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High concentrations of cadmium, cerium and lanthanum in indoor air due to environmental tobacco smoke
Science of the Total Environment 414 (2012) 738–741
Contents lists available at SciVerse ScienceDirect
Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv
Short Communication
High concentrations of cadmium, cerium and lanthanum in indoor air due to environmental tobacco smoke Antje Böhlandt a,⁎, Rudolf Schierl a, Juergen Diemer b, Christoph Koch b, Gabriele Bolte c, Mandy Kiranoglu c, Hermann Fromme c, Dennis Nowak a a b c
Institute and Outpatient Clinic for Occupational, Social and Environmental Medicine, Ludwig-Maximilians-University, Munich, Germany Bavarian Environment Agency, Augsburg, Germany Bavarian Health and Food Safety Authority, Munich, Germany
a r t i c l e
i n f o
Article history: Received 26 August 2011 Received in revised form 27 October 2011 Accepted 7 November 2011 Available online 2 December 2011 Keywords: Cerium Lanthanum Environmental tobacco smoke Rare earth elements Indoor air
a b s t r a c t Background: Environmental tobacco smoke (ETS) is one of the most important sources for indoor air pollution and a substantial threat to human health, but data on the concentrations of the trace metals cerium (Ce) and lanthanum (La) in context with ETS exposure are scarce. Therefore the aim of our study was to quantify Ce and La concentrations in indoor air with high ETS load. Methods: In two subsequent investigations Ce, La and cadmium (Cd) in 3 smokers' (11 samples) and 7 nonsmokers' (28 samples) households as well as in 28 hospitality venues in Southern Germany were analysed. Active sampling of indoor air was conducted continuously for seven days in every season in the smokers' and non-smokers' residences, and for 4 h during the main visiting hours in the hospitality venues (restaurants, pubs, and discotheques). Results: In terms of residences median levels of Cd were 0.1 ng/m3 for non-smokers' and 0.8 ng/m3 for smokers' households. Median concentrations of Ce were 0.4 ng/m3 and 9.6 ng/m3, and median concentrations of La were 0.2 ng/m3 and 5.9 ng/m3 for non-smokers' and for smokers' households, respectively. In the different types of hospitality venues median levels ranged from 2.6 to 9.7 ng/m3 for Cd, from 18.5 to 50.0 ng/m3 for Ce and from 10.6 to 23.0 ng/m3 for La with highest median levels in discotheques. Conclusions: The high concentrations of Ce and La found in ETS enriched indoor air of smokers' households and hospitality venues are an important finding as Ce and La are associated with adverse health effects and data on this issue are scarce. Further research on their toxicological, human and public health consequences is urgently required. © 2011 Elsevier B.V. All rights reserved.
1. Introduction Environmental tobacco smoke (ETS) is the most significant and critical factor for indoor air quality in health concerns and is classified as carcinogenic in humans. It contains many trace and toxic elements including heavy metals and rare earth elements (REE) of which cadmium (Cd) is a well known marker for ETS burden (Wu et al., 1995). However, for some elements, data are very scarce and little attention has been paid for the REE cerium (Ce) and lanthanum (La) in ETS. Contrary to Cd, Ce and La are not mentioned in the comprehensive reviews of the International Agency for Research on Cancer (2004) and the U.S. Department of Health and Human Services (2006). Reports on health effects and indoor air concentrations of Ce and La are scarce (Adgate
⁎ Corresponding author at: Institute and Outpatient Clinic for Occupational, Social and Environmental Medicine, Ziemssenstrasse 1, D-80336 Muenchen, Germany. Tel.: +49 89 5160 2463; fax: +49 89 5160 3957. E-mail address: [email protected] (A. Böhlandt). 0048-9697/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.scitotenv.2011.11.017
et al., 2007; Graney et al., 2004; Kinney et al., 2002; U.S. EPA, 2009) and no human data on inhalation exposure for Ce or La are available. Despite the paucity of data regarding exposures in the indoor environment there is a concern about the health effects of Ce and La emissions and uptake. In fact, inhalation of lanthanides has been associated with various acute and chronic systemic toxicological effects with the respiratory system as the primary target. Adverse health effects, such as pneumoconiosis and lung fibrosis due to long-term occupational inhalation exposure (e.g. carbon arc lamp fumes, photoengraving industry, printing industry) have been described in several human case reports (U.S. EPA, 2009), but Ce and La exposures were not quantified in any of these cases. Ce exposure has also been related to inflammation or granulomatosis of lung tissue as well as to endomyocardial fibrosis and myocardial infarction (Gomez-Aracena et al., 2006; Haley, 1991; Kuruvilla and Kartha, 2006). Earlier investigations revealed that Ce and La could be present in settled house dust (Powell et al., 2002), which could probably be attributed to tobacco smoke. As tobacco smoke considerably contributes to trace metal concentrations in the indoor environment and as adverse health effects of inhaled lanthanides
A. Böhlandt et al. / Science of the Total Environment 414 (2012) 738–741
have been reported, measurements of Ce and La in ETS will be of great value to human exposure analysis and to risk assessment. This study presents the airborne concentrations of Ce, La and Cd in non-smokers' and smokers' residences and in hospitality venues in Germany in context with ETS, an issue which has not been previously published. 2. Materials and methods 2.1. Sampling sites Measurements from two subsequent investigations on indoor air concentrations of the heavy metals Ce and La as well as Cd from households and from hospitality venues (restaurants or cafés, bars or pubs, discotheques or clubs) with high ETS exposure were evaluated. 2.1.1. Indoor air measurements in residences Indoor air sampling was carried out from August 2003 until March 2005 in ten residences in the area of Munich, a city with 1.2 million inhabitants in southern Germany. Seven of the ten sampling sites were non-smokers' residences (reference sites) and in three residences cigarette smoking occurred occasionally or daily. Samples were continuously collected over one week (seven days) in each season, as described in detail in the doctoral thesis of Deichsel (2007), resulting in 28 filter samples from the seven non-smokers' households and 11 filter samples (one filter sample missing) from the three smokers' homes. Air sampling was performed in rooms where residents spent most of their time e.g. living room and kitchen. Study participants continued with their normal living habits. Information about presence time and number of residents, cigarette smoking, open windows, etc. was recorded in a daily protocol. None of the residences had air conditioning (Deichsel, 2007). 2.1.2. Indoor air measurements in hospitality venues Sampling of indoor air was performed during 4 h in 28 hospitality venues with smoking permission in the cities of Augsburg and Munich, Germany, from April 2005 to May 2006 (Bolte et al., 2008). According to their characteristics the locations were categorised into cafés or restaurants (n = 11), pubs or bars (n = 7), and discotheques or clubs (n = 10). The measurements were performed during the main visiting hours of each individual location as described in detail in the publication of Bolte et al. (2008). In the majority of sampling sites smoking was allowed in the whole location. Only in five locations sampling was performed in a separate smoking section. Fieldworkers were present during the complete measurement time (average: 4 h) and recorded characteristics of the sampling sites. In smaller locations, the proportion of smoking was calculated as ratio of the average number of smokers and of the average number of guests (counted each hour) and ranged from 11 to 50% (restaurant or café) and from 30 to 60% (pub or bar) with estimated average numbers of persons in the range of 7–350 and 25–88, respectively. In larger and more crowded locations such as discotheques or clubs, data on total number of guests during the evening or the expected total number were obtained from the manager and 80% of this number was assumed as estimated average number of persons at one point in time (range: 180–1200 persons). The smoking rate in such larger locations was calculated based on estimations of smoking rates among the guests, mostly ranging from 50% to 60%. 2.2. Sampling and analytical procedure In the non-smokers' and smokers' homes air sampling was conducted continuously over seven days at a flow rate of 1.2 L/min with a Grimm dust monitor obtaining a sample volume of 12 m 3 (Deichsel, 2007). Airborne dust was collected on 47 mm diameter (1.2 μm pore size) Teflon membrane filters (Grimm). In the hospitality
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venues samples were collected on 47 mm quartz fibre filters (Pieper, Bad Zwischenahn, Germany) using a medium volume sampler equipped with a PM2.5 sampler as sample inlet, operated at a constant flow of 3 m 3/h with a sample volume of 10 m3 (Bolte et al., 2008). Teflon filter samples were decomposed in a closed-vessel system (High Pressure Asher, Anton Paar) using 4 mL nitric acid (65%, suprapur) and 0.5 mL hydrochloric acid (30%, suprapur) as oxidising agents. Quartz fibre filter samples were digested using a microwave closedvessel system (MLS) using 8 mL nitric acid (65%, suprapur) and 2 mL hydrogen peroxide (30%, suprapur) as oxidising agents (method DIN EN 14902 for the determination of element concentrations in suspended particulate matter). As quartz fibre filters may contain relatively high amounts of analyte elements, filters from the same production batch were analysed for their heavy metal blank values. Blank values were subtracted from analytical results, as recommended by DIN EN 14902. After tenfold dilution of the resulting solutions by adding 2% nitric acid and after addition of rhodium and lutetium as internal standards Cd, Ce and La were measured by inductively coupled plasma-mass spectrometry (ICP-MS). For Ce and La detection limits of 0.1 ng/m3 and for Cd detection limits of 0.02 ng/m3 were obtained (calculated for sample volume 10 m 3). For quality control reasons, a portion of the CW8 road dust reference material (also known as BCR-723) was decomposed with each series of filter samples. Results for Cd (2.16 ± 0.14 mg/kg) and La (15.0 ± 1.7 mg/kg) are in good agreement with the indicative values (for Cd 2.5 and for La 17.3 mg/kg). Thus, recovery rates of 87% are obtained for both elements. Unfortunately, the analytical result for Ce in CW8 (34.1 ± 6.1 mg/kg) cannot be used for calculating a recovery rate as no certified or indicative value for Ce in this material is provided. 2.3. Statistical analysis The statistical analysis was performed using SPSS Statistics Version 19.0. The data distribution of normality was calculated using the Kolmogorov–Smirnov test. Since data were not normally distributed, the median and the range were presented for indoor air concentrations of Ce, La and Cd in residences and hospitality venues. For comparison reasons also the mean and the standard deviation were shown. Concentrations below the LOD were assigned half of the LOD value. 3. Results and discussion In screening analyses on indoor air quality in German households high Ce and La concentrations were revealed in locations with intensive tobacco smoking, which was to our knowledge not yet described in international publications. Consequently, this study focussed on Ce and La as well as on Cd concentrations and the indoor air in three smokers' households and in seven non-smokers' residences was analysed. In a second investigation the indoor air in 28 hospitality venues with smoking permission was analysed in and around the cities of Munich and Augsburg, Germany. In Table 1 the number of samples and the median, arithmetic mean ± standard deviation and the range of Cd, Ce and La concentrations from both investigations (ten residences and 28 hospitality venues) are presented. In the households air samples were taken in each season, resulting in four samples for each residence. As tobacco contains high amounts of Cd, which are released in the tobacco smoke, Cd is a well known marker for ETS and is classified as carcinogenic substance to humans according to the International Agency for Research on Cancer (1993). The Cd air concentrations in the smokers' households ranged between 0.1 and 3.0 ng/m 3 and in the non-smokers' households between b0.1 and 1.3 ng/m3 (Table 1). While Cd levels in the non-smoker residences correspond with previously published average air concentrations of 0.145 ng/m 3 (Kinney et al., 2002) and 0.30 ng/m3 (Adgate et al., 2007), the Cd levels in the smokers' households were even below average concentrations in
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Table 1 Statistics of metal concentrations in indoor air with ETS exposure (ng/m3) in residences (PM10) and hospitality venues (PM2.5). Number of samples
Residences Non-smokers
Cd
Ce
La
a
Median Mean Range Median Mean Range Median Mean Range
Hospitality venues with smoking activity Smokers a
n = 28
n = 11
0.1 0.2 ± 0.2 0.01–1.3 0.4 2.0 ± 6.8 0.1–36.2 0.2 0.9 ± 2.7 0.01–14.4
0.8 1.1 ± 0.9 0.1–3.0 9.6 20.1 ± 25.0 0.2–70.6 5.9 10.7 ± 13.0 0.2–38.7
Restaurant/café n = 10
a
2.6 3.2 ± 2.1 1.2–7.7 18.5 21.3 ± 14.9 5.5–48.0 10.6 11.5 ± 7.4 2.3–23.0
Pub/bar
Discotheque/club
n=7
n = 10
3.7 7.4 ± 9.0 1.7–27.0 24.0 67.0 ± 99.4 17.0–290.0 15.0 38.8 ± 58.5 7.8–170.0
9.7 10.2 ± 4.1 5.3–16.0 50.0 62.8 ± 34.9 28.0–130.0 23.0 29.3 ± 16.4 13.0–60.0
One filter sample missing.
other ETS rich indoor environments, e.g. 7.6 ng/m3 in a smoker's office (Slezakova et al., 2009). In hospitality venues Cd levels ranged from 1.2 ng/m 3 to 27 ng/m 3 with a median of 2.6 ng/m 3 for restaurants or cafés, a median of 3.7 ng/m 3 for bars or pubs and 9.7 ng/m3 in discotheques or clubs (Table 1), which is in agreement with Cd levels between 4.0 and 37.9 ng/m 3 in public sites with ETS influence found in international literature (Landsberger and Wu, 1995; Slezakova et al., 2009). In comparison, outdoor Cd concentrations in Bavaria are in the range of 0.08–0.22 ng/m 3 (annual mean of seven air monitoring sites in Bavaria) corresponding to mean concentrations between 0.04 and 0.157 ng/m3 on near-highway or urban sites in the United States (Hays et al., 2011; Kinney et al., 2002). Remarkably, very high concentrations for Ce and La were found in indoor places with moderate or heavy tobacco smoking activity. In the smokers' households Ce and La concentrations ranged from 0.2 to 71 ng/m 3 and from 0.2 to 39 ng/m 3, respectively. La and Ce levels from the non-smokers' households (median 0.2 and 0.4 ng/m 3) correspond with previous published findings from non-smokers' residences (Adgate et al., 2007; Graney et al., 2004; Kinney et al., 2002) with medians or means ranging from 0.02 to 0.72 ng/m3 for La and 0.018 to 0.057 ng/m 3 for Ce. In the smokers' residences the median Ce and La concentrations were 26-fold and 37-fold higher, compared to the non-smokers' residences. In hospitality venues the indoor air concentrations were even higher (Ce: range 5.5–290 ng/m3, La: range 2.3–170 ng/m3) with the highest median levels in discotheques and clubs. In comparison, outdoor Ce concentrations ranged from 0.1 to 0.6 ng/m3 and La concentrations from b0.1 to 0.3 ng/m3 (annual mean of seven air monitoring sites in Bavaria). Measurements in the Los Angeles area reported Ce concentrations about 0.5 ng/m3 in the urban PM (HEI, 2001), which is in accordance with airborne Ce and La concentrations in recently published studies from urban near-highway or industry areas (Hammond et al., 2008; Hays et al., 2011; Kinney et al., 2002; Lim et al., 2011). Thus, indoor Ce and La levels from ETS exceeded average outdoor Ce and La levels measured in vicinity to industry (e.g. ceramic related industry, oil combustion, refineries) or heavy traffic areas with resuspension of road dust components and release by catalytic converters by far. The predominant source for Ce and La in indoor air obviously is tobacco smoke as already shown by Slezakova et al. (2009), who found average values of 18.7 and 26.8 ng/m 3 in PM2.5 for Ce and of 4.79 and 26.0 ng/m 3 for La in an ETS rich office and a cafeteria in Portugal. Moreover, very high concentrations of Ce and La were found during a narghile (shisha) smoking session in a room with values of 129 ng/m 3 and 63 ng/m 3 in PM2.5, respectively (Fromme et al., 2009). A notable enrichment of those trace elements at the indoor environment compared to the outdoor was found in an office where indoor activities like smoking and cooking occurred (Lim et al., 2011), but the concentrations in the range 0.06 to 2.77 ng/m 3 for Ce and 0.09 to 3.77 ng/m 3 for La were far below the levels of the here presented findings from ETS enriched locations. Trace elements in cigarette tobacco
have been determined in diverse studies from several countries (Hamidatou et al., 2009; Iskander, 1992; Nada et al., 1999), but quantified Ce and La concentrations received no further attention nor were they further discussed. It is known that rare earth elements are added to fertiliser in high concentrations (Tyler, 2004) and accumulate in the soil–plant-system. However, it is speculative, whether the Ce and La in cigarette tobacco can be traced back to the tobacco plant itself because of agricultural impacts (e.g.; soil, fertiliser composition, frequency of application) or whether their concentrations are influenced by processing techniques and additives during tobacco blending. Numerous procedures to reduce the formation of carcinogens in tobacco smoke have been developed and patented from the tobacco industry (ASH, 1999). Because the industrial manufacturing processes are confidential, it is not known to which extent those patents are applied. Literature on the health effects of Ce and La is limited. Inhalation data in humans consist of reports describing numerous cases of workers who developed adverse lung effects such as interstitial lung disease or pneumoconiosis due to long term occupational inhalation exposure (U.S. EPA, 2009), but exposure concentrations were not quantified in any of these reports. Regarding long-term inhalation exposure to animals, the EPA derived an inhalation reference concentration (RfC) of 900 ng/m 3 for Ce oxide with the increased incidence of alveolar epithelial hyperplasia as critical effect which is based on a single subchronic toxicity study in rats (U.S. EPA, 2009). For La no comparable data are available. Although lanthanides are components of cigarette tobacco and their uptake has been associated with adverse effects on pulmonary and cardiac tissue (Gomez-Aracena et al., 2006; Haley, 1991; U.S. EPA, 2009), so far no study has brought this important issue into the research focus yet and no comparable data of Ce and La in context with ETS have been published yet. As Ce and La were found in comparatively high concentrations in ETS rich indoor air in this study, future investigations could address to evaluation of applicability of Ce and La as a sensitive indoor marker for ETS burden as already considered recently (Lim et al., 2011). The small sample size in smokers' residences might be judged as a limitation of the presented study. As for the hospitality venues, a true random sample could not be achieved: due to the amount of measurement rather small and heavily crowded pubs or clubs could not be sampled. On the other hand, the sampling time of 4 h was a comprehensive monitoring of real life exposure to ETS components. The continuous seven day-measurements in smokers' households reflecting a long-term overview of real life exposure to ETS during each season oppose to the small sample size of smokers' households. 4. Conclusions In conclusion, the high indoor concentrations of Ce and La found in smokers' households and hospitality venues as components of ETS are an important finding, and investigation of their toxicological and
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health consequences is urgently needed. Further research is required to confirm these findings and to understand their plausibility and their public health implications as well as to examine how these findings can be translated into preventive action. Due to the obviously very high concentrations emitted, Ce and La could be a sensitive marker for the amount of ETS exposure. Acknowledgements We thank Heike Deichsel and Isak Qorolli for conducting the sampling in the residences. The study was funded by the Bavarian State Ministry of the Environment and Public Health. The sponsor of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the manuscript. References Adgate JL, Mongin SJ, Pratt GC, Zhang J, Field MP, Ramachandran G, et al. Relationships between personal, indoor, and outdoor exposures to trace elements in PM2.5. Sci Total Environ 2007;386:21–32. ASH (Action on Smoking and Health). The safer cigarette: what the tobacco industry could do…and why it hasn't done it. London, March. www.ash.org.uk/html/regulation/ html/patent.html; 1999. Bolte G, Heitmann D, Kiranoglu M, Schierl R, Diemer J, Koerner W, et al. Exposure to environmental tobacco smoke in German restaurants, pubs and discotheques. J Expo Sci Environ Epidemiol 2008;18(3):262–71. Deichsel H, 2007. [Zeitliches Profil von Partikeln verschiedener Größe der Außen- und Innenraumluft genutzter Räume in München und Umgebung]. Dissertation, LMU München: Medizinische Fakultät: http://edoc.ub.uni-muenchen.de/7473/1/Deichsel_ Heike.pdf. Fromme H, Dietrich S, Heitmann D, Dressel H, Diemer J, Schulz T, et al. Indoor air contamination during a waterpipe (narghile) smoking session. Food Chem Toxicol 2009;47(7):1636–41. Gomez-Aracena J, Riemersma RA, Gutierrez-Bedmar M, Bode P, Kark JD, Garcia-Rodriguez A, et al. Toenail cerium levels and risk of a first acute myocardial infarction: the EURAMIC and heavy metals study. Chemosphere 2006;64(1):112–20. Graney JR, Landis MS, Norris GA. Concentrations and solubility of metals from indoor and personal exposure PM2.5 samples. Atmos Environ 2004;38(2):237–47. Haley PJ. Pulmonary toxicity of stable and radioactive lanthanides. Health Phys 1991;61(6):809–20. Hamidatou LA, Khaled S, Akhal T, Ramdhane M. Determination of trace elements in cigarette tobacco with the k(0)-based NAA method using Es-Salam research reactor. J Radioanal Nucl Chem 2009;281(3):535–40.
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Hammond DM, Dvonch JT, Keeler GJ, Parker EA, Kamal AS, Barres JA, et al. Sources of ambient fine particulate matter at two community sites in Detroit, Michigan. Atmos Environ 2008;42(4):720–32. Hays MD, Cho S-H, Baldauf R, Schauer JJ, Shaferd M. Particle size distributions of metal and non-metal elements in an urban near-highway environment. Atmos Environ 2011;45(4):925–34. HEI (Health Effects Institute). Evaluation of human health risk from cerium added to diesel fuel. Communication, 9. Boston, MA: Health Effects Institute; 2001. IARC (International Agency for Research on Cancer). Monographs on the evaluation of carcinogenic risks to humans. Beryllium, cadmium, mercury, and exposures in the glass manufacturing industry, vol. 58. Lyon: IARC Press; 1993. IARC (International Agency for Research on Cancer). Tobacco smoke and involuntary smoking. IARC monographs on the evaluation of carcinogenic risks to humans, vol. 83. Lyon: IARC Press; 2004. Iskander FY. Multielement determination in a Chinese cigarette brand. J Radioanal Nucl Chem Art 1992;159(1):105–10. Kinney PL, Chillrud SN, Ramstrom S, Ross J, Spengler JD. Exposures to multiple air toxics in New York city. Environ Health Perspect 2002;110(Suppl. 4):539–46. Kuruvilla L, Kartha CC. Cerium depresses endocardial endothelial cell-mediated proliferation of cardiac fibroblasts. Biol Trace Elem Res 2006;114(1–3):85–92. Landsberger S, Wu D. The impact of heavy metals from environmental tobacco smoke on indoor air quality as determined by Compton suppression neutron activation analysis. Sci Total Environ 1995;173(1–6):323–37. Lim JM, Jeong JH, Lee JH, Moon JH, Chung YS, Kim KH. The analysis of PM2.5 and associated elements and their indoor/outdoor pollution status in an urban area. Indoor Air 2011;21:145–55. Nada A, Abdel-Wahab M, Sroor A, Abdel-Haleem AS, Abdel-Sabour MF. Heavy metals and rare earth elements source-sink in some Egyptian cigarettes as determined by neutron activation analysis. Appl Radiat Isot 1999;51(1):131–6. Powell JWD, Hunt A, Abraham JL. Anthropogenic vanadium–chromium–iron and cerium– lanthanum–iron particles in settled urban house dust: CCSEM identification and analysis. Water Air Soil Pollut 2002;135(1–4):207–17. Slezakova K, Pereira MC, Alvim-Ferraz MC. Influence of tobacco smoke on the elemental composition of indoor particles of different sizes. Atmos Environ 2009;43(3): 486–93. Tyler G. Rare earth elements in soil and plant systems — a review. Plant Soil 2004;267(1–2):191–206. U.S. Department of Health and Human Services. The health consequences of involuntary exposure to tobacco smoke: a report of the surgeon general. Atlanta, GA: US Department of Health and Human Services, Centers for Disease Control and Prevention, Coordination Center for Health Promotion, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health; 2006. U.S. EPA (United States Environmental Protection Agency). Toxicological review of cerium oxide and cerium compounds. EPA/635/R-08/002f. Available online at http://www.epa.gov/iris/toxreviews/1018tr.pdf; 2009. Washington, D.C. Wu D, Landsberger S, Larson SM. Evaluation of elemental cadmium as a marker for environmental tobacco-smoke. Environ Sci Technol 1995;29(9):2311–6.
Contents lists available at SciVerse ScienceDirect
Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv
Short Communication
High concentrations of cadmium, cerium and lanthanum in indoor air due to environmental tobacco smoke Antje Böhlandt a,⁎, Rudolf Schierl a, Juergen Diemer b, Christoph Koch b, Gabriele Bolte c, Mandy Kiranoglu c, Hermann Fromme c, Dennis Nowak a a b c
Institute and Outpatient Clinic for Occupational, Social and Environmental Medicine, Ludwig-Maximilians-University, Munich, Germany Bavarian Environment Agency, Augsburg, Germany Bavarian Health and Food Safety Authority, Munich, Germany
a r t i c l e
i n f o
Article history: Received 26 August 2011 Received in revised form 27 October 2011 Accepted 7 November 2011 Available online 2 December 2011 Keywords: Cerium Lanthanum Environmental tobacco smoke Rare earth elements Indoor air
a b s t r a c t Background: Environmental tobacco smoke (ETS) is one of the most important sources for indoor air pollution and a substantial threat to human health, but data on the concentrations of the trace metals cerium (Ce) and lanthanum (La) in context with ETS exposure are scarce. Therefore the aim of our study was to quantify Ce and La concentrations in indoor air with high ETS load. Methods: In two subsequent investigations Ce, La and cadmium (Cd) in 3 smokers' (11 samples) and 7 nonsmokers' (28 samples) households as well as in 28 hospitality venues in Southern Germany were analysed. Active sampling of indoor air was conducted continuously for seven days in every season in the smokers' and non-smokers' residences, and for 4 h during the main visiting hours in the hospitality venues (restaurants, pubs, and discotheques). Results: In terms of residences median levels of Cd were 0.1 ng/m3 for non-smokers' and 0.8 ng/m3 for smokers' households. Median concentrations of Ce were 0.4 ng/m3 and 9.6 ng/m3, and median concentrations of La were 0.2 ng/m3 and 5.9 ng/m3 for non-smokers' and for smokers' households, respectively. In the different types of hospitality venues median levels ranged from 2.6 to 9.7 ng/m3 for Cd, from 18.5 to 50.0 ng/m3 for Ce and from 10.6 to 23.0 ng/m3 for La with highest median levels in discotheques. Conclusions: The high concentrations of Ce and La found in ETS enriched indoor air of smokers' households and hospitality venues are an important finding as Ce and La are associated with adverse health effects and data on this issue are scarce. Further research on their toxicological, human and public health consequences is urgently required. © 2011 Elsevier B.V. All rights reserved.
1. Introduction Environmental tobacco smoke (ETS) is the most significant and critical factor for indoor air quality in health concerns and is classified as carcinogenic in humans. It contains many trace and toxic elements including heavy metals and rare earth elements (REE) of which cadmium (Cd) is a well known marker for ETS burden (Wu et al., 1995). However, for some elements, data are very scarce and little attention has been paid for the REE cerium (Ce) and lanthanum (La) in ETS. Contrary to Cd, Ce and La are not mentioned in the comprehensive reviews of the International Agency for Research on Cancer (2004) and the U.S. Department of Health and Human Services (2006). Reports on health effects and indoor air concentrations of Ce and La are scarce (Adgate
⁎ Corresponding author at: Institute and Outpatient Clinic for Occupational, Social and Environmental Medicine, Ziemssenstrasse 1, D-80336 Muenchen, Germany. Tel.: +49 89 5160 2463; fax: +49 89 5160 3957. E-mail address: [email protected] (A. Böhlandt). 0048-9697/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.scitotenv.2011.11.017
et al., 2007; Graney et al., 2004; Kinney et al., 2002; U.S. EPA, 2009) and no human data on inhalation exposure for Ce or La are available. Despite the paucity of data regarding exposures in the indoor environment there is a concern about the health effects of Ce and La emissions and uptake. In fact, inhalation of lanthanides has been associated with various acute and chronic systemic toxicological effects with the respiratory system as the primary target. Adverse health effects, such as pneumoconiosis and lung fibrosis due to long-term occupational inhalation exposure (e.g. carbon arc lamp fumes, photoengraving industry, printing industry) have been described in several human case reports (U.S. EPA, 2009), but Ce and La exposures were not quantified in any of these cases. Ce exposure has also been related to inflammation or granulomatosis of lung tissue as well as to endomyocardial fibrosis and myocardial infarction (Gomez-Aracena et al., 2006; Haley, 1991; Kuruvilla and Kartha, 2006). Earlier investigations revealed that Ce and La could be present in settled house dust (Powell et al., 2002), which could probably be attributed to tobacco smoke. As tobacco smoke considerably contributes to trace metal concentrations in the indoor environment and as adverse health effects of inhaled lanthanides
A. Böhlandt et al. / Science of the Total Environment 414 (2012) 738–741
have been reported, measurements of Ce and La in ETS will be of great value to human exposure analysis and to risk assessment. This study presents the airborne concentrations of Ce, La and Cd in non-smokers' and smokers' residences and in hospitality venues in Germany in context with ETS, an issue which has not been previously published. 2. Materials and methods 2.1. Sampling sites Measurements from two subsequent investigations on indoor air concentrations of the heavy metals Ce and La as well as Cd from households and from hospitality venues (restaurants or cafés, bars or pubs, discotheques or clubs) with high ETS exposure were evaluated. 2.1.1. Indoor air measurements in residences Indoor air sampling was carried out from August 2003 until March 2005 in ten residences in the area of Munich, a city with 1.2 million inhabitants in southern Germany. Seven of the ten sampling sites were non-smokers' residences (reference sites) and in three residences cigarette smoking occurred occasionally or daily. Samples were continuously collected over one week (seven days) in each season, as described in detail in the doctoral thesis of Deichsel (2007), resulting in 28 filter samples from the seven non-smokers' households and 11 filter samples (one filter sample missing) from the three smokers' homes. Air sampling was performed in rooms where residents spent most of their time e.g. living room and kitchen. Study participants continued with their normal living habits. Information about presence time and number of residents, cigarette smoking, open windows, etc. was recorded in a daily protocol. None of the residences had air conditioning (Deichsel, 2007). 2.1.2. Indoor air measurements in hospitality venues Sampling of indoor air was performed during 4 h in 28 hospitality venues with smoking permission in the cities of Augsburg and Munich, Germany, from April 2005 to May 2006 (Bolte et al., 2008). According to their characteristics the locations were categorised into cafés or restaurants (n = 11), pubs or bars (n = 7), and discotheques or clubs (n = 10). The measurements were performed during the main visiting hours of each individual location as described in detail in the publication of Bolte et al. (2008). In the majority of sampling sites smoking was allowed in the whole location. Only in five locations sampling was performed in a separate smoking section. Fieldworkers were present during the complete measurement time (average: 4 h) and recorded characteristics of the sampling sites. In smaller locations, the proportion of smoking was calculated as ratio of the average number of smokers and of the average number of guests (counted each hour) and ranged from 11 to 50% (restaurant or café) and from 30 to 60% (pub or bar) with estimated average numbers of persons in the range of 7–350 and 25–88, respectively. In larger and more crowded locations such as discotheques or clubs, data on total number of guests during the evening or the expected total number were obtained from the manager and 80% of this number was assumed as estimated average number of persons at one point in time (range: 180–1200 persons). The smoking rate in such larger locations was calculated based on estimations of smoking rates among the guests, mostly ranging from 50% to 60%. 2.2. Sampling and analytical procedure In the non-smokers' and smokers' homes air sampling was conducted continuously over seven days at a flow rate of 1.2 L/min with a Grimm dust monitor obtaining a sample volume of 12 m 3 (Deichsel, 2007). Airborne dust was collected on 47 mm diameter (1.2 μm pore size) Teflon membrane filters (Grimm). In the hospitality
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venues samples were collected on 47 mm quartz fibre filters (Pieper, Bad Zwischenahn, Germany) using a medium volume sampler equipped with a PM2.5 sampler as sample inlet, operated at a constant flow of 3 m 3/h with a sample volume of 10 m3 (Bolte et al., 2008). Teflon filter samples were decomposed in a closed-vessel system (High Pressure Asher, Anton Paar) using 4 mL nitric acid (65%, suprapur) and 0.5 mL hydrochloric acid (30%, suprapur) as oxidising agents. Quartz fibre filter samples were digested using a microwave closedvessel system (MLS) using 8 mL nitric acid (65%, suprapur) and 2 mL hydrogen peroxide (30%, suprapur) as oxidising agents (method DIN EN 14902 for the determination of element concentrations in suspended particulate matter). As quartz fibre filters may contain relatively high amounts of analyte elements, filters from the same production batch were analysed for their heavy metal blank values. Blank values were subtracted from analytical results, as recommended by DIN EN 14902. After tenfold dilution of the resulting solutions by adding 2% nitric acid and after addition of rhodium and lutetium as internal standards Cd, Ce and La were measured by inductively coupled plasma-mass spectrometry (ICP-MS). For Ce and La detection limits of 0.1 ng/m3 and for Cd detection limits of 0.02 ng/m3 were obtained (calculated for sample volume 10 m 3). For quality control reasons, a portion of the CW8 road dust reference material (also known as BCR-723) was decomposed with each series of filter samples. Results for Cd (2.16 ± 0.14 mg/kg) and La (15.0 ± 1.7 mg/kg) are in good agreement with the indicative values (for Cd 2.5 and for La 17.3 mg/kg). Thus, recovery rates of 87% are obtained for both elements. Unfortunately, the analytical result for Ce in CW8 (34.1 ± 6.1 mg/kg) cannot be used for calculating a recovery rate as no certified or indicative value for Ce in this material is provided. 2.3. Statistical analysis The statistical analysis was performed using SPSS Statistics Version 19.0. The data distribution of normality was calculated using the Kolmogorov–Smirnov test. Since data were not normally distributed, the median and the range were presented for indoor air concentrations of Ce, La and Cd in residences and hospitality venues. For comparison reasons also the mean and the standard deviation were shown. Concentrations below the LOD were assigned half of the LOD value. 3. Results and discussion In screening analyses on indoor air quality in German households high Ce and La concentrations were revealed in locations with intensive tobacco smoking, which was to our knowledge not yet described in international publications. Consequently, this study focussed on Ce and La as well as on Cd concentrations and the indoor air in three smokers' households and in seven non-smokers' residences was analysed. In a second investigation the indoor air in 28 hospitality venues with smoking permission was analysed in and around the cities of Munich and Augsburg, Germany. In Table 1 the number of samples and the median, arithmetic mean ± standard deviation and the range of Cd, Ce and La concentrations from both investigations (ten residences and 28 hospitality venues) are presented. In the households air samples were taken in each season, resulting in four samples for each residence. As tobacco contains high amounts of Cd, which are released in the tobacco smoke, Cd is a well known marker for ETS and is classified as carcinogenic substance to humans according to the International Agency for Research on Cancer (1993). The Cd air concentrations in the smokers' households ranged between 0.1 and 3.0 ng/m 3 and in the non-smokers' households between b0.1 and 1.3 ng/m3 (Table 1). While Cd levels in the non-smoker residences correspond with previously published average air concentrations of 0.145 ng/m 3 (Kinney et al., 2002) and 0.30 ng/m3 (Adgate et al., 2007), the Cd levels in the smokers' households were even below average concentrations in
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Table 1 Statistics of metal concentrations in indoor air with ETS exposure (ng/m3) in residences (PM10) and hospitality venues (PM2.5). Number of samples
Residences Non-smokers
Cd
Ce
La
a
Median Mean Range Median Mean Range Median Mean Range
Hospitality venues with smoking activity Smokers a
n = 28
n = 11
0.1 0.2 ± 0.2 0.01–1.3 0.4 2.0 ± 6.8 0.1–36.2 0.2 0.9 ± 2.7 0.01–14.4
0.8 1.1 ± 0.9 0.1–3.0 9.6 20.1 ± 25.0 0.2–70.6 5.9 10.7 ± 13.0 0.2–38.7
Restaurant/café n = 10
a
2.6 3.2 ± 2.1 1.2–7.7 18.5 21.3 ± 14.9 5.5–48.0 10.6 11.5 ± 7.4 2.3–23.0
Pub/bar
Discotheque/club
n=7
n = 10
3.7 7.4 ± 9.0 1.7–27.0 24.0 67.0 ± 99.4 17.0–290.0 15.0 38.8 ± 58.5 7.8–170.0
9.7 10.2 ± 4.1 5.3–16.0 50.0 62.8 ± 34.9 28.0–130.0 23.0 29.3 ± 16.4 13.0–60.0
One filter sample missing.
other ETS rich indoor environments, e.g. 7.6 ng/m3 in a smoker's office (Slezakova et al., 2009). In hospitality venues Cd levels ranged from 1.2 ng/m 3 to 27 ng/m 3 with a median of 2.6 ng/m 3 for restaurants or cafés, a median of 3.7 ng/m 3 for bars or pubs and 9.7 ng/m3 in discotheques or clubs (Table 1), which is in agreement with Cd levels between 4.0 and 37.9 ng/m 3 in public sites with ETS influence found in international literature (Landsberger and Wu, 1995; Slezakova et al., 2009). In comparison, outdoor Cd concentrations in Bavaria are in the range of 0.08–0.22 ng/m 3 (annual mean of seven air monitoring sites in Bavaria) corresponding to mean concentrations between 0.04 and 0.157 ng/m3 on near-highway or urban sites in the United States (Hays et al., 2011; Kinney et al., 2002). Remarkably, very high concentrations for Ce and La were found in indoor places with moderate or heavy tobacco smoking activity. In the smokers' households Ce and La concentrations ranged from 0.2 to 71 ng/m 3 and from 0.2 to 39 ng/m 3, respectively. La and Ce levels from the non-smokers' households (median 0.2 and 0.4 ng/m 3) correspond with previous published findings from non-smokers' residences (Adgate et al., 2007; Graney et al., 2004; Kinney et al., 2002) with medians or means ranging from 0.02 to 0.72 ng/m3 for La and 0.018 to 0.057 ng/m 3 for Ce. In the smokers' residences the median Ce and La concentrations were 26-fold and 37-fold higher, compared to the non-smokers' residences. In hospitality venues the indoor air concentrations were even higher (Ce: range 5.5–290 ng/m3, La: range 2.3–170 ng/m3) with the highest median levels in discotheques and clubs. In comparison, outdoor Ce concentrations ranged from 0.1 to 0.6 ng/m3 and La concentrations from b0.1 to 0.3 ng/m3 (annual mean of seven air monitoring sites in Bavaria). Measurements in the Los Angeles area reported Ce concentrations about 0.5 ng/m3 in the urban PM (HEI, 2001), which is in accordance with airborne Ce and La concentrations in recently published studies from urban near-highway or industry areas (Hammond et al., 2008; Hays et al., 2011; Kinney et al., 2002; Lim et al., 2011). Thus, indoor Ce and La levels from ETS exceeded average outdoor Ce and La levels measured in vicinity to industry (e.g. ceramic related industry, oil combustion, refineries) or heavy traffic areas with resuspension of road dust components and release by catalytic converters by far. The predominant source for Ce and La in indoor air obviously is tobacco smoke as already shown by Slezakova et al. (2009), who found average values of 18.7 and 26.8 ng/m 3 in PM2.5 for Ce and of 4.79 and 26.0 ng/m 3 for La in an ETS rich office and a cafeteria in Portugal. Moreover, very high concentrations of Ce and La were found during a narghile (shisha) smoking session in a room with values of 129 ng/m 3 and 63 ng/m 3 in PM2.5, respectively (Fromme et al., 2009). A notable enrichment of those trace elements at the indoor environment compared to the outdoor was found in an office where indoor activities like smoking and cooking occurred (Lim et al., 2011), but the concentrations in the range 0.06 to 2.77 ng/m 3 for Ce and 0.09 to 3.77 ng/m 3 for La were far below the levels of the here presented findings from ETS enriched locations. Trace elements in cigarette tobacco
have been determined in diverse studies from several countries (Hamidatou et al., 2009; Iskander, 1992; Nada et al., 1999), but quantified Ce and La concentrations received no further attention nor were they further discussed. It is known that rare earth elements are added to fertiliser in high concentrations (Tyler, 2004) and accumulate in the soil–plant-system. However, it is speculative, whether the Ce and La in cigarette tobacco can be traced back to the tobacco plant itself because of agricultural impacts (e.g.; soil, fertiliser composition, frequency of application) or whether their concentrations are influenced by processing techniques and additives during tobacco blending. Numerous procedures to reduce the formation of carcinogens in tobacco smoke have been developed and patented from the tobacco industry (ASH, 1999). Because the industrial manufacturing processes are confidential, it is not known to which extent those patents are applied. Literature on the health effects of Ce and La is limited. Inhalation data in humans consist of reports describing numerous cases of workers who developed adverse lung effects such as interstitial lung disease or pneumoconiosis due to long term occupational inhalation exposure (U.S. EPA, 2009), but exposure concentrations were not quantified in any of these reports. Regarding long-term inhalation exposure to animals, the EPA derived an inhalation reference concentration (RfC) of 900 ng/m 3 for Ce oxide with the increased incidence of alveolar epithelial hyperplasia as critical effect which is based on a single subchronic toxicity study in rats (U.S. EPA, 2009). For La no comparable data are available. Although lanthanides are components of cigarette tobacco and their uptake has been associated with adverse effects on pulmonary and cardiac tissue (Gomez-Aracena et al., 2006; Haley, 1991; U.S. EPA, 2009), so far no study has brought this important issue into the research focus yet and no comparable data of Ce and La in context with ETS have been published yet. As Ce and La were found in comparatively high concentrations in ETS rich indoor air in this study, future investigations could address to evaluation of applicability of Ce and La as a sensitive indoor marker for ETS burden as already considered recently (Lim et al., 2011). The small sample size in smokers' residences might be judged as a limitation of the presented study. As for the hospitality venues, a true random sample could not be achieved: due to the amount of measurement rather small and heavily crowded pubs or clubs could not be sampled. On the other hand, the sampling time of 4 h was a comprehensive monitoring of real life exposure to ETS components. The continuous seven day-measurements in smokers' households reflecting a long-term overview of real life exposure to ETS during each season oppose to the small sample size of smokers' households. 4. Conclusions In conclusion, the high indoor concentrations of Ce and La found in smokers' households and hospitality venues as components of ETS are an important finding, and investigation of their toxicological and
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health consequences is urgently needed. Further research is required to confirm these findings and to understand their plausibility and their public health implications as well as to examine how these findings can be translated into preventive action. Due to the obviously very high concentrations emitted, Ce and La could be a sensitive marker for the amount of ETS exposure. Acknowledgements We thank Heike Deichsel and Isak Qorolli for conducting the sampling in the residences. The study was funded by the Bavarian State Ministry of the Environment and Public Health. The sponsor of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the manuscript. References Adgate JL, Mongin SJ, Pratt GC, Zhang J, Field MP, Ramachandran G, et al. Relationships between personal, indoor, and outdoor exposures to trace elements in PM2.5. Sci Total Environ 2007;386:21–32. ASH (Action on Smoking and Health). The safer cigarette: what the tobacco industry could do…and why it hasn't done it. London, March. www.ash.org.uk/html/regulation/ html/patent.html; 1999. Bolte G, Heitmann D, Kiranoglu M, Schierl R, Diemer J, Koerner W, et al. Exposure to environmental tobacco smoke in German restaurants, pubs and discotheques. J Expo Sci Environ Epidemiol 2008;18(3):262–71. Deichsel H, 2007. [Zeitliches Profil von Partikeln verschiedener Größe der Außen- und Innenraumluft genutzter Räume in München und Umgebung]. Dissertation, LMU München: Medizinische Fakultät: http://edoc.ub.uni-muenchen.de/7473/1/Deichsel_ Heike.pdf. Fromme H, Dietrich S, Heitmann D, Dressel H, Diemer J, Schulz T, et al. Indoor air contamination during a waterpipe (narghile) smoking session. Food Chem Toxicol 2009;47(7):1636–41. Gomez-Aracena J, Riemersma RA, Gutierrez-Bedmar M, Bode P, Kark JD, Garcia-Rodriguez A, et al. Toenail cerium levels and risk of a first acute myocardial infarction: the EURAMIC and heavy metals study. Chemosphere 2006;64(1):112–20. Graney JR, Landis MS, Norris GA. Concentrations and solubility of metals from indoor and personal exposure PM2.5 samples. Atmos Environ 2004;38(2):237–47. Haley PJ. Pulmonary toxicity of stable and radioactive lanthanides. Health Phys 1991;61(6):809–20. Hamidatou LA, Khaled S, Akhal T, Ramdhane M. Determination of trace elements in cigarette tobacco with the k(0)-based NAA method using Es-Salam research reactor. J Radioanal Nucl Chem 2009;281(3):535–40.
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