Associations between long-term exposure to particulate matter and mortality from multiple causes among the oldest-old...

Older people are considered more vulnerable to particulate matter (PM) exposure in terms of mortality risk. However, little is known about the associations among the oldest-old people in the era of rapid ageing. Thus, the objective of this study was to estimate the associations between long-term exposure to PM and the risk of mortality from multiple causes among the oldest-old people (aged over 80). In total, all-cause mortality and mortality from eight broad and 23 specific causes were estimated on the basis of 7-year cohort data for almost 10 thousand oldest-old people in China. Moreover, time-dependent characteristics of the associations were determined. PM exposure was associated with increased mortality risks for a wide range of causes, including neoplasms and nervous system diseases, which have rarely been assessed before. With respect to specific causes, pulmonary heart diseases and diseases of pulmonary circulation was more affected by PM exposure. Notably, the impacts on some diseases, such as the circulatory system and hypertensive diseases, decreased during the COVID-19 pandemic. The effect may be modified by some social factors during the pandemic. Understanding the dynamic associations between PM exposure and mortality from multiple causes is highly important for identifying sensitive cause-specific deaths.