Increased circulating levels of persistent organic pollutants (POPs) have been associated with myocardial infarction, an atherosclerotic disease. Lind et al. investigated the association between level of POPs exposure and atherosclerosis in the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study (n = 1,016 participants 70 years of age). The authors determined the number of carotid artery plaques by ultrasound and measured the thickness and grey scale (IS-GSM) of the intima-media complex. Seven of the POPs (PCB congeners 153, 156, 157, 170, 180, 206, and 209) were positively associated with the number of carotid arteries with plaques. Highly chlorinated PCBs (congeners 194, 206, and 209) were associated with an echolucent IM-GSM. Circulating levels of PCBs were associated with atherosclerotic plaques and echogenicity of the intima-media complex. This suggests that POPs may be a risk factor for myocardial infarction, but associations need to be confirmed in prospective studies.
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Exposure to asbestos from contaminated vermiculite ore from Libby Montana occurred in many processing sites, including a densely populated urban residential neighborhood in Minneapolis, Minnesota. Alexander et al. obtained posteroanterior chest radiographs to study the prevalence of pleural abnormalities in community residents who never worked at the plant or lived with a plant worker (n = 461). They estimated cumulative asbestos exposure with air dispersion model data and activity-based exposure estimates for vermiculite processing waste contact. Associations between pleural abnormalities and asbestos exposure were modeled using multiple logistic regression to adjust for year of birth, sex, and potential occupational asbestos exposure. The authors report radiographic evidence of changes in the lung that were consistent with exposure to asbestos. These results indicate that nonoccupational exposures to asbestos may potentially be associated with adverse health outcomes.
Related News Article: The Traveling Libby Legacy: Minnesota Community Exhibits Nonoccupational Health Impacts Consistent with Asbestos Damage
Automobile exhaust contains precursors to ozone and fine particulate matter (PM), which are associated with adverse health outcomes. Reliance on commuting by car also reduces physical fitness opportunities. Grabow et al. simulated census-tract level changes in hourly pollutant concentrations from the elimination of automobile round trips ≤ 8 km in 11 metropolitan areas using the Community Multiscale Air Quality model. They then estimated annual changes in health outcomes and monetary costs expected from pollution changes using the Benefits Mapping Analysis Program (BenMAP). The World Health Organization Health Economic Assessment Tool (HEAT) was used to calculate benefits of increased physical activity if 50% of short trips were made by bicycle. The authors estimated that the annual average urban concentrations of PM2.5 would decline by 0.1 µg/m3
and that summer O3 would increase slightly in cities but decline regionally, resulting in net health benefits of $4.94 billion/year. Across the study region, mortality was predicted to decline by approximately 1,295 deaths/year because of improved air quality and increased exercise. Making 50% of short trips by bicycle would yield savings of approximately $3.8 billion/year from avoided mortality and reduced health care costs. The combined benefits of improved air quality and physical fitness were estimated to exceed $8 billion/year. These findings suggest that significant health and economic benefits are possible if bicycling replaces short car trips. Less dependence on automobiles in urban areas would also improve health in downwind rural settings.
Related News Article: Big Biking Payoff: Alternative Transportation Could Net Midwest over $8 Billion
Claus Henn et al. prospectively studied whether coexposure to manganese and lead in early childhood is associated with neurodevelopmental deficiencies that are more severe than expected based on effects of exposure to each metal alone. Children in an ongoing longitudinal cohort study (n = 455) were enrolled at birth in Mexico City, provided blood samples, and were followed until 36 months of age. Lead and manganese were measured at 12 and 24 months of age, and neurodevelopment was assessed at 6-month intervals from 12 to 36 months of age using Bayley Scales of Infant Development–II. The authors observed evidence of synergism between lead and manganese; lead toxicity was increased among children with high manganese coexposure. The results of this study highlight the importance of understanding health effects of mixed exposures, particularly during potentially sensitive developmental stages such as early childhood.
Related News Article: Mixed Metals Toxicity: More than the Sum of Its Parts?