The Influence Of Oxidative Potential, Components And Sources Of PM_2.5 On Hospital Outpatient Visits

Objective:PM2.5 mass concentration levels have been extensively used in population health studies,and its composition is complex and an important factor in health hazards,but there is still a lack of research.The health effects of PM2.5 may vary depending on the source.Therefore,this study analyzed the relationship between PM2.5 mass concentration,oxidation potential,components and sources,and the number of daily hospital outpatient visits,hospital admissions,respiratory medicine outpatient visits and cardiovascular medicine outpatient visits,in order to investigate the impact of PM2.5 oxidation potential,components and sources on population health,and to provide a reference for the prevention and control of PM2.5 health hazards.Methods:In this study,PM2.5 data were sampled for 15 days in four time periods,October 2015,December 2015,16 April-15 May 2016 and August 2016,for a total of 60 days.The PM2.5 mass concentration levels were measured using the weighing method,the oxidation potential levels of PM2.5 were measured using the dithiothreitol(DTT)method,the components of PM2.5 were measured using the ion chromatography method and inductively coupled plasma mass spectrometry(ICP-MS)instrument,and the proportion of different sources of PM2.5 was obtained using the pollutant emission inventory accounting method;the sampling period was also collected from Jiaozuo City The data on the daily number of registered patients and daily hospital admissions in each department(including neurology,cardiovascular medicine,respiratory medicine,orthopedics,pediatrics,etc.)of the Second People’s Hospital were also collected during the sampling period.Finally,Poisson regression and lag analysis were used to analyze the relative risk ratios(RRs)between the oxidative potential,components and sources and the total number of hospital outpatient visits,hospital admissions,respiratory outpatient visits and cardiovascular outpatient visits per day,on the basis of which the health effects of PM2.5 oxidative potential,components and sources were assessed.The statistical analysis of the above data was performed using the R 4.1.2 software package.Results:1.the total number of outpatient registrations in this hospital during the sampling period was 61,224,with an average of 1020.4 per day;the total number of inpatient admissions was 5,229,with an average of 87.2 per day;the total number of respiratory medicine outpatient registrations was 1,486,with an average of 24.77 per day;the number of cardiovascular medicine outpatient registrations was 1,401,with an average of 23.35 per day;2.the DTTm increased by 10 units,the RR for total outpatient visits was 1.00689(95%CI:1.004291,1.009489);the RR for cardiovascular medicine outpatient visits was 1.000259(95%CI:1.000008,1.00051)for a 10-unit increase in DTTv;3.PM2.5 mass concentration for total outpatient visits,inpatient admissions and respiratory RR values for medical outpatient visits increased with increasing lag time;DTTm showed a gradual decreasing trend for total outpatient visits,inpatient and respiratory outpatient visits,while cardiovascular outpatient visits reached the maximum lag at Lag5 with an RR value of 1.012055(95%CI:0.7251071,1.420943);DTTv For inpatient and respiratory medicine outpatient visits the trend in RR values was progressively decreasing,with statistically significant results for inpatient admissions.The RR values for both general outpatient visits and cardiovascular medicine outpatient visits were greatest for Lag3,with statistically significant results for general outpatient visits;4.There was a significant lag in the carbonaceous fraction,watersoluble ions,and the results were statistically significant.;5.Considering the combined effect of oxidative potential and components,for general outpatient visits,the addition of carbonaceous fractions(OC and EC)decreased the RR value of oxidative potential and increased with the addition of water-soluble ions;for the respiratory medicine clinic and cardiovascular medicine clinic,the addition of organic carbon(OC)and inorganic carbon(EC)resulted in a smaller RR value of oxidative potential.For the respiratory medicine clinic,nitrate ions and ammonium ions lead to an increase in the RR value of the oxidation potential;for the cardiovascular medicine clinic,water-soluble ions increase the RR value of the oxidation potential,but the results are not statistically significant;6.The results of the source analysis show that for the general clinic visits,respiratory medicine clinic and cardiovascular medicine clinic,mobile sources have the highest RR values,followed by biomass combustion sources,stationary sources dust sources,and process sources;for hospital admissions,process sources had the highest RR values,followed by dust sources,stationary sources,biomass combustion,and mobile sources.Conclusion:1.DTTm was a risk factor for total daily outpatient visits and DTTv was a risk factor for cardiovascular medicine outpatient visits;2.Carbonaceous fractions and water-soluble ions had a greater effect than metals on total outpatient visits and hospital admissions,etc.;3.The carbonaceous component enhances the RR value of the oxidation potential,and the water-soluble ions reduce its RR value.;4.The influence of PM2.5 from mobile sources and biomass burning on outpatient visits was greater,and the effect of cardiovascular medicine and respiratory medicine outpatient visits was more significant.