Effect of particulate matter air pollution on hospital admissions and medical visits for lung and heart disease in two southeast Idaho cities.

Few, if any, published time series studies have evaluated the effects of particulate matter air exposures by combining hospital admissions with medical visit data for smaller populations. We investigated the relationship between daily particulate matter (<10 microm in aerometric diameter or PM10) exposures with admissions and medical visits (emergency room, urgent care, and family practice) for respiratory and cardiovascular disease in Pocatello and Chubbuck, Idaho (population about 60,000), from November 1994 through March 2000. Within generalized linear models, time, weather, influenza, and day-of-week effects were controlled. In single-pollutant models, respiratory disease admissions and visits increased (7.1-15.4% per 50 microg/m3 PM10) for each age group analyzed, with the highest increases in two groups, children and especially the elderly. Statistical analyses suggest that the results probably did not occur by chance. Sensitivity analyses did not provide strong evidence that the respiratory disease effect estimates were sensitive to reasonable changes in the final degrees of freedom choice for time and weather effects. No strong evidence of confounding by NO2 and SO2 was found from results of multi-pollutant models. Ozone and carbon monoxide data were not available to include multi-pollutant models, but evidence suggests that they were not a problem. Unexpectedly, evidence of an association between PM10 with cardiovascular disease was not found, possibly due to the lifestyles of the mostly Mormon study population. Successful time series analyses can be performed on smaller populations if diverse, centralized databases are available. Hospitals that offer urgent or other primary care services may be a rich source of data for researchers. Using data that potentially represented a wide-range of disease severity, the findings provide evidence that evaluating only hospital admissions or emergency room visit effects may underestimate the overall morbidity due to acute particulate matter exposures. Further work is planned to test this conclusion.

Electromagnetic fields, polychlorinated biphenyls, and prostate cancer mortality in electric utility workers.

The purpose of this study was to determine whether there was an association between occupational exposure to electromagnetic fields (EMFs) or polychlorinated biphenyls (PCBs) and mortality from prostate cancer among US electric utility workers. Data on participants, who were current and former employees of five large US electric utility companies, had been collected during 1987-1994, and the mortality of the cohort was followed through 1988. This nested case-control study contained 387 cases, men whose underlying cause of death was prostate cancer, and five controls for each case. Workers categorized in the highest 10 percent of EMF exposure were twice as likely to die from prostate cancer as those exposed to EMFs at lower levels, after adjustment for PCB exposure, race, and active work status within the past 2 years (odds ratio = 2.02, 95% confidence interval (CI): 1.34, 3.04). The odds ratio for PCB exposure and prostate cancer mortality was 1.47 (95% CI: 0.97, 2.24) after adjustment for suspected confounding factors. Exposure to high levels of both EMFs and PCBs showed no association with prostate cancer mortality. Non-White race was strongly associated with risk of prostate cancer mortality (odds ratio = 3.67, 95% CI: 2.66, 5.06). The association between EMF exposure and prostate cancer mortality warrants further investigation.

Associations of particulate matter and daily mortality in Bangkok, Thailand.

The association between airborne particles and daily mortality has been reported in many locations, but mainly in western countries. There is a need to investigate the association in locations where the emission sources, weather, and other environmental conditions differ from those in western countries. In this study, the acute effects of PM10 and visibility on daily mortality in Bangkok, Thailand, from 1992 to 1997, were examined. A Poisson regression model was developed to estimate the excess daily mortality associated with PM10 and visibility, while controlling for long-term trends, season, and variations in weather. It was found that increasing PM10 and decreasing visibility levels were independently associated with increasing daily mortality from all non-external causes, cardiovascular, respiratory, and other diseases. The observed associations were stronger for respiratory diseases than for cardiovascular and other diseases and were stronger for persons aged > or = 65 years than for those in the younger age group. The results of the PM10/mortality and visibility/mortality models were consistent, suggesting that visibility may be considered as a surrogate marker for the assessment of the adverse health effects of fine particulate matter when data from direct gravimetric measurements are not available.

Characterization of spirometric function in residents of three comparison communities and of three communities located near waste incinerators in North Carolina.

Waste incinerators are an increasingly common means of solid waste disposal. However, little is documented about the physical health of community members who live close to incinerators. During a 3-yr epidemiological study, spirometric lung function was tested once annually among residents from 3 communities surrounding a hazardous waste, biomedical, or municipal incinerator and among residents in 3 comparison communities. A total of 1,016 nonsmoking individuals, aged 8-80 yr, participated during at least 1 of the 3 yr of the study; 358 individuals participated all 3 yr. Daily air-quality sampling was done for 1 mo/yr in all 6 communities. The average monthly concentrations of particulate matter with diameters of 2.5 microns and less (PM2.5 [range = 14.6-31.5 micrograms/m3]) in all communities were similar during the 3 yr of study. The mean daily PM2.5 concentrations were significantly less than the U.S. Environmental Protection Agency's allowable 24-hr standard of 65 micrograms/m3. Individual incinerators contributed less than 2.5% of the areas' total PM2.5 levels. There was no difference in percent predicted forced vital capacity, forced expiratory volume in 1 sec, or forced expiratory flow rate over the middle 50% of the forced vital capacity among members of the incinerator communities, compared with nonincinerator communities, and there were no significant differences in lung function within the 3 sets of communities. There was no evidence from this study that an association existed between residence in these 3 waste incinerator areas, which met state and federal emissions regulations, and average spirometric pulmonary function of nonsmoking community members.