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Biological effects of air pollution in São Paulo and Cubatão
ENVIRONMENTALRESEARCH49, 208--216 (1989)
Biological Effects of Air Pollution in S.5o Paulo and Cubat&o GYORGY MIKL6S BOHM, PAULO HILARIO NASCIMENTO SALDIVA, CARLOS AUGUSTO GONt~ALVES PASQUALUCCI, EDUARDO MASSAD, MILTON DE ARRUDA MARTINS, WALTER ARAOJO g i N , WELLINGTON VERAS CARDOSO, PATRICIA MARTINS PERE1RA CRIADO, MARCIA KOMATSUZAKI, REGINA SILVIA SAKAE, ELNARA MARCIA NEGR1, MIRIAM LEMOS, VERA DEL MONTE CAPELOZZI, CASSIANA CRESTANA, AND RUBERVAL DA SILVA Laborat6rio de Poluiffto Atmosfdrica Experimental and Instituto do Corafdo, Faculdade de Medicina da USP, Av. Dr. Arnaldo 455, 01246 Sdo Paulo, SP, Brazil, and Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil Received June 29, 1988 Rats were used as biological indicators of air quality in two heavily polluted Brazilian towns: Silo Paulo and Cubatio. They were exposed for 6 months to ambient air in areas where the pollution was known to be severe. The following parameters were studied and compared to those of control animals: respiratory mechanics, mucociliary transport, morphometry of respiratory epithelium and distal air spaces, and general morphological alterations. The results showed lesions of the distal and upper airways in rats exposed in Cubatfio, whereas the animals from Silo Paulo showed only alterations of the upper airways but of greater intensity than those observed in the Cubatio group. There are both qualitative and quantitative differences in the pollutants of these places: in Silo Paulo automobile exhaust gases dominate and in Cubatfio the pollution is due mainly to particulates of industrial sources. The correlation of the pathological findings with the pollutants is discussed and it is concluded that biological indicators are useful to monitor air pollutions which reached dangerous levels in Sio Paulo and Cubatfio. © 1989AcademicPress, Inc.
INTRODUCTION In the last 30 years a large number of studies have been published about the relation between outside air pollution and adverse health effects (Shy, 1979; American Thoracic Society, 1985). Both experimental and epidemiological methods have been used in attempts to determine what concentrations of specific air pollutants are needed in order to give rise to health effects. In such studies the combined and/or sinergic action of the complex atmospheric mixture of heavily polluted areas always have to be considered. So, it has not been possible to make hazard evaluations solely on the basis of experiments on animals or humans. One has been forced to rely on epidemiological studies in which it is very difficult to establish a direct cause--effect relationship, especially in situations of exposure to low levels of pollutants. In order to verify the possible health effects of urban air pollution,we used rats as biological indicators of air quality in two heavily polluted areas in Brazil: Silo Paulo and Cubatfio. Silo Paulo is a town with about 8,500,000 inhabitants; however, with its satellites it is an urban conglomeration of 16 million people. It is also the most indus208 0013-9351/89 $3.00 Copyright© 1989by AcademicPress,Inc. Allrightsof reproductionin anyformreserved.
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trialized center of Latin America and it has about 2,850,000 light duty cars and 300,000 trucks. Sho Paulo is 715-900 m above sea level with frequent thermal inversions. Thus, air pollution is a serious problem. Cubat~o was initially developed as a petrochemical center close to the harbor of Santos. Today it is a town squeezed between the sea and a wall of mountains (700--1000 m) with an enormous concentration of great factories and 100,000 inhabitants. The total amount of pollutants yield by factories is estimated as 175,000 tons per year and the traffic is jammed with big lorries. Because of the quality of the air it is significantly called "The Valley of Death." To experimentally reproduce the air composition of these places is virtually impossible. Therefore, the Laboratory of Experimental Air Pollution (LPAE) decided to expose laboratory rats to ambient air in downtown S~to Paulo. The animals lived in the tower of a church (Igreja Nossa Senhora do Ros~irio, Largo do Paissandti), situated 200 m from the air measurement station of the State (CETESB), where the pollution is known to be severe. Another group of animals were raised in a rented room at Vila Parisi, which is the worst "borough" of Cubaffto as far as air quality is concerned. The room was about 100 m from CETESB's measurement station. The control animals were in Ubatuba at the Oceanographic Institute of SCto Paulo University (at the seashore), where air pollution was assumed to be nil. This resort town is surrounded by mountains covered by rain forest and there are no industrial activities within 50 km around Ubatuba. There are no air pollution measurement stations in this region. In this paper the comparison of several biological parameters are presented after 6 months of constant exposure to ambient air in S~io Paulo, Cubatfio, and Ubatuba. MATERIAL AND METHODS
To each testing place 40 female 2.5-month-old common (nonspecific pathogen free) Wistar rats, bred in the animal house of the Faculty of Medicine of S~o Paulo University, were sent. The animals were housed in groups of 10 and given balanced food and water ad libitum. In the experience of the LPAE, common Wistar rats are excellent biological indicators of air pollution (Saldiva et al., 1985b; Massad et al., 1986) and the best period for respiratory function studies is young adulthood (Saldiva et al., 1988). Therefore, the investigations were performed after 6 months, when the animals were 8.5 months old. The following parameters were studied: (1) Respiratory mechanics. In order to evaluate respiratory mechanical impairment two methods were used: forced expiration and single-breath method. The first technique consists of simulating a maximal inspiration followed by a forced expiration, by applying positive and negative pressures to the airways (Saldiva et al., 1985a, b). This method allows the determination of pulmonary capacities (total lung capacity, TLC; inspiratory capacity, IC; and functional residual capacity, FRC) and volumes (expiratory reserve volume, ERV, and residual volume, RV). It also provides parameters pertaining to forced volume-flow loops:
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forced vital capacity, FVC; peak expiratory flow lklmax; and forced expiratory flows between 0-25, FEFo_25; 25-50, FEF25_5o; 50-75, FEF50_75;and 75-100% of FVC, FEF75_100, respectively. To obtain these data, the best of three trials was chosen in each animal. The single-breath method provides the values of respiratory system elastance (Ers), resistance (Rrs), and time constant ('rr~) (Zin et al., 1982). In each animal six measurements were performed and the results averaged. Further details on technical procedures and applicability of these methods to small animals are published elsewhere (Saldiva et al., 1987; Caldeira et al., 1988). (2) Mucociliary transport. Based on the frog palate technique (Morgan et al., 1984) to measure mucociliary transport we developed a new approach to perform the same study in the rat trachea. The animals were killed by exsanguination after anesthesia with thiobarbital (5 mg/kg i.p.) and their tracheas, as well as their left main bronchus, were exposed without opening these airways. The rat was then placed in a chamber saturated with water vapor at 37°C for 10 min in order to stabilize the whole preparation. By means of a needle mounted on a syringe, the left bronchus was punctured and 200 Ixl of colloidal carbon was carefully laid onto the epithelium. Thereafter, the airways were transilluminated with cold light and the displacement of the carbon particles was registered by means of a microscope provided with reticulated lenses. The speed values were expressed as means of three measurements performed every 30 min until the transportation stopped spontaneously. This was caused by want of mucus since the ciliary movements were still visible at this very moment. The decay in particle speed could be expressed as an exponential function of time. Velocity was integrated with respect to time and the resulting index was called ciliary transport capacity (CTC). Thus, CTC indicates the distance that an ideal colloidal carbon particle was displaced until the total halt of the mucociliar system. (3) Morphometry of the respiratory epithelium. Epithelial thickness was measured in the nose and axial left bronchus in 10 fields at 1000-fold magnification in each rat. To estimate the irritative response in central and peripheral airways, the number of mucous cells and their type of secretion was counted in 10 fields (1000-fold magnification) of the nose and axial and lateral bronchi. To identify the type of mucus a combination of Schiff's periodic acid and Alcian blue was employed at pH 2.5 (Lopes-Vidriero and Reid, 1978). With this technique, neutral and acid glycoproteins are stained in red and blue, respectively. (4) Morphometry of distal air spaces. This analysis was performed in lungs fixed by intratracheal instillation of neutral formalin at a transpulmonary pressure of 20 cm H20. One-micrometer-thick slides of the peripheral areas of the lungs were prepared and stained with hematoxylin and eosin. In each rat 10 fields (1000-fold magnification) were observed and five types of cells were counted and their relative proportion defined: epithelial, spindle (fibroblasts, septal, and endothelial cells), mononucleated (macrophages, monocytes, and lymphocytes), polimorphonucleated, and unclassified cells (Auler et al., 1986). (5) Morphological studies of other organs. In order to detect macro- and microscopical alterations, complete autopsies and histopathological examination of the central nervous system, heart, lungs, liver, kidneys, adrenals, spleen, stomach, and intestines were performed.
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Statistical evaluation was done using one-way analyses of variance (ANOVA) with a 5% significance level. In order to test the variation in cellular profile of distal air spaces, a codependence analysis was performed (Cordeiro, 1987). RESULTS The results of the respiratory function tests are displayed in Table I. The alterations observed in Cubatfio animals suggest lesions in the distal airways due to tissular modifications (see below), since resistance and elastance increased in the presence of normal expiratory flows. The only abnormal parameter in the rats of Silo Paulo was a reduction of TLC. This finding alone does not allow a pathophysiological interpretation. In Table 2 CTC and morphometrical data are listed. The results indicate a larger CTC in the rats of Silo Paulo caused by mucus hypersecretion. This suggests a chronic aggression to the airways. Morphometric data of respiratory epithelium and CTC alterations were found in Silo Paulo: the animals presented epithelial hyperplasia and increased number of mucous cells with neutral and acid secretion in the nose and airways. Cubat~o rats showed an increased number of acid secretory cells in the nose and axial and lateral bronchi and fewer cells with neutral TABLE 1 RESPIRATORY MECHANICAL PARAMETERSIN RATS EXPOSED TO AIR POLLUTION IN THREE DIFFERENT REGIONS OF SAO PAULO STATE Variable
Ubatuba
Number of rats Body weight (kg) VT (ml/kg) f(breaths/min) TLC (ml/kg) IC (ml/kg) FRC (ml/kg) ERV (ml/kg) RV (ml/kg) FVC (ml/kg) V ~ , (ml/sec) FEFo_25% (ml/sec) FEF25_5o~ (ml/sec) FEF5o_75~ (ml/sec) FEF75_10o% (ml/sec) E~ (cm H20/ml) Rrs (cm H20/ml/sec) Trs (sec)
10 0.26 - 0.04 4.95 - 0.51 98.10 ± 17.48 81.29 - 16.92 42.00 - 9.95 39.29 --- 7.65 14.81 -+ 3.92 24.50 -+ 5.77 56.81 ± 13.6 78.04 ± 10.62 7.10 --- 1.85 76.00 _+ 11.46 62.40-+ 11.75 8.70 +- 1.83 2.74 +- 0.40 0.197 +- 0.060 0.072 ± 0.018
Cubatfio 0.29 4.47 104.20 74.19 31.31 42.87 13.47 29.40 44.78 67.03 5,50 64.40 50.70 8.00 3.41 0.276 0.082
10 +-- 0.02 - 1.23 --_ 11,39 +- 8.70 --- 3.14" --_ 10.04 - 3.32 ± 11.22 ___4.01 - 13,11 ~ 1.10 --_ 15.01 ± 14.82 + 1.41 --- 0.52* ± 0.080* ± 0.025
Silo Paulo 9 0.29 --- 0.03 5.75 ± 1.42 95.89 --. 20.58 65.90 ± 8.06* 40.07 +- 7,79 25.85 +- 8.48 10.28 -+ 2.23 15.56 -+ 7.62 50.35 +- 7,63 75,07 --- 10,36 8.44 --+ 2,87 69.33 --- 10.95 51,33--- 10.04 11.56 -+ 2.55 2.59--- 0.69 0.195 -+ 0.090 0.076 --- 0.026
Note. Values are means _+ SD. Vrr, tidal volume;f, respiratory frequency; TLC, total lung capacity; IC, inspiratory capacity; FRC, functional residual capacity; ERV, expiratory reserve volume; RV, residual volume; FVC, forced vital capacity; ~'m~x, peak expiratory flow; FEFo_25%, FEF25_5o~, FEFso_75%, and FEF75_loo~, forced expiratory flows between 0 and 25%, 25 and 50%, 50 and 75%, and 75 and 100% of FVC, respectively; Ers, Rr~, and %s, respiratory system elastance, resistance, and time constant, respectively. * Statistically significant difference among groups (P < 0.05).
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TABLE 2 MUCOCILIARY TRANSPORT, MORPHOMETRY~ AND CELL CHARACTERIZATION IN RATS EXPOSED TO AIR POLLUTION IN THREE DIFFERENT REGIONS OF S.~o PAULO STATE
CTC (mm) Epithelial height (~m) Nose Axial bronchi M u c o u s cells (/field) Nose Neutral Acid Axial bronchi Neutral Acid Lateral bronchi Neutral Acid Other cells (% total) Epithelial Spindle Mononucleated Polimorphonucleated Unclassified
Ubatuba
Cubatho
S~o Paulo
360.5 - 122.5
332.0 + 87.0
730.0 --- 236.6*
41.17 -4- 5.29 24.65 + 6.10
37.06 + 2.40 27.70 - 8.44
42.02 -+ 2.96 35.83 - 6.65*
18.41 -+ 4.73 2.31 --- 1.60"
11.04 --- 6.35* 5.19 -+ 2.11
18.86 -+ 3.45 6.07 -+ 3.22
6.86 -+ 1.51' 9.88 -+ 4.42
2.07 -+ 1.87" 11.15 - 4.77
9.06 -+ 1.52' 12.52 --- 2.31
6.09 -+ 0.96 0.45 - 0.55*
1.90 ± 1.31 2.68 ± 1.87"
7.71 ± 1.07 5.94 - 2.67*
25.5 24.5 26.4 13.9 9.2
19.0 18.1 41.8 14.1 7.3
26.3 30.5 23.6 11.9 7.8
± 2.2 --_ 2.3 -+ 2.5 ± 2.2 - 2.2
-+ 2.3** -+ 2.9** -+ 4.9** -+ 1.0"* - 1.3"*
-+ 2.6 ± 3.4 -+ 1.4 ± 0.8 ~ 1.2
Note. Values are m e a n s --+ SD. CTC, ciliary transport capacity. * Statistically significant difference a m o n g groups (analysis of variance, P < 0.05). ** Statistically significant different cellular profile a m o n g groups (analysis o f covariance, P < 0.05).
mucus in all examined sites when compared to control animals, indicating an aggression of lesser intensity. The cellular profile of distal air spaces was abnormal in rats of Cubat~o, which presented a statistically significant increased proportion of chronic inflammatory cells, supporting the mechanical data (Table 1). The body weight of every animal was measured monthly and no differences were observed between the three groups. Macroscopical and histopathological examination of the several studied organs did not disclose any significant difference between the three groups of rats. DISCUSSION
Air pollution in S~o Paulo is patchy: there are bad and worse areas; really clean air is only found in some privileged regions in the periphery of the city. The pollution is caused by different factors but the main sources are industrial and automotor exhaust pipes. There is a huge quantity of alcohol-fueled light duty cars which tend to diminish air pollution (BOhm et al., 1983, 1986; Massad et al., 1985, 1986; Saldiva et al., 1985c). Air pollution in Cubatho is almost entirely dependent on industrial emissions. The air quality in S~o Paulo and Cubat~o is monitored by CETESB. We do not have the complete information about the amount of atmospheric pollutants in 1987, but in 1986 CO, SO2, NOx, 0 3, C H 4, H C ' s , Pb, fluorides, and particulates in suspension were measured s o m e t i m e and s o m e w h e r e .
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HEALTH EFFECTS OF URBAN AIR POLLUTION
Continuous monitoring of several pollutants was performed according to the region: in downtown Sfto Paulo CO and SO2, and in Cubatfto, Vila Parisi, SOz and particulate matter in suspension were measured during the whole year of 1986. For each pollutant there are quality patterns prescribed by State Law No. 997. Thus, the mean levels of CO, SO2, and particulate matter should not exceed 40,000 ixg/m3 (I hr), 365 txg/m3 (24 hr), and 240 ixg/m3 (24 hr), respectively, more than once per year. There are also criteria for acute air pollution situations to CO, SO2, photochemical oxidants, and particulates. For example, in the case of CO, "attention" is declared when CO reaches 15 ppm (8 hr), "alert" with 30 ppm (8 hr), and "emergency" with 40 ppm (8 hr). SO2 = 0.8 ppm (24 hr). Daily reports are issued to the public qualifying the air quality as "good," "acceptable," "inadequate," "bad," "very bad," and "critical." These indexes follow international standards and always reflect the worst situation of any pollutant. The percentage of days during 1986 with the air quality indexes in downtown Sfto Paulo and Vila Parisi are in Tables 3 and 4. The results of these measurements indicate that the levels of pollution in both places were very high. In Sgto Paulo, at the place where our rats were exposed, the pollution is due to traffic and, therefore, the level of pollutants varied daily and weekly during the present experiment (Table 5). In Cubatfto the variations of the levels of air pollutants were less marked during the 6 months of exposure of our animals. Particulates represented the most important pollutant (Table 6). Compared to control animals, rats living in S~o Paulo and Cubatfio developed respiratory distress. The differences in the sources of pollutants could explain the different patterns of respiratory impairment observed in both places. Rats of Cubatfto, with increased respiratory system resistance and elastance and increased numbers of mononucleated cells in the alveolar region, seem to have been affected by pollutants with a greater capacity to penetrate the lungs and, hence, damage the distal airspaces. There is no available information about the physical TABLE 3 AIR QUALITY IN DOWNTOWN S,g,O PAULO Percentage during 1986 Index of air quality Good Acceptable Inadequate Bad Very bad Critical
Carbon monoxide
Sulfur dioxide
0.5 11.5 51.2 36.8 ---
89.5 10.5 -----
Note. Data provided by CETESB (1987). Daily reports are issued to the public qualifying the air quality as "good" (mean level of CO less than 4.5 ppm (8 hr) and that of SO 2 less than 80 i~g/m3 (24 hr)), "acceptable" (CO between 4.5 and 9.0 ppm, SO 2 between 80 and 365 t~g/m3), "inadequate" (CO between 9.0 and 15.0 ppm, SO 2 between 365 and 800 ixg/m3), " b a d " (CO between 15.0 and 30.0 ppm, SO2 between 800 and 1600 p,g/m3), "very bad" (CO between 30.0 and 40.0 ppm, SO2 between 1600 and 2100 ixg/m3), and "critical" (CO between 40.0 and 50.0 ppm, SO2 between 2100 and 2620 ixg/m3).
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BOHM ET AL.
TABLE 4 AIR QUALITY XN CUBAT~,O Percentage during 1986 Index of air quality Good Acceptable Inadequate Bad Very bad Critical
Particulates
Sulfur dioxide
4.2 38.9 35.3 19.5 2.1 --
98.1 1.9 ----
Note. Data provided by CETESB (1987). Daily reports are issued to the public qualifying the air quality as "good" (mean level of particulates and of SO 2 for 24 hr, less than 80 ixg/m3 for each pollutant), "acceptable" (particulates between 80 and 240 ~g/m 3, SO2 between 80 and 365 v~g/m3), "inadequate" (particulates between 240 and 375 ixg/m3, SO2 between 365 and 800 v~g/m3), " b a d " (particulates between 375 and 625/~g/m 3, SO 2 between 800 and 1600 i~g/m3), "very bad" (particulates between 625 and 875 txg/m3, SO2 between 1600 and 2100 ~g/m3), and "critical" (particulates between 875 and 1000 wg/m 3, SO 2 between 2100 and 2620 #xg/m3).
and chemical properties of the particulates in Cubatfio. Our data suggest that a great proportion of the particulate material in this region is represented by particles which easily reach the alveoli. In the rats of Cubatfio an increased number of acid mucus secreting cells in the nose and airways were also observed, indicating a discrete affection of the airways. The smaller number of neutral mucus secreting cells in these rats may indicate a change in the secretory pattern of the airways (Lopes-Vidriero and Reid, 1978). The predominant upper airway lesions, epithelial hyperplasia, and mucous hypersecretion of Sao Paulo rats suggest the presence of a highly soluble pollutant with low penetration. The lack of information about the physical and chemical characteristics of atmospheric pollutants thwarts the identification of the agent(s). SO2 and CO were the unique pollutants measured during the time of exposure in Silo Paulo. SO 2 could conceivably cause lesions to the airways; however, the levels of this pollutant were very low in Sio Paulo (Table 5). Bouhuys et al. (1979) claim a significant correlation between SO2 levels and airway obstruction in humans in annual rates as low as 0.001 to 0.0047 ppm. Ferin and Leach (1973) TABLE 5 LEVELS OF AIR POLLUTANTS (MEANS ~ SD) IN DOWNTOWN S,~O PAULO DURING THE 6 MONTHS EXPOSURE CO (ppm) Weekend From Monday to Friday 8:00 AM to I0:00 PM 11:00 PM to 7:00 AM
6.43 9.54 10.96 4.77
-+ 0.62 _+ 0.59 --+ 0.91 --+ 0.31
SO z (ppm) 0.0018 0.0027 0.0027 0.0019
--- 0.0003 -+ 0.0001 -----0.0002 --+ 0.0003
Note. Data provided by CETESB (unpublished). EPA ambient air quality standards: CO = 9 ppm or 10,000 i~g/m3 (8 hr); SO 2 = 0.03 ppm or 80 ~g/m 3 (24 hr).
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HEALTH EFFECTS OF URBAN AIR POLLUTION
TABLE 6 LEVELS OF AIR POLLUTANTS(MEANS ± SD) IN CUBATAODURINGTHE 6 MONTHS EXPOSURE Particulates (l~g/m3) Weekend From Monday to Friday 8:00 AM to 10:00 PM 11:00 PM to 7.'00 AM
129.77 143.97 130.11 164.61
± 26.89 ± 28.55 --+ 21.29 --+ 38.31
SO2 (ppm) 0.0010 0.0010 0.0011 0.0011
± 0.0009 ± 0.0007 -----0.0008 ± 0.0007
Note. Data provided by CETESB (unpublished). EPA ambient air quality standards: particulates = 75 ixg/m3 (annual); SO2 = 0.03 ppm or 80 ixg/m3 (24 hr).
demonstrated mucociliary disfunctions in rats exposed to 0.1 ppm of 802 for 1 week. Considering the data above, we cannot exclude the participation of SO2, perhaps added to nonmeasured pollutants, as particulates and hydrocarbons, in causing the respiratory lesions in our rats. The present results strongly encourage the use of biological indicators to study the effects of air pollution. This monitoring should be done continuously, since it is not very expensive and provides accurate information about the real impact of air pollution on biological systems. Furthermore, information can be gathered at specific locations under the actual ambient air composition. Finally, unfortunately, there are no adequate data to identify precisely the "adverse health effects" (American Thoracic Society, 1985) of air pollution in Silo Paulo and Cubat~o. All that can be said is that air pollution has reached very dangerous levels and undoubtedly causes increased morbidity and, perhaps, mortality, to the population. ACKNOWLEDGMENT This work was supported by Grants FINEP 4286050900 and HC-FMUSP-LIM-05.
REFERENCES American Thoracic Society. (1985). Guidelines as to what constitutes an adverse respiratory health effect, with special reference to epidemiologic studies of air pollution. Amer. Rev. Respir. Dis. 131, 666-668. Auler, J. O. C., Jr., Calheiros, D. F., Brentani, M. M., Santello, J. L., Lemos, P. C. P., and Saldiva, P. H. N. (1986). Adult respiratory distress syndrome: Evidence of early fibrogenesis and absence of glucocorticoid receptors. Eur. J. Respir. Dis. 69, 261-269. B6hm, G. M., Massad, E., Saldiva, P. H. N., Gouveia, M. A., Pasqualucci, C. A., Cardoso, L. M. N., Caldeira, M. P. R., and Calheiros, D. F. (1983). Comparative toxicity of alcohol and gasoline fueled automobile exhaust fumes. In "Developments in the Science and Practice of Toxicology" (A. W. Hayes, R. C. Schnell, and T. S. Miya, Eds.), pp. 479--482. Elsevier, Amsterdam. B6hm, G. M., Massad, E., Saldiva, P. H. N., Pasqualucci, C. A., Gouveia, M. A., Cardoso, L. M. N., Caldeira, M. P. R., Calheiros, D. F., Carneiro, P., Serrano, M. I. P., Munoz, D. R., and Silva, R. (1986). Toxicity assessment of the Brazilian ethanol autoengine program. "Proceedings of the 7th World Clean Air Congress," pp. 247-254. Bouhuys, A., Beck, G. J., and Schoenberg, J. B. (1979). Priorities in prevention of chronic lung diseases. Lung 156, 12%148. Caldeira, M. P. R., Saldiva, P. H. N., and Zin, W. A. (1988). Vagal influences on respiratory mechanics, pressures, and control in rats. Respir. Physiol., 73, 43-54.
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CETESB. (1987). "Qualidade do ar na regi~o metropolitana de S~o Paulo e em Cubatho 1986." [In Portuguese] Cordeiro, J. O. (1987). "Analysis of Dependency." Technical report No. 48/87, University of Campihas. Ferin, J., and Leach, L. J. (1973). The effect of SO2 on lung clearance of TiO2 particles in rats. Amer. Ind. Hyg. Assoc. J. 34, 260-263. Lopez-Vidriero, M. T., and Reid, L. (1978). Bronchial mucus in health and disease. Brit. Med. Bull. 34, 63-74. Massad, E., Saldiva, C. D., Cardoso, L. M. N., Silva, R., Saldiva, P. H. N., and B6hm, G. M. (1985). Acute toxicity of gasoline and ethanol automobile engine exhaust gases. Toxicol. Lett. 26, 187-192. Massad, E., Saldiva, P. H. N., Saldiva, C. D., Caldeira, M. P. R., Cardoso, L. M. N., Morals, A. M. S., Calheiros, D. F., Silva, R., and B6hm, G. M. (1986). Toxicity of prolonged exposure to ethanol and gasoline autoengine exhaust gases. Environ. Res. 40, 479-486. Morgan, K. T., Patterson, D. L., and Cross, E. A. (1984). Frog palate mucociliary apparatus: Structure, function and response to formaldehyde gas. Fundam. Appl. Toxicol. 4, 58--68. Saldiva, P. H. N., Caldeira, M. P. R., Massad, E., Calheiros, D. F., Cardoso, L. M. N., Saldiva, C. D., and B6hm, G. M. (1985a). Effects of formaldehyde and acetaldehyde inhalations on rat pulmonary mechanics. J. Appl. Toxicol. 5, 286-292. Saldiva, P. H. N., Caldeira, M. P. R., and Zin, W. A. (1988). Respiratory mechanics in the aging rat. Braz. J. Med. Biol. Res. 21, 863-868. Saldiva, P. H. N., Cardoso, W. V., Caldeira, M. P. R., and Zin, W. A. (1987). Mechanics in rats by the end-inflation occlusion and single-breath methods. J. Appl. Physiol. 63, 1711-1718. Saldiva, P. H. N., Massad, E., Caldeira, M. P. R., Calheiros, D. F., Saldiva, C. D., and B6hm, G. M. (1985b). The study of mechanical properties of rat lungs by whole body plethysmography. Acta Physiol. Latinoamer. 35, 16-24. Saldiva, P. H. N., Massad, E., Caldeira, M. P. R., Calheiros, D. F., Saldiva, C. D., Nicolelis, M. A., and B6hm, G. M. (1985c). Pulmonary function on rats exposed to ethanol and gasoline fumes. Braz. J. Med. Biol. Res. 18, 573-577. Shy, C. M. (1979). Epidemiologic evidence and the United States air quality standards. Amer. J. Epiderniol. 110, 661-671. Zin, W. A., Pengelly, L. D., and Milic-Emili, J. (1982). Single-breath method for measurement of respiratory mechanics in anesthetized animals. J. Appl. Physiol. 52, 1266-1271.
Biological Effects of Air Pollution in S.5o Paulo and Cubat&o GYORGY MIKL6S BOHM, PAULO HILARIO NASCIMENTO SALDIVA, CARLOS AUGUSTO GONt~ALVES PASQUALUCCI, EDUARDO MASSAD, MILTON DE ARRUDA MARTINS, WALTER ARAOJO g i N , WELLINGTON VERAS CARDOSO, PATRICIA MARTINS PERE1RA CRIADO, MARCIA KOMATSUZAKI, REGINA SILVIA SAKAE, ELNARA MARCIA NEGR1, MIRIAM LEMOS, VERA DEL MONTE CAPELOZZI, CASSIANA CRESTANA, AND RUBERVAL DA SILVA Laborat6rio de Poluiffto Atmosfdrica Experimental and Instituto do Corafdo, Faculdade de Medicina da USP, Av. Dr. Arnaldo 455, 01246 Sdo Paulo, SP, Brazil, and Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil Received June 29, 1988 Rats were used as biological indicators of air quality in two heavily polluted Brazilian towns: Silo Paulo and Cubatio. They were exposed for 6 months to ambient air in areas where the pollution was known to be severe. The following parameters were studied and compared to those of control animals: respiratory mechanics, mucociliary transport, morphometry of respiratory epithelium and distal air spaces, and general morphological alterations. The results showed lesions of the distal and upper airways in rats exposed in Cubatfio, whereas the animals from Silo Paulo showed only alterations of the upper airways but of greater intensity than those observed in the Cubatio group. There are both qualitative and quantitative differences in the pollutants of these places: in Silo Paulo automobile exhaust gases dominate and in Cubatfio the pollution is due mainly to particulates of industrial sources. The correlation of the pathological findings with the pollutants is discussed and it is concluded that biological indicators are useful to monitor air pollutions which reached dangerous levels in Sio Paulo and Cubatfio. © 1989AcademicPress, Inc.
INTRODUCTION In the last 30 years a large number of studies have been published about the relation between outside air pollution and adverse health effects (Shy, 1979; American Thoracic Society, 1985). Both experimental and epidemiological methods have been used in attempts to determine what concentrations of specific air pollutants are needed in order to give rise to health effects. In such studies the combined and/or sinergic action of the complex atmospheric mixture of heavily polluted areas always have to be considered. So, it has not been possible to make hazard evaluations solely on the basis of experiments on animals or humans. One has been forced to rely on epidemiological studies in which it is very difficult to establish a direct cause--effect relationship, especially in situations of exposure to low levels of pollutants. In order to verify the possible health effects of urban air pollution,we used rats as biological indicators of air quality in two heavily polluted areas in Brazil: Silo Paulo and Cubatfio. Silo Paulo is a town with about 8,500,000 inhabitants; however, with its satellites it is an urban conglomeration of 16 million people. It is also the most indus208 0013-9351/89 $3.00 Copyright© 1989by AcademicPress,Inc. Allrightsof reproductionin anyformreserved.
HEALTH EFFECTS OF URBAN AIR POLLUTION
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trialized center of Latin America and it has about 2,850,000 light duty cars and 300,000 trucks. Sho Paulo is 715-900 m above sea level with frequent thermal inversions. Thus, air pollution is a serious problem. Cubat~o was initially developed as a petrochemical center close to the harbor of Santos. Today it is a town squeezed between the sea and a wall of mountains (700--1000 m) with an enormous concentration of great factories and 100,000 inhabitants. The total amount of pollutants yield by factories is estimated as 175,000 tons per year and the traffic is jammed with big lorries. Because of the quality of the air it is significantly called "The Valley of Death." To experimentally reproduce the air composition of these places is virtually impossible. Therefore, the Laboratory of Experimental Air Pollution (LPAE) decided to expose laboratory rats to ambient air in downtown S~to Paulo. The animals lived in the tower of a church (Igreja Nossa Senhora do Ros~irio, Largo do Paissandti), situated 200 m from the air measurement station of the State (CETESB), where the pollution is known to be severe. Another group of animals were raised in a rented room at Vila Parisi, which is the worst "borough" of Cubaffto as far as air quality is concerned. The room was about 100 m from CETESB's measurement station. The control animals were in Ubatuba at the Oceanographic Institute of SCto Paulo University (at the seashore), where air pollution was assumed to be nil. This resort town is surrounded by mountains covered by rain forest and there are no industrial activities within 50 km around Ubatuba. There are no air pollution measurement stations in this region. In this paper the comparison of several biological parameters are presented after 6 months of constant exposure to ambient air in S~io Paulo, Cubatfio, and Ubatuba. MATERIAL AND METHODS
To each testing place 40 female 2.5-month-old common (nonspecific pathogen free) Wistar rats, bred in the animal house of the Faculty of Medicine of S~o Paulo University, were sent. The animals were housed in groups of 10 and given balanced food and water ad libitum. In the experience of the LPAE, common Wistar rats are excellent biological indicators of air pollution (Saldiva et al., 1985b; Massad et al., 1986) and the best period for respiratory function studies is young adulthood (Saldiva et al., 1988). Therefore, the investigations were performed after 6 months, when the animals were 8.5 months old. The following parameters were studied: (1) Respiratory mechanics. In order to evaluate respiratory mechanical impairment two methods were used: forced expiration and single-breath method. The first technique consists of simulating a maximal inspiration followed by a forced expiration, by applying positive and negative pressures to the airways (Saldiva et al., 1985a, b). This method allows the determination of pulmonary capacities (total lung capacity, TLC; inspiratory capacity, IC; and functional residual capacity, FRC) and volumes (expiratory reserve volume, ERV, and residual volume, RV). It also provides parameters pertaining to forced volume-flow loops:
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forced vital capacity, FVC; peak expiratory flow lklmax; and forced expiratory flows between 0-25, FEFo_25; 25-50, FEF25_5o; 50-75, FEF50_75;and 75-100% of FVC, FEF75_100, respectively. To obtain these data, the best of three trials was chosen in each animal. The single-breath method provides the values of respiratory system elastance (Ers), resistance (Rrs), and time constant ('rr~) (Zin et al., 1982). In each animal six measurements were performed and the results averaged. Further details on technical procedures and applicability of these methods to small animals are published elsewhere (Saldiva et al., 1987; Caldeira et al., 1988). (2) Mucociliary transport. Based on the frog palate technique (Morgan et al., 1984) to measure mucociliary transport we developed a new approach to perform the same study in the rat trachea. The animals were killed by exsanguination after anesthesia with thiobarbital (5 mg/kg i.p.) and their tracheas, as well as their left main bronchus, were exposed without opening these airways. The rat was then placed in a chamber saturated with water vapor at 37°C for 10 min in order to stabilize the whole preparation. By means of a needle mounted on a syringe, the left bronchus was punctured and 200 Ixl of colloidal carbon was carefully laid onto the epithelium. Thereafter, the airways were transilluminated with cold light and the displacement of the carbon particles was registered by means of a microscope provided with reticulated lenses. The speed values were expressed as means of three measurements performed every 30 min until the transportation stopped spontaneously. This was caused by want of mucus since the ciliary movements were still visible at this very moment. The decay in particle speed could be expressed as an exponential function of time. Velocity was integrated with respect to time and the resulting index was called ciliary transport capacity (CTC). Thus, CTC indicates the distance that an ideal colloidal carbon particle was displaced until the total halt of the mucociliar system. (3) Morphometry of the respiratory epithelium. Epithelial thickness was measured in the nose and axial left bronchus in 10 fields at 1000-fold magnification in each rat. To estimate the irritative response in central and peripheral airways, the number of mucous cells and their type of secretion was counted in 10 fields (1000-fold magnification) of the nose and axial and lateral bronchi. To identify the type of mucus a combination of Schiff's periodic acid and Alcian blue was employed at pH 2.5 (Lopes-Vidriero and Reid, 1978). With this technique, neutral and acid glycoproteins are stained in red and blue, respectively. (4) Morphometry of distal air spaces. This analysis was performed in lungs fixed by intratracheal instillation of neutral formalin at a transpulmonary pressure of 20 cm H20. One-micrometer-thick slides of the peripheral areas of the lungs were prepared and stained with hematoxylin and eosin. In each rat 10 fields (1000-fold magnification) were observed and five types of cells were counted and their relative proportion defined: epithelial, spindle (fibroblasts, septal, and endothelial cells), mononucleated (macrophages, monocytes, and lymphocytes), polimorphonucleated, and unclassified cells (Auler et al., 1986). (5) Morphological studies of other organs. In order to detect macro- and microscopical alterations, complete autopsies and histopathological examination of the central nervous system, heart, lungs, liver, kidneys, adrenals, spleen, stomach, and intestines were performed.
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Statistical evaluation was done using one-way analyses of variance (ANOVA) with a 5% significance level. In order to test the variation in cellular profile of distal air spaces, a codependence analysis was performed (Cordeiro, 1987). RESULTS The results of the respiratory function tests are displayed in Table I. The alterations observed in Cubatfio animals suggest lesions in the distal airways due to tissular modifications (see below), since resistance and elastance increased in the presence of normal expiratory flows. The only abnormal parameter in the rats of Silo Paulo was a reduction of TLC. This finding alone does not allow a pathophysiological interpretation. In Table 2 CTC and morphometrical data are listed. The results indicate a larger CTC in the rats of Silo Paulo caused by mucus hypersecretion. This suggests a chronic aggression to the airways. Morphometric data of respiratory epithelium and CTC alterations were found in Silo Paulo: the animals presented epithelial hyperplasia and increased number of mucous cells with neutral and acid secretion in the nose and airways. Cubat~o rats showed an increased number of acid secretory cells in the nose and axial and lateral bronchi and fewer cells with neutral TABLE 1 RESPIRATORY MECHANICAL PARAMETERSIN RATS EXPOSED TO AIR POLLUTION IN THREE DIFFERENT REGIONS OF SAO PAULO STATE Variable
Ubatuba
Number of rats Body weight (kg) VT (ml/kg) f(breaths/min) TLC (ml/kg) IC (ml/kg) FRC (ml/kg) ERV (ml/kg) RV (ml/kg) FVC (ml/kg) V ~ , (ml/sec) FEFo_25% (ml/sec) FEF25_5o~ (ml/sec) FEF5o_75~ (ml/sec) FEF75_10o% (ml/sec) E~ (cm H20/ml) Rrs (cm H20/ml/sec) Trs (sec)
10 0.26 - 0.04 4.95 - 0.51 98.10 ± 17.48 81.29 - 16.92 42.00 - 9.95 39.29 --- 7.65 14.81 -+ 3.92 24.50 -+ 5.77 56.81 ± 13.6 78.04 ± 10.62 7.10 --- 1.85 76.00 _+ 11.46 62.40-+ 11.75 8.70 +- 1.83 2.74 +- 0.40 0.197 +- 0.060 0.072 ± 0.018
Cubatfio 0.29 4.47 104.20 74.19 31.31 42.87 13.47 29.40 44.78 67.03 5,50 64.40 50.70 8.00 3.41 0.276 0.082
10 +-- 0.02 - 1.23 --_ 11,39 +- 8.70 --- 3.14" --_ 10.04 - 3.32 ± 11.22 ___4.01 - 13,11 ~ 1.10 --_ 15.01 ± 14.82 + 1.41 --- 0.52* ± 0.080* ± 0.025
Silo Paulo 9 0.29 --- 0.03 5.75 ± 1.42 95.89 --. 20.58 65.90 ± 8.06* 40.07 +- 7,79 25.85 +- 8.48 10.28 -+ 2.23 15.56 -+ 7.62 50.35 +- 7,63 75,07 --- 10,36 8.44 --+ 2,87 69.33 --- 10.95 51,33--- 10.04 11.56 -+ 2.55 2.59--- 0.69 0.195 -+ 0.090 0.076 --- 0.026
Note. Values are means _+ SD. Vrr, tidal volume;f, respiratory frequency; TLC, total lung capacity; IC, inspiratory capacity; FRC, functional residual capacity; ERV, expiratory reserve volume; RV, residual volume; FVC, forced vital capacity; ~'m~x, peak expiratory flow; FEFo_25%, FEF25_5o~, FEFso_75%, and FEF75_loo~, forced expiratory flows between 0 and 25%, 25 and 50%, 50 and 75%, and 75 and 100% of FVC, respectively; Ers, Rr~, and %s, respiratory system elastance, resistance, and time constant, respectively. * Statistically significant difference among groups (P < 0.05).
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TABLE 2 MUCOCILIARY TRANSPORT, MORPHOMETRY~ AND CELL CHARACTERIZATION IN RATS EXPOSED TO AIR POLLUTION IN THREE DIFFERENT REGIONS OF S.~o PAULO STATE
CTC (mm) Epithelial height (~m) Nose Axial bronchi M u c o u s cells (/field) Nose Neutral Acid Axial bronchi Neutral Acid Lateral bronchi Neutral Acid Other cells (% total) Epithelial Spindle Mononucleated Polimorphonucleated Unclassified
Ubatuba
Cubatho
S~o Paulo
360.5 - 122.5
332.0 + 87.0
730.0 --- 236.6*
41.17 -4- 5.29 24.65 + 6.10
37.06 + 2.40 27.70 - 8.44
42.02 -+ 2.96 35.83 - 6.65*
18.41 -+ 4.73 2.31 --- 1.60"
11.04 --- 6.35* 5.19 -+ 2.11
18.86 -+ 3.45 6.07 -+ 3.22
6.86 -+ 1.51' 9.88 -+ 4.42
2.07 -+ 1.87" 11.15 - 4.77
9.06 -+ 1.52' 12.52 --- 2.31
6.09 -+ 0.96 0.45 - 0.55*
1.90 ± 1.31 2.68 ± 1.87"
7.71 ± 1.07 5.94 - 2.67*
25.5 24.5 26.4 13.9 9.2
19.0 18.1 41.8 14.1 7.3
26.3 30.5 23.6 11.9 7.8
± 2.2 --_ 2.3 -+ 2.5 ± 2.2 - 2.2
-+ 2.3** -+ 2.9** -+ 4.9** -+ 1.0"* - 1.3"*
-+ 2.6 ± 3.4 -+ 1.4 ± 0.8 ~ 1.2
Note. Values are m e a n s --+ SD. CTC, ciliary transport capacity. * Statistically significant difference a m o n g groups (analysis of variance, P < 0.05). ** Statistically significant different cellular profile a m o n g groups (analysis o f covariance, P < 0.05).
mucus in all examined sites when compared to control animals, indicating an aggression of lesser intensity. The cellular profile of distal air spaces was abnormal in rats of Cubat~o, which presented a statistically significant increased proportion of chronic inflammatory cells, supporting the mechanical data (Table 1). The body weight of every animal was measured monthly and no differences were observed between the three groups. Macroscopical and histopathological examination of the several studied organs did not disclose any significant difference between the three groups of rats. DISCUSSION
Air pollution in S~o Paulo is patchy: there are bad and worse areas; really clean air is only found in some privileged regions in the periphery of the city. The pollution is caused by different factors but the main sources are industrial and automotor exhaust pipes. There is a huge quantity of alcohol-fueled light duty cars which tend to diminish air pollution (BOhm et al., 1983, 1986; Massad et al., 1985, 1986; Saldiva et al., 1985c). Air pollution in Cubatho is almost entirely dependent on industrial emissions. The air quality in S~o Paulo and Cubat~o is monitored by CETESB. We do not have the complete information about the amount of atmospheric pollutants in 1987, but in 1986 CO, SO2, NOx, 0 3, C H 4, H C ' s , Pb, fluorides, and particulates in suspension were measured s o m e t i m e and s o m e w h e r e .
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HEALTH EFFECTS OF URBAN AIR POLLUTION
Continuous monitoring of several pollutants was performed according to the region: in downtown Sfto Paulo CO and SO2, and in Cubatfto, Vila Parisi, SOz and particulate matter in suspension were measured during the whole year of 1986. For each pollutant there are quality patterns prescribed by State Law No. 997. Thus, the mean levels of CO, SO2, and particulate matter should not exceed 40,000 ixg/m3 (I hr), 365 txg/m3 (24 hr), and 240 ixg/m3 (24 hr), respectively, more than once per year. There are also criteria for acute air pollution situations to CO, SO2, photochemical oxidants, and particulates. For example, in the case of CO, "attention" is declared when CO reaches 15 ppm (8 hr), "alert" with 30 ppm (8 hr), and "emergency" with 40 ppm (8 hr). SO2 = 0.8 ppm (24 hr). Daily reports are issued to the public qualifying the air quality as "good," "acceptable," "inadequate," "bad," "very bad," and "critical." These indexes follow international standards and always reflect the worst situation of any pollutant. The percentage of days during 1986 with the air quality indexes in downtown Sfto Paulo and Vila Parisi are in Tables 3 and 4. The results of these measurements indicate that the levels of pollution in both places were very high. In Sgto Paulo, at the place where our rats were exposed, the pollution is due to traffic and, therefore, the level of pollutants varied daily and weekly during the present experiment (Table 5). In Cubatfto the variations of the levels of air pollutants were less marked during the 6 months of exposure of our animals. Particulates represented the most important pollutant (Table 6). Compared to control animals, rats living in S~o Paulo and Cubatfio developed respiratory distress. The differences in the sources of pollutants could explain the different patterns of respiratory impairment observed in both places. Rats of Cubatfto, with increased respiratory system resistance and elastance and increased numbers of mononucleated cells in the alveolar region, seem to have been affected by pollutants with a greater capacity to penetrate the lungs and, hence, damage the distal airspaces. There is no available information about the physical TABLE 3 AIR QUALITY IN DOWNTOWN S,g,O PAULO Percentage during 1986 Index of air quality Good Acceptable Inadequate Bad Very bad Critical
Carbon monoxide
Sulfur dioxide
0.5 11.5 51.2 36.8 ---
89.5 10.5 -----
Note. Data provided by CETESB (1987). Daily reports are issued to the public qualifying the air quality as "good" (mean level of CO less than 4.5 ppm (8 hr) and that of SO 2 less than 80 i~g/m3 (24 hr)), "acceptable" (CO between 4.5 and 9.0 ppm, SO 2 between 80 and 365 t~g/m3), "inadequate" (CO between 9.0 and 15.0 ppm, SO 2 between 365 and 800 ixg/m3), " b a d " (CO between 15.0 and 30.0 ppm, SO2 between 800 and 1600 p,g/m3), "very bad" (CO between 30.0 and 40.0 ppm, SO2 between 1600 and 2100 ixg/m3), and "critical" (CO between 40.0 and 50.0 ppm, SO2 between 2100 and 2620 ixg/m3).
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BOHM ET AL.
TABLE 4 AIR QUALITY XN CUBAT~,O Percentage during 1986 Index of air quality Good Acceptable Inadequate Bad Very bad Critical
Particulates
Sulfur dioxide
4.2 38.9 35.3 19.5 2.1 --
98.1 1.9 ----
Note. Data provided by CETESB (1987). Daily reports are issued to the public qualifying the air quality as "good" (mean level of particulates and of SO 2 for 24 hr, less than 80 ixg/m3 for each pollutant), "acceptable" (particulates between 80 and 240 ~g/m 3, SO2 between 80 and 365 v~g/m3), "inadequate" (particulates between 240 and 375 ixg/m3, SO2 between 365 and 800 v~g/m3), " b a d " (particulates between 375 and 625/~g/m 3, SO 2 between 800 and 1600 i~g/m3), "very bad" (particulates between 625 and 875 txg/m3, SO2 between 1600 and 2100 ~g/m3), and "critical" (particulates between 875 and 1000 wg/m 3, SO 2 between 2100 and 2620 #xg/m3).
and chemical properties of the particulates in Cubatfio. Our data suggest that a great proportion of the particulate material in this region is represented by particles which easily reach the alveoli. In the rats of Cubatfio an increased number of acid mucus secreting cells in the nose and airways were also observed, indicating a discrete affection of the airways. The smaller number of neutral mucus secreting cells in these rats may indicate a change in the secretory pattern of the airways (Lopes-Vidriero and Reid, 1978). The predominant upper airway lesions, epithelial hyperplasia, and mucous hypersecretion of Sao Paulo rats suggest the presence of a highly soluble pollutant with low penetration. The lack of information about the physical and chemical characteristics of atmospheric pollutants thwarts the identification of the agent(s). SO2 and CO were the unique pollutants measured during the time of exposure in Silo Paulo. SO 2 could conceivably cause lesions to the airways; however, the levels of this pollutant were very low in Sio Paulo (Table 5). Bouhuys et al. (1979) claim a significant correlation between SO2 levels and airway obstruction in humans in annual rates as low as 0.001 to 0.0047 ppm. Ferin and Leach (1973) TABLE 5 LEVELS OF AIR POLLUTANTS (MEANS ~ SD) IN DOWNTOWN S,~O PAULO DURING THE 6 MONTHS EXPOSURE CO (ppm) Weekend From Monday to Friday 8:00 AM to I0:00 PM 11:00 PM to 7:00 AM
6.43 9.54 10.96 4.77
-+ 0.62 _+ 0.59 --+ 0.91 --+ 0.31
SO z (ppm) 0.0018 0.0027 0.0027 0.0019
--- 0.0003 -+ 0.0001 -----0.0002 --+ 0.0003
Note. Data provided by CETESB (unpublished). EPA ambient air quality standards: CO = 9 ppm or 10,000 i~g/m3 (8 hr); SO 2 = 0.03 ppm or 80 ~g/m 3 (24 hr).
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HEALTH EFFECTS OF URBAN AIR POLLUTION
TABLE 6 LEVELS OF AIR POLLUTANTS(MEANS ± SD) IN CUBATAODURINGTHE 6 MONTHS EXPOSURE Particulates (l~g/m3) Weekend From Monday to Friday 8:00 AM to 10:00 PM 11:00 PM to 7.'00 AM
129.77 143.97 130.11 164.61
± 26.89 ± 28.55 --+ 21.29 --+ 38.31
SO2 (ppm) 0.0010 0.0010 0.0011 0.0011
± 0.0009 ± 0.0007 -----0.0008 ± 0.0007
Note. Data provided by CETESB (unpublished). EPA ambient air quality standards: particulates = 75 ixg/m3 (annual); SO2 = 0.03 ppm or 80 ixg/m3 (24 hr).
demonstrated mucociliary disfunctions in rats exposed to 0.1 ppm of 802 for 1 week. Considering the data above, we cannot exclude the participation of SO2, perhaps added to nonmeasured pollutants, as particulates and hydrocarbons, in causing the respiratory lesions in our rats. The present results strongly encourage the use of biological indicators to study the effects of air pollution. This monitoring should be done continuously, since it is not very expensive and provides accurate information about the real impact of air pollution on biological systems. Furthermore, information can be gathered at specific locations under the actual ambient air composition. Finally, unfortunately, there are no adequate data to identify precisely the "adverse health effects" (American Thoracic Society, 1985) of air pollution in Silo Paulo and Cubat~o. All that can be said is that air pollution has reached very dangerous levels and undoubtedly causes increased morbidity and, perhaps, mortality, to the population. ACKNOWLEDGMENT This work was supported by Grants FINEP 4286050900 and HC-FMUSP-LIM-05.
REFERENCES American Thoracic Society. (1985). Guidelines as to what constitutes an adverse respiratory health effect, with special reference to epidemiologic studies of air pollution. Amer. Rev. Respir. Dis. 131, 666-668. Auler, J. O. C., Jr., Calheiros, D. F., Brentani, M. M., Santello, J. L., Lemos, P. C. P., and Saldiva, P. H. N. (1986). Adult respiratory distress syndrome: Evidence of early fibrogenesis and absence of glucocorticoid receptors. Eur. J. Respir. Dis. 69, 261-269. B6hm, G. M., Massad, E., Saldiva, P. H. N., Gouveia, M. A., Pasqualucci, C. A., Cardoso, L. M. N., Caldeira, M. P. R., and Calheiros, D. F. (1983). Comparative toxicity of alcohol and gasoline fueled automobile exhaust fumes. In "Developments in the Science and Practice of Toxicology" (A. W. Hayes, R. C. Schnell, and T. S. Miya, Eds.), pp. 479--482. Elsevier, Amsterdam. B6hm, G. M., Massad, E., Saldiva, P. H. N., Pasqualucci, C. A., Gouveia, M. A., Cardoso, L. M. N., Caldeira, M. P. R., Calheiros, D. F., Carneiro, P., Serrano, M. I. P., Munoz, D. R., and Silva, R. (1986). Toxicity assessment of the Brazilian ethanol autoengine program. "Proceedings of the 7th World Clean Air Congress," pp. 247-254. Bouhuys, A., Beck, G. J., and Schoenberg, J. B. (1979). Priorities in prevention of chronic lung diseases. Lung 156, 12%148. Caldeira, M. P. R., Saldiva, P. H. N., and Zin, W. A. (1988). Vagal influences on respiratory mechanics, pressures, and control in rats. Respir. Physiol., 73, 43-54.
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CETESB. (1987). "Qualidade do ar na regi~o metropolitana de S~o Paulo e em Cubatho 1986." [In Portuguese] Cordeiro, J. O. (1987). "Analysis of Dependency." Technical report No. 48/87, University of Campihas. Ferin, J., and Leach, L. J. (1973). The effect of SO2 on lung clearance of TiO2 particles in rats. Amer. Ind. Hyg. Assoc. J. 34, 260-263. Lopez-Vidriero, M. T., and Reid, L. (1978). Bronchial mucus in health and disease. Brit. Med. Bull. 34, 63-74. Massad, E., Saldiva, C. D., Cardoso, L. M. N., Silva, R., Saldiva, P. H. N., and B6hm, G. M. (1985). Acute toxicity of gasoline and ethanol automobile engine exhaust gases. Toxicol. Lett. 26, 187-192. Massad, E., Saldiva, P. H. N., Saldiva, C. D., Caldeira, M. P. R., Cardoso, L. M. N., Morals, A. M. S., Calheiros, D. F., Silva, R., and B6hm, G. M. (1986). Toxicity of prolonged exposure to ethanol and gasoline autoengine exhaust gases. Environ. Res. 40, 479-486. Morgan, K. T., Patterson, D. L., and Cross, E. A. (1984). Frog palate mucociliary apparatus: Structure, function and response to formaldehyde gas. Fundam. Appl. Toxicol. 4, 58--68. Saldiva, P. H. N., Caldeira, M. P. R., Massad, E., Calheiros, D. F., Cardoso, L. M. N., Saldiva, C. D., and B6hm, G. M. (1985a). Effects of formaldehyde and acetaldehyde inhalations on rat pulmonary mechanics. J. Appl. Toxicol. 5, 286-292. Saldiva, P. H. N., Caldeira, M. P. R., and Zin, W. A. (1988). Respiratory mechanics in the aging rat. Braz. J. Med. Biol. Res. 21, 863-868. Saldiva, P. H. N., Cardoso, W. V., Caldeira, M. P. R., and Zin, W. A. (1987). Mechanics in rats by the end-inflation occlusion and single-breath methods. J. Appl. Physiol. 63, 1711-1718. Saldiva, P. H. N., Massad, E., Caldeira, M. P. R., Calheiros, D. F., Saldiva, C. D., and B6hm, G. M. (1985b). The study of mechanical properties of rat lungs by whole body plethysmography. Acta Physiol. Latinoamer. 35, 16-24. Saldiva, P. H. N., Massad, E., Caldeira, M. P. R., Calheiros, D. F., Saldiva, C. D., Nicolelis, M. A., and B6hm, G. M. (1985c). Pulmonary function on rats exposed to ethanol and gasoline fumes. Braz. J. Med. Biol. Res. 18, 573-577. Shy, C. M. (1979). Epidemiologic evidence and the United States air quality standards. Amer. J. Epiderniol. 110, 661-671. Zin, W. A., Pengelly, L. D., and Milic-Emili, J. (1982). Single-breath method for measurement of respiratory mechanics in anesthetized animals. J. Appl. Physiol. 52, 1266-1271.