A study released by Columbia University has found a connection between mothers exposed during pregnancy to high levels of two commonly used phthalates, BBP and DBP (also referenced as BBzP and DnBP), and asthma in their children. While these two phthalates were banned in children’s products in 2009 by the Consumer Product Safety Improvement Act (CPSIA), they are still used in many, many household products, automobile interiors, and fragrances.
The number of cases of asthma has increased globally, but there is no consensus as to why. Earlier theories suspected increases in improved sanitation (the “hygiene hypothesis”) as a possibility, but although this might explain increases in allergies, it appears to not work in explaining asthma, according to a 2011 article in Scientific American.
Whatever the case, rates of asthma have increased, particularly in children. According to the Centers for Disease Control and Prevention (CDC), the number of people diagnosed with asthma grew by 4.3 million from 2001 to 2009, with African-American children seeing an almost 50% increase in asthma in that time frame.
A fact sheet provided by The American Lung Association (ALA) reveals that asthma affects 7.1 million children under 18 years in the U.S.. The ALA claims that asthma ranks as the third leading cause of hospitalization among children under the age of 15, with around 29% of all asthma hospital discharges in 2010 falling in that age bracket (even though only 20% of the U.S. population fell in that demographic). Asthma is one of the leading causes of school absenteeism.
The Columbia University Study
The peer-reviewed study, published Sept. 17, 2014 in the journal Environmental Health Perspectives, was led by Robin Whyatt from the Columbia Center for Children’s Environmental Health in New York, part of the Mailman School of Public Health at Columbia University. The study measured metabolites (biomarkers left after the body metabolizes the chemicals) of four phthalates in urine samples collected from 300 pregnant women in New York City, and then measured these metabolites in their children after they were born. The study builds on previous research of the same set of parent/child as part of a long term study.
Study results suggest a “significant” association between concentrations of prenatal metabolites of the phthalates BBP and DBP and later childhood asthma, but did not find a correlation between exposure to the phthalates DEHP and DEP and asthma.
The percentages found in the study were high. Almost one third of the children, 94 of them to be exact, ages 5-11, developed physician-diagnosed asthma. An additional 60 children had a history of wheeze and other asthma-like symptoms without the asthma diagnosis.
The findings are significant and warrant additional study. At this point, researchers are unclear on the mechanisms for how the phthalates might increase the risk for asthma, although other studies suggest that inflammation and oxidative stress* may play a role.
In the U.S. in 2007, asthma cost about $56 billion in medical costs, lost work and school days, and early deaths.
*For a summary description of oxidative stress, check out Dr. Andrew Weil’s explanation on his website.