Volatile Organic Compounds in Exhaled Air of Asthma Children

The objective of this study was to clarify the differences of volatile organic compounds (VOCs) in exhaled air between the asthmatic children and the non-asthmatic children. This article also discusses the correlation between the VOCs and several different indoor environments with questionnaire and statistics.
This was a cross-sectional study and purposive selection was taken. All cases came from the out-patient departments of pediatrics and ophthalmology of a medical center in northern Taiwan. There were 60 children total and the range of age was from 4 to 12 years old. 30 of them were asthmatic and others were non-asthmatic. Basic demographic data, life styles, indoor environments and the conditions of asthma were all collected by questionnaire. The exhaled air and the indoor air collected at the out-patient departments of pediatrics and ophthalmology were analyzed by GC/MS and semiquantitative analyses were also done.
We focused on 64 kinds of VOCs, such as hydrocarbon, ketone, aldehyde, alcohol, furan, aromatics, sulfur compounds, chlorinate species, nitrogen containing species, etc. The results of the experiment were analyzed by statistical software SPSS13.0. 12 kinds of VOCs showed significant differences in alveolar gradients between the two groups (P＜0.05). 10 out of these 12 kinds of VOCs showed significant differences (P＜0.05) with regard to the means of transport to school, parents smoke, family handiwork, pets, upholsteries, dust, the frequency of cooking, aromatic and mosquito coil incense usage by multiple regression.
This research has demonstrated that asthmatic children exhaled 2-methyl-1,3-pentadiene, butanenitrile, 1-methyl-1H-pyrrole and 3-hexanone, but the children in the control group didn’t. Isoprene and 1-(methylthio)-propane are endogenous compounds (proved by positive AG value) and were exhaled in both groups. The AG values of isoprene and 1-(methylthio)-propane were greater in the asthmatic group than in the control group. These compounds may be the candidates for markers of asthma.