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Rarely today do mothers gaze lovingly at their mud-encrusted offspring and remark to fellow mums, “Y’ gotta eat a peck of dirt before you die.” Maybe we’re being overprotective, but beyond catching some kind of bug, today’s children face ubiquitous environmental toxicants, many of which were barely a gleam in a chemist’s eye in our grandmothers’ days.
One such chemical is the antimicrobial triclosan, that was reviewed by Health Canada and Environment Canada in 2012. Surprisingly we do not know how much triclosan is imported or disposed of annually in Canada (it is all imported – no Canadian company makes it). It is difficult, and possibly irrelevant, to disentangle effects of the parent chemical, breakdown products and contaminants. We do know that triclosan contains traces of dioxins, and can react in surface waters to form more of these toxic chemicals.
Triclosan sails through sewage treatment plants largely unchanged, and the untold tonnes washed down Canadian drains annually (in effluent waters, or runoff from sewage sludge applied to agricultural land) affect development of aquatic life. Acute or chronic human toxicities of triclosan are less certain, as Canadian assessments are based on US exposure data, meshed with high dose animal toxicology. Thus it is unclear how low dose thyroid effects seen in animals in the laboratory and in the wild may be relevant to people, although triclosan is probably an endocrine disruptor. Notably, thyroid cancer is rising rapidly, especially in young women.
Today parents may go beyond avoidance of substances such as lead and pesticides and desires for “clean and shiny,” in a quest for an aseptic household. With no one saying, “No!” chemicals such as triclosan moved from healthcare into myriad household products, including soap, toothpaste, lotions, cosmetics, cleaning products, and impregnated materials including plastic food cutting boards, knives, towels, clothing and items such as children’s furniture, toys, school supplies and scissors impregnated with triclosan (Microban®).
Could triclosan contribute to community-acquired antimicrobial resistant infections? Antibiotic overuse in humans, and animal husbandry prophylaxis/“growth enhancement” are already fingered as culprits, but widespread and broad-spectrum actions of triclosan cannot escape implication as well. The Canadian Medical Association stated in 2009 that household antibacterial products should be banned. The CMA’s position notwithstanding, ultimately environmental rather than human health effects may lead to triclosan being curtailed in consumer products.
Recent research into both effectiveness and safety of antimicrobial chemicals caused the US FDA to require additional proof from companies wishing to continue marketing them. Despite its widespread use, and presence in all of our bodies, there is no evidence that triclosan prevents community-acquired infections any better than plain old washing. Indeed, most healthcare applications require only soap and scrubbing.
So, it appears that triclosan’s days in household products may be limited, whether it is banned in Canada, or we ride on the coat-tails of our southerly neighbours. In the meantime, we are masters of what we purchase, and “anti-microbial” products are best left on the shelf.
Meg Sears PhD is an Ottawa environmental health researcher, and a Board Member of Prevent Cancer Now
CTV News (December 16, 2013)
Antibacterial soap makers must prove the chemicals are safe
Published: February 4th, 2014