A Prospective Study On Relationship Between Air Pollution And Development Of Children's Lung Function In Anshan City

ObjectiveTo study the relationship between ambient air pollution and lung function prospectively with an emphasis on the effect of air pollution on lung function development among the children.MethodsThe polluted and clean area were categorized according to the monitoring data of TSP,SO₂ and NO_X from 1991 to 1998 in Anshan city.Pupils around age of 10 in two primary schools located at polluted or clean area(less than 1.5km from the air pollution monitoring set) were selected with cluster sampling for the two-year follow-up study. Pulmonary function test with CHESTAC-â…¡was conducted among the pupils at the beginning,middle and the end of the study.The standard questionnaire for respiratory disease(American Thoracic Society) with modification was adopted for collectting information on respiratory symptoms and relevant factors.The data collected was analyzed with SPSS13.0.The predicting equation was formulated for calculating adjusted average values of FVC,FEV₁,MMEF and PEF.The increase rates of FVC, FEV₁,MMEF and PEF were analyzed with liner regression and relevant factors to development of FVC and FEV₁ were explored with logistic regression.Results1.Overall 421 pupils were selected and 392 eligible questionnaire were collected with a response rate of 93.11%.The 379 students residing in the polluted or clean area over 3 years were assigned as study subjects and 342(90.24%) completed all 3 pulmonary function testing.The loss rate of follow-up was 9.88%for subjects in polluted area and 9.66%for clean area.A total of 4564 lung function measurements were gathered with an average measurements of 13.35±1.97 per subject in the study. 2.Continuous yearly lung function measuremt from 1999 to 2001 showed that the means of FVC,FEV₁,MMEF and PEF for subjects in clean area were higher than that of in polluted area.For yearly measument of 2000,the mean PEF of subjects in clean area was significantly higher than that of polluted area(p＜0.05);the means of FEV₁, MMEF for girls in clean area were significantly higher than that of polluted area(p＜0.05).The mean FVC of subjects in clean area was significantly higher than that of polluted area(p＜0.05) and the mean PEF of boys in clean area was significantly higher than that of polluted area(p＜0.05).The mean of yearly FVC increment of boys and yealy FVC,FEV₁ increment of girls in clean area were significantly higher than that of in polluted area.3.There was a difference in adjusted means for the subjects' lung function between clean and polluted area.By yealy lung function measurement,adjusted means of FVC,FEV₁,MMEF and PEF of subjects in clean area were generally higher than that of in polluted area except for lower FEV₁ of boys,MMEF and PEF of girls in 1999, and lower MMEF of boys,FVC of girls in 2000.The results indicated that air pollution affected the lung function development of the subjects.4.The FVC increase rate of subjects in clean area was higher than that of in polluted area(278.13 vs 219.68 ml/yr for boys,222.76 vs 201.82 ml/yr for girls).The increase rate of FEV₁ of boys in clean area was higher than that in pollution area but the girls in clean area had a lower FEV₁ increment than girls in pollution area(253.12 vs 267.82 ml/yr).For girls,the MMFF increase rate of clean area was higher than that of polluted area(476.03 vs 329.78 ml/yr) but for boys the MMFF increase rate of clean area was lower than that of polluted area(235.03 vs 253.36 ml/yr).The rate of PEF increment for subjects in clean area was higher than that of polluted area(754.08 vs 529.30 ml/yr for boys,972.23 vs 781.83 ml/yr for girls).All yearly lung function increase rates of girls were higher than that of boys except for FVC perhaps owing to early physical development of girl.5.The hight increment＜11cm and weight increment＜8kg within 2 years were were factors inhibiting FVC development.Passive smoking and living in polluted area were inhibiting factors for FVC development and heating with coal stove was a factor inhibiting FEV₁ development.Conclusions 1.The FVC,FEV₁,MMEF and PEF of children in polluted area were lower than that in clean area.The results indicated air pollution can exert adverse effect on lung function of children.2.The air pollution can inhibit lung function development of children.3.The lung function development was positively correlative with the increase of height and weight growth in children.4.Passive smoking may slow down FVC development rate and heating with coal stove was a major risk factor for FEV₁ development in children.