That antibacterial soap might not be so good for your health after all, according to a new UC Davis study.
A coalition of UC Davis researchers studying two antimicrobial chemical compounds – triclosan and triclocarban – found in a wide variety of hygienic products, recently published an article in Environmental Health Perspectives documenting their discoveries of the negative effects of these chemicals on reproductive hormone activity and cell signaling through studies of human and animal cells.
“Americans spend nearly $1 billion a year on these products even though recent studies show that they are no better than regular soap and water at reducing the spread of illness,“ said Daniel Chang, professor emeritus of civil and environmental engineering and co-author of the study in a press release. “Now we have added evidence that, in some cases, the benefits may not be worth the risks.“
The UCD study is being coordinated by the Superfund Basic Research Program – a national network created to assess the effects of exposure to environmental substances on human health – and is under the direction of Bruce Hammock, professor emeritus of entomology at UCD.
“Most liquid soaps and toothpastes sold in the nation make use of one of these chemicals,” Hammock said. “These [chemicals] were originally intended for use as surgical scrubs, where I think they are very valuable, but they don’t break down well and recently there’s been growing concern about their buildup in the environment.“
Researchers at UCD have published two additional articles regarding their analyses of the chemicals, and have found that on a cellular level in humans, there are side effects on sex hormone activity, the presence of calcium ions in nerve cells and the operation of enzyme pathways.
Ki Chang Ahn, co-author of the study and a researcher in the department of entomology and cancer research, determined that the presence of the chemicals causes an increased level of human sex hormones.
High levels of these chemicals in the body implicate the potential for the compounds to be considered as neurotoxins, the presence of which has recently been associated with increasing levels of autism, Ahn said.
On an environmental level, changes in soil microorganism populations have been documented and are currently still in the early phases of investigation by professor Kate Scow in the land, air and water resources department.
“Our studies have not shown that these chemicals are incredibly dangerous,” Hammock said. “But they have shown that the increasing presence of these chemicals and their potential effects are definitely something that society really needs to look into.“
Discoveries made at UCD have been shared with the Food and Drug Administration and Environmental Protection Agency, and a special session discussing anti-microbial compounds will be held at UCD in October.
“The discoveries of the potential for subtle and previously unknown health effects of these two compounds are significant,” said Chang in an e-mail interview. “They are so widely used and people are exposing themselves to them.“
Chang, who previously used both products on a daily basis, continues to use triclosan-containing toothpaste, and believes that currently there is insufficient research to show an adverse effect of the compounds on humans.
“One consideration is that, while these compounds may be of value in a hospital or clinical setting, there is little or no evidence that, as used by consumers, hand-washing products … are any better than ordinary soap and water,” Chang said.
Nationwide research into these products has been under way for approximately three years, and the FDA is expected to begin an in-depth study of the chemicals beyond the cellular level later this year.
CHARLES HINRIKSSON can be reached at campus@californiaaggie.com.
