Researchers at North Carolina State University say that a study they conducted on rats showed a dramatic decrease in the thyroid hormone thyroxine following exposure to increasing concentrations of triclosan.
The study used newly weaned rats that were fed quantities of triclosan in doses of 0, 3, 30, 100, 200 or 300mg/kg of body weight over a 31 day period.
Effect of triclosan on the thyroid
The purpose of the experiment was to determine what effect triclosan has on thyroid hormone levels as a means of gauging how this might impact the onset of puberty.
The researchers found that at doses of up to 3mg there was no detectable difference in thyroid activity. However, at 30mg thyroxine levels decreased by 47 per cent and at 300mg activity decreased by 81 per cent.
Likewise, the study also points out that at the 300mg doseage level, the colloid area of the thyroid gland was smaller than in all the other test groups.
Thyroxine crucial to development
As thyroxine is a crucial chemical in the development of puberty and a functioning metabolism in males, the researchers suggest that excessive expsosure to triclosan may lead to a variety of health-related issues both before and after birth.
One of the key health-related issues the researchers are concerned about is hypothyroidism, which causes the thyroid to produce lower than normal levels of hormones.
This can lead to a variety of serious conditions such as obesity, infertility and even neurological problems - condition that are related to the all-important influence the thyroxine has on the metabolism.
Adds to growing scientific evidence
The research findings reaffirm a gbody of scientific evidence underlining the potential toxicity of triclosan, a danger that is exacerbated by the fact that it is used in a wide number of personal care products, including toothpaste, soap and deodorant.
Although regulatory authorities all over the world dictate that formulators use doses of Triclosan at levels deemed not to pose a risk to human health, some industry experts believe that concurrent use of multiple personal care products might lead to a cumulative exposure that could pose a greater danger.
Back in September, the International NGO ChemSec released a list of chemical substances, that included triclosan, for which it feels companies should be searching for alternatives.
267 chemicals under scrutiny
The Substitute it Now (SIN) list was presented by ChemSec (the International Chemicals Secretariat) in Brussels and includes 267 chemicals that the group feels are of high concern.
As part of the REACH legislation, the European Chemicals Agency ECHA is due to release a similar list of Substances of Very High Concern, in October, however this list may contain as few as 12 substances.
The list of 267 chemicals, which can be viewed via ChemSec’s website, was compiled in collaboration with nine consumer and environmental NGOs and a number of businesses.