Association Between Meteorological Factors And Mortality In Hulunbuir,Inner Mongolia

Objective:The main purpose of this study was to analyze the daily average temperature and humidity on the risk of non-accidental death,circulatory system and respiratory system disease death,explore the total effect and cumulative lag effect of different levels of temperature and humidity on 7 kinds of main causes of death of residents,and determine the minimum effect temperature and humidity value of the total effect of diseases of each cause of death.Through quantitative analysis of the cumulative hysteresis effect between extreme temperature and humidity values and different gender and age groups,the population with the greatest risk of death can be identified,and targeted protection measures can be provided for sensitive populations.Methods:Meteorological data,air pollutant data and residents’cause of death were collected in Hulunbuir during 2015-2019.This paper used the generalized additive model combined with the time series analysis method of distributed lag nonlinear model to explore the effect of meteorological factors（temperature and humidity）on the death of three major categories and four minor causes of residents in Hulunbuir during 2015-2019.Temperature and humidity were classified according to the percentiles P₁,P₁₀,P₂₅,P₇₅,P₉₀and P₉₉,and the total effect and cumulative lag effect of temperature and humidity levels on the causes of death of residents were studied respectively.Stratified analysis was carried out to analyze the population with the greatest effect of extreme temperature and humidity on each cause of death.Results 1.Effect relationship between temperature and resident causes of death:1.1 There is a nonlinear relationship between temperature and daily resident deaths by cause of death.1.2P₂₅（-17.20℃）temperature had a lag effect on death from non-accidental diseases,circulatory diseases,acute myocardial infarction and cerebral infarction,and an acute effect trend on respiratory diseases,COPD and pneumonia.It has cumulative lag effect on non-accidental death,circulatory disease,acute myocardial infarction and cerebral infarction.P₇₅（14.90℃）temperature had an acute effect on non-accidental death and circulatory disease,but had a delayed effect on the risk of death from acute myocardial infarction,respiratory disease,COPD and pneumonia.It has cumulative lag effect on respiratory diseases,COPD and pneumonia.1.3 Extreme Cold temperature（P₁:-33.69℃）had a mortality effect only on respiratory diseases,COPD and pneumonia,and the maximum RR values were 2.084（1.494,2.907）,2.385（1.493,3.810）and 4.068（1.662,9.959）within 30 days lag,respectively.Cold temperature(P₁₀:-25.10℃)was associated with the death of other fatal diseases except acute myocardial infarction,cerebral infarction and pneumonia,and all of them had significant effects after 0-30 days lag（P<0.05）.Thermal temperature(P₉₉:24.82℃)only had significant death effects on respiratory diseases,COPD and pneumonia.The maximum effect of respiratory diseases and COPD was 2.748（1.690,4.469）and 2.172（1.056,4.470）in 0-21days,respectively.The maximum effect of pneumonia was reached at 0-30 days.RR was13.234（3.225,54.299）.1.4 Extreme cold temperature（P₁:-33.69℃）had statistically significant effects on non-accidental death≥65 years old,female respiratory disease,male acute myocardial infarction,female and≥65 years old COPD and pneumonia.The cold effect of female pneumonia（P₁:-33.69℃）and cold temperature(P₁₀:-25.10℃))was the largest effect of all causes of death.RR at 0-30 days lagged was 9.729（2.234,42.375）（P<0.05）.Cold temperature was statistically significant for circulatory disease,acute myocardial infarction and COPD in women and≥65 years old,non-accidental death in women and<65 years old,respiratory disease in men and≥65 years old,and pneumonia in men and<65 years old.The thermal effect was significant in males and<65 years old population with respiratory disease,<65 years old population with COPD,males and<65 years old population with pneumonia(P₉₉:24.82℃),and the mild thermal temperature(P₉₀:19.70℃)had no significant risk of death for each cause of death（P<0.05）.2.Effect relationship between humidity and resident cause of death:2.1 There is a nonlinear relationship between humidity and the number of daily resident deaths of each cause of death,and both low humidity and high humidity have death effect.2.2 P₂₅（58.8%）had a lag effect on non-accidental death,acute myocardial infarction and respiratory disease,and had an acute effect on circulatory disease,cerebral infarction,COPD and pneumonia.There was a cumulative lag effect on non-accidental death,acute myocardial infarction and respiratory disease.The humidity of P₇₅（75.3%）had delayed effect on the other 5 causes of death except acute myocardial infarction and pneumonia,and had short-term acute effect on the death effect of acute myocardial infarction and pneumonia.Cumulative lag effect on non-accidental death,respiratory disease and COPD.2.3 At low humidity(very low humidity（P₁:27.72%）and slightly low humidity(P₁₀:45%)),there was a significant risk of death only for non-accidental deaths.The maximum RR of death at very low humidity and slightly low humidity was 1.104（1.008,1.209）（0-7 days）and 1.068（1.006,1.134）（0-15 days）,respectively.High humidity(very high humidity P₉₉:91.87%,slightly high humidity P₉₀:81%)had no significant death effect.2.4 Very low humidity（P₁:27.72%）had a significant effect on non-accidental death and circulatory disease death in female,female and≥65 years old respiratory disease death population,and only had a death effect on male non-accidental death and circulatory disease population and female COPD population.Extremely high humidity(P₉₉:91.87%)only had death effect on female cerebral infarction death population,but no significant death effect on other population.Conclusions:Low temperature and high temperature,low humidity and high humidity were associated with the death risk of residents,and the death effect was non-linear trend.Extreme cold and hot temperatures had significant mortality effects only with respiratory diseases,COPD and pneumonia,while low humidity（very low humidity and slightly low humidity）had significant mortality risks only with non-accidental deaths.Extreme cold temperature was significantly associated with non-accidental death≥65 years old,acute myocardial infarction in males,respiratory disease in females,COPD and pneumonia in females≥65 years old.The thermal temperature has significant effect on male respiratory disease and pneumonia<65years old and COPD<65 years old.Extremely low humidity had significant death effect only on female non-accidental death,circulatory system disease and respiratory system disease,and extremely high humidity was related to female cerebral infarction death.The results of this study can provide a reliable basis for relevant health administration departments to formulate protection policies and relevant measures for sensitive population,so as to minimize the harmful effects of adverse meteorological factors on population.