Home Ventilation And Its Associations With Asthma And Allergies Among Preschool Children In Chongqing

Children’s asthma and allergic dieases, which are noted to be related to indoor environment, have performed as a prevalent phenonmena. With the aim of analyzing the impact of indoor environmental facors on children’s asthma and allergies, clarifying dominant factors and improving indoor environment, Chind, Children, Home, Health(CCHH) study was carried out.This research is part of first stage of CCHH, which has focused on the correlation between ventilation status and children’s astham and allergic dieases in Chongqing. The impact of indoor odor sensation, dampness, new furniture and re-decoration, smoke as well as pet keeping under different habbits of opening windows on children’s asthma and allergic dieases was analyzied by pearson’s chi-squared test and multivariate logistic regression. Secondly, the relationship between indoor air exchange rate and children’s asthma and allergic dieases was further obtained through in-site investigation and air exchange rate calculated from tested CO2 concentration in residental apartments.The analysis of 4720 samples(children from 3-6 years old) by cross-sectional study has shown that the rates of children who have symptoms, e.g. wheeze in the last past year, rhinitis ever, rhinitis in the past year and eczema ever are relatively high(more than 20%). There is obvious relationship between children’ asthma and allergic dieases and gender, age as well as family allergic history. Specificly, the rate of boys is higher than girls and the rate decreases significantly with respect to the increase of age. Moreover, children have higher possibilities of getting asthma or allergic dieases when they have family allergic history. Apartments in Chongqing are well-ventilated in all seasons except for winter. The rate of opening windows in winter is less than 36%. Risk of children’s asthma and allergic dieases can be decreased significantly as it results to dereasing indoor odor sensation and dampness. Additionally, there is a obvious difference between opening and not opening windows when new furniture, re-decoration, smoking and pet-keeping are taken into consideration. With refer to epidimeologic reaserch method, about 10-20% of children who suffer asthma and allergic dieases can be contributed to insufficient ventialtion.The air exchange rate obtained by CO2 trace gas has indicated that the proportion of bedrooms and living rooms which had not reached the benchmark of minimum ventilation rate at night was 53.8% and 55.8%, respectively. In the day time, most apartments could fulfill the basic requirement of ventilation. There is certain relation between ventilation rate and odor sensation as well as indoor dampness, especially for bedrooms at night. Furthermore, the percentage of children influnced by asthma and allergic dieases could be increased when air exchange rate was lower than the minimum requirement. On the contrary, higher ventilation rate performed as a protective factor for children’s asthma and allergic dieases.