Effects of Air Pollution on Daily Non-accidental Mortalities of Residents in a County and a District

Objectives To analyze and compare effects of air pollution on daily non-accidental mortalities of residents in county/district level administrative areas.

Methods The F County of Chengde and the S District of Beijing were selected as study areas. Data on daily non-accidental mortality, air pollutant concentration, and meteorological factors from 2014 to 2015 was collected. A time-series Generalized Additive Model (GAM) was applied to quantitatively investigate the effects of five air pollutants (PM_2.5, PM₁₀, SO₂, NO₂, and CO) on non-accidental mortalities of residents. Analysis was employed to the elderly (≥ 65 years old) and population with different genders respectively. Results were compared with the researches in large and medium-sized cities in China.

Results Daily average concentrations of PM_2.5, PM₁₀, SO₂, NO₂, and CO in the air environment of F County were 53.4, 79.3, 22.4, 18.1 μg/m³, and 0.9 mg/m³, respectively. The corresponding concentrations in S District were 83.3, 108.8, 13.8, 44.0 μg/m³, and 1.2 mg/m³, respectively. The average daily non-accidental mortalities in F County and S District were 5.8 and 10.7, respectively. A significant correlation exists between all other air pollutants and the total non-accidental mortality except for SO₂. With every 10 μg/m³ increase in the concentration of all pollutants, the daily non-accidental mortality caused by PM_2.5 in F County and S District increased by 1.20% (lag5) and 0.44% (lag4), respectively. The corresponding increases were 1.25% (lag5) and 0.38% (lag3) for PM₁₀, 2.65% (lag1) and 1.32% (lag4) for SO₂, 3.90% (lag0) and 1.45% (lag4) for NO₂, and 0.05% (lag0) and 0.04% (lag4) for CO. Effects of PM_2.5, PM₁₀, and NO₂ on non-accidental mortality on the elderly were all stronger than those on the total population in these two areas, but CO showed higher effects on the total population. Effects of PM₁₀ were higher on females in these two areas, but NO₂ and CO both posed higher effects on males.

Conclusions The short-term exposure of air pollution was associated with the increase of daily non-accidental mortalities of residents in these two areas. The risks have a statistical significance (except for SO₂), and is obviously higher than that in the studies of large and medium cities in China (except for CO). The risks of 5 kinds of air pollutants in F County were all higher than those in S District, and the risks of population with different genders and ages have a certain difference.