Typhoon-boosted biogenic emission aggravates cross-regional ozone pollution in China

Enhanced anthropogenic and biogenic interaction by approaching typhoons deteriorates cross-regional ozone pollution in China.

Long-Term Change Analysis of PM2.5 and Ozone Pollution in China’s Most Polluted Region during 2015–2020

In this study, a time change analysis of fine particulate (PM2.5) emission in multi-resolution emission inventory in China (MEIC) from 2013 to 2016 was conducted. It was found that PM2.5 emissions showed a decreasing trend year by year, and that the annual total emission of PM2.5 decreased by 28.5% in 2016 compared with that of 2013. When comparing the observation data of PM2.5 and ozone (O3), it was found that both PM2.5 and O3 show obvious seasonal changes. The emission of PM2.5 in autumn and winter is higher than that in summer, while that of O3 is not. Our study showed that in the 2015–2020 period, annual mean concentrations of PM2.5 and O3 in Beijing varied from 80.87 to 38.31 μg m-3 and 110.75 to 106.18 μg m-3, respectively. Since 2015, the observed value of PM2.5 has shown an obvious downward trend. Compared with 2015, the average annual PM2.5 concentrations in Beijing, Shanghai, Xuzhou, Zhengzhou, and Hefei in 2020 had decreased by 52.62%, 40.35%, 22.2%, 46.84%, and 45.11%, respectively, while O3 showed an upward trend. Compared with the annual averages of 2015 and 2020, Beijing and Shanghai saw a decrease of 4.13% and 8.46%, respectively, while Xuzhou, Zhengzhou, and Hefei saw an increase of 7.08%, 19.46%, and 41.57%, respectively. The comparison shows that PM2.5 is becoming less threatening in China and that ozone is becoming more difficult to control. Air pollution is a modifiable risk factor. Appropriate sustainable control policies are recommended to protect public health.

Gene–environment interactions increase the risk of pediatric-onset multiple sclerosis associated with ozone pollution

Background: We previously reported a relationship between air pollutants and increased risk of pediatric-onset multiple sclerosis (POMS). Ozone is an air pollutant that may play a role in multiple sclerosis (MS) pathoetiology. CD86 is the only non-HLA gene associated with POMS for which expression on antigen-presenting cells (APCs) is changed in response to ozone exposure. Objectives: To examine the association between county-level ozone and POMS, and the interactions between ozone pollution, CD86, and HLA- DRB1*15, the strongest genetic variant associated with POMS. Methods: Cases and controls were enrolled in the Environmental and Genetic Risk Factors for Pediatric MS study of the US Network of Pediatric MS Centers. County-level-modeled ozone data were acquired from the CDC’s Environmental Tracking Network. Participants were assigned ozone values based on county of residence. Values were categorized into tertiles based on healthy controls. The association between ozone tertiles and having MS was assessed by logistic regression. Interactions between tertiles of ozone level and the GG genotype of the rs928264 (G/A) single nucleotide polymorphism (SNP) within CD86, and the presence of DRB1*15:01 ( DRB1*15) on odds of POMS were evaluated. Models were adjusted for age, sex, genetic ancestry, and mother’s education. Additive interaction was estimated using relative excess risk due to interaction (RERI) and attributable proportions (APs) of disease were calculated. Results: A total of 334 POMS cases and 565 controls contributed to the analyses. County-level ozone was associated with increased odds of POMS (odds ratio 2.47, 95% confidence interval (CI): 1.69–3.59 and 1.95, 95% CI: 1.32–2.88 for the upper two tertiles, respectively, compared with the lowest tertile). There was a significant additive interaction between high ozone tertiles and presence of DRB1*15, with a RERI of 2.21 (95% CI: 0.83–3.59) and an AP of 0.56 (95% CI: 0.33–0.79). Additive interaction between high ozone tertiles and the CD86 GG genotype was present, with a RERI of 1.60 (95% CI: 0.14–3.06) and an AP of 0.37 (95% CI: 0.001–0.75) compared to the lowest ozone tertile. AP results indicated that approximately half of the POMS risk in subjects can be attributed to the possible interaction between higher county-level ozone carrying either DRB1*15 or the CD86 GG genotype. Conclusions: In addition to the association between high county-level ozone and POMS, we report evidence for additive interactions between higher county-level ozone and DRB1*15 and the CD86 GG genotype. Identifying gene–environment interactions may provide mechanistic insight of biological processes at play in MS susceptibility. Our work suggests a possible role of APCs for county-level ozone-induced POMS risk.

Joint Occurrence of Heatwaves and Ozone Pollution and Increased Health Risks in Beijing, China: Roles of Synoptic Weather Pattern and Urbanization

Heatwaves (HWs) paired with higher ozone (O3) concentration at surface level pose a serious threat to human health. Their combined modulation of synoptic patterns and urbanization remains unclear. By using five years of summertime temperature and O3 concentrations observation in Beijing, this study explored potential drivers of compound HWs and O3 pollution events. Three unfavourable synoptic weather patterns were identified to dominate the compound HWs and O3 pollution events. The weather patterns contributing to enhance those conditions are characterized by sinking air motion, low boundary layer height, and hot temperatures. Under the synergistic stress of HWs and O3 pollution, the public mortality risk increased by approximately 12.59 % (95 % confidence interval: 4.66 %, 21.42 %). Relative to rural areas, urbanization caused higher risks for HWs, but lower risks for O3 over urban areas. In general, unfavourable synoptic patterns and urbanization can enhance the compound risk of events in Beijing by 45.46 % and 8.08 %, respectively. Our findings provide robust evidence and implications for forecasting compound heatwaves and O3 pollution event and its health risks in Beijing or in other urban areas all over the word having high concentrations of O3 and high-density populations.