Epidemiologic evidence for asthma and exposure to air toxics: linkages between occupational, indoor, and community air pollution research.

Abstract

Outdoor ambient air pollutant exposures in communities are relevant to the acute exacerbation and possibly the onset of asthma. However, the complexity of pollutant mixtures and etiologic heterogeneity of asthma has made it difficult to identify causal components in those mixtures. Occupational exposures associated with asthma may yield clues to causal components in ambient air pollution because such exposures are often identifiable as single-chemical agents (e.g., metal compounds). However, translating occupational to community exposure-response relationships is limited. Of the air toxics found to cause occupational asthma, only formaldehyde has been frequently investigated in epidemiologic studies of allergic respiratory responses to indoor air, where general consistency can be shown despite lower ambient exposures. The specific volatile organic compounds (VOCs) identified in association with occupational asthma are generally not the same as those in studies showing respiratory effects of VOC mixtures on nonoccupational adult and pediatric asthma. In addition, experimental evidence indicates that airborne polycyclic aromatic hydrocarbon (PAH) exposures linked to diesel exhaust particles (DEPs) have proinflammatory effects on airways, but there is insufficient supporting evidence from the occupational literature of effects of DEPs on asthma or lung function. In contrast, nonoccupational epidemiologic studies have frequently shown associations between allergic responses or asthma with exposures to ambient air pollutant mixtures with PAH components, including black smoke, high home or school traffic density (particularly truck traffic), and environmental tobacco smoke. Other particle-phase and gaseous co-pollutants are likely causal in these associations as well. Epidemiologic research on the relationship of both asthma onset and exacerbation to air pollution is needed to disentangle effects of air toxics from monitored criteria air pollutants such as particle mass. Community studies should focus on air toxics expected to have adverse respiratory effects based on biological mechanisms, particularly irritant and immunological pathways to asthma onset and exacerbation.

Health risk assessment of exposure to formaldehyde in dental materials

“…Epidemiological studies indicate a relationship between exposure to formaldehyde and clinical manifestation of asthma and sensitization to common allergens [4,[30][31][32][33]. Our results did not reveal significant differences between the investigated groups in terms of history of symptoms and suspected or diagnosed allergic diseases.…”

Occupational Exposure to Volatile Organic Compounds and Aldehydes in the U.S. Trucking Industry

“…Volatile organic compounds (VOCS) have also been suspected to be associated with other noncancer health effects, such as asthma, although these associations remain largely unproven (12). Despite these potentially harmful human health impacts, there are relatively few studies that quantify exposure to VOCs and aldehydes in diesel-heavy and other vehicle exhaust-related microenvironments (13,14).…”

A real-time monitoring and assessment method for calculation of total amounts of indoor air pollutants emitted in subway stations

“…Concentrations of PM 10 and PM 2.5 are proportional to the quantity of dust, which is a result of outdoor air entering through the ventilation system and due to the movement of passengers. Recent studies (Delfino, 2002;Ormstad, 2000) on PMs of indoor showed that they contain large amounts of potential allergy carriers, and they could cause respiratory illness such as asthma. Especially, PM 2.5 can lodge deeply into the lungs because of their small size.…”