Indoor Exposure and Sensitization to Formaldehyde among Inner-City Children with Increased Risk for Asthma and Rhinitis

Inhalation of formaldehyde leads to rapid absorption by the respiratory airway, followed by metabolism by erythrocytes and the enzymes formaldehyde dehydrogenase and aldehyde dehydrogenase. [...]formaldehyde has an estimated biologic half-life of about 1–2 minutes (1). [...]inhaled formaldehyde may cause irritation and inflammation of the respiratory system (1). In addition to the cumulative irritant effect, formaldehyde as a small molecule is known to conjugate with large protein molecules in serum (such as albumin), thus provoking the formation of specific IgE antibodies, in turn leading to mast cell degranulation associated with the allergic response (9, 10). [...]formaldehyde exposure can influence the immune response, thereby increasing T-helper cell type 2 polarization through an adjuvant effect (9, 10). [...]our results demonstrated that exposure to formaldehyde in school classrooms was significantly associated with rhinitis, peripheral olfactory dysfunction, increased pharmacologically reversible nasal obstruction, small airway impairment, and elevated FeNO (Figure 1). [...]mitigation strategies for reducing exposure to formaldehyde are warranted for school environments to prevent these problems in vulnerable children.