The lag-effects of meteorological factors and air pollutants on child respiratory diseases in Fuzhou, China

Background The effects of meteorological factors and air pollutants on re-spiratory diseases (RDs) were various in different populations according to the demographic characteristics, and children were considered a vulnerable population. Previous studies were mainly based in cities with serious air pol-lution. This study aimed to qualify the lag effects of meteorological factors and air pollution on respiratory diseases among children under 18 years old in Fuzhou. Methods Meteorological data, air pollutants concentrations and hospital ad-mission data of Fujian Maternity and Child Health Hospital between 2015 and 2019 were collected. A Distributed Lag Nonlinear Model (DLNM) was used to evaluate the nonlinear and lagged effect of meteorological factors and air pollutants on daily RDs number. A subgroup analysis was also conducted to evaluate the effect on different sex groups and age groups.Results A total number of 796125 RDs visits was included during the study period. For meteorological factors, lower mean temperature and relative hu-midity were significantly associated with daily RDs number (peak relative risk (RR) = 1.032 (95% confidence interval (CI) = 1.011-1.053) and 1.021 (95% CI = 1.013-1.029)), while lower wind speed showed a significant asso-ciation at low range (peak RR= 0.995 (95% CI = 0.992-0.999)). Temperature warming was a significant protective factor for RDs (peak RR= 0.989 (95% CI = 0.986-0.993)). For air pollutants, SO2, NO2, PM10 and PM2.5 were all significantly associated with RDs (peak RR= 1.028 (95% CI = 1.022-1.035), 1.024 (95% CI = 1.013-1.034), 1.036 (95% CI = 1.025-1.047), 1.028 (95% CI = 1.019-1.037)), and the relationship had no threshold. The estimated RR and peak lag day did not change extremely between subgroups. Conclusions The findings provide statistical evidence for the prevention of child RDs. In addition, our findings suggested that even at low concentra-tions, air pollutants still have negative effects on the respiratory system.