New research shows link between childhood exposure to mold and asthma

A study led by UC Berkeley School of Public Health researcher Siyuan Xiao finds that childhood exposure to household mold increases risk for asthma, and that this increased risk was more pronounced for boys than for girls.

“Asthma is one of the most common childhood chronic diseases in the industrialized world,” Xiao said. “Dampness and mold are common exposures nowadays, with 18-50% of buildings having dampness and mold exposures.”

Researchers used cross-sectional 2017 and 2018 data from the National Surveys of Children’s Health, which tracked household mold and pesticide exposures over the course of a year alongside physician-diagnosed childhood asthma. Researchers found that among over 40,000 U.S. children, almost 11% of children in mold-exposed households had asthma, while about 7% of children in non-exposed households had asthma.

“Our findings suggest that household mold is associated with current asthma among children in the U.S., independent of other major risk factors,” said co-author Yeyi Zhu, professor at UCSF and researcher at Kaiser Permanente. “Our findings may inform strategies targeting mitigation of household mold as an important indoor environment factor to address childhood asthma.”

Researchers adjusted for other factors, such as obesity and household pesticide use, that also increase the likelihood of developing childhood asthma. However, researchers found that after adjusting for such covariates, these covariates did not increase a child’s risk for developing asthma.

Previous studies that linked household mold to childhood asthma were based on data restricted to certain ethnic groups at city or state levels. Comprehensive and diverse population-based data is needed for future studies.

“Data on household pesticide use and childhood asthma in the U.S. are scant,” Zhu said. “To address these important knowledge gaps we investigated the associations of household mold and pesticide use with current childhood asthma while taking into account the child’s age, sex, and race/ethnicity and household poverty status.”

Read the original study at the National Library of Medicine