AbstractI review an important study that Professor Evans published early in his career examining the role of cross‐sectional mortality studies in air pollution risk assessment. At a time when both risk assessment and particle effects on mortality were controversial, John's thoughtful analysis of the issues and data relevant to assessing long‐term mortality risks from airborne particles provides a comprehensive primer that is still relevant today. The paper includes a critical literature review, a meta‐analysis of published particle effect estimates, and a reanalysis of landmark cross‐sectional mortality data set. EPA criteria documents and related literature had largely discounted the cross‐sectional mortality findings on the basis of criticisms about exposure assessment and control for confounding. John's analysis reached a different conclusion, that is, "we are of the opinion that the cross‐sectional studies reflect a causal relationship between exposure to airborne particles and premature mortality. From our point of view it is as likely that parameters have been underestimated … as that they are overestimated due to confounding." The paper acknowledged the impossibility of precisely quantifying the long‐term mortality effect of particle air pollution, and that there is a need for further research utilizing alternative approaches. These conclusions foreshadow the emergence, a decade later, of the influential particulate matter (PM) mortality findings from the Harvard Six Cities and American Cancer Society cohort studies. I conclude by suggesting that well designed cross‐sectional studies could play a role in identifying exposure–response associations in resource‐poor settings where there is a paucity of local evidence to support air pollution regulations.
Across the United States, cities are creating sustainability and climate action plans (CAPs) that call to increase local vegetation. These greening initiatives have the potential to not only benefit the environment but also human health. In epidemiologic literature, greenness has a protective effect on mortality through various direct and indirect pathways. We aimed to assess how an increase in greenness could decrease mortality in the largest urban areas in the United States. We conducted a nationwide quantitative health impact assessment to estimate the predicted reduction in mortality associated with an increase in greenness across two decades (2000, 2010, and 2019). Using a recently published exposure-response function, Landsat 30 m 16-day satellite imagery from April to September, and publicly available county-level mortality data from the CDC, we calculated the age-adjusted reduction in all-cause mortality for those 65 years and older within 35 of the most populated metropolitan areas. We estimated that between 34,000 and 38,000 all-cause deaths could have been reduced in 2000, 2010, and 2019 with a local increase in green vegetation by 0.1 unit across the most populated metropolitan areas. We found that overall greenness increased across time with a 2.86% increase from 2000 to 2010 to 11.11% from 2010 to 2019. These results can be used to support CAPs by providing a quantitative assessment to the impact local greening initiatives can have on mortality. Urban planners and local governments can use these findings to calculate the co-benefits of local CAPs through a public health lens and support policy development.
AbstractCoccidioidomycosis, or valley fever, is an infectious fungal disease currently endemic to the southwestern United States. Symptoms of valley fever range in severity from flu-like illness to severe morbidity and mortality. Warming temperatures and changes in precipitation patterns may cause the area of endemicity to expand northward throughout the western United States, putting more people at risk for contracting valley fever. This may increase the health and economic burdens from this disease. We developed an approach to describe the relationship between climate conditions and valley fever incidence using historical data and generated projections of future incidence in response to both climate change and population trends using the Climate Change Impacts and Risk Analysis (CIRA) framework developed by the U.S. Environmental Protection Agency. We also developed a method to estimate economic impacts of valley fever that is based on case counts. For our 2000–15 baseline time period, we estimated annual medical costs, lost income, and economic welfare losses for valley fever in the United States were $400,000 per case, and the annual average total cost was $3.9 billion per year. For a high greenhouse gas emission scenario and accounting for population growth, we found that total annual costs for valley fever may increase up to 164% by year 2050 and up to 380% by 2090. By the end of the twenty-first century, valley fever may cost $620,000 per case and the annual average total cost may reach $18.5 billion per year. This work contributes to the broader effort to monetize climate change–attributable damages in the United States.
Background: Exposure to air pollutants including polycyclic aromatic hydrocarbons (PAH), and specifically pyrene from combustion of fuel oil, coal, traffic and indoor sources, has been associated with adverse respiratory health outcomes. However, time trends of airborne PAH and metabolite levels detected via repeat measures over time have not yet been characterized. We hypothesized that PAH levels, measured repeatedly from residential indoor and outdoor monitors, and children׳s urinary concentrations of PAH metabolites, would decrease following policy interventions to reduce traffic-related air pollution. Methods: Indoor PAH (particle- and gas-phase) were collected for two weeks prenatally (n=98), at age 5/6 years (n=397) and age 9/10 years (n=198) since 2001 and at all three age-points (n=27). Other traffic-related air pollutants (black carbon and PM2.5) were monitored indoors simultaneous with PAH monitoring at ages 5/6 (n=403) and 9/10 (n=257) between 2005 and 2012. One third of the homes were selected across seasons for outdoor PAH, BC and PM2.5 sampling. Using the same sampling method, ambient PAH, BC and PM2.5 also were monitored every two weeks at a central site between 2007 and 2012. PAH were analyzed as semivolatile PAH (e.g., pyrene; MW 178–206) (∑8PAHsemivolatile: Including pyrene (PYR), phenanthrene (PHEN), 1-methylphenanthrene (1-MEPH), 2-methylphenanthrene (2-MEPH), 3-methylphenanthrene (3-MEPH), 9-methylphenanthrene (9-MEPH), 1,7-dimethylphenanthrene (1,7-DMEPH), and 3,6-dimethylphenanthrene (3,6-DMEPH)) and the sum of eight nonvolatile PAH (∑8PAHnonvolatile: Including benzo[a]anthracene (BaA), chrysene/iso-chrysene (Chry), benzo[b]fluoranthene (BbFA), benzo[k]fluoranthene (BkFA), benzo[a]pyrene (BaP), indeno[1,2,3-c,d]pyrene (IP), dibenzo[a,h]anthracene (DahA), and benzo[g,h,i]perylene (BghiP); MW 228–278). A spot urine sample was collected from children at child ages 3, 5, 7 and 9 between 2001 and 2012 and analyzed for 10 PAH metabolites. Results: Modest declines were detected in indoor BC and PM2.5 levels between 2005 and 2012 (Annual percent change [APC]=−2.08% [p=0.010] and −2.18% [p=0.059] for BC and PM2.5, respectively), while a trend of increasing pyrene levels was observed in indoor and outdoor samples, and at the central site during the comparable time periods (APC=4.81%, 3.77% and 7.90%, respectively; p<0.05 for all). No significant time trend was observed in indoor ∑8PAHnonvolatile levels between 2005 and 2012; however, significant opposite trends were detected when analyzed seasonally (APC=−8.06% [p<0.01], 3.87% [p<0.05] for nonheating and heating season, respectively). Similarly, heating season also affected the annual trends (2005–2012) of other air pollutants: the decreasing BC trend (in indoor/outdoor air) was observed only in the nonheating season, consistent with dominating traffic sources that decreased with time; the increasing pyrene trend was more apparent in the heating season. Outdoor PM2.5 levels persistently decreased over time across the seasons. With the analyses of data collected over a longer period of time (2001–2012), a decreasing trend was observed in pyrene (APC=−2.76%; p<0.01), mostly driven by measures from the nonheating season (APC=−3.54%; p<0.01). In contrast, levels of pyrene and naphthalene metabolites, 1-hydroxypyrene and 2-naphthol, increased from 2001 to 2012 (APC=6.29% and 7.90% for 1-hydroxypyrene and 2-naphthol, respectively; p<0.01 for both). Conclusions: Multiple NYC legislative regulations targeting traffic-related air pollution may have led to decreases in ∑8PAHnonvolatile and BC, especially in the nonheating season. Despite the overall decrease in pyrene over the 2001–2012 periods, a rise in pyrene levels in recent years (2005–2012), that was particularly evident for measures collected during the heating season, and 2-naphthol, indicates the contribution of heating oil combustion and other indoor sources to airborne pyrene and urinary 2-naphthol.
Abstract China is one of the largest producers and consumers of coal in the world. The National Action Plan on Air Pollution Prevention and Control in China (2013–2017) particularly aimed to reduce emissions from coal combustion. Here, we show whether the acute health effects of PM2.5 changed from 2013 to 2018 and factors that might account for any observed changes in the Beijing–Tianjin–Hebei (BTH) and the surrounding areas where there were major reductions in PM2.5 concentrations. We used a two-stage analysis strategy, with a quasi-Poisson regression model and a random effects meta-analysis, to assess the effects of PM2.5 on mortality in the 47 counties of BTH. We found that the mean daily PM2.5 levels and the SO42− component ratio dramatically decreased in the study period, which was likely related to the control of coal emissions. Subsequently, the acute effects of PM2.5 were significantly decreased for total and circulatory mortality. A 10 μg/m3 increase in PM2.5 concentrations was associated with a 0.16% (95% CI: 0.08, 0.24%) and 0.02% (95% CI: −0.09, 0.13%) increase in mortality from 2013 to 2015 and from 2016 to 2018, respectively. The changes in air pollution sources or PM2.5 components appeared to have played a core role in reducing the health effects. The air pollution control measures implemented recently targeting coal emissions taken in China may have resulted in significant health benefits.
