Acute Effects Of Carbonaceous Components And Their Proportions Change In PM₁₀ On FEV₁ Of Healthy College Students

Objective To evaluate the acute effects of carbonaceous components(TC,EC and OC)volume and their proportions change in inhalable particles(PM10)on forced expiratory volume in one second(FEV1)of healthy college students.Methods A panel of 37 college students at Wuhan were chosen and the investigation was divided into four periods:29 October 2009-11 November 2009(autumn),23 December 2009-5 January 2010(winter),24 March 2010-6 April 2010(spring)and 24 July 2010-6 August 2010(summer).Each study period lasted 14 days.Daily morning and evening FEV1 were measured by subjects themselves.Meanwhile,the daily data of PM10,carbonaceous components,temperature,and relative humidity were collected.Linear mixed-effects models were used to quantitatively estimate the influence of carbonaceous components and their proportional change in PM10 on FEV1.Results(1)The concentration of PM10 and it's carbonaceous components(TC,EC,OC)indoor were lower than outdoor in different seasons.On the contrary,the proportion of carbonaceous components(TC/PM10,EC/PM10,OC/PM10)and OC/EC in the PM10 were higher than that in the outdoors;(2)The adverse effect of indoor pollutants on evening FEV1 of healthy college students was higher than outdoor.Among which,the indoor carbon components(TC,EC,OC)had the most adverse effect on evening FEV1 in autumn,After controlling the influence of PM10 on the carbonaceous components,TC had the greatest effect on evening FEV1 at 3 days of accumulated lag(lag0-3),Each 10?g/m3 increase in TC was associated with the decrease of FEV1 of 2.17%(95%Cl:0.25%?4.09%);EC had the greatest effect on evening FEV1 at 3 days of accumulated lag(lag0?3),Each lOpg/m3 increase in EC was associated with the decrease of FEV1 of 4.81%(95%CI:0.02%?9.61%);OC had the greatest effect on evening FEV1 at 2 days lag(lag2),Each 10?g/m3 increase in OC was associated with the decrease of FEV1 of 1.07%(95%Cl:0.12%?2.02%);(3)The proportion change of carbonaceous components(TC/PM10,EC/PM10,OC/PM10)indoor had the most adverse effects on evening FEV1 in spring.After controlling the influence of PM10 on the proportion change of carbonaceous components,TC/PM10,EC/PM10 and OC/PM10 had the greatest effect on evening FEV1 at 3 days of accumulated lag(lag0?3),Each IQR increase in TC/PM10,EC/PM10 and OC/PM10 was associated with the decrease of FEV1 of 5.16%(95%CI:0.69%?9.62%),5.80%(95%CI:0.34%?11.27%)and 3.29%(95%CI:0.08%?6.50%),respectively.There was no significant difference in the effect of OC/EC on evening FEV1 in any season(P>0.05).Conclusions(1)The change of carbonaceous components concentration and their proportions in PM10 had acute adverse effect on evening FEV1 of healthy college students.varying in effects by different seasons.(2)The effect of carbon components and its proportions change in PM10 on evening lung function of healthy adults indoor was stronger than that of outdoor;(3)The acute adverse effect of carbonaceous component EC on evening lung function in healthy adults was higher than that of OC.