SO: Chest 1984, 86:830-838.
AB: The prevalence of respiratory symptoms, as ascertained by questionnaire, was evaluated in 6,666 nonsmokers who had lived for at least 11 years in either a high photochemical pollution are (4,379 individuals) or a low photochemical pollution area (2,287 individuals). Of these, 5,178 had never smoked, and none was currently smoking. The risk estimate for "definite" COPD, as defined in this study, was 15 percent higher in the high pollution area (p=0.03), after adjusting for sex, age, race, education, occupational exposure, and past smoking history. Past smokers had a high risk estimate 22 percent higher than never smokers (p=0.01). Multivariate analysis showed a significant effect of air pollution on the prevalence of "definite" COPD which univariate analysis failed to demonstrate.
SO: Arch Environ Health 1987, 42(4):213-222.
AB: Risk of chronic obstructive pulmonary disease symptoms due to long-term exposure to ambient levels of total suspended particulates (TSP) and sulfur dioxide (SO2) symptoms ascertained using the National Heart, Lung, and Blood Institute (NHLBI) respiratory symptoms questionnaire on 7,445 Seventh-day Adventists. They were non-smokers, at least 25 yr of age, and had lived 11 yr or more in areas ranging from high to low photochemical air pollution in California. Participant cumulative exposures to each pollutant in excess of four thresholds were estimated using monthly residence zip code histories and interpolated dosages from state air monitoring stations. These pollutant thresholds were entered individually and in combination in multiple logistic regression analyses with eight covariables including passive smoking. Statistically significant associations with chronic symptoms were seen for: SO2 exposure above 4 pphm (104 mcg/m3), (p=0.03), relative risk 1.18 for 500 hr/yr of exposure; and for total suspended particulates (TSP) above 200 mcg/m3, (p < 0.00001), relative risk of 1.22 for 750 hr/yr.
SO: Arch Environ Health 1988, 43(4):279-285.
AB: To assess the risk of chronic obstructive pulmonary disease symptoms due to long-term exposure to ambient levels of total oxidants and nitrogen dioxide (NO2), symptoms were ascertained using the National Heart, Lung, and Blood Institute (NHLBI) respiratory symptoms questionnaire. A total of 7,445 Seventh-day Adventist (SDA) non-smokers who were 25 yr of age or older and had resided at least 11yr in areas of California with high to low phytochemical air pollution were included in this study. Cumulative exposures to each pollutant in excess of four thresholds were estimated for each participant, using zip codes for months of residence and interpolated dosages from state air-monitoring stations. Multiple logistic regression analyses were conducted individually and together for pollutants and included eight covariables, including passive smoking. A statistically significant association with chronic symptoms was seen for total oxidants above 10 pphm (196 mcg/m3) (p < 0.004, relative risk of 1.20 for 750 hr/yr). Chronic respiratory disease symptoms were not associated with relatively low NO2 exposure levels in this population. When these pollutant exposures were studied with exposures to total suspended particulates (TSP) and sulfur dioxide (SO2), only TSP exposure above 200 mcg/m3 showed statistical significance (p < 0.01). Exposure to TSP is either more strongly associated with symptoms of chronic obstructive pulmonary disease than the other measured exposures or is the best single surrogate representing the mix of pollutants present.
SO: JAPCA 1989, 39(4):437-445.
AB: A method for setting air quality standards for long-term cumulative exposures of a population based on epidemiological studies has been developed. It uses exposure estimates interpolated from monitoring stations to zip code centroids, each month applied to zip code by month residence histories of the population. Two alternative cumulative exposure indices are used-hours in excess of a threshold, and the sum of concentrations above a threshold. The indices are then used with multiple logistic regression models for the health outcome data to form dose response curves for relative risk, adjusting for covariates. These curves are useful for determination of at what exposure amounts and threshold levels, effects wh8ich have both statistical and public health significance begin to occur. The method is applied to a ten year follow-up of a sub cohort of 7,343 members of the National Cancer Institute-funded Adventist Health Study. Up to 20 years of residence history was available. Analysis for prevalence of symptoms was conducted for four air pollutants-total oxidants, sulfur dioxide, nitrogen dioxide, and total suspended particulates. For each pollutant, cumulated exposures were calculated above each of five different thresholds. Statistically significant effects were noted for total suspended particulates, total oxidants, sulfur dioxide, past and passive smoking.
SO: Environ Health Perspec 1991, 94:43-50.
AB: Cancer incidence and mortality in a cohort of 6,000 non-smoking California Seventh-day Adventists was monitored for a six year period and relationships with long term cumulative ambient air pollution were observed. Total suspended particulates (TSP) and ozone (OZ) were measured in terms of number of hours in excess of several threshold levels corresponding to national standards as well as mean concentration. For all malignant neoplasms among females, risk increased with increasing exceedance frequencies of all thresholds of TSP except the lowest one, and those increased risks were highly statistically significant. For respiratory cancers, increased risk was associated with only one threshold of OZ and this result was of borderline significance.
Respiratory disease symptoms were assessed in 1977 and again in 1987 using the NHLBI respiratory symptoms questionnaire on a subcohort of 3,914 individuals. Multivariate analyses which adjusted for past and passive smoking, and occupational exposures, indicated statistically significantly (p < 0.05) elevated relative risks ranging up to 1.7 for incidence of asthma, definite symptoms of airway obstructive disease (AOD), and chronic bronchitis with TSP in excess of all thresholds except the lowest one but not for any thresholds of ozone. A trend association (p = 0.056) was noted between the threshold of 10 pphm ozone and incidence of asthma. These results are presented within the context of standards setting for these constituents of air pollution.
SO: Arch Environ Health 1991, 46(5):281-287.
AB: Methods for estimating cumulative ambient air pollution concentrations for individuals enrolled in an epidemiological cohort study are described and studied. The methods used monthly interpolations from fixed site monitoring stations in California to zip code centroids. The precision of the interpolation methods for total suspended particulates and ozone was assessed using fixed site monitoring stations in turn as receptor sites. Actual versus interpolated two year mean concentrations did not differ significantly and were correlated with a Pearson correlation coefficient of 0.78 for total suspended particulates and 0.87 for ozone. In order to evaluate the impact of the change from monitoring total oxidants to ozone on oxidant/ozone cumulations, monthly mean concentrations for total oxidants were compared to ozone for 435 station months where both pollutants were simultaneously monitored. Average concentrations did not differ significantly and were highly correlated, r=0.94. Exceedance frequency statistics averaged slightly higher for ozone than for total oxidants though they were also highly correlated.
SO: Arch Environ Health 1991, 46(5):271-280.
AB: Cancer incidence and mortality in a cohort of six thousand non-smoking Seventh-day Adventist residents of California were monitored for a six-year period, and relationships with long-term ambient concentrations of total suspended particulates (TSP) and ozone (OZ) were studied. Ambient concentrations were expressed in terms of both mean concentrations and exceedance frequencies, the numbers of hours during which concentrations exceed specified cutoffs. The cutoffs included federal and California air quality standards. Risk of malignant neoplasms in females increased with increasing exceedance frequency for all TSP cutoffs except the lowest, and these increased risks were highly statistically significant. Increased risk of respiratory cancers was associated with only one cutoff of OZ, and this result was of borderline significance. These results are presented in the context of setting standards for these two air pollutants.
SO: Arch Environ Health 1993, 48(1):33-46.
AB: Seventh-day Adventist non-smokers who had resided since 1966 within five miles of their 1977 residence (N=3914), completed the National Heart, and Lung Institute (NHLI) respiratory symptoms questionnaire in 1977 and again in 1987. For each participant cumulative ambient concentrations of total suspended particulates (TSP), ozone, and sulfur dioxide (SO2) in excess of several cutoffs were estimated by month, by interpolating ambient concentrations from state air monitoring stations to their residential and workplace zip codes for the month. Statistically significant relationships between ambient concentrations of TSP and ozone were found with several respiratory disease outcomes but not for SO2. Multivariate analyses adjusted for past and passive smoking and occupational exposures. Results are discussed within the context of standards setting for TSP and ozone.
SO: J Exposure Anal and Environ Epidemiol 1993, 3(S1):99-115.
AB: Seventh-day Adventist (SDA) non-smokers who had resided since 1966 within five miles of their 1977 residence (n = 3914) completed a standardized respiratory symptoms questionnaire in 1977 and again in 1987. For each participant, cumulative ambient concentrations from 1977 to 1987 of suspended sulfates (SO4) in excess of several cutoffs as well as mean concentrations were estimated by interpolating monthly ambient concentration statistics from state air monitoring stations to the individual's residential and workplace zip codes. There were statistically significant associations between ambient concentrations of suspended sulfates and development of new cases of asthma, but not new cases of airway obstructive disease (AOD) or chronic bronchitis. Comparison of previous analyses, in this population, of respiratory disease symptoms and total suspended particulates (TSP), ozone, and sulfur dioxide (SO2) and multipollutant analyses of these pollutants with SO4 indicated these results were not due to a surrogate relationship with other air pollutants. Development of definite symptoms of AOD and chronic bronchitis was most strongly related to TSP.
SO: J Exposure Anal and Environ Epidemiol 1993, 3(2):181-202.
AB: A prospective epidemiologic cohort study of 6,000 residentially stable and non-smoking Seventh-day Adventists (SDA) in California was conducted to evaluate long-term cumulative levels of ambient nitrogen dioxide (NO2) in association with several chronic diseases. These diseases included respiratory symptoms, cancer, myocardial infarction (MI), and all natural cause mortality. Cumulative ambient concentrations of NO2 were estimated for each study subject using monthly interpolations from fixed site monitoring stations and applying these estimates to the monthly residence and work place zip code histories of study participants.
In addition, a personal NO2 exposure study on a randomly selected sample of 650 people in southern California was conducted to predict total personal NO2 exposure using household and lifestyle characteristics and ambient NO2 concentrations. It was found that good predictability could be obtained (correlation coefficient between predicted and observed values = 0.79) from a model predicting personal NO2. The resulting regression equations from the personal NO2 exposure study were applied to the epidemiologic study cohort to adjust ambient concentrations of NO2. No statistically significant associations were found between either the adjusted or unadjusted mean concentration estimates of NO2 and the development of new cases of respiratory symptoms or change in respiratory symptom severity. Also, no statistically significant associations were found between long-term ambient concentrations of NO2 and incidence of cancer, MI, or all natural cause mortality. However, the last three outcomes were based on a larger population that could not be adjusted for indoor concentrations.
SO: J of Occup and Environ Med 1993, 35(9):909-915.
AB: We attempted to determine the association between occupational and air pollutant exposure with the development of adult asthma through the analysis of a standardized respiratory questionnaire administered to a cohort of 3914 nonsmoking adults in 1977 and again in 1987. Ambient air pollution concentrations were estimated over a 20-year period using monthly interpolations from fixed-site monitoring stations applied to zip code locations by month of residence and work site. Second-hand smoke exposure was significantly associated with the development of asthma (relative risk [RR]=1.45, confidence interval [CI]=1.21 to 1.75). Airways obstructive disease before age 16 was related to a marked increased risk (RR=4.24, CI=4.03 to 4.45). An increased risk of asthma was significantly associated with increased ambient concentrations of ozone exposure in men (RR=3.12, CI=1.61 to 5.85).
SO: Intl J Epidemiol 1993, 22:809-817.
AB: A prospective study was conducted to investigate the possible effects of environmental tobacco smoke (ETS) on the development of definite symptoms of airway obstructive disease (AOD) in a non-smoking adult population. 3914 subjects completed a standardized respiratory symptoms questionnaire in 1977 and 1987 and a computerized algorithm was used to identify new cases of definite symptoms of AOD during the follow-up period. In multivariate logistic regression models which adjusted for age, gender, income, educational level, years smoked in the past, and concentrations of ambient air pollutants, ETS exposure during childhood only was associated with a relative risk (RR) of 1.09 (95% confidence interval [CI], 0.69-1.79), during adulthood only with a RR of 1.28 (95% CI, 0.90-1.79), and during both childhood and adult life with a RR of 1.72 (95% CI, 1.31-2.23). Results were not significantly changed when only lifetime never-smokers were used in analyses, and no interaction between ETS exposure and concentrations of ambient air pollutants was observed.
SO: Arch Environ Health 1995, 50(2):139-150.
AB: Site- and season-specific regressions of particulates less than 10µ in diameter (PM10) on total suspended particulates (TSPs) were formed throughout California during years when both were monitored. The regressions were then applied to monitored TSPs for the years 1973 to 1987, and indirect estimates of PM10 were formed. These estimates of PM10 were validated by interpolating them to other monitoring stations. The split-halves correlation between the estimated and monitored mean concentration, obtained when both were first cumulated for a 2-y period, was 0.86. Indirect estimates of PM10 at monitoring stations were interpolated, by month, to zip code centroids of home and work location and were cumulated for a cohort of 3,914 California Seventh-day Adventist (SDA) nonsmokers. Multivariate analyses, adjusted for several covariates, showed statistically significant (p <.05), but small, positive associations between PM10 and development of (a) definite symptoms of overall airway obstructive disease, (b) chronic productive cough, and (c) increasing severity of airway obstructive disease and asthma. The relative risk (RR) associated with 1 000 h/y (42 d) exposure of concentrations of PM10 that exceeded 100 µg/m3 for development of airway obstructive disease was 1.17 (95% confidence interval [CI]: 1.02, 1.33); for development of productive cough, the RR was 1.21 (CI 1.02, 1.44); and for development of asthma, the RR was 1.30 (CI, 0.97, 1.73). Stronger associations were observed for those who were exposed occupationally to dusts and fumes. The RR of developing airway obstructive disease as an adult for those who had airway obstructive disease as a child was 1.66 (CI 1.15, 2.33)
SO: Inhalat Toxicol 1995, 7:19-34.
AB: A cohort of 6340 non-smoking California Seventh-day Adventists (SDAs) who had resided within 5 miles of their present residence for the past 10 years have been followed since 1977 for: incidence of cancer and myocardial infarction (M.I.) through 1982, development of definite symptoms of, and increasing severity of, airway obstructive disease (AOD), chronic bronchitis, and asthma through 1987, and all natural cause mortality through 1987. Cumulative ambient concentrations of specific pollutants have been estimated for study participants from 1967 to 1987 by interpolating monthly statistics from statewide air monitoring stations to zip codes of residence and work location. Statistics include excess concentrations and exceedance frequencies above a number of cutoffs as well as mean ambient concentration and mean ambient concentration adjusted for time spent indoors. Indoor sources or nitrogen (NO2), and of particulate pollution such as environmental tobacco smoke, both at home and at work, as well as occupational dusts and fumes, have been adjusted for in multivariate statistical models. Particulates included total suspended particulates (TSP), monitored from 1973-1987; inhalable particulates less than 10 µm in diameter (PM10), estimated from site/seasonal specific regressions on TSP for 1973-1987; fine particulates less than 2.5 µm in diameter estimated from airport visibility data for 1967-1987; and suspended sulfates (SO4), monitored from 1977-1987. A direct measure of visibility, and gaseous pollutants--ozone, sulfur dioxide (SO2), and (NO2) monitored from 1973-1987 were also included in analyses. No statistically significant associations between any of the disease outcomes studied and NO2 or SO2 were found in this cohort. None of the pollutants studied showed statistically significant associations with all natural cause mortality or incidence of all malignant neoplasms in males. Statistically significant associations were observed between elevated ambient concentrations of one or more particulate pollutants and each of the other disease outcomes. In addition, ozone was significantly associated with increasing severity of asthma, and with the development of asthma in males. Multipollutant analyses indicated that none of the associations between particulate pollutants and disease outcomes were due to correlations with gaseous pollutants studied except possibly for PM2.5 and increasing severity of asthma, which could be due to a correlation with ozone. Observed associations between disease outcomes and PM2.5 or PM10 could be biased towards the null because of increased measurement error due to their indirect methods of estimation.
SO: J of Exposure Anal and Environ Epidemiol 1995, 5(2):161-180.
AB: Methods were developed for estimating fine particulates less than 2.5 microns in aerodynamic diameter (PM2.5) from airport visibility data which detected seasonality and allowed for possible site and season specific regressions of PM2.5 on visibility. The methods were applied to 9 airports in California to produce estimates of PM2.5 for the years 1966-1986 based on 1767 paired PM2.5/visibility data points where PM2.5 had been measured at a monitoring station near the airport. General F tests indicated that site and seasonal specific regression equations resulted in a statistically significant reduction in residual error. The split halves correlation for estimating PM2.5 from visibility over all areas was 0.82. The methods were used to estimate long term concentrations of ambient PM2.5 for an epidemiological cohort of 1,868 individuals.
SO: J Exposure Anal and Environ Epidemiol 1995, 5(2):137-159.
AB: Seventh-day Adventists (SDAs) nonsmokers who had resided since 1966 in the vicinity of nine airports throughout California (n=1868) completed a standardized respiratory symptoms questionnaire in 1977 and again in 1987. For each participant, cumulative ambient concentrations of fine particulates <2.5 microns (µm) in aerodynamic diameter (PM2.5) were estimated from airport visibility data. Long-term ambient concentrations of estimated PM2.5 in excess of 20 micrograms per cubic meter (g/m3) was found to be associated with development of definite symptoms of chronic bronchitis between 1977 and 1987. Estimated mean concentrations of PM2.5 were associated with increasing severity of respiratory symptoms related to overall airway obstructive disease, chronic bronchitis and asthma. It was felt that the observed relationships could be due to surrogate relationships with other ambient pollutants with the exception of increasing severity of chronic bronchitis symptoms and PM2.5, could be due to surrogate relationships with other ambient pollutants.
SO: Environmetrics 1996, 7:453-470.
AB: A number of alternative metrics for characterizing ambient air pollution concentrations were compared with regards to their relative power for detecting health effects as associated with long-term ambient concentrations of ozone and total suspended particulates (TSP). The health effects studied included development of overall airway obstructive disease (AOD), chronic bronchitis, and asthma, as well as increasing severity for AOD, chronic bronchitis, and asthma. These health effects were studied in a cohort of 3,914 California non-smoking Seventh-day Adventists who had 20 years of residence and work location history. The alternative metrics for ozone included the 24 hour mean, an 8 hour average (9:00 a.m. to 5:00 p.m.) as well as exceedance frequencies (hours above) and excess concentrations (the integrated sum of time × concentration above) for cutoffs of 6, 8, 10, 12, and 15 parts per hundred million (pphm). For TSP the alternative metrics were the 24 hour mean, as well as exceedance frequencies and excess concentrations for cutoffs of 60, 100, 150, and 200 micro grams per cubic meter (g/m3). The relative power for detecting health effects was assessed using the ratio of the estimated pollutant regression coefficient to its estimated standard error in multiple logistic regression models for development of disease and multiple linear regression models for increasing severity of disease. For ozone the metric with the greatest power for the most health outcomes was the 8 hour average. For TSP the metric with the greatest power for the most health outcomes was excess concentration above 200 g/m3 of TSP.
SO: Applied Occup Environ Hyg 1998, 13(6):444-452.
AB: Standardized respiratory symptoms questionnaires were completed by 3,091 nonsmoking California Seventh-day Adventists in 1977, 1987 and 1992. Ambient concentrations of air pollutants estimated included total suspended particulates (TSP), 1973-1987; particulates 10 microns in diameter (PM10), indirectly estimated from TSP, 1973-1987, and directly estimated from monitored PM10, 1987-1992; suspended sulfates (SO4) 1977-1992; sulfur dioxide (SO2) 1973-1992; and 8-hour average of ozone (O3) 1973-1992. Adjustments to ambient concentrations have been made for time spent indoors. Chronic bronchitis was defined as cough only (cough type) or with sputum production (chronic productive cough) on most days, for at least three months/year, for two-years or more. Using indirect estimates of PM10 prior to 1987 and direct estimates after 1987, multiple logistic regression models adjusting for covariates have been used to study development of chronic bronchitis (235 new cases) and chronic productive cough (169 new cases) between 1977 and 1992. For chronic productive cough, gender specific analyses indicated similar effects of PM10 and covariates for both genders. Hence, a pooled analyses was conducted using gender as a covariate. The relative risk for developing chronic productive cough was 1.25 (95% confidence interval: 1.04, 1.51) (p = 0.02) for an interquartile range increase of 41 days/year in excess of 100 µg/m3 of PM10, while no association was found with O3, SO4, or SO2. Statistically significant associations were also seen for development of chronic productive cough for days when PM10 daily mean concentration exceeded 80 µg/m3. The estimated relative risk for developing definite symptoms of overall chronic bronchitis (either cough or sputum type) in 1992 as associated with an interquartile range increase of 41 days/year when PM10 concentrations exceeded 100 µg/m3 was 1.33 (95% confidence interval: 1.14, 1.55) (p = 0.0005).
SO: Respiratory Medicine 1998, 92:914-921.
AB: Objectives: To develop spirometric reference equations for healthy, never-smoking, older adults. Design: Cross-sectional observational study. Participants: 1510 Seventh-Day Adventists, ages 43-79 yrs. enrolled in a study of health effects of air pollutants. Methods: Individuals were excluded from the reference group (n=565) for a history of current respiratory illness, smoking, or chronic respiratory disease, and for a number of "nonrespiratory" conditions which were observed in these data to be related to lower values of FEV1. Gender-specific reference equations were developed for the entire reference group and for a subset above age 65 yrs (n=312). Results: Controlling for height and age, lung function was found to be positively related to the difference between armspan and height, and in males was found to be quadratically related to age. Conclusions: The predicted values for this population generally fell within the range of those of other population groups containing large numbers of adults over the age of 65 years. Individuals with lung function below the fifth percentile in this sample, however, could not be reliably identified by using the lower limits of normal predictions commonly used in North America and Europe.
SO: Chest 1997, 112:895-901.
AB: Objective: to determine the success rate and correlates of ambulatory peak expiratory flow (PEF) monitoring in an epidemiologic study; Design: an observational survey; Setting: several communities in California; Participants: We studied 1,223 nonsmoking men and women (mean age, 66 years) from an established cohort; Outcome measures: a standard respiratory symptoms and diagnoses questionnaire, spirometry before and after bronchodilator, and a diary of PEF recorded 4 times per day for 7 days at home. Results: A physician diagnosis of asthma was reported in 8.6% of the women and 9.4% of the men. Of those who agreed to complete PEF diaries at home, 87% successfully provided a valid measure of PEF lability. The mean PEF lability from those with asthma was significantly higher than the others (12.0% vs. 8.9% in women and 10.2% vs 8.1% in men). Independent correlates of higher PEF lability included asthma, wheezing symptoms, airways obstruction by spirometry, older age and male gender. Conclusions: middle-aged and elderly persons are largely successful at providing a measure of PEF lability at home. In non-smoking adults living in California, increased PEF lability is correlated with asthma, wheezing, airways obstruction, and older age; validating its use in epidemiology studies as an index of airways hyperreactivity.
SO: Am J Resp Crit Care Med 1998, 158:289-298.
AB: The associations between lung function measures (spirometry and PEF lability) and estimated 20 year ambient concentrations of respirable particles, suspended sulfates, sulfur dioxide, ozone and indoor particles were studied in a sample of 1,391 nonsmokers followed since 1977. Differences in air pollutants across the population were associated with decrements of lung function. An increase of 54- days/year when particles <10µm in diameter (PM10) exceeded 100µg/m3 was associated with a 7.2% decrement in FEV1 percent predicted in males whose parents had asthma, bronchitis, emphysema or hay fever and increased PEF lability of 0.8% for all females and 0.6% for all males. An increase in mean concentration of SO4 of 1.6µg/m3 was associated with a 1.5% decrement in FEV1 percent predicted in all males. An increase of 23 ppb of ozone 8-hr. average was associated with a 6.3% decrement in FEV1 percent predicted in males whose parents had asthma, bronchitis, emphysema or hay fever.
SO: Environ Health Perspec 1998, 106(12):813-823.
AB: Purpose: To evaluate the relationship of long-term concentrations of ambient air pollutants and risk of incident lung cancer in nonsmoking California adults.
Methods: A cohort study of 6,338 nonsmoking non-Hispanic white California adults ages 27-95 was followed from 1977-1992 for newly diagnosed cancers. Monthly ambient air pollution data were interpolated to zip code centroids according to home and work location histories, cumulated and then averaged over time.
Results: The increased relative risk (RR) of incident lung cancer in males associated with an interquartile range (IQR) increase in 100 ppb ozone (O3) was 3.56; 95% confidence interval (CI): (1.35-9.42). Incident lung cancer in males was also positively associated with IQR increases for mean concentrations of PM10 [RR=5.21; (95% CI=1.94-13.99)] and SO2 [RR=2.66; (95% CI=1.62-4.39)]. For females, incident lung cancer was positively associated with IQR increases for SO2 [RR=2.14; (95% CI=1.36-3.37)] and IQR increases for PM10 exceedance frequencies of 50 µg/m3 [RR=1.21; (95% CI=0.55-2.66)] and 60 µg/m3 [RR=1.25; (95% CI=0.57-2.71)].
Conclusions: Increased risks of incident lung cancer were associated with elevated long-term ambient concentrations of PM10 and SO2 in both genders and with O3 in males. The gender differences for the O3 and PM10 results appeared to be partially due to gender differences in exposure.
SO: Environ Research 1999, 80:110-121.
AB: We conducted a prospective study of a cohort of 3091 nonsmokers, ages 27 to 87 years, to evaluate the association between long-term ambient ozone exposure and development of adult-onset asthma. Over a 15 year period, 3.2% of males and 4.3% of females reported new doctor diagnoses of asthma. For males, we observed a significant relationship between report of doctor diagnosis of asthma and 20 year mean 8-hour average ambient ozone concentration (relative risk (RR)= 2.09 for a 27 ppb increase in ozone concentration, 95%CI = 1.03 to 4.16). We observed no such relationship for females. Other variables significantly related to development of asthma were a history of ever-smoking for males (RR= 2.37, 95%CI=1.13 to 4.81), and for females, number of years worked with a smoker (RR=1.21 for a 7 year increment, 95%CI=1.04 to 1.39), age (RR=0.61 for a 16 year increment, 95%CI=0.44 to 0.84), and a history of childhood pneumonia or bronchitis (RR=2.96, 95%CI=1.68 to 5.03). Addition of other pollutants (PM10, SO4, NO2, and SO2) to the models did not diminish the relationship between ozone and asthma for males. These data suggest that long-term exposure to ambient ozone is associated with development of asthma in adult males.
SO: Chest 1999, 115(1):49-59.
AB: Objective: To examine risk factors for chronic airway disease (CAD) in elderly nonsmokers, as determined by pulmonary function tests (PFTs), and to correlate reported respiratory symptoms with PFT measures.
Design: An observational survey.
Setting: Several communities in California.
Measurements: Exposures and respiratory history were assessed by standardized questionnaire. PFTs were performed and prediction equations derived.
Results: Significant risk factors for obstruction on PFTs in multiple logistic regression included reported environmental tobacco smoke (ETS) exposure (relative risk [RR] = 1.44), parental CAD or hay fever (RR = 1.47), history of childhood respiratory illness (RR = 2.15), increasing age, and male gender. Years of past smoking was of borderline significance (RR = 1.29 for 10 years smoking, p = 0.06). Prevalence of obstruction on PFTs was 24.9% in those with definite symptomatic CAD, compared to 7.5% in those with no symptoms of CAD. For those with asthma, prevalence of obstruction was 36.0%, while it was 70.6% in those with emphysema. Also, symptomatic CAD correlated with reduction in lung function by analysis of covariance (ANCOVA). The mean percent predicted forced expiratory volume in one second (PPFEV1) adjusted for covariates was 90.6% in persons with definite symptoms of CAD, compared to 97.8% in those without it (p < 0.001).
Conclusions: Age, gender, parental history, childhood respiratory illness, and reported ETS exposures were significant risk factors for obstruction on PFTs. Self-reported respiratory symptoms also correlated significantly with PFTs.
SO: Am J Resp Crit Care Med 1999, 159:373-382.
AB: Long-term ambient concentrations of inhalable particles less than 10 µm in diameter (PM10) (1973-1992) and other air pollutants-total suspended sulfates, sulfur dioxide, ozone (O3), and nitrogen dioxide-were related to 1977-1992 mortality in a cohort of 6,338 nonsmoking California Seventh-day Adventists. In both genders, PM10 showed a strong association with mortality for any mention of nonmalignant respiratory disease on the death certificate adjusting for a wide range of potentially confounding factors including occupational and indoor sources of air pollutants. The adjusted relative risk (RR) for this cause of death as associated with an interquartile range (IQR) difference of 43 days per year when PM10 exceeded 100 µg/m3 was 1.18 [95% confidence interval (CI): 1.02, 1.36]. In males, PM10 showed a strong association with lung cancer deaths-RR for an IQR was 2.38 (95% CI: 1.42, 3.97). Ozone showed an even stronger association with lung cancer mortality for males with a RR of 4.19 (95% CI: 1.81, 9.69) for the IQR difference of 551 hours per year when O3 exceeded 100 ppb. Sulfur dioxide showed strong associations with lung cancer mortality for both genders. Other pollutants showed weak or no associations with mortality.
The purpose of this study was to assess the effect of long-term ambient particulate matter (PM) on risk of fatal coronary heart disease (CHD). A cohort of 3,239 nonsmoking, non-Hispanic white adults was followed for 22 years. Monthly concentrations of ambient air pollutants were obtained from monitoring stations [PM < 10 um in aerodynamic diameter (PM10), Ozone, sulfur dioxide, nitrogen dioxide] or airport visibility data [PM < 2.5 um in aerodynamic diameter (PM2.5)] and interpolated to ZIP code centroids of work and residence locations. All participants had completed a detailed lifestyle questionnaire at baseline (1976) and follow-up information on environmental tobacco smoke and other personal sources of air pollution were available from four subsequent questionnaires from 1977 through - 2000. Persons with prevalent CHD, stroke, or diabetes at baseline (1976) were excluded and analyses were controlled for a number of potential confounders including lifestyle. In females, the relative risk (RR) for fatal CHD with each 10 μg/m3 increase in PM2.5 was 1.42 (95% confidence interval (CI): 1.06, 1.90) in the single-pollutant model and 2.00 (95 % CI: 1.51, 2.64) in the two-pollutant model with O3. Corresponding RRs for a 10 μg/m3 increases in PM10-2.5 and PM10 were 1.62 and 1.45, respectively in all females and 1.85 and 1.52 in postmenopausal females. No associations were found in males. A positive association with fatal CHD was found with all three PM fractions in females, but not in males. The risk estimates were strengthened when adjusting for gaseous pollutants, especially O3, and were highest for PM2.5. These findings could have great implication for policy regulations.