By Tong Xu
Washing your hands with antibacterial hand soaps probably protects you from bacterial infections.
But when that soap gets washed down the drain to the waters of the Great Lakes, the harm may outweigh its benefit.
The Food and Drug Administration (FDA) reports that many consumer products, including antibacterial soaps, contain triclosan. That’s a chemical added to prevent and reduce bacterial contamination. Although it has not been found hazardous to people, scientific studies found that it alters hormones in animals, according to the FDA.
“Changes between the life stages of fish, includes hatching from eggs, are regulated by hormones,” said Rebecca Ives, a research technologist at Michigan State University. “If you disrupt the hormone pathways, a fish may not successfully reach the next stage in development, or the female/male ratio of the population may be skewed.”
This may cause a population of fish to have a much smaller number of reproducing adults. And that would lead to a much smaller population of fish in general, Ives said. “A lot of other animals, including humans, eat fish, but with a smaller population of fish, fewer fish will be available to eat.”
Some states are regulating triclosan.
“The state of Minnesota passed legislation, and I won’t be surprised to see other states follow suit,” said Rick Hobrla, the chief of the Great Lakes Coordination Program at the Michigan Department of Environmental Quality.
Legislation was proposed in Michigan a year ago, but it didn’t get passed, Hobrla said. “As far as I know, there is nothing happening right now in Michigan on that issue.”
Hobrla’s division is responsible for wastewater discharges and water quality monitoring.
“Most of their monitoring efforts are more towards inland waters, and usually the monitoring of the Great Lakes is done at the federal level,” he said.
As for actions to reduce the chemicals in the Great Lakes, Hobrla said, “for the most part, it is up to the legislators to take action. The most effective means of controlling is likely going to be a full or partial ban [of triclosan].”
Triclosan has already harmed fisheries in the Great Lakes, Hobrla said. “There is not much that I am aware of that you could do in terms of a treatment once the chemicals are in the water.”
A concern is if triclosan leads to the formation of dioxin, which could potentially affect growth or hormonal changes in fish, Ives said. “Triclosan can react with chemicals in wastewater to produce other chemical compounds. When exposed to sunlight, some of these chemicals can react further to form members of the dioxin family.”
You can reduce the chemicals through the water treatment process, she said.
“They are not typically designed to remove all of the chemical,” Ives said. “They are designed to reduce it to a certain point, for several reasons, including cost and actual technical capability of reducing the chemicals.”
In a lot of personal care products such as soap, triclosan is simply being removed entirely from the production lines.
Triclosan is used as an antibacterial additive and at most concentrations it will basically prevent something from growing, Ives said. Some producers chose to remove it. For personal care products, such as shampoos and body wash, people apply something and then immediately wash the rest down the drain, Ives said. The percentage of the product that stays on the body is very low. Thus, for the most part, manufacturers are removing it entirely from their product line.
“One of the toothpaste manufacturers prefers to keep it in there, but it is a different situation when you actually use a product for a longer period of time,” Ives said. “Toothpaste manufacturers think it is actually a benefit, so they want to keep it in.”
It can be replaced with other bacteriostats, the term referring to chemicals that prevent bacteria from growing, Ives said.
Another way to remove triclosan is with ozone.
“Ozone is a way to remove the triclosan a little bit effectively,” said Ives. “However, ozone is not one of the more common disinfectants that’s used in the majority of water treatment processes.”
Knowing the harm of chemicals in everyday hand soap affects some consumers’ buying decisions.
“After I heard ‘antibacterial’ hand soaps contained chemicals that would hurt the water of the Great Lakes, I would definitely avoid using it from now on as a responsible consumer,” said Manyun Zhao, a Michigan State University nursing student.
“I think the label of ‘antibacterial’ really does not make a big difference in sanitization,” she said. “The regular hand soaps are as effective in terms of cleaning hands when I interned in the hospital.”
Rebecca Ives, a lab technician and a master’s student studying fisheries and wildlife at Michigan State University, explains triclosan impact on water and fish: