and ever smokers did not show substantially different effect estimates on the outcomes listed in Table 4 (data not shown).
4. Discussion In this large national sample of adults we have found a statistically significant positive association between chronic bronchitis and traffic-related air pollutants using type of street at current home address as a surrogate measure. The positive associations between traffic intensity and nocturnal coughing attacks, current wheeze, and hay fever were not statistically significant. Statistically nonsignificant associations were observed with asthma and allergic sensitization. The statistically
ARTICLE IN PRESS 246
J. Heinrich et al. / Environmental Research 98 (2005) 240–249
Fig. 1. Traffic intensity (high versus low) and respiratory outcomes and allergic sensitization by community size after adjustment for age, gender, education, and smoking. Data from The National German Health Survey 1998, 6896 adults aged 18–79 years.
significant and the nonsignificant effect estimates were generally robust, did not change after multiple adjustments for potential confounders, and were similar in several subgroups. No single subgroup that might be considered to have a stronger susceptibility than others was identified. Even for the low socioeconomic status, where exposure to traffic is slightly higher, all effect estimates were similar to those of the other SES strata. Results of the present study on adults are in good agreement with the results of other studies on the effects of exposure to traffic-related pollutants and prevalence rates of bronchitis in children (Hirsch et al., 1999; Braun-Fahrla¨nder et al., 1992; Studnicka et al., 1997) and adults (Nitta et al., 1993), cough in children (Hirsch et al., 1999; Brunekreef et al., 1997; van Vliet et al., 1997; Braun-Fahrla¨nder et al., 1992; Ciccone et al., 1998; Gehring et al., 2002; Nicolai et al., 2003) and adults (Nitta et al., 1993), and wheeze in children (Wjst et al., 1993; Oosterlee et al., 1996; van Vliet et al., 1997; Ciccone et al., 1998; Nicolai et al., 2003; Brunekreef et al., 1997; Duhme et al., 1996) and adults. For reported asthma the results are less clear. However, the effects on nonallergic respiratory outcomes are more consistent in children than in adults. The wheezing effects are not consistent in adults and in children. While some studies found increased reporting of asthma (van Vliet et al., 1997; Studnicka et al., 1997; Guo et al., 1999; Duhme et al., 1996; Zmirou et al., 2004; Nicolai et al., 2003), others found no increased prevalence rates
(Braun-Fahrla¨nder et al., 1992; Hirsch et al., 1999; Wyler et al., 2000; Brauer et al., 2002; Janssen et al., 2003; Oosterlee et al., 1996; Lercher et al., 1995). The few studies that explicitly analyzed associations with hay fever also showed diverse results. Increased reporting of hay fever in relation to high exposure to traffic-related pollutants was found in studies in metropolitan areas (Weiland et al., 1994; Duhme et al., 1996; Lercher et al., 1995; Hirsch et al., 1999; Lee et al., 2003) or when the analysis was restricted to the urban/metropolitan areas (Ciccone et al., 1998; Kra¨mer et al., 2000), however, several other studies, also conducted in large communities, reported no statistically significant associations for hay fever (Wyler et al., 2000; Nicolai et al., 2003). When assessment of allergic sensitization by skin prick testing or blood test was implemented in studies on traffic-related health effect, some studies failed to show statistically significant positive associations in the total study population (Hirsch et al., 1999; Kra¨mer et al., 2000; Wyler et al., 2000; Nicolai et al., 2003), but others could find positive associations if the analyses were restricted to urban areas (Ciccone et al., 1998; Kra¨mer et al., 2000) or if only pollen sensitization was considered (Wyler et al., 2000; Janssen et al., 2003). It should be noted that most of these traffic-related studies exclusively investigated children and that most of these studies were conducted in Europe. The studies that include both children and adults found stronger associations between adverse respiratory health and traffic exposure in children than in adults (Lercher et al., 1995) and concluded that children might be more susceptible than adults (Oosterlee et al., 1996). Furthermore, children with hyperreactive airways and/or sensitization to common allergens were considered sensitive subgroup, since traffic-related increased respiratory health risks were restricted to them (Janssen et al., 2003). This study used the type of residential address street as a simple surrogate for exposure to traffic-related air pollutants. This might be in particular a major limitation if the study area is very heterogeneous with respect to population density and consequently traffic density. With increased population density or community sizes it seems plausible to assume more traffic and consequently increased ambient concentrations of exposure to trafficrelated air pollutants. However, the relative frequencies of the high traffic exposure category only slightly increase with increasing community size (Table 3). A similarly weak association was also seen between community size and traffic annoyance (Table 3). Therefore, an adjustment for community size and a sensitivity analysis for subjects living in areas of different community sizes are crucial. Indeed, analyses stratified by community size showed that the total effect estimates for chronic bronchitis, cough, and wheeze were mainly caused by the effect estimates for the metropolitan
ARTICLE IN PRESS J. Heinrich et al. / Environmental Research 98 (2005) 240–249
areas. We speculate that exposure misclassification in the smaller communities might be larger due to a lower heterogeneity in traffic-related exposures, within each of the community size strata. We might therefore speculatively conclude that exposure misclassification is different between community size classes. The subjective assessment of exposure to traffic-related pollutants by living at a specific type of street was validated by air pollution measurements (Oglesby et al., 2000a; Kuhlisch et al., 2002; Forsberg et al., 1997). However, these comparative studies on subjective versus objective assessment of exposure to traffic-related air pollution were mostly performed in homogeneous settings. When the study was heterogeneous as in the Swiss SAPALDIA study, the authors concluded that population mean score (subjective) rather than individual scores may serve as a simple tool for grading air quality within an area (Oglesby et al., 2000a, b). Another possible explanation for the observed affect in the largest communities (4500,000 inhabitants, see Fig. 1) might be that the entire exposure distribution is shifted toward sufficiently high concentrations where effects are detected. Although subjects living on a busy road are obviously exposed to higher levels of traffic-related pollutants than those living on a side street in areas with mostly low or even no traffic, several other factors such as lower active ventilation to avoid exposure to traffic noise need to be considered. Consequently indoor pollutants that have strong indoor sources such as tobacco smoke might be increased. In addition, buildings on busy streets might be different from those in quiet residential areas with regard to age, size, and height. Finally, subjects who were categorized according to their address street type might differ in many aspects other than the exposure of interest. Although we found only a weak association between type of street and SES, we could not exclude that using classifications other than educational level might lead to stronger associations. We cannot exclude residual confounding by SES, which is in agreement with the study of Nicolai et al. (2003), which also did not find any effect modification by SES. Low SES, even in the affluent society of Germany with no major social deprivation, is a strong predictor for poor health with the few exceptions of atopic dermitis and hay fever (Heinrich et al., 2000). The higher prevalence rates of hay fever and mild asthma in higher-social-class subjects and the supposed lower exposure to several environmental pollutants including traffic-related air pollutants might mask the association between traffic intensity and atopic outcomes even after adjustment for SES. In addition, several lifestyle-related factors such as diet, living characteristics, and smoking are known to be different among different socioeconomic strata (Heinrich et al., 2000). Thus, one might also speculate that the observed adverse effects of living
247
close to a busy freeway in Holland, which was seen only in low- to medium-SES children (van Vliet et al., 1997) might be related to the lower coping capability of lowsocial-class children. In addition, the cross-sectional design of this study did not allow for the evaluation of whether subjects with respiratory illness prefer not to live along busy traffic streets. Selective migration might be in particular a problem if the association between traffic-related air pollution exposure and asthma is assessed by crosssectional studies. A further limitation is related to the validity of selfreported respiratory health outcomes. Particular attention has to be paid to self-reported wheeze in adult studies and to using the German language, where no corresponding word is available. Whether wheeze is specific for asthma in the German language is still questionable. In adults, the wheeze symptom in particular is also associated with bronchitis. Even atopic wheeze was highly associated with chronic bronchitis in this study (16.6% versus 3.1% in subjects with and without chronic bronchitis). Thus, we are hesitant to evaluate the reported association between traffic intensity and wheeze exclusively as a major symptom of asthma. We could not exclude that perception of traffic intensity is equally distributed between diseased and nondiseased groups. So the effect estimates could be biased. However, no increased risk for attacks of asthma in relation to traffic-related exposures was found, although there is a common belief in the public that ambient air pollution causes asthma and strong evidence that ambient air pollutants might exacerbate asthma. Therefore, we would not consider our positive findings between exposure to traffic-related pollutants and respiratory health strongly biased by differential exposure misclassification, but we could not exclude bias for sure.
5. Conclusion Exposure to traffic-related air pollutants increased the risk of nonallergic respiratory symptoms such as chronic bronchitis but not the risk of atopic disorders or in particular the prevalence of allergic sensitization in adults.
Acknowledgments The authors thank Dr. Heribert Stolze (RKI, Berlin), who provided support to use the public use file, Hubert Schneller who designed the figures, and Regina Gillig for cautiously writing and editing the manuscript.
ARTICLE IN PRESS 248
J. Heinrich et al. / Environmental Research 98 (2005) 240–249
References Bellach, B.M., Knopf, H., Thefeld, W., 1998. The German Health Survey. 1997/98. Gesundheitswesen 60 (Suppl 2), S59–S68. Bellander, T., Berglind, N., Gustavsson, P., Jonson, T., Nyberg, F., Pershagen, G., Jarup, L., 2001. Using geographic information systems to assess individual historical exposure to air pollution from traffic and house heating in Stockholm. Environ. Health Perspect. 109 (6), 633–639. Brauer, M., Hoek, G., Van Vliet, P., Meliefste, K., Fischer, P.H., Wijga, A., Koopman, L.P., Neijens, H.J., Gerritsen, J., Kerkhof, M., Heinrich, J., Bellander, T., Brunekreef, B., 2002. Air pollution from traffic and the development of respiratory infections and asthmatic and allergic symptoms in children. Am. J. Respir. Crit. Care. Med. 166, 1092–1098. Braun-Fahrla¨nder, C., Ackermann-Liebrich, U., Schwartz, J., Gnehm, H.P., Rutishauser, M., Wanner, H.U., 1992. Air pollution and respiratory symptoms in preschool children. Am. Rev. Respir. Dis. 145, 42–47. Briggs, D., Collins, S., Elliott, P., Fischer, P., Kingham, S., Lebret, E., Pryl, K., van Reeuwijk, H., Smallbone, K., van der Veen, A., 1997. Mapping urban air pollution using GIS: a regression-based approach. Int. J. Geogr. Information Sci. 11, 699–718. Briggs, D.J., de Hoogh, C., Gulliver, J., Wills, J., Elliott, P., Kingham, S., Smallbone, K., 2000. A regression-based method for mapping traffic-related air pollution: application and testing in four contrasting urban environments. Sci. Total Environ. 253, 151–167. Brunekreef, B., Janssen, N.A., de Hartog, J., Harssema, H., Knape, M., van Vliet, P., 1997. Air pollution from truck traffic and lung function in children living near motorways. Epidemiology 8, 298–303. Burney, P.G., Luczynska, C., Chinn, S., Jarvis, D., 1994. The European Community Respiratory Health Survey. Eur. Respir. J. 7 (5), 954–960. Carr, D., von Ehrenstein, O., Weiland, S., Wagner, C., Wellie, O., Nicolai, T., von Mutius, E., 2002. Modeling annual benzene, toluene, NO2, and soot concentrations on the basis of road traffic characteristics. Environ. Res. 90 (2), 111–118. Ciccone, G., Forastiere, F., Agabiti, N., Biggeri, A., Bisanti, L., Chellini, E., Corbo, G., Dell’Orco, V., Dalmasso, P., Volante, T.F., Galassi, C., Piffer, S., Renzoni, E., Rusconi, F., Sestini, P., Viegi, G., 1998. Road traffic and adverse respiratory effects in children. SIDRIA Collaborative Group. Occup. Environ. Med. 55, 771–778. de Marco, R., Poli, A., Ferrari, M., Accordini, S., Giammanco, G., Bugiani, M., Villani, S., Ponzio, M., Bono, R., Carrozzi, L., Cavallini, R., Cazzoletti, L., Dallari, R., Ginesu, F., Lauriola, P., Mandrioli, P., Perfetti, L., Pignato, S., Pirina, P., Struzzo, P., 2002. ISAYA study group. Italian Study on Asthma in Young Adults. The impact of climate and traffic-related NO2 on the prevalence of asthma and allergic rhinitis in Italy. Clin. Exp. Allergy 32 (10), 1405–1412. Duhme, H., Weiland, S.K., Keil, U., Kraemer, B., Schmid, M., Stender, M., Chambless, L., 1996. The association between selfreported symptoms of asthma and allergic rhinitis and self-reported traffic density on street of residence in adolescents. Epidemiology 7, 578–582. Ehrenstein, O.S.V., Mutius, E.v., Nicolai, T., et al., 1999. Prevalence of asthma, BHR and atopy in children reporting increased exposure to traffic jam in Munich. Epidemiology 10, S171. English, P., Neutra, R., Scalf, R., Sullivan, M., Waller, L., Zhu, L., 1999. Examining associations between childhood asthma and traffic flow using a geographic information system. Environ. Health Perspect. 107, 761–767. Fillinger, P., Puybonnieux-Texier, V., Schneider, J., 1999. PM10 Population Exposure Technical Report on air pollution. Health Costs due to Road Traffic-related Air Pollution. An Impact
assessment project of Austria, France and Switzerland. Prepared for the Third WHO Ministerial Conference of Environment & Health, London, Bern, Paris, Wien. Forsberg, B., Stjernberg, N., Wall, S., 1997. People can detect poor air quality well below guideline concentrations: a prevalence study of annoyance reactions and air pollution from traffic. Occup. Environ. Med. 54 (1), 44–48. Gehring, U., Cyrys, J., Sedlmeir, G., Brunekreef, B., Bellander, T., Fischer, P., Bauer, C.P., Reinhardt, D., Wichmann, H.E., Heinrich, J., 2002. Traffic-related air pollution and respiratory health during the first 2 years of life. Eur. Respir. J. 19 (4), 690–698. Guo, Y.L., Lin, Y.C., Sung, F.C., Huang, S.L., Ko, Y.C., Lai, J.S., Su, H.J., Shaw, C.K., Lin, R.S., Dockery, D.W., 1999. Climate, trafficrelated air pollutants, and asthma prevalence in middle-school children in taiwan. Environ. Health Perspect. 107, 1001–1006. Heinrich, J., Mielck, A., Schafer, I., Mey, W., 2000. Social inequality and environmentally related diseases in Germany: review of empirical results. Soz. Praventivmed. 45 (3), 106–118. Heinrich, J., Richter, K., Frye, C., Meyer, I., Wo¨lke, G., Wjst, M., Nowak, D., Magnussen, H., Wichmann, H.E., 2002. Die Europa¨ische Studie zu Atemwegserkrankungen bei Erwachsenen (ECRHS). Pneumologie 56, 297–303. Hirsch, T., Weiland, S.K., von Mutius, E., Safeca, A.F., Grafe, H., Csaplovics, E., Duhme, H., Keil, U., Leupold, W., 1999. Inner city air pollution and respiratory health and atopy in children. Eur. Respir. J. 14, 669–677. Janssen, N.A., Brunekreef, B., van Vliet, P., Aarts, F., Meliefste, K., Harssema, H., Fischer, P., 2003. The relationship between air pollution from heavy traffic and allergic sensitization, bronchial hyperresponsiveness, and respiratory symptoms in Dutch schoolchildren. Environ. Health Perspect. 111 (12), 1512–1518. Junge, B., Nagel, M., 1999. Smoking behavior in Germany. Gesundheitswesen 61 (Dec), S121–S125. Kra¨mer, U., Koch, T., Ranft, U., Ring, J., Behrendt, H., 2000. Trafficrelated Air Pollution is associated with atopy in children living in urban areas. Epidemiology 11, 64–70. Kuhlisch, W., Hirsch, T., Olunczek, U., Vollheim, B., Gross, B., During, I., Weiland, S.K., Leupold, W., 2002. Validierung von subjektiven Angaben zur Verkehrsexposition durch Verkehrsza¨hlungen, NO2-Ausbreitungsmodellierungen und NO2-Immissionsmes-sungen. Soz. Praventivmed. 47 (2), 116–123. Kunzli, N., Kaiser, R., Medina, S., Studnicka, M., Chanel, O., Filliger, P., Herry, M., Horak, F., Puybonnieux-Texier, V., Quenel, P., Schneider, J., Seethaler, R., Vergnaud, J.C., Sommer, H., 2000. Public-health impact of outdoor and traffic-related air pollution: a European assessment. Lancet 356, 795–801. Lee, Y.L., Shaw, C.K., Su, H.J., Lai, J.S., Ko, Y.C., Huang, S.L., Sung, F.C., Guo, Y.L., 2003. Climate, traffic-related air pollutants and allergic rhinitis prevalence in middle-school children in Taiwan. Eur. Respir. J. 21 (6), 964–970. Lercher, P., Schmitzberger, R., Kofler, W., 1995. Perceived traffic air pollution, associated behavior and health in an alpine area. Sci. Total Environ. 169 (1–3), 71–74. Nakatsuka, H., Watanabe, T., Ikeda, M., Hisamichi, S., Shimizu, H., Fujisaka, S., Ichinowatari, Y., Konno, J., Kuroda, S., Ida, Y., et al., 1991. Comparison of the health effects between indoor and outdoor air pollution in Northeastern Japan. Environ. Int. 17, 956–963. Nicolai, T., Carr, D., Weiland, S.K., Duhme, H., von Ehrenstein, O., Wagner, C., von Mutius, E., 2003. Urban traffic and pollutant exposure related to respiratory outcomes and atopy in a large sample of children. Eur. Respir. J. 21 (6), 956–963. Nitta, H., Sato, T., Nakai, S., Maeda, K., Aoki, S., Ono, M., 1993. Respiratory health associated with exposure to automobile exhaust. I. Results of cross-sectional studies in 1979, 1982, and 1983. Arch. Environ. Health. 48, 53–58.
ARTICLE IN PRESS J. Heinrich et al. / Environmental Research 98 (2005) 240–249 Oglesby, L., Kunzli, N., Monn, C., Schindler, C., AckermannLiebrich, U., Leuenberger, P., 2000a. Validity of annoyance scores for estimation of long term air pollution exposure in epidemiologic studies: the Swiss Study on Air Pollution and Lung Diseases in Adults (SAPALDIA). Am. J. Epidemiol. 152 (1), 75–83. Oglesby, L., Kunzli, N., Roosli, M., Braun-Fahrlander, C., Mathys, P., Stern, W., Jantunen, M., Kousa, A., 2000b. Validity of ambient levels of fine particles as surrogate for personal exposure to outdoor air pollution—results of the European EXPOLIS-EAS Study (Swiss Center Basel). J Air. Waste. Manage. Assoc. 50 (7), 1251–1261. Oosterlee, A., Drijver, M., Lebret, E., Brunekreef, B., 1996. Chronic respiratory symptoms in children and adults living along streets with high traffic density. Occup. Environ. Med. 53, 241–247. Pirie, W., 1983. Jonckheere tests for ordered alternatives. In: Kotz, S., Johnson, N.L. (Eds.), Encyclopedia of Statistical Sciences, vol. 4. Wiley, New York, pp. 315–318. Studnicka, M., Hackl, E., Pischinger, J., Fangmeyer, C., Haschke, N., Kuhr, J., Urbanek, R., Neumann, M., Frischer, T., 1997. Trafficrelated NO2 and the prevalence of asthma and respiratory symptoms in seven year olds. Eur. Respir. J. 10, 2275–2278. Thefeld, W., Stolzenberg, H., Bellach, B.M., 1999. The Federal Health Survey: response, composition of participants and non-responder analysis. Gesundheitswesen 61, S57–S61. van Vliet, P., Knape, M., de Hartog, J., Janssen, N., Harssema, H., Brunekreef, B., 1997. Motor vehicle exhaust and chronic respira-
249
tory symptoms in children living near freeways. Environ. Res. 74, 122–132. Venn, A., Lewis, S., Cooper, M., Hubbard, R., Hill, I., Boddy, R., Bell, M., Britton, J., 2000. Local road traffic activity and the prevalence, severity, and persistence of wheeze in school children: combined cross sectional and longitudinal study. Occup. Environ. Med. 57 (3), 152–158. Weiland, S.K., Mundt, K.A., Ruckmann, A., Keil, U., 1994. Selfreported wheezing and allergic rhinitis in children and traffic density on street of residence. Ann. Epidemiol. 4, 243–247. Wjst, M., Reitmeir, P., Dold, S., Wulff, A., Nicolai, T., LoeffelholzColberg, E.F., von Mutius, E., 1993. Road traffic and adverse effects on respiratory health in children. Br. Med. J. 307, 596–600. Wyler, C., Braun-Fahrla¨nder, C., Ku¨nzli, N., Schindler, C., Ackermann-Liebrich, U., Perruchoud, A.P., Leuenberger, P., Wu¨thrich, B., and the Swiss Study on Air Pollution and Lung Diseases in Adults (SAPALDIA) Team, 2000. Exposure to Motor Vehicle Traffic and Allergic Sensitization. Epidemiology 11(4), 450–456. Zmirou, D.S., Gauvin, Pin, I., Momas, I., Sahraoui, F., Just, J., Le Moullec, Y., Reungoat, P., Bremont, F., Cassadou, S., Albertini, M., Lauvergne, N., Chiron, M., Labbe, A., 2004. Traffic-related air pollution and incidence of childhood asthma: results of the VESTA case control study. J. Epidemiol. Commun. Health 58 (1), 18–23.