Indoor air pollutants — effects on health
Dampness, moisture and mould are emerging biological pollutants that impair health by causing various respiratory and other disorders such as asthma and allergy. However, the precise role and mechanisms underlying the pathophysiology of these indoor pollutants are mostly unclear, mainly due to a lack of exposure data. The reported adverse health effects could be caused by microbes, other biological agents such as allergens, volatile organic compounds (VOCs), phthalates, and fine particles. Chemical agents from maintenance and cleaning could also be damaging to human health. The responses to these agents could be allergy, irritation or some toxic or inflammatory mechanism. In order to elucidate the impact of indoor exposures on children and adults in school buildings and residential homes, the EU-funded HITEA study brought together researchers from seven European countries. The project focused on moisture damage and dampness and microbial exposures related to these conditions, but also explored the potential protective effects of microbial exposures in early childhood, and considered the role of allergens, ventilation, and exposure to fine particles. Field studies in schools were conducted in three countries that represent different climatic regions (Spain, the Netherlands and Finland). The study assessed the respiratory health of students and teachers in relation to exposures in the school building environment. Laboratory analyses of microbial components and toxins were performed alongside immunotoxicological studies. Moisture problems were found to be relatively common, with 20% to 41% of school buildings being affected. Results indicated that dampness is linked to elevated exposure to some microbes and their partly toxic metabolites, however, effects were strongly depending on the country or climatic region. School dampness was also associated with respiratory tract symptoms in students and teachers but did not affect the students' lung function, as indicated by respiratory function measurements. Another study to assess indoor microbial exposures in European homes and their impact on children’s and adult’s health was also conducted. More than 3 000 house dust samples were analyzed for different microbial agents. First findings indicate a large variation of indoor microbial exposures in European homes, with the levels depending on different factors in different countries, including housing characteristics, climatic conditions, pet keeping, dampness, as well as a high household crowding index. In-depth analyses of the potential health effects relating to microbial exposures in homes and schools are on-going. The HITEA findings should alert national and European authorities to take appropriate action to improve safety and health. Controlling indoor biological and chemical pollutants by improving building conditions should become a priority to avoid health problems.