ObjectiveTo study the relationship between atmospheric PM2.5 concentration and daily visits of children with wheezing.

MethodsUsing the generalized additive model of time series on the basis of controlling for the medium and long-term effects of time, holiday effects, and week effects, we retrospectively analyzed the daily visits of wheezing children in the pediatric emergency department of a tertiary hospital in the eastern region of Shanghai influenced by weather (average daily temperature, relative humidity) and atmospheric pollutants (PM2.5, PM10, SO₂, NO₂ and O₃). The excess risk (ER) of the corresponding concentration range of the above indicators was inferred.

ResultsPM2.5 concentration in the eastern region of Shanghai had an impact on the daily visits of wheezing children. Atmospheric PM2.5 concentrations were positively correlated with PM10, SO₂ and NO₂ concentrations (r=0.780, 0.601, 0.658, P < 0.05), and negatively correlated with relative humidity and temperature (r=-0.015, -0.270, P < 0.05). There was a lagged effect of PM2.5 exposure on daily visits, with the greatest effect occurring with a 1-day lag. The results of the single-pollutant model showed a daily visit ER (95%CI) value of 4.251% (0.824%-7.796%) for each 10 μg/m³ increase in PM2.5 concentration. The two-pollutant model was established by introducing SO₂, NO₂ and O₃ on the same day, respectively, and the daily visit ER (95%CI) values for each 10 μg/m³ increase in atmospheric PM2.5 concentration in PM2.5+SO₂, PM2.5+NO₂ and PM2.5+O₃ (95%CI) were 5.442% (0.747%-10.355%), 5.371% (1.378%-9.522%) and 4.535% (1.481%-7.682%), respectively.

ConclusionsExposure to high atmospheric PM2.5 concentration may affect and increase the daily visits of children with wheezing.