Effects of air pollution and greenspace exposure on cause-specific mortality among older adults in Guangzhou, China

Abstract

In light of increasing recognition of the detrimental impacts of air pollution and beneficial impacts of greenspace on public health, limited research has examined how greenspace modifies air pollution-related mortality risks in high-density urban contexts in China. This study utilized Guangzhou death registration data (2017–2019) and negative binomial regression models to evaluate the effects of PM_2.5, PM₁₀, and NO₂ concentrations and NDVI on non-accidental, cardiovascular, and respiratory mortality among adults aged 60 and over across 2774 neighborhoods. Results indicate that non-accidental mortality risk rose by 5.6 % (95 % CI: 3.5 %, 7.6 %), 2.7 % (95 % CI: 1.8 %, 3.5 %), and 14.7 % (95 % CI: 9.6 %, 20 %) for every 1 μg/m³ increase in PM_2.5 and PM₁₀ concentrations and 1 ppbv increase in NO_{2 concentration}, respectively. Similar trends were found for cardiovascular and respiratory mortality, with the strongest effects observed for respiratory mortality. Higher greenness mitigated the impact of PM on respiratory mortality but exacerbated the adverse effects of NO₂ on cardiovascular mortality. Stratified analyses showed stronger effects of air pollution and greenspace among females and disadvantaged neighborhoods. These findings highlight the need to integrate air pollution control and greenspace system planning into urban environmental health interventions to reduce mortality risk, particularly in high-density urban areas and among vulnerable populations.