Health Effects of Long-term Exposure to Ozone on Chinese Adults: Analysis of an Existing Longitudinal Cohort

Project: Research

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AimThe overall aim of this proposed project is to investigate the effects of long-term exposure to Ozone (O3) on various health outcomes in a longitudinal cohort consisting of 0.6 million Chinese adults.Project backgroundAmbient air pollution, which increases mortality and morbidity and shortens life expectancies, is the leading contributor to the global disease burden. The current evidence concerning air pollution and health mostly focuses on particulate matter, which is regarded as the most important air pollutant. In contrast, the evidence on O3 is far less and more inconsistent. Many countries recognizing air pollution as a crucial public health challenge, and have striven to control air pollution in the past decades, and the concentrations of particulate matters (e.g. PM2.5 and PM10) and other criteria pollutants (NOx and SO2) have begun to decrease in some developed countries. However, the level of O3 has not exhibited a discernible downward trend due to the complexity of O3 formation. Consequently, O3 is emerging as an important environmental health issue, especially given the projected increases in temperature related to climate change. O3 is a respiratory irritant that can cause bronchial inflammation and hyper-responsiveness. However, data on the effects of long-term exposure to O3 are scarce. In addition, most existing data are derived from Western countries and focus on the short-term effects O3 exposure on limited health outcomes.Project descriptionWe propose to investigate the emerging public health concerns related to O3 applying data from an existing longitudinal cohort. This cohort database includes 620,000 participants recruited during the 1996–2017 period with 1,440,000 medical examination records. Information on the demographic and socio-economic status, lifestyle, residential address and physical activity (PA) was collected during each medical examination. In our previous research, we additionally obtained data on the participants’ vital statuses and exposure to PM2.5. We will use a spatiotemporal statistical model—geographically and temporally weighted regression (GTWR) mode to evaluate the concentration of O3. A Cox regression model will be used to analyse data corresponding to dichotomous health outcomes (mortality and morbidities), and a generalised linear mixed model will be used to analyse data on continuous health outcomes (e.g., lung function, blood pressure and glucose levels). Mediation analyses will be used to examine the mediating effects of habitual PA on the associations between ambient O3 and various health outcomes.Significance of the projectThe World Health Organisation (WHO) suggested that air pollution ranked as the 5th risk factor for death worldwide. As a key component of photochemical air pollution mixture, O3 is becoming an important air pollutant. An enhanced understanding of the health effects of ambient O3 would have enormous implications for the development of health guidelines and air pollution control policies, especially in areas with high concentrations of pollutants.


Project number9043483
Grant typeGRF
Effective start/end date1/01/22 → …