The Characteristics Of PM_2.5 And The Relationship Between PM_2.5 And Children Health, In Urban Areas In Nanchang

Objective: This study aimed to understand the characteristics of PM_2.5 and the concentration of polycyclic aromatic hydrocarbons, metallic elements and water-soluble inorganic ions in urban areas in Nanchang; In order to provide a scientific basis for the prevention of health hazard, this study aimed to explore the association between PM_2.5 pollution and hospital pediatrics outpatient visits for total and cause-specific diseases in urban areas in Nanchang. Method:?1? Daily counts of PM_2.5 from Jan 1 to Dec 31, 2015, were obtained from Qingyunpu area, in urban areas in Nanchang. This study monitored the concentrations of PM_2.5 during 10 to 16 per month. Then, we tested the content of 16 kinds of polycyclic aromatic hydrocarbons by liquid chromatography, and tested determine the content of 12 kinds of metal elements by inductively coupled plasma-mass spectrometry,and using ion chromatography to test the content of four kinds of water-soluble inorganic ions. Finally, using factor analysis explored to the source of PM_2.5's component.?2? Daily counts of hospital pediatrics admissons in the children's hospital of Jiangxi province from 2014 to 2015, were obtained from the hospital management system. Concurrently, data on PM_2.5 and meteorology were collected from the Nanchang Environmental Protection Bureau, including 6 ambient air quality monitoring stations. We used semiparametric generalized additive model?GAM?, to explore the association between PM_2.5 pollution and hospital pediatrics outpatient visits for total and causespecific diseases in urban areas in Nanchang, after controlling for confounding factors including the trend of time, the effects of week, meteorological factors etc. Results:?1? The results of sampling monitoring showed that PM_2.5 pollution presented "J" type curve distribution in urban areas in Nanchang, which is “winter > autumn > spring > summer”. Daily average concentration of PM_2.5 was 88.77 ?g/m3?24 392 ?g/m3?.The environmental protection department monitoring data automatically, on January 1, 2014 to December 31, 2015, nanchang urban area of PM_2.5 value of 63.04 ?g/m3, the range of 7.00 347.90 ?g/m3, winter > aut?mn > spring > s?mmer, a "J" type curve distribution, monitoring and sampling are basically identical.?2? The concentration of ?PAHs in PM_2.5 was 15.274 ng/m3?2.252 120.559 ng/m3?, but the Acc was not checked out, while other 15 kinds of the content of PAHs in the order was BbF > IcdP > BghiP > BaP > Pyr > Flt > CRH > Bk F > Ba A> Phe > DBA > Nap > Ant > help > Any; In the n?mber of benzene ring PAHs contents in different order 4 ring > 5 loops > 2 > 3 ring > 6;Seasonal trends of PM_2.5 ?PAHs contents in existence, winter > aut?mn > spring > s?mmer, check out the content of 15 kinds of PAHs in winter is significantly greater than other seasons.?3? The concentrations of metal elements in PM_2.5 was 714.407 ng/m3?283.846 1110.203 ng/m3?, and the order of the concentrations of metal elements was Al > Pb > As Mn > Cr > Se > Sb > Ni > Cd > Hg > Ti > Be; 12 kinds of metal elements in the four seasons had no significant difference.?4? The average concentrations of total water-soluble inorganic ions in PM_2.5 was 18.118 ?g/m3?1.967 44.875 ?g/m3?; The order of four kinds of water-soluble inorganic ion content was SO42- > NH4+ > NO3- > Cl-. The average concentrations of inorganic water-soluble ions in winter was significantly higher than other seasons, the order of the content of total soluble inorganic ion was winter > autumn > summer > spring, and the content of sulphate was always highest in all seasons.?5? PM_2.5 source analysis showed that the sources of PAHs pollution sources were gasoline, automobile exhaust; the pollution sources of metal elements were industrial metallurgical dust, coal dust, construction dust, soil dust, exhaust; 4 kinds of watersoluble inorganic ion pollution were from industrial metallurgical dust and coal dust; The main sources of PM_2.5 pollution were coal, automobile exhaust and metallurgical industry.?6? The results of GAM model analysis showed that pediatric respiratory admissons and the maximum of the total hospital pediatrics admissons were lags 0²d, and the effect of maximum cumulative lag was 5d; Every 10 ?g/m3 increase in PM_2.5 concentration at lag0 was associated with an increase in pediatric respiratory admissons and the total hospital pediatrics admissons, as follows 0.28%?95% CI: 0.22% 0.34%? for the total hospital pediatrics admissons, and 0.43%?95% CI: 0.20% 0.66%? for the pediatric respiratory admissons. Conclusion:PM_2.5 pollution was mild polluted in urban areas in Nanchang, and the main pollution sources were coal, automobile exhaust, metallurgical industry. PM_2.5 was significantly associated with the increase of the pediatric respiratory admissons and the total of hospital pediatric admissons. Government should strengthen the prevention and control of the harm of PM_2.5.