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C A Pope

Publications and source records attributed to C A Pope.

At least 37 records · Page 2Linked to original sources

Synoptic weather modeling and estimates of the exposure-response relationship between daily mortality and particulate air pollution.

This study estimated the association between particulate air pollution and daily mortality in Utah Valley using the synoptic climatological approach to control for potential weather effects. This approach was compared with alternative weather modeling approaches. Although seasonality explained a significant amount of variability in mortality, other weather variables explained only a very small amount of additional variability in mortality. The synoptic climatological approach performed as well or slightly better than alternative approaches to controlling for weather. However, the estimated effect of particulate pollution on mortality was mostly unchanged or slightly larger when synoptic categories were used to control for weather. Furthermore, the shape of the estimated dose-response relationship was similar when alternative approaches to controlling for weather were used. The associations between particulate pollution and daily mortality were not significantly different from a linear exposure-response relationship that extends throughout the full observed range of pollution.

Air Pollution↗

Particulate air pollution as a predictor of mortality in a prospective study of U.S. adults.

Time-series, cross-sectional, and prospective cohort studies have observed associations between mortality and particulate air pollution but have been limited by ecologic design or small number of subjects or study areas. The present study evaluates effects of particulate air pollution on mortality using data from a large cohort drawn from many study areas. We linked ambient air pollution data from 151 U.S. metropolitan areas in 1980 with individual risk factor on 552,138 adults who resided in these areas when enrolled in a prospective study in 1982. Deaths were ascertained through December, 1989. Exposure to sulfate and fine particulate air pollution, which is primarily from fossil fuel combustion, was estimated from national data bases. The relationships of air pollution to all-cause, lung cancer, and cardiopulmonary mortality was examined using multivariate analysis which controlled for smoking, education, and other risk factors. Although small compared with cigarette smoking, an association between mortality and particulate air pollution was observed. Adjusted relative risk ratios (and 95% confidence intervals) of all-cause mortality for the most polluted areas compared with the least polluted equaled 1.15 (1.09 to 1.22) and 1.17 (1.09 to 1.26) when using sulfate and fine particulate measures respectively. Particulate air pollution was associated with cardiopulmonary and lung cancer mortality but not with mortality due to other causes. Increased mortality is associated with sulfate and fine particulate air pollution at levels commonly found in U.S. cities. The increase in risk is not attributable to tobacco smoking, although other unmeasured correlates of pollution cannot be excluded with certainty.

Air Pollutants↗

Health effects of particulate air pollution: time for reassessment?

Numerous studies have observed health effects of particulate air pollution. Compared to early studies that focused on severe air pollution episodes, recent studies are more relevant to understanding health effects of pollution at levels common to contemporary cities in the developed world. We review recent epidemiologic studies that evaluated health effects of particulate air pollution and conclude that respirable particulate air pollution is likely an important contributing factor to respiratory disease. Observed health effects include increased respiratory symptoms, decreased lung function, increased hospitalizations and other health care visits for respiratory and cardiovascular disease, increased respiratory morbidity as measured by absenteeism from work or school or other restrictions in activity, and increased cardiopulmonary disease mortality. These health effects are observed at levels common to many U.S. cities including levels below current U.S. National Ambient Air Quality Standards for particulate air pollution.

Acute Disease↗

Lung cancer and air pollution.

Epidemiologic studies over the last 40 years suggest rather consistently that general ambient air pollution, chiefly due to the incomplete combustion of fossil fuels, may be responsible for increased rates of lung cancer. This evidence derives from studies of lung cancer trends, studies of occupational groups, comparisons of urban and rural populations, and case-control and cohort studies using diverse exposure metrics. Recent prospective cohort studies observed 30 to 50% increases in lung cancer rates associated with exposure to respirable particles. While these data reflect the effects of exposures in past decades, and despite some progress in reducing air pollution, large numbers of people in the United States continue to be exposed to pollutant mixtures containing known or suspected carcinogens. It is not known how many people in the United States are exposed to levels of fine respirable particles that have been associated with lung cancer in recent epidemiologic studies. These observations suggest that the most widely cited estimates of the proportional contribution of air pollution to lung cancer occurrence in the United States based largely on the results of animal studies, may be too low. It is important that better epidemiologic research be conducted to allow improved estimates of lung cancer risk from air pollution among the general population. The development and application of new epidemiologic methods, particularly the improved characterization of population-wide exposure to mixtures of air pollutants and the improved design of ecologic studies, could improve our ability to measure accurately the magnitude of excess cancer associated with air pollution.

Air Pollutants↗

Women's respiratory health in the cotton textile industry: an analysis of respiratory symptoms in 973 non-smoking female workers.

As part of a 1992 survey of both environmental and occupational determinants of health, 973 non-smoking women aged 20-40 years who were employed in three comparable modern Chinese cotton textile mills were given a questionnaire that included questions on standard respiratory history and symptoms. All women had some potential exposure to cotton dust; mean employment was 8.7 years. Comparisons were made between those with lowest or no current exposure (job classification in administration, quality control, and testing, n = 112) and those in the more heavily exposed classifications (yarn production areas, n = 861). Association of symptoms with job was tested by logistic regression, adjusting for age, passive smoking at home, and the use of home coal burning stoves. Odds ratios for prevalence of current frequent symptoms in those working in production jobs, after adjustment for home exposure to passive tobacco smoke and coal heating, were frequent cough 2.23 (95% confidence interval (95% CI) 1.05-4.75), frequent phlegm 3.24 (1.54-6.84), shortness of breath 4.54 (1.40-14.72), and wheeze 2.96 (1.16-7.55). Nine cases with grade I byssinosis (chest tightness or shortness of breath on return to work after two days off) were found; all were in production jobs. In these non-smoking women textile workers, chronic respiratory symptoms were associated with job category after correction for domestic indoor air quality. These data support evidence for an increased prevalence of respiratory disease in populations exposed to cotton dust.

Adult↗

An association between air pollution and mortality in six U.S. cities.

BACKGROUND: Recent studies have reported associations between particulate air pollution and daily mortality rates. Population-based, cross-sectional studies of metropolitan areas in the United States have also found associations between particulate air pollution and annual mortality rates, but these studies have been criticized, in part because they did not directly control for cigarette smoking and other health risks. METHODS: In this prospective cohort study, we estimated the effects of air pollution on mortality, while controlling for individual risk factors. Survival analysis, including Cox proportional-hazards regression modeling, was conducted with data from a 14-to-16-year mortality follow-up of 8111 adults in six U.S. cities. RESULTS: Mortality rates were most strongly associated with cigarette smoking. After adjusting for smoking and other risk factors, we observed statistically significant and robust associations between air pollution and mortality. The adjusted mortality-rate ratio for the most polluted of the cities as compared with the least polluted was 1.26 (95 percent confidence interval, 1.08 to 1.47). Air pollution was positively associated with death from lung cancer and cardiopulmonary disease but not with death from other causes considered together. Mortality was most strongly associated with air pollution with fine particulates, including sulfates. CONCLUSIONS: Although the effects of other, unmeasured risk factors cannot be excluded with certainty, these results suggest that fine-particulate air pollution, or a more complex pollution mixture associated with fine particulate matter, contributes to excess mortality in certain U.S. cities.

Adult↗

Acute effects of PM10 pollution on pulmonary function of smokers with mild to moderate chronic obstructive pulmonary disease.

This study assessed the association between respirable particulate air pollution (PM10) and changes in the pulmonary function (FEV1, FEV1/FVC, and FVC) of smokers with mild to moderate airflow limitation. Spirometric data of Salt Lake City participants in The Lung Health Study were used from two screening visits 10 to 90 days apart after an initial screening visit, which included spirometry. We analyzed differences in pulmonary function (delta FEV1, delta FEV1/FVC, and delta FVC) for participants between the two spirometry visits. Significant associations between changes in pulmonary function and PM10 were observed. delta FEV1 and delta FEV1/FVC were inversely associated with changes in PM10. Although these associations were small, explaining only about 2 to 3% of the variance in delta FEV1, they were consistently negative and statistically significant (p < or = 0.01). On average, an increase in PM10 equal to 100 micrograms/m3 was associated with a marginal decline in FEV1 equal to approximately 2%. Associations between delta FVC and PM10 were consistently negative, but they were not statistically significant. No consistent or statistically significant associations between delta FEV1, delta FEV1/FVC, or delta FVC with changes in daily temperatures were observed. The effect of PM10 was greater for men than for women. The effect was nearly the same for those with nonspecific airway hyperresponsiveness (AHR), based on methacholine inhalation challenge testing, versus those without AHR. We conclude that in current smokers PM10 possibly has a small transient negative effect on lung function that is not entirely obscured by their smoking habit.

Adult↗

Passive cigarette smoke, coal heating, and respiratory symptoms of nonsmoking women in China.

In this study we evaluated data from a sample of 973 never-smoking women, ages 20-40, who worked in three similar textile mills in Anhui Province, China. We compared prevalence rates of respiratory symptoms across homes with and without coal heating and homes with different numbers of smokers. Multiple logistic regression models that controlled for age, job title, and mill of employment were also estimated. Respiratory symptoms were associated with combined exposure to passive cigarette smoke and coal heating. Effects of passive cigarette smoke and coal heating on respiratory symptoms appeared to be nearly additive, suggesting a dose-response relationship between respiratory symptoms and home indoor air pollution from these two sources. The prevalence of chest illness, cough, phlegm, and shortness of breath (but not wheeze) was significantly elevated for women living in homes with both smokers and coal heating.

Adult↗

Elementary school absences and PM10 pollution in Utah Valley.

This study assessed the association between school absenteeism and respirable particulate pollution (PM10) in Utah Valley for the six school years of 1985 to 1990. Weekly absenteeism data from the Provo School District and daily data from a single elementary school in the Alpine School District were analyzed for kindergarten through sixth grade. PM10 concentrations during the study period averaged approximately 50 micrograms/m3 with the 24-hr maximum equal to 365 micrograms/m3. Absenteeism was regressed on PM10 pollution levels, temperature, snowfall, and variables indicating day of week, month of school year, and days preceding and following holidays and extended weekends. Estimated associations between absenteeism and PM10 pollution in both data sets were positive, statistically significant (P less than 0.01), and robust to different model specifications. PM10 effects persisted for up to 3 or 4 weeks. Regression results from both data sets indicated that an increase in 28-day moving average PM10 equal to 100 micrograms/m3 was associated with an increase in the absence rate equal to approximately two percentage points, or an increase in overall absences equal to approximately 40%. Similar relationships were observed for all grade levels, although the response of absences to air pollution was generally greater for grades 1-3 compared with grades 4-6. Associations between absenteeism and PM10 pollution were observed even for levels below 150 micrograms/m3.

Age Factors↗

Acute health effects of PM10 pollution on symptomatic and asymptomatic children.

This study assessed the association between daily changes in respiratory health and respirable particulate pollution (PM10) in Utah Valley during the winter of 1990-1991. During the study period, 24-h PM10 concentrations ranged from 7 to 251 micrograms/m3. Participants included symptomatic and asymptomatic samples of fifth- and sixth-grade students. Relatively small but statistically significant (p less than 0.01) negative associations between peak expiratory flow (PEF) and PM10 were observed for both the symptomatic and asymptomatic samples. The association was strongest for the symptomatic children. Large associations between the incidence of respiratory symptoms, especially cough, and PM10 pollution were also observed for both samples. Again the association was strongest for the symptomatic sample. Immediate and delayed PM10 effects were observed. Respiratory symptoms and PEF changes were more closely associated with 5-day moving-average PM10 levels than with concurrent-day levels. These associations were also observed at PM10 levels below the 24-h standard of 150 micrograms/m3. This study indicates that both symptomatic and asymptomatic children may suffer acute health effects of respirable particulate pollution, with symptomatic children suffering the most.

Air Pollution↗

Respiratory health and PM10 pollution. A daily time series analysis.

This study evaluated changes in respiratory health associated with daily changes in fine particulate pollution (PM10). Participants included a relatively healthy school-based sample of fourth and fifth grade elementary students, and a sample of patients with asthma 8 to 72 yr of age. Elevated PM10 pollution levels of 150 micrograms/m3 were associated with an approximately 3 to 6% decline in lung function as measured by peak expiratory flow (PEF). Current day and daily lagged associations between PM10 levels and PEF were observed. Elevated levels of PM10 pollution also were associated with increases in reported symptoms of respiratory disease and use of asthma medication. Associations between compromised respiratory health and elevated PM10 pollution were observed even when PM10 levels were well below the 24-h national ambient air quality standard of 150 micrograms/m3. Associations between elevated PM10 levels, reductions in PEF, and increases in symptoms of respiratory disease and asthma medication use remained statistically significant even when the only pollution episode that exceeded the standard was excluded. Concurrent measurements indicated that little or no strong particle acidity was present.

Adolescent↗

Respiratory disease associated with community air pollution and a steel mill, Utah Valley.

This study assessed the association between hospital admissions and fine particulate pollution (PM10) in Utah Valley during the period April 1985-February 1988. This time period included the closure and reopening of the local steel mill, the primary source of PM10. An association between elevated PM10 levels and hospital admissions for pneumonia, pleurisy, bronchitis, and asthma was observed. During months when 24-hour PM10 levels exceeded 150 micrograms/m3, average admissions for children nearly tripled; in adults, the increase in admissions was 44 per cent. During months with mean PM10 levels greater than or equal to 50 micrograms/m3 average admissions for children and adults increased by 89 and 47 per cent, respectively. During the winter months when the steel mill was open, PM10 levels were nearly double the levels experienced during the winter months when the mill was closed. This occurred even though relatively stagnant air was experienced during the winter the mill was closed. Children's admissions were two to three times higher during the winters when the mill was open compared to when it was closed. Regression analysis also revealed that PM10 levels were strongly correlated with hospital admissions. They were more strongly correlated with children's admissions than with adult admissions and were more strongly correlated with admissions for bronchitis and asthma than with admissions for pneumonia and pleurisy.

Adolescent↗

Referrals and notifications by British optometrists.

1031 British optometrists completed a questionnaire to give information on their rates of referral and notification to the medical profession. Data were collected in relation to the conditions concerned, the age and sex of the patient, and the spectacle correction. Major causes of referral were cataract, glaucoma, fundus changes, headaches/migraine/eye pain and lowered visual acuity; 6.5% of all patients seen were referred to their general medical practitioner notified, and of this group it was estimated that 25-30% could have managed with reading glasses which comprised spherical lenses of equal power. If such glasses could be self-selected, without reference to a medical practitioner or optometrist, a significant number of people would not benefit from the health screening aspects of the eye examination.

Adolescent↗

Differences in lung function among school children in communities in Israel.

Differences in lung functions of school-age children who lived near two electrical power plants in the Ashkelon district of Israel were studied. Lung-function tests were performed, and the American Thoracic Society questionnaire was administered in three study periods during the following years: (1) 1990, (2) 1994, and (3) 1997. Measurements of air pollutants (i.e., sulfur dioxide, nitric oxides, ozone) were also taken during the aforementioned study periods. Statistical analysis included an estimation of a series of fixed-effects regression models. A total of 2,455, 1,613, and 4,346 observations were included in the analyses for study years 1990, 1994, and 1997, respectively. The authors controlled for age, sex, height, weight, parents' education and smoking status, and being born out of Israel, and, consequently, substantial differences in lung function across the different communities and study periods were demonstrated in the study area. No robust association with air pollution was demonstrated. The cause of these differences in the respiratory health of children remains unknown.

Air Pollutants↗

Respiratory hospital admissions associated with PM10 pollution in Utah, Salt Lake, and Cache Valleys.

This study assessed the association between respiratory hospital admissions and PM10 pollution in Utah, Salt Lake, and Cache valleys during April 1985 through March 1989. Utah and Salt Lake valleys had high levels of PM10 pollution that violated both the annual and 24-h standards issued by the Environmental Protection Agency (EPA). Much lower PM10 levels occurred in the Cache Valley. Utah Valley experienced the intermittent operation of its primary source of PM10 pollution: an integrated steel mill. Bronchitis and asthma admissions for preschool-age children were approximately twice as frequent in Utah Valley when the steel mill was operating versus when it was not. Similar differences were not observed in Salt Lake or Cache valleys. Even though Cache Valley had higher smoking rates and lower temperatures in winter than did Utah Valley, per capita bronchitis and asthma admissions for all ages were approximately twice as high in Utah Valley. During the period when the steel mill was closed, differences in per capita admissions between Utah and Cache valleys narrowed considerably. Regression analysis also demonstrated a statistical association between respiratory hospital admissions and PM10 pollution. The results suggest that PM10 pollution plays a role in the incidence and severity of respiratory disease.

Adolescent↗

Daily mortality and PM10 pollution in Utah Valley.

The association between daily mortality and respirable particulate pollution (PM10) in Utah County was assessed from April 1985 through December 1989. Poisson regression analysis was used to regress daily death counts on PM10 pollution levels, controlling for variability in the weather. A significant positive association between nonaccidental mortality and PM10 pollution was observed. The strongest association was with 5-d moving average PM10 levels, including the concurrent day and the preceding 4 d. An increase in 5-d moving average PM10 levels, equal to 100 micrograms/m3, was associated with an estimated increase in deaths per day equal to 16%. The association with mortality and PM10 was largest for respiratory disease deaths, next largest for cardiovascular deaths, and smallest for all other deaths. Mean PM10 concentrations during the study period equaled 47 micrograms/m3. The maximum 24-h and 5-d moving average PM10 levels equaled 365 and 297 micrograms/m3, respectively. Relatively low levels of sulfur dioxide, aerosol acidity, and ozone suggested an independent association between mortality and PM10. The relative risk of death increased monotonically with PM10, and the relationship was observed at PM10 levels that were well below the current National Ambient Air Quality Standard of 150 micrograms/m3.

Air Pollutants↗

Air pollution and mortality in elderly people: a time-series study in Sao Paulo, Brazil.

The relationship between daily mortality of elderly (65+ y) persons and air pollution in the metropolitan area of Sao Paulo, Brazil, for the period May 1990 to April 1991 was evaluated by time series regression, controlling for season, weather, and other factors. Mortality was associated with respirable particles (PM10), nitrogen oxides (NOx), sulfur dioxide (SO2), and carbon monoxide (CO). The association with PM10 was most statistically significant, robust, and independent of other air pollutants. An increase in PM10 equal to 100 micrograms/m3 was associated with an increase in overall mortality equal to approximately 13%. This association was consistent across various model specifications and estimation techniques. The dose-response relationship between mortality and respirable particulate pollution was almost linear, with no evidence of a "safe" threshold level. The results were similar to those observed in London and several U.S. cities. The results were also supportive of recent animal studies that have observed adverse health outcomes in experimental animals exposed to air pollution in Sao Paulo.

Age Factors↗