Mold Exposure in First Year of Life May Lead to Asthma Development

Brian P. Leaderer, Ph.D.
Yale University Department of Medicine
R01ES7456 and R01ES05410

Background: Asthma clinicians and researchers have reported a substantial rise in the prevalence and severity of asthma in children over the past decade. Genetic predisposition and exposure to various environmental agents, such as environmental tobacco smoke, endotoxin, and indoor allergens especially during early childhood, have been reported as risk factors for the development of sensitivities to inhaled allergens and the development and exacerbation of asthma. Suspect allergens include those from cockroaches, cats, dust mites, molds, and environmental tobacco smoke. Additional studies have shown a link between risk of a child developing asthma and maternal asthma history, however there have been very studies that have related allergen sensitization and asthma development to maternal history of asthma.

Advance: In a birth cohort study conducted by an NIEHS grantee at the Yale University Department of Medicine and colleagues at the University of Rochester, Harvard Medical School, Brigham and Women's Hospital, and the University of Virginia Medical Center, the issue of mold exposure and asthma development was addressed. The investigative team measured a number of indoor exposures early in life, including mold exposure, using questionnaires and by measuring airborne cultural spores. The association between these exposures and the development of wheeze and cough by twelve months of age was studied. A strong association was found for mold exposure, whether assessed by questionnaire or measured exposure, in children whose mothers had asthma.

Implication: This finding suggests potential differences in susceptibility to these exposures for children with and without asthmatic mothers. It also suggests that the differences in susceptibility are genetically based making some children more sensitive to specific environmental agents. The overall results of the study suggest that early mold exposure may increase the risk of asthma. These findings should be interpreted carefully because of the poor predictability of early wheeze and cough in asthma development. Continued research into specific gene-environment interactions may help to elucidate the cause of these differences.

Citation: Belanger K, Beckett W, Triche E, Bracken MB, Holdford T, Red, P, McSharry J, Gold DR, Platts-Mills TAE, and Leaderer BP. Symptoms of Wheeze and Persistent Cough in the First Year of Life: Associations with Indoor Allergens, Air Contaminants, and Maternal History of Asthma. Am J Epidemol 2003; 158:195-202.