[The effect of rural exposure on allergic asthma in Anhui province]

To establish the evidence of exposure to rural areas would reduce the risk of atopic asthma and sensitization.

A cross-sectional survey was carried out in 2986 school-age children and their parents completed standardized questionnaires on atopic asthma and sensitization, wheezing. A radioallergosorbent technique-fluorescence enzyme immunoassay (RAST-FEIA) was used to measure the level of specific IgE in serum.

The risks of atopic and non-atopic asthma (OR = 0.45, 95% CI:0.13-0.96 and OR=0.41, 95% CI:0.15-0.95), atopic sensitization. and wheezing (OR= 0.32, 95% CI:0.11-0.62; OR =0.44, 95% CI:0.13-0.91) were lower in subjects living in village area compared with those living in towns. The risks of atopic asthma and sensitization were lower in subjects exposed to stables in first year (OR=0.23, 95% CI:0.04-0.91 and OR =0.32, 95% CI:0.17-0.78) and were lowest in those exposed continually until the age of 6 (OR = 0.21, 95% CI:0.03-0.87 and OR = 0.31, 95% CI:0.15-0.78) compared with those non-exposed in the first 6 years.

Exposure to rural environment might have a protective effect on children against atopic asthma and sensitization while continual exposure could strengthen the effects.