Ambient air pollution, asthma drug response, and telomere length in African American youth.

BACKGROUND: Telomere length (TL) can serve as a potential biomarker for conditions associated with chronic oxidative stress and inflammation, such as asthma. Air pollution can induce oxidative stress. Understanding the relationship between TL, asthma, and air pollution is important for identifying risk factors contributing to unhealthy aging in children. OBJECTIVES: We sought to investigate associations between exposures to ambient air pollutants and TL in African American children and adolescents and to examine whether African ancestry, asthma status, and steroid medication use alter the association. METHODS: Linear regression was used to examine associations between absolute telomere length (aTL) and estimated annual average residential ozone (O3) and fine particulate matter with a diameter of 2.5 µm or less (PM2.5) exposures in a cross-sectional analysis of 1072 children in an existing asthma case-control study. African ancestry, asthma status, and use of steroid medications were examined as effect modifiers. RESULTS: Participants' aTLs were measured by using quantitative PCR. A 1-ppb and 1 µg/m3 increase in annual average exposure to O3 and PM2.5 were associated with a decrease in aTL of 37.1 kilo-base pair (kb; 95% CI, -66.7 to -7.4 kb) and 57.1 kb (95% CI, -118.1 to 3.9 kb), respectively. African ancestry and asthma were not effect modifiers; however, exposure to steroid medications modified the relationships between TL and pollutants. Past-year exposure to O3 and PM2.5 was associated with shorter TLs in patients without steroid use. CONCLUSION: Exposure to air pollution was associated with shorter TLs in nonasthmatic children and adolescents. This was not the case for asthmatic children as a group, but those receiving steroid medication had less shortening than those not using steroids. Reduced exposure to air pollution in childhood might help to preserve TL.

American Thoracic Society member survey on climate change and health.

The American Thoracic Society (ATS), in collaboration with George Mason University, surveyed a random sample of ATS members to assess their perceptions of, clinical experiences with, and preferred policy responses to climate change. An e-mail containing an invitation from the ATS President and a link to an online survey was sent to 5,500 randomly selected U.S. members; up to four reminder e-mails were sent to nonrespondents. Responses were received from members in 49 states and the District of Columbia (n = 915); the response rate was 17%. Geographic distribution of respondents mirrored that of the sample. Survey estimates' confidence intervals were ±3.5% or smaller. Results indicate that a large majority of ATS members have concluded that climate change is happening (89%), that it is driven by human activity (68%), and that it is relevant to patient care ("a great deal"/"a moderate amount") (65%). A majority of respondents indicated they were already observing health impacts of climate change among their patients, most commonly as increases in chronic disease severity from air pollution (77%), allergic symptoms from exposure to plants or mold (58%), and severe weather injuries (57%). A larger majority anticipated seeing these climate-related health impacts in the next 2 decades. Respondents indicated that physicians and physician organizations should play an active role in educating patients, the public, and policy makers on the human health effects of climate change. Overall, ATS members are observing that human health is already adversely affected by climate change and support responses to address this situation.

Climate change. A global threat to cardiopulmonary health.

Recent changes in the global climate system have resulted in excess mortality and morbidity, particularly among susceptible individuals with preexisting cardiopulmonary disease. These weather patterns are projected to continue and intensify as a result of rising CO2 levels, according to the most recent projections by climate scientists. In this Pulmonary Perspective, motivated by the American Thoracic Society Committees on Environmental Health Policy and International Health, we review the global human health consequences of projected changes in climate for which there is a high level of confidence and scientific evidence of health effects, with a focus on cardiopulmonary health. We discuss how many of the climate-related health effects will disproportionally affect people from economically disadvantaged parts of the world, who contribute relatively little to CO2 emissions. Last, we discuss the financial implications of climate change solutions from a public health perspective and argue for a harmonized approach to clean air and climate change policies.

Occupational contribution to the burden of chronic obstructive pulmonary disease.

OBJECTIVE: As a past recipient of the Jean Spencer Felton Award for Excellence in Scientific Writing from the Western Occupational and Environmental Medicine Association, it is truly an honor to contribute to this festschrift. What stands out in my mind about Dr Felton is that he loved to delve into the history of occupational medicine and tried to apply the lessons of that history to the modern practice of the discipline. He once wrote that "The name Ramazzini marks the beginning of society's concern with the well-being and physical and emotional health of its workers from the shops of the crafts to the offices of the executives." This review of a common disease for which an occupational contribution is too frequently ignored is offered in the spirit of both the father of modern occupational medicine and one of his 20th-century acolytes. CONCLUSIONS: The biological plausibility of the capacity of occupational exposures to irritating dusts, gases, and fumes to cause chronic obstructive pulmonary disease (COPD) is high. Epidemiological evidence from both worker cohort and community studies supports an increased risk of COPD associated with such exposures. The occupational contribution to the burden of COPD is sufficiently great that preventive interventions are warranted.

Predictors of lung cancer among asbestos-exposed men in the {beta}-carotene and retinol efficacy trial.

Despite numerous published studies, debate continues regarding the risk of developing lung cancer among men exposed occupationally to asbestos, particularly those without radiographic or functional evidence of asbestosis. The beta-Carotene and Retinol Efficacy Trial (CARET), a study of vitamin supplementation for chemoprevention of lung cancer, has followed 4,060 heavily exposed US men for 9-17 years. Lung cancer incidence for 1989-2002 was analyzed using a stratified proportional hazards model. The study confirmed excessive rates of lung cancer among men with radiographic asbestosis. Comparison of study arms revealed a strong, unanticipated synergy between radiographic profusion category and the active intervention. In the large subgroup of men with normal lung parenchyma on chest radiograph at baseline, there was evidence of exposure-related lung cancer risk: Men with more than 40 years' exposure in high-risk trades had a risk approximately fivefold higher than men with 5-10 years, after adjustment for covariates. The effect in these men was independent of study intervention arm, but pleural plaques on the baseline radiograph and abnormal baseline flow rate were strong independent predictors of subsequent lung cancer. Residual confounding by subclinical asbestosis, exposure to unmeasured lung carcinogens, or differences in smoking are unlikely to explain these observations better than a carcinogenic effect of asbestos per se.