Effects of outdoor air fine particle (PM_2.5) pollution on respiratory diseases in children in Jiangbei district of Ningbo

ObjectiveTo evaluate the effect of outdoor air fine particle (PM_2.5) on pediatric outpatient visits due to respiratory diseases in Jiangbei district of Ningbo.

MethodsData of pediatric outpatient visits due to respiratory diseases in hospitals of Jiangbei district from 2014 to 2017 was collected, and the air pollution and meteorological data during the same period were collected too. The relative risk was calculated by using the distributed lag nonlinear model.

ResultsA total of 984 941 pediatric outpatient visits due to respiratory diseases were recorded in Jiangbei district from 2014 to 2017. The effect of PM_2.5 increased slowly at low concentration, but increased quickly at high concentration. The effect of PM_2.5 at the same concentration decreased with the increase of lag days. The lag days of PM_2.5 effects at different concentrations were different, and the longest could be 20 days. The effects of PM_2.5 on boys and girls showed no difference, but the effects were different on age groups, the effects on 3 and 4–6 years old children were strongest. PM_2.5 was more likely to cause acute upper respiratory tract infection before 10 lag days, but after 10 lag days, the effect on chronic lower respiratory diseases was stronger and longer.

ConclusionThe rise of PM_2.5 concentration would increase the pediatric outpatient visits due to respiratory diseases and has a lag effect. A PM_2.5 concentration has different health hazards to children with different age, but there is no gender specific difference. PM_2.5 is more likely to cause acute upper respiratory tract infection in early stage, but the effect on chronic lower respiratory tract disease is longer.