Isolating an environmental trigger could lead to better informed preventive efforts to reduce the incidence of asthma, a condition on the rise nationwide and an important public health concern. According to previous studies, asthma is estimated to cause several thousand deaths annually and cost more than $15 billion per year in direct medical expense.
“Early life exposure to mold seems to play a critical role in childhood asthma development,” Tiina Reponen, Ph.D. , lead author on the study and a UC professor of environmental health, was quoted as saying in a UC Healthnews press release . “Genetic factors are also important to consider in asthma risk, since infants whose parents have an allergy or asthma are at the greatest risk of developing asthma.”
The findings also have implications for reducing health disparities, since asthma occurs at higher rates in low-income communities where mold is more likely to occur in residences, especially those without air conditioning. The standardized approach used in the study may offer outreach workers a more sensitive assessment for accurately identifying homes with potentially harmful levels of mold.
Using a standardized approach to quantify mold exposures
The research team analyzed seven years of comprehensive data for 176 children who were a subset of the more than 700 children participating in the prospective Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS), led by Grace LeMasters, Ph.D. , who is also the lead researcher on research and training grants from NIEHS. CCAAPS looked at the effects of environmental particles on childhood respiratory health and allergy development. Participants were identified during infancy as at high risk to develop allergies based on having at least one parent with an allergy.
Using the Environmental Relative Moldiness Index (ERMI), a DNA-based tool developed by the U.S. Environmental Protection Agency (EPA) for PCR analysis that measures 36 different molds in floor dust, the team identified homes with a high ERMI rating for exposure to molds. The homes were evaluated when study participants were 1 and 7 years old, and children were evaluated for asthma at age 7, the age at which asthma can be accurately diagnosed.
Higher moldiness associated with asthma at age 7
Results of the study indicated that the odds of developing asthma were more than two-fold if a child lived in a home with a high ERMI value during infancy. Reinforcing the utility of ERMI ratings of moldiness was another finding from the study, which failed to find an association between visual and olfactory observations of moldiness - a subjective approach - in the homes of children at ages 1 and 7, with asthma diagnosis at age 7.
“This study does not prove that exposures to mold are a cause of asthma,” the authors concluded, “but it does provide impetus to reduce the mold burden in infant homes based on the ERMI.”
In addition to NIEHS support for CCAAPS, funding for the study was provided by the U.S. Department of Housing and Urban Development and the EPA Communities in Action Asthma Initiative.
Citation: Reponen T, Vesper S, Levin L, Johansson E, Ryan P, Burkle J, Grinshpun SA, Zheng S, Bernstein DI, Lockey J, Villareal M, Khurana Hershey GK, Lemasters G. 2011. High environmental relative moldiness index during infancy as a predictor of asthma at 7 years of age. Ann Allergy Asthma Immunol 107(2):120-126.
“This study should motivate expectant parents - especially if they have a family history of allergy or asthma - to correct water damage and reduce the mold burden in their homes to protect the respiratory health of their children,” Reponen said in an interview with Amanda Harper of UC Healthnews. (Photo courtesy of the University of Cincinnati)
LeMasters has served as lead researcher on NIEHS grants since 1999 and now oversees three grants to UC. She is also a member of the NIEHS National Advisory Environmental Health Sciences Council. (Photo courtesy of the University of Cincinnati)