(Beyond Pesticides, May 20, 2010) Dioxins derived from the antibacterial agent triclosan account for an increasing proportion of total dioxins found in water: researchers at the University of Minnesota found that though levels of all other dioxins have dropped by 73-90% over the last thirty years, the levels of four different dioxins derived from triclosan have risen by 200-300%. The study, which was a collaborative effort between researchers at the University of Minnesota, Pace Analytical (Minneapolis), the Science Museum of Minnesota and Virginia Tech appears in the journal Environmental Science and Technology. Leading the research is the recent Ph.D. graduate in chemistry, Jeff Buth and supervisors William Arnold, a civil engineering professor, and his colleague Krostopher McNeill, all from University of Minnesota.
Researchers looked at sediment core samples that contained pollution accumulation records from the past 50 years from Lake Pepin, a part of the Mississippi River 120 miles downstream from the Minneapolis-St. Paul metro area. The sediment samples were then analyzed for triclosan, the four dioxins that are derived from triclosan and the entire family of dioxin chemicals.
In papers published in 2003 and 2009, Dr. Arnold and Dr. McNeill discovered that triclosan, when exposed to sunlight, generated a specific suite of four dioxins. Dioxin refers to a family of chemicals linked to cancer, weakened immune systems and reproductive problems. They are persistent organic pollutants that bioaccumulate in humans and other animals, especially in fatty tissue. Dioxin can be highly carcinogenic and can cause health problems as severe as weakening of the immune system, decreased fertility, altered sex hormones, miscarriage, birth defects, and cancer. Because of the chemical structure as a polychloro phenoxy phenol, it is possible that dioxin can be found in triclosan as synthesis impurities. In addition to being formed during the manufacturing process, dioxin may also be formed upon incineration of triclosan.
â€śThese four dioxins [found in the sediment core samples] only come from triclosan. They didnâ€™t exist in Lake Pepin before triclosan was introduced,â€ť Dr. Arnold said in a Science Daily news release. â€śIn the most current sediments, these triclosan-derived dioxins account for about 30 percent of the total dioxin mass.â€ť
Triclosan is one of the most detected chemicals in U.S. waterways; according to the study, about 96 percent of triclosan from consumer products is disposed of in residential drains. This leads to large loads of the chemical in water entering wastewater treatment plants, which are incompletely removed during the wastewater treatment process. When treated wastewater is released to the environment, sunlight converts some of the triclosan (and related compounds) into dioxins. Researchers believe that triclosan and the dioxins ended up in Lake Pepin sediments by sticking to organic particles in the river, which then sank when they reached the calmer waters of the lake. Additionally, Triclosan can combine with chlorine in tap water to form chloroform, which is listed as a probable human carcinogen.
There are many additional human health and environmental hazards associated with the extensive use of triclosan. 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. Another study 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.
Beyond Pesticides, in partnership with Food and Water Watch and 78 other groups, submitted petitions to both the FDA and EPA requiring that they all non-medically prescribed triclosan uses on the basis that those uses violate several federal statutes. Prompted by this petition, which was then echoed by Rep. Markeyâ€™s (D-MA) letters of concern, the FDA responded, â€śexisting data raise valid concerns about the [health] effects of repetitive daily human exposure to these antiseptic ingredients,â€ť and announced plans to address the use of triclosan in cosmetics or other products. EPA, however, in its response maintains that the agency does not currently plan to reevaluate its regulations surrounding the use of triclosan until 2013.
Since the 2004 publication of â€śThe Ubiquitous Triclosan,â€ť Beyond Pesticides has been exposing the dangers of this toxic chemical. Now, along with Food and Water Watch and over 80 environmental and public health groups, Beyond Pesticides is leading a national grassroots movement calling for the ban of triclosan from consumer products. Beyond Pesticides is calling on manufacturers, retailers, school districts, local businesses and communities to wash their hands of triclosan and protect our nationâ€™s waters and public health from this toxic pesticide. To learn more about this grassroots campaign and the join the movement, visit our triclosan homepage.
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.
Source: Science Daily