Abstract: Objective To understand effect of air pollutant concentration on first aid visits of residents in Guangzhou, so as to improve the ability and control of early prevention of air pollution related diseases. Methods A semi-parametric generalized additive model （GAM） was used to examine the relationship between the concentrations of SO₂, NO₂, CO, PM_2.5, PM₁₀, O_3-1h and O_3-8h in the atmosphere and emergency department visits due to the first aid from January 1 to December 31, 2017 in Guangzhou after controlling long time trend, the “day of the week” effect and confounding meteorological factors. Results In 2017, the main pollutants in the air was CO in Guangzhou. The concentrations of PM_2.5, PM₁₀, NO₂ and CO in the air were highest in December and lowest in June, concentrations of O₃ （O_3-1h and O_3-8h） were highest in August and lowest in January, and concentration of SO₂ was highest in December and lowest in January. In 2017, the daily average number of first aid cases was 405.08, and the daily number of first aid cases was 26.57 for respiratory diseases and 38.44 for cardiovascular diseases. GAM analysis showed that each 10-unit increment in SO₂, NO₂, and CO concentrations was associated with an increment in the total number of first aid cases at the same day and within lag3 days. The increase in SO₂ concentration at the same day and three-day lag time had the greatest impact on the number of emergency department visits due to first aid for respiratory diseases, for every 10-unit increment in SO₂ concentration, the number of first aid cases for respiratory diseases increased by 8.01% and 9.62%, respectively. Conclusion Air pollution was associated with increased risk of emergency visits due to the first aid, especially for the respiratory diseases in Guangzhou. The health protection for the sensitive population should be emphasized in moderate and heavy pollution weather.

Key words: Air pollutants, First aid, Time series study