Indoor pet allergen exposures modify the effects of chemical air pollutants on respiratory symptoms.

SETTING

Indoor volatile organic compound (VOC) levels, which are generally correlated with each other, may have an additive or synergistic effect on health. VOC synergy with allergens is a suspected mechanism affecting respiration.

OBJECTIVE

To determine the effect of exposure to interactions between VOCs and allergens on respiratory symptoms in individuals aged ≥15 years.

DESIGN

A national cross-sectional survey measured 20 VOCs and dog and cat aeroallergens in 490 main residential dwellings in France. A standardised questionnaire was used to elicit responses on respiratory conditions in 1012 inhabitants. Four VOC factor scores (linear combinations of VOCs) were generated using principal component analysis. In order to take into account the phenomenon of multi-pollution, marginal models were used to model the relationships between exposure to VOC mixture and respiratory conditions. Stratified models were used to examine the interaction between allergens and VOCs.

RESULTS

The aromatic hydrocarbon score was associated with rhinitis and wheezing, the aliphatic hydrocarbon score with asthma and cough, the halogenated hydrocarbons with asthma, wheezing and rhinitis. Aldehydes and Can f1 had a significant synergistic effect on wheezing and rhinitis. Aliphatic hydrocarbons had an antagonist effect with Can f1 on wheezing.

CONCLUSION

Our data support evidence of adverse effects of exposure to VOC mixture on respiratory conditions; this effect is aggravated in the presence of pet allergens.