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BackgroundPrevious studies have reported decreased birth weight associated with increased air pollutant concentrations during pregnancy. However, it is not clear when during pregnancy increases in air pollution are associated with the largest differences in birth weight.ObjectivesUsing the natural experiment of air pollution declines during the 2008 Beijing Olympics, we evaluated whether having specific months of pregnancy (i.e., 1st…8th) during the 2008 Olympics period was associated with larger birth weights, compared with pregnancies during the same dates in 2007 or 2009.MethodsUsing n = 83,672 term births to mothers residing in four urban districts of Beijing, we estimated the difference in birth weight associated with having individual months of pregnancy during the 2008 Olympics (8 August-24 September 2008) compared with the same dates in 2007 and 2009. We also estimated the difference in birth weight associated with interquartile range (IQR) increases in mean ambient particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO) concentrations during each pregnancy month.ResultsBabies whose 8th month of gestation occurred during the 2008 Olympics were, on average, 23 g larger (95% CI: 5 g, 40 g) than babies whose 8th month occurred during the same calendar dates in 2007 or 2009. IQR increases in PM2.5 (19.8 μg/m3), CO (0.3 ppm), SO2 (1.8 ppb), and NO2 (13.6 ppb) concentrations during the 8th month of pregnancy were associated with 18 g (95% CI: -32 g, -3 g), 17 g (95% CI: -28 g, -6 g), 23 g (95% CI: -36 g, -10 g), and 34 g (95% CI: -70 g, 3 g) decreases in birth weight, respectively. We did not see significant associations for months 1-7.ConclusionsShort-term decreases in air pollution late in pregnancy in Beijing during the 2008 Summer Olympics, a normally heavily polluted city, were associated with higher birth weight.CitationRich DQ, Liu K, Zhang J, Thurston SW, Stevens TP, Pan Y, Kane C, Weinberger B, Ohman-Strickland P, Woodruff TJ, Duan X, Assibey-Mensah V, Zhang J. 2015. Differences in birth weight associated with the 2008 Beijing Olympics air pollution reduction: results from a natural experiment. Environ Health Perspect 123:880-887; http://dx.doi.org/10.1289/ehp.1408795.

BackgroundAlongside the major health risks posed by environmental pollution in China are recent achievements on several environmental issues that have affluent Western nations racing to catch up. The country has propelled itself to a position of leadership in clean energy and efficiency, for instance, with important consequences for public health.ObjectivesWe comment on China's challenges and recent accomplishments in addressing environmental problems from domestic pollution to global climate change. We compare China's commitment to clean energy technology with that of other leading nations and discuss key achievements in other areas, including vehicle efficiency standards and transportation policy.DiscussionWe discuss policy directions that would secure much-needed improvements to environmental quality and health in China, along with actions that could motivate global action on issues of energy conservation and pollution reduction.ConclusionsA comprehensive regulatory and institutional framework for environmental policy is within reach in China but will require addressing major hurdles such as the lack of an independent monitoring mechanism and the need for greater transparency and enforcement in environmental matters. Meanwhile, China can continue to set important examples by investing in renewable energy, improving energy efficiency, and limiting greenhouse gas emissions.

Background: Maternal smoking during pregnancy is related to altered DNA methylation in infant umbilical cord blood. The extent to which low levels of smoke exposure among nonsmoking pregnant women relates to offspring DNA methylation is unknown. Objective: This study sought to evaluate relationships between maternal prenatal plasma cotinine levels and DNA methylation in umbilical cord blood in newborns using the Infinium HumanMethylation 450K BeadChip. Methods: Participants from the Newborn Epigenetics Study cohort who reported not smoking during pregnancy had verified low levels of cotinine from maternal prenatal plasma (0 ng/mL to Results: Multivariable linear regression models yielded 29,049 CpGs that were differentially methylated in relation to increases in cotinine at a 5% false discovery rate. Top CpGs were within or near genes involved in neuronal functioning (PRKG1, DLGAP2, BSG), carcinogenesis (FHIT, HSPC157) and inflammation (AGER). Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses suggest cotinine was related to methylation of gene pathways controlling neuronal signaling, metabolic regulation, cell signaling and regulation, and cancer. Further, enhancers associated with transcription start sites were enriched in altered CpGs. Using an independent sample from the same study population (n = 115), bisulfite pyrosequencing was performed with infant cord blood DNA for two genes within our top 20 hits (AGER and PRKG1). Results from pyrosequencing replicated epigenome results for PRKG1 (cg17079497, estimate = - 1.09, standard error (SE) = 0.45, p = 0.018) but not for AGER (cg09199225; estimate = - 0.16, SE = 0.21, p = 0.44). Discussion: Secondhand smoke exposure among nonsmoking women may alter DNA methylation in regions involved in development, carcinogenesis, and neuronal functioning. These novel findings suggest that even low levels of smoke exposure during pregnancy may be sufficient to alter DNA methylation in distinct sites of mixed umbilical cord blood leukocytes in pathways that are known to be altered in cord blood from pregnant active smokers. https://doi.org/10.1289/EHP8099, Introduction Smoking is consistently linked with alterations in DNA methylation (Philibert et al. 2012, 2013; Wan et al. 2012; Zeilinger et al. 2013). Several epigenome-wide association studies (EWAS) comparing smokers [...]

The field of environmental health has lost a visionary leader, charismatic advocate, and tireless humanitarian. Kirk R. Smith passed away on 15 June 2020 at the age of 73 following [...]

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Air pollution in China, one of the world’s oldest civilizations, reflects a combination of traditional and modern-day factors. Severe air pollution in Chinese cities is the result of rapid industrialization, urbanization, and growth in vehicle use. At the same time, traditional indoor burning of solid fuels such as coal and dung presents acute, severe exposures to pollutants including particulate matter, carbon monoxide, arsenic, and mercury. In this podcast, Junfeng (Jim) Zhang tells host Ashley Ahearn about some of the factors that make air pollution a significant problem in China.