(Beyond Pesticides, November 30, 2010) Young people who are overexposed to antibacterial soaps containing triclosan may suffer more allergies, and exposure to higher levels of Bisphenol A among adults may negatively influence the immune system, a new University of Michigan School of Public Health study finds. Triclosan is a chemical compound widely used in products such as antibacterial soaps, toothpaste, pens, diaper bags and medical devices. Bisphenol A (BPA) is found in many plastics and, for example, as a protective lining in food cans. Both of these chemicals are in a class of environmental toxicants called endocrine-disrupting compounds (EDCs), which are believed to negatively impact human health by mimicking or affecting hormones.
Using data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES), U-M researchers compared urinary BPA and triclosan with cytomegalovirus (CMV) antibody levels and diagnosis of allergies or hay fever in a sample of U.S. adults and children over age 6. Allergy and hay fever diagnosis and CMV antibodies were used as two separate markers of immune alterations. The study, ‚ÄúThe Impact of Bisphenol A and Triclosan on Immune Parameters in the US Population, NHANES 2003-2006,‚ÄĚ was published online November 30, 2010 in the journal Environmental Health Perspectives.
“We found that people over age 18 with higher levels of BPA exposure had higher CMV antibody levels, which suggests their cell-mediated immune system may not be functioning properly,” said Erin Rees Clayton, PhD, research investigator at the U-M School of Public Health and first author on the paper.
Researchers also found that people age 18 and under with higher levels of triclosan were more likely to report diagnosis of allergies and hay fever. There is growing concern among the scientific community and consumer groups that these EDCs are dangerous to humans at lower levels than previously thought.
“The triclosan findings in the younger age groups may support the ‘hygiene hypothesis,’ which maintains living in very clean and hygienic environments may impact our exposure to micro-organisms that are beneficial for development of the immune system,” said Allison Aiello, PhD, associate professor at the U-M School of Public Health and principal investigator on the study. As an antimicrobial agent found in many household products, triclosan may play a role in changing the micro-organisms to which we are exposed in such a way that our immune system development in childhood is affected. “It is possible that a person can be too clean for their own good,” said Dr. Aiello.
Previous animal studies indicate that BPA and triclosan may affect the immune system, but this is the first known study to look at exposure to BPA and triclosan as it relates to human immune function, Dr. Aiello said.
One surprise finding is that with BPA exposure, age seems to matter, said Dr. Clayton. In people 18 or older, higher amounts of BPA were associated with higher CMV levels, but in people younger than 18 the reverse was true.
“This suggests the timing of the exposure to BPA and perhaps the quantity and length of time we are exposed to BPA may be affecting the immune system response,” Dr. Clayton said. This is just the first step, she said, but a very important one. Going forward, researchers would like to study the long-term effects of BPA and triclosan in people to see if they can establish a causal relationship.
One limitation of the study is that it measured disease and exposure simultaneously and thus shows only part of the picture, Dr. Aiello said. “It is possible, for example, that individuals who have an allergy are more hygienic because of their condition, and that the relationship we observed is, therefore, not causal or is an example of reverse causation.‚ÄĚ
Earlier this month, Members of Congress, led by Rep. Louise Slaughter (D-NY), urged the U.S. Food and Drug Administration (FDA) to ban triclosan due to the hazards that this chemical poses, including antibiotic resistance and potentially leading to higher health care costs. In the letter, which cited the work of Beyond Pesticides, Food and Water Watch and others, the Representatives stated concerns about the endocrine disrupting potential of triclosan.
The scientific literature has extensively linked the non-medical uses of triclosan to many health and environmental hazards. Triclosan is an endocrine disruptor and has been shown to affect male and female reproductive hormones, which could potentially increase risk for breast cancer. Triclosan is also shown to alter thyroid function, and other studies have found that due to its extensive use in consumer goods, triclosan and its metabolites are present in, fish, umbilical cord blood and human milk. A study published in Environmental Health Perspectives also found that triclosan was present in the urine of 75% of the U.S. population, with higher levels in people in their third decade of life and among people with the highest household income.
TAKE ACTION: Join the ban triclosan campaign and sign the pledge to stop using triclosan today. Avoid products containing triclosan, and encourage your local schools, government agencies, and local businesses to use their buying power to go triclosan-free. Urge your municipality, institution or company to adopt the model resolution which commits to not procuring or using products containing triclosan.