Washing your hands might be bad for fish
ALEXANDRIA— A lot of questionable decisions were made in the 1960s. Was introducing the antibacterial agent triclosan one of them?
The antimicrobial ingredient was first used decades ago in Dial soap and pesticides. It can now be found in personal care products, housewares and toys. Triclosan has also found its way into Lake Winona in Alexandria.
Gov. Mark Dayton signed an executive order this month requiring state agencies to cease buying cleaning products that contain triclosan by June. Johnson and Johnson will be phasing the chemical out of its products by 2015. Canada and Japan have banned consumer products containing triclosan.
When triclosan combines with chlorine and sunlight, it produces dioxins that are central in a debate over whether the substance is harmful to humans and the environment. Chlorine is used in the disinfecting process employed by the Alexandria Lake Area Sanitary District wastewater processing plant that empties into Lake Winona.
According to the Food and Drug Administration, triclosan is not known to be hazardous to humans. It does, however, accumulate in the body over time, and 75 percent of the population showed traces of the substance in a urinalysis sampling by the Centers for Disease Control and Prevention. It has also been detected in breast milk. The jury’s still out on what it does to the environment and lake ecosystems.
“We’re very concerned,” said Dennis Cin, Lake L’Homme Dieu Association board treasurer. “Whether it’s affecting humans or not, it’s affecting the ecology of the lake.”
A study conducted by the University of Minnesota and chronicled in the journal Environmental Science and Technology evaluated dioxins in Minnesota lakes based on core samples. Dioxins are byproducts of industrial processes, like wastewater treatment plants, and commonly regarded as highly toxic compounds that are environmental and organic pollutants.
Researchers pulled meter-long samples out of eight lakes of various sizes in the state. Sediment samples date back 100 years. Triclosan toxins make up 60 percent of dioxins in Lake Winona’s sediment.
Large and small lakes with a wastewater source showed increased levels of triclosan since the 1970s. Triclosan was patented in 1964 and registered as a pesticide in 1969.
Overall, triclosan and chlorinated triclosan derivatives, or CTDs, are a dominant source of dioxins after 1965 in waters linked to wastewater systems. CTDs are formed by a photochemical reaction when water containing triclosan is treated with chlorine, deposited into a lake and exposed to sunlight. Water treatment facilities remove most contaminants but not all. These dioxins have been credited with causing harmful effects on the environment.
No triclosan was detected in one lake sampled that did not have wastewater input. In one lake where ultraviolet technology replaced chlorine in wastewater disinfection, CTDs decreased.
However, the study reported that in cores collected in northern Minnesota, the dioxins derived from triclosan were present before triclosan’s patent. This evidence suggests a secondary source, according to University of Minnesota scientists.
Lakes studied by the University of Minnesota were: Lake Pepin, Lake St. Croix, Lake Winona, East Lake Gemini, Lake Shagawa, Duluth Harbor, Lake Superior and Little Wilson Lake.
Process in Alexandria
The ability to measure the amount of triclosan that gets into Lake Winona depends on whether the concentration is above the minimum detection limit, according to Bruce Nelson, executive director for the Alexandria Lake Area Sanitary District.
The ALASD treats chlorine with sodium bisulfate before discharging into Lake Winona.
“This process is called sulfonation and removes chlorine to well below safe levels,” Nelson said. The district tests residual chlorine in discharge effluent daily.
The ALASD had a feasibility study done in 2004 to determine the best method of disinfection. The engineering firm Brown and Caldwell recommended continued use of chlorination because dose control is less precise with ultraviolet systems, equipment is subject to breakage, some metals and solids interfere with the disinfection process and the costs are higher than chlorination. Nelson said the plant superintendent also had concerns with the extensive cleaning requirements regarding the high concentration of hardness and rust in local water.
The lake association has a different view on the issue.
“We’ve been battling for years with the ALASD on the downstream impacts of the plant on Lake Winona,” Cin said. He added usually a plant discharges into a river where moving water helps dilute the effluent.
“They do an excellent job using current technology to treat sanitary waste,” Cin said. “The plant’s just in the wrong place.”
Use it or lose it?
Although there is strong opposition to triclosan by environmental groups, some companies will continue to use the product until a directive is handed down by the government. Proctor and Gamble will continue using triclosan until evidence supports a necessary change in product composition.
The FDA states on its website it “does not have sufficient safety evidence to recommend changing consumer use of products that contain triclosan at this time.”
At the same time, the FDA is conducting an ongoing scientific and regulatory review of the agent and acknowledges that animal studies have shown alterations in hormone regulation due to triclosan exposure.
The U.S. Environmental Protection Agency reported that triclosan is expected to be immobile in soil and not expected to volatilize from soil to water surfaces. It is when triclosan attaches to the surface of suspended solids and sediments where it poses risks for aquatic life. The EPA is continuing research on the ingredient.
Scientists are also investigating the possibility that triclosan could work too well at reducing bacterial contamination and may make bacteria resistant to antibiotics.
The FDA urges consumers to check product labels if they are concerned. Triclosan is sometimes listed as Microban or Biofresh. The only product the FDA has specified as receiving an added benefit from triclosan was Colgate Total toothpaste; it helped prevent gingivitis. Colgate reportedly stopped using the ingredient by 2012, according to the National Center for Toxicological Research.
Article written by Crystal Dey of Forum News Service,