| Objective:The purpose of this study is to explore the short-term effects of meteorological factors and air pollutants on HFMD,and to provide reference for the prevention and early warning of HFMD in Shenzhen.Methods:Based on the daily monitoring data of HFMD in Shenzhen from 2013 to 2016 and the meteorological and pollutant data of the same period,the non-linear and delayed effects of meteorological factors and air pollutants on HFMD were evaluated by using the distributed lag non-linear model.The single factor and multi-factor model analysis were carried out successively,and the seasonal analysis and subgroup analysis were carried out in different seasons and populations.Results:1.From 2013 to 2016,205531 cases of HFMD were reported in Shenzhen.The incidence of HFMD in male was higher than that in female(sex ratio:1.52:1).94.54%of HFMD cases were children aged 5 years and below.The incidence of HFMD increased year by year;2.The results of single factor model showed that there was no correlation between rainfall,SO2,NO2,CO and HFMD;and temperature,relative humidity,wind speed,sunshine duration,03,PM2.5 and PM10 were associated with HFMD;3.The results of multi-factor model showed that the effect of temperature was approximately inverted V-shaped peaking at 28.8 ℃ The lag effect of extremely high temperature(P95:30.1℃)turned significant at lag9 day,and its cumulative lag effect peaked at lag14 day;With the increase of relative humidity,the risk of HFMD gradually increased,and the cumulative lag effect of extremely low relative humidity(P5:49%)peaked at lag14 day;With the decrease of wind speed,the risk of HFMD increased gradually.When the wind speed dropped below 2m/s,the risk of HFMD increased sharply.The lag effect of extremely low and extremely high wind speed(P5:1m/s;P95:3.4m/s)both turned significant at lagl day,and their cumulative effect both peaked at lag14 day;Sunshine duration had no relationship with HFMD;The effect of O3 was similarly V-shaped,56.3-111.4μg/m3 03 showed significant protective effect,peaking at 88.6μg/m3.The lag effect of extremely high O3(P95:97.0μg/m3)turned significant at lag2 day,and peaked at the lag6 day,and its cumulative effect peaked at lag 14 day;the effect of PM2.5 was similar to "W" shape,when the concentration of PM2.5 was 7.5-28.2 μg/m3,45.4-96.3μg/m3,it showed significant protective effect.The lag effect of extremely low PM2.5(P5:10.4μg/m3)turned significant at lag2 day,and reached the maximum at lag6 day.The lag effect of extremely high PM2.5(P95:72.1μg/m3)turned significant and peaked at lag0 day,with short duration.The cumulative effect of extremely low and extremely high PM2.5 both peaked at lag 14 day.The effect of PM10 was also similar to "W”shape,21.1-45.1μg/m3,86.3-115.1μg/m3 PM10 showed significant protective effect.The lag effect of extremely low PM10(P5:20.8μg/m3)turned significant from lag3 to lag5 day,and its cumulative effect peaked at lag10 day.The lag effect of extremely high PM10(P95:110.0μg/m3)was nonsignificant at every lag day,and its cumulative effect turned significant at lag 14 day.Summarized as follows:extremely high temperature(RR=1.33,95%CI:1.10-1.59)and extremely low wind speed(RR=1.28,95%CI:1.10-1.50)were the risk factors of HFMD,extremely low relative humidity(RR=0.78,95%CI:0.64-0.95),extremely high wind speed(RR=0.78,95%CI:0.66-0.92),extremely high O3(RR=0.75,95%CI:0.63-0.89),extremely low and extremely high PM2.5(RR=0.82,95%CI:0.71-0.94;RR=0.71,95%CI:0.58-0.88),extremely low and extremely high PM10(RR=0.87,95%CI:0.78-0.98;RR=0.79,95%CI:0.64-0.98)were the protective factors of HFMD;4.Seasonal analysis showed that the results of seasonal analysis of temperature,relative humidity,wind speed and O3 were similar with that of annual analysis.The extremely low temperature(P5:13.5℃)showed significant protective effect in cold season(November to April)(RR=0.20,95%CI:0.11-0.37),and the extremely high relative humidity(P95:92%)showed significant harmful effect in warm season(May to October)(RR=1.36,95%CI:1.06-1.76).The extremely long sunshine duration(P95:10.8h/d)showed harmful effect in warm season(RR=1.37,95%CI:1.07-1.77),and protective effect in cold season(RR=0.32,95%CI:0.14-0.75).The protective effect of low PM2.5(14.8-28.2 μg/m3)was still significant in warm season,but the effect of extremely high PM2.5 was no longer significant.The effects of PM10 were no longer significant in cold and warm seasons.5.The results of subgroup analysis showed that compared with other age groups,children under one year were more susceptible to the above risk factors and protective factors;for different genders,the harmful effect of extremely high temperature was greater on male,the protective effect of extremely high O3 and extremely low PM2.5 was greater on female,and the protective effects of extremely low and extremely high PM10 were only significant for female,apart from this,the gender difference of other effects was not obvious.Conclusions:From 2013 to 2016,the incidence of HFMD in Shenzhen showed an overall upward trend;temperature,relative humidity,wind speed,sunshine duration,O3,PM2.5 and PM10 had nonlinear lag effects on HFMD,which showed differences in different season,gender and age.These findings contribute to the development of an environment-based early warning system for HFMD,which has certain public health significance... |
