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Background: Association between fine particulate matter (PM2.5) and hypertensive disorders of pregnancy (HDP) is inconsistent and appears to change in each trimester. We aim to investigate the association of exposure to ambient PM2.5 in early pregnancy with HDP.Methods: A retrospective cohort study was performed among 8776 women with singleton pregnancy who attended the antenatal clinic before 20 gestational weeks in a tertiary women's hospital during 2014-2015. Land use regression models were used to predict individual levels of PM2.5 exposure.Results: The average PM2.5 concentration during the first 20 gestational weeks ranged from 28.6 to 74.8 μg m- 3 [median, 51.4 μg m- 3; interquartile range, 47.3-57.8 μg m- 3]. A total of 440 (5.0%) women was diagnosed with HDP. The restricted cubic spline showed a positive exposure-response relationship between the PM2.5 concentration and risk of HDP. We observed an association between PM2.5 exposure during the first trimester with HDP (RR = 3.89 per 10 μg m- 3, 95% CI: 1.45-10.43), but not during the second trimester (RR = 0.71 per 10 μg m- 3, 95% CI: 0.40-1.27). Compared with their counterparts, nulliparous women who were exposed to high levels of PM2.5 in the index pregnancy had a higher risk of developing HDP [the relative excess risk due to interaction was 0.92 (0.46-1.38)].Conclusion: Our findings suggest that PM2.5 exposure during the first trimester is associated with the development of HDP. The effect estimate is more obvious for nulliparous women than multiparous women. [ABSTRACT FROM AUTHOR]

Background Shanghai, along with many major cities in China, faces deterioration of air quality and increases in air pollution-related respiratory diseases (RDs) in children due to rapid industrialization and urbanization. The Contingent Valuation Method (CVM) was used to qualitatively and quantitatively measure the willingness to pay (WTP) for reducing children's RDs through air quality improvement. Methods: Between April and May, 2014, 975 face-to-face interviews were collected from parents in a community-based and a hospital-setting in Shanghai. Multiple imputation and the Probit model were used to determine the relationship between the WTP and the related environmental factors, child health factors and the socio-economic status. Results Most respondents reported being willing to make a financial contribution to improve air quality in both the community (52.6%) and hospital (70.2%) samples. Those in the hospital setting were willing to pay significantly more ¥504 (USD$80.7) compared to the community sample ¥428 ($68.5) as expected. Reasons for those not being willing to pay included lack of disposable income and believing that responsibility of the air quality was a community issue. These did not differ by sample. Annual household income and education were related to WTP. Conclusion This study indicated that parents in Shanghai would be willing to pay for improved air quality. Children's health can be the incentive for the citizens' participation and support in the air quality improvement, therefore, hospital settings may present unique places to improve education about air quality and enhance advocacy efforts. This study also suggested that future environmental policies be addressed more rigorously for targeted populations. [ABSTRACT FROM AUTHOR]