Relationship between the concentration of formaldehyde in the air and asthma in children: a meta-analysis.

The aim of our study is to systematically assess the impact of formaldehyde in the air on asthma. Publications from year 1995 to 2014 on asthma were retrieved from PubMed, online Chinese periodical full-text databases of Chongqing VIP, China National Knowledge Index (CNKI) and Wan fang. Meta-Analyst was used to analyze the relationship between the concentration of formaldehyde and asthma in children. After evaluating the quality of the literature, 8 papers were finally included in our study, and the total sample sizes were 718, including the case group 362 and control group 356. The heterogeneous text display P=0.000, I(2)=0.876, Q=40.451, Meta-analyst finding showed that the pooled weighted mean difference (WMD) in concentration of formaldehyde is 0.021 (95% CI: 0.009-0.033). Children will have a larger probability to get asthma due to the higher level of formaldehyde. Therefore, we should reduce the level of formaldehyde in the air, which can protect our children.