Associations of outdoor fine particulate air pollution and cardiovascular disease: Results from the Prospective Urban and Rural Epidemiology Study in China (PURE-China).

BACKGROUND: Evidence on whether an excess risk of incidence and mortality of cardiovascular disease (CVD) among people exposed to a high level of ambient PM2.5 in low- and middle-income countries (LMICs) is lacking. This study aimed to investigate the associations between long-term exposure to ambient fine particulate matter<2.5 µm (PM2.5) concentrations and the risk of incidence and mortality of CVD in a large cohort study from 115 communities. METHODS: In this cohort study, we followed 42 160 adults aged 35-75 years at baseline who enrolled in the Prospective Urban and Rural Epidemiology Study conducted in China (PURE-China) between 2005 and 2009 with ambient PM2.5 estimates, and followed up until August 2021. Cox proportional hazards frailty models were used to estimate the associations between long-term mean outdoor PM2.5 concentrations and CVD events, CVD mortality, and all-cause mortality. FINDINGS: During a median follow-up period of 11.8 years, we documented 2 190 deaths, including 732 CVD deaths. There were 4 559 (10.8 %) of 42 160 participants who experienced incident total CVD, among them there were 861 myocardial infarctions (MI) and 2 338 S. The 3-year median concentration of ambient PM2.5 before the cohort commencement was 52.7 µg/m3 (interquartile range [IQR] 30.3-74.6). In full adjusted model, a 10 µg/m3 increase in PM2.5 was associated with a hazard ratio (HR) of 1.12 (95 % CI 1.11-1.14) for major CVD and 1.03 (95 % CI 1.01-1.05) for all-cause mortality. Besides, long-term PM2.5 concentrations had a significantly positive gradient association with total CVD and a similar pattern of associations with other CVD outcomes was observed. INTERPRETATION: This study demonstrated that long-term ambient PM2.5 concentrations is positively associated with increased risks of CVD in adults aged 35-70 years from China. This finding reinforces the need for policymakers to adopt more effective strategies to improve air quality.

Adverse health impacts of cooking with kerosene: A multi-country analysis within the Prospective Urban and Rural Epidemiology Study.

BACKGROUND: Kerosene, which was until recently considered a relatively clean household fuel, is still widely used in low- and middle-income countries for cooking and lighting. However, there is little data on its health effects. We examined cardiorespiratory effects and mortality in households using kerosene as their primary cooking fuel within the Prospective Urban Rural Epidemiology (PURE) study. METHODS: We analyzed baseline and follow-up data on 31,490 individuals from 154 communities in China, India, South Africa, and Tanzania where there was at least 10% kerosene use for cooking at baseline. Baseline comorbidities and health outcomes during follow-up (median 9.4 years) were compared between households with kerosene versus clean (gas or electricity) or solid fuel (biomass and coal) use for cooking. Multi-level marginal regression models adjusted for individual, household, and community level covariates. RESULTS: Higher rates of prevalent respiratory symptoms (e.g. 34% [95% CI:15-57%] more dyspnea with usual activity, 44% [95% CI: 21-72%] more chronic cough or sputum) and lower lung function (differences in FEV1: -46.3 ml (95% CI: -80.5; -12.1) and FVC: -54.7 ml (95% CI: -93.6; -15.8)) were observed at baseline for kerosene compared to clean fuel users. The odds of hypertension was slightly elevated but no associations were observed for blood pressure. Prospectively, kerosene was associated with elevated risks of all-cause (HR: 1.32 (95% CI: 1.14-1.53)) and cardiovascular (HR: 1.34 (95% CI: 1.00-1.80)) mortality, as well as major fatal and incident non-fatal cardiovascular (HR: 1.34 (95% CI: 1.08-1.66)) and respiratory (HR: 1.55 (95% CI: 0.98-2.43)) diseases, compared to clean fuel use. Further, compared to solid fuel users, those using kerosene had 20-47% higher risks for the above outcomes. CONCLUSIONS: Kerosene use for cooking was associated with higher rates of baseline respiratory morbidity and increased risk of mortality and cardiorespiratory outcomes during follow-up when compared to either clean or solid fuels. Replacing kerosene with cleaner-burning fuels for cooking is recommended.

Impact of socio-economic factors on stroke prevalence among urban and rural residents in Mainland China.

BACKGROUND: An inverse relationship between better socioeconomic status (total household income, education or occupation) and stroke has been established in developed communities, but family size has generally not been considered in the use of socioeconomic status indices. We explored the utility of Family Average Income (FAI) as a single index of socioeconomic status to examine the association with stroke prevalence in a region of China, and we also compared its performance as a single index of socioeconomic status with that of education and occupation. METHODS: A population-based cross-sectional study was conducted in Nanjing municipality of China during the period between October 2000 and March 2001. A total of 45 administrative villages were randomly selected using a multi-stage sampling approach and all regular local residents aged 35 years or above were included. Descriptive statistics and logistic regression models were used in analysis. RESULTS: The overall prevalence of diagnosed stroke was 1.54% in all 29,340 eligible participants. An elevated prevalence of stroke was associated with increasing levels of FAI. After adjustment for basic demographic variables (age, urban/rural area and gender) and a group of defined conventional risk factors, this gradient still remained significant, with participants in the highest (OR = 1.94, 95% CI = 1.40, 2.70) and middle (OR = 1.43, 95% CI = 1.01, 2.02) categories of FAI having higher risks compared with the lowest category. A significantly elevated OR of stroke prevalence was found in white collar workers compared to blue collar workers, while no significant relationship was observed with education. CONCLUSION: Our study consistently revealed that the prevalence of stroke was associated with increasing levels of all SES indices, including FAI, education, and occupation. However, a significant gradient was only observed with FAI after controlling for important confounding factors. The findings suggested that, compared with occupation and education, FAI could be used as a more sensitive index of socio-economic status for public health studies in China.