Cardiovascular disease averted by China’s Clean Air Act and the potential benefit of further air pollution intervention: evidence based on the parametric G-computation

AIMS: This study quantified cardiovascular benefits attributable to China's Clean Air Act (CCAA), expressed as cases averted for cardiovascular disease (CVD), and estimated additional gains under stricter air-pollution interventions. METHODS AND RESULTS: We used data from the China Multi-Ethnic Cohort to estimate the numbers of averted CVD cases under CCAA policy and potential stricter intervention strategies for two air pollutants (PM2.5 and O3), including CCAA benefit evaluation (simulating the scenario without CCAA implementation), threshold intervention (limiting pollutant levels to specified thresholds), ratio intervention (reducing pollutant concentrations by a fixed percentage annually), and phased intervention (staged reductions at specific intervals over time). The parametric G-formula was employed to estimate the number of CVD cases averted per 100 000 people and relative risk. All interventions significantly reduced the cumulative morbidity of CVD. In CCAA benefit evaluation, the number of CVD cases averted per 100 000 people (95% CI) was 541 (184, 914) for PM2.5. Among potential stricter interventions, WHO AQG in threshold intervention yielded the largest number of CVD cases averted per 100 000 participants, 13 530 (7,400, 17,405) for PM2.5, 6498 (1,189, 10,840) for O3, and 15 449 (10,148, 17,998) for joint pollutant intervention, respectively. CONCLUSION: Existing air pollutant intervention policies have achieved considerable public health benefits in reducing CVD risk, and there is still significant room for improvement. Potential stricter interventions can be used as future target-oriented strategies to minimize the impact of air pollution on cardiovascular health.