Air quality and acute myocardial infarction in adults during the 2016 Hangzhou G20 summit

Explore the Relationship Between Short-Term Ambient Air Pollution Exposure and Daily Outpatient Visits for Metabolic Related Fatty Liver

Background

Many studies have shown that the pollution of fine particles in the air is related to the incidence of chronic diseases. However, research on air pollution and metabolism-associated fatty liver disease (MAFLD) is limited.

Objective

The purpose of this study was to explore the relationship between short-term ambient air pollution and daily outpatient visits for metabolic-related fatty liver.

Methods

We used a quasi-Poisson regression generalized additive model to stratify analyses by season, age, and gender.

Results

From January 1, 2017, to August 31, 2019, 10,562 confirmed MAFLD outpatient visits were recorded. A 10 µg/m³ increase of fine particular matter (PM10and PM2.5) and NO₂ concentrations corresponding with percent change were 0.82 (95% confidence interval [CI], 0.49–1.15), 0.57 (95% CI, 0.18–0.98), and 0.86 (95% CI, 0.59–1.13) elevation in MAFLD outpatient visits. In terms of season, the impact estimates of NO₂ and PM2.5% change were 3.55 (95% CI, 1.23–5.87) and 1.12 (95% CI, 0.78–1.46) in the hot season and transition season, respectively. Compared with the warm season, the impact estimates of PM10were more significant in the cool season: 2.88 (95% CI, 0.66–5.10). NO₂ has the greatest effect in the transition season, whereas PM10 has the greatest highest effect in the cool and hot seasons. Compared with other pollutants, PM2.5 has the greatest impact in the age stratification, which percent change are 2.69 (95% CI, 0.77–5.61) and 2.88 (95% CI, 0.37–6.40) respectively. The impact values of PM2.5 in male and female percent change were 3.60 (95% CI, 0.63–6.57) and 1.65 (95% CI, 1.05–2.25), respectively.

Conclusion

This study shows that the air pollutants are related to the number of outpatient visits for MAFLD. The effects of different air pollutants on MAFLD outpatient visits were different by season, ages, and gender.

Characteristics and source attribution of PM2.5 during 2016 G20 Summit in Hangzhou: Efficacy of radical measures to reduce source emissions

A field campaign was conducted to study the PM_2.5 and atmospheric gases and aerosol's components to evaluate the efficacy of radical measures implemented by the Chinese government to improve air quality during the 2016 G20 Summit in Hangzhou China. The lower level of PM_2.5 (32.48 ± 11.03 µg/m³) observed during the control period compared to pre-control and post-control periods showed that PM_2.5 was alleviated by control policies. Based on the mass concentrations of particulate components, the emissions of PM_2.5 from local sources including fossil fuel, coal combustion, industry and construction were effectively reduced, but non-exhaust emission was not reduced as effectively as expected. The accumulation of SNA (SO₄^2-, NO₃^-, NH₄⁺) was observed during the control period, due to the favourable synoptic weather conditions for photochemical reactions and heterogeneous hydrolysis. Because of transboundary transport during the control period, air masses from remote areas contributed significantly to local PM_2.5. Although, secondary organic carbon (OC_sec) exhibited more sensitivity than primary organic carbon (OC_pri) to control measures, and the increased nitrogen oxidation ratio (NOR) implied the regional transport of aged secondary aerosols to the study area. Overall, the results from various approaches revealed that local pollution sources were kept under control, indicating that the implementation of mitigation measures were helpful in improving the air quality of Hangzhou during G20 summit. To reduce ambient levels of PM_2.5 further in Hangzhou, regional control policies may have to be taken so as to reduce the impact of long-range transport of air masses from inland China.

Quantitative Analysis of Health Risk Perception, Exposure Levels, and Willingness to Pay/Accept of PM2.5 during the 2014 Nanjing Youth Olympic Games

Local governments in China regularly implement short-term emission control measures to improve air quality during important sporting events. As a condition for hosting the 2014 Youth Olympic Games (YOG), the Nanjing government agreed to temporarily and substantially improve air quality. Regression analysis, Spearman correlation analysis, χ² test, and the contingent valuation method were used to explore the effects of robust, short-term air pollution control measures on risk perception, daily exposure to PM_2.5, risk acceptance levels, and willingness to pay/accept (WTP/WTA) for reductions in air pollution for the benefit of reducing health risks. Postimplementation, the respondents' risk perception levels presented the following changes: during the YOG, the respondents perceived the lowest effects of haze pollution while after the YOG, they perceived the highest effects. The changes in risk acceptance levels showed the same tendency. Furthermore, after the YOG, the respondents asked for the most economic compensation, and their willingness to pay for risk reduction also reached the highest level. This study reveals the need to increase the public's understanding of the health risks of air pollution, protect those populations most exposed to high levels of PM_2.5, and take more effective long-term measures to meet local residents' demands for improved air quality.