JMIR Publications

ABSTRACT

Background:

Despite mechanistic data imply the adverse impact of particulate matters (PMs) on multiple body systems, epidemiological evidence is sparse on the mortality risk and burden of a whole spectrum of death causes attributable to size-fractionated PMs. We aimed to examine the wide range of susceptible diseases affected by different sizes of PMs.

Objective:

We aimed to assess the association between particulate matters (PMs) with an aerodynamic diameter less than 1 µm (PM1), 2.5 µm (PM2.5), and 10 µm (PM10) and deaths from 36 causes in Guangzhou, China.

Methods:

Daily data were obtained on cause-specific mortality, PMs and meteorology during 2014-2016. A time-stratified case-crossover approach was applied to estimate the risk and burden of cause-specific mortality attributable to PMs after adjusting for the potential confounding variables, such as long-term trend and seasonality, relative humidity, temperature, air pressure and public holidays. Stratification analyses were further conducted to explore the potential modification effects of season and demographic characteristics (gender and age). We also assessed the mortality reduction by attaining the new air quality guidelines of World Health Organization (WHO).

Results:

Positive and monotonic associations were generally observed between PMs and mortality. For each 10 μg/m3 increase in four-day moving average concentrations of PM1, PM2.5 and PM10, the risk of all-cause mortality increased by 2.00% (95%CI: 1.08–2.92%), 1.54% (95%CI: 0.93–2.16%) and 1.38% (95%CI: 0.95–1.82%), respectively. Significant effects of size-fractionated PMs were observed for deaths from non-accidental cause, cardiovascular disease, respiratory disease, neoplasms, chronic rheumatic heart diseases, hypertensive diseases, cerebrovascular diseases, stroke, influenza and pneumonia. If daily concentrations of PM1, PM2.5 and PM10 reached the WHO target levels of 10, 15 and 45 μg/m3, 7921 (95%CI: 4454–11206), 8303 (95%CI: 95%CI: 5063–11248) and 8326 (5980–10690) deaths can be saved, respectively. The effect estimates of PMs were relatively higher among hot months, females and those aged 85 years or above, although the difference between subgroups was not statistically significant.

Conclusions:

We observed positive and monotonical exposure‒response curves between PMs and deaths from several diseases. The effect of PM1 was stronger on mortality than PM2.5 and PM10. Substantial premature deaths could be avoidable when PMs attained the WHO’s new guidelines. Our findings highlight the importance of size-based strategy in the control of PMs and management of their health impact.