Positive associations between respiratory outcomes and fungal index in rural inhabitants of a representative sample of French dwellings

Our study aims at estimating exposure to molds at home, based on microbial Volatile Organic Compounds (MVOCs) assessment, and evaluating its effect on respiratory diseases in a representative sample of dwellings. In the framework of a national campaign, indoor pollution was monitored in a sample of the 24 million dwellings of metropolitan France (n = 567). 727 subjects answered to a standardized questionnaire on respiratory diseases and had MVOCs sampled in their bedrooms and a fungal index (FI) defined. Among the 431 dwellings with complete data, one out of three was contaminated by molds as assessed by a positive FI: 27.0% in urban, 38.2% in periurban and 34.9% in rural dwellings respectively. Positive associations were observed between fungal index and current asthma (8.6%) and chronic bronchitis-like symptoms (8.4%), especially in rural areas (OR = 2.95, 95%CI (1.10; 7.95) and 3.35, 95%CI (1.33; 8.48) respectively). Our study, based on objective assessments of fungal contamination, is in agreement with previous results suggesting mold-related respiratory effects. Moreover associations found among rural population could indicate specific pollution and impact in this environment.