The Environmental Working Group claims that 95 per cent of wastewater samples in the San Francisco Bay area are contaminated by hormone-disrupting substances, calling for a consumer boycott on cosmetics products and plastics containing the chemicals.
The results of the report state that 18 out of the 19 wastewater samples that were examined contained trace levels of at least one of the three substances concerned - phthalates, bisphenol A and triclosan.
The report suggests that the chemicals may be harmful for both the environment and humans, advocating that consumers take action by avoiding certain groups of products on the market.
Phthalates are a group of chemicals used to make plastics soft and flexible, however they are also found in many perfumes and perfumed products where they 'fix' the fragrance to make it last longer, and in nail varnishes where they prevent chips and breakages.
Bisphenol A is similarly used in many plastics, for example shatter proof baby water bottles and as an inner coating on tinned food cans, and Triclosan is found in many personal care and household products with antibacterial properties.
Using high doses in laboratory studies, some phthalates have been shown to disrupt normal sexual development in rodents and a recent study suggests that triclosan may disrupt the endocrine system of the American bullfrog - hence the label hormone-disrupters.
The report cites data from the United States Geological Data Surveys suggesting that the 'number of male fish with immature eggs in their testes have been documented with increasing frequency throughout the US' which may lead to 'detrimental consequences to local fisheries and aquatic ecosystems'.
The study, conducted by the Environmental Working Group (EWG) and East Bay Municipal Utility District (EMUD), tested 19 wastewater samples including those from residential areas, nail salons and medical facilities, before the water had reached the treatment plant.
Two samples were also taken from water entering the plant although these were not published in the report for reasons that were not stated.
In addition, three samples were taken from treated water leaving the treatment plant and some of the chemicals were found to be still present, although at trace levels.
From this data the report concludes that the sophisticated wastewater treatment systems of the bay are not effective in removing these chemicals and importantly that it would not be economically efficient to improve these services.
Instead the report suggests that consumers attempt to stop pollution at source by avoiding products containing these types of chemicals, in addition to pushing for an overhaul of the US system of chemical regulation.
The EWG notes that these chemicals are unregulated coming under the Toxic Substances Control Act passed in 1976.
The commentary states that under this law 'companies are not required to test chemicals for safety before they are sold, and are not required to track whether their products end up in people or the environment at unsafe levels. As a result, phthalates, bisphenol A, and triclosan are widely used, are allowed in unlimited quantities in a broad range of consumer products, are found in people, fish, and wildlife, and often lack safety standards.'
In addition, the EWG state that reducing exposure to these chemicals may also benefit human health, referencing a small number of studies that suggest these chemicals may have detrimental health effects on human reproductive function.
For example one study has suggested that 'boys that are exposed to higher levels of phthalates in the womb or in breast milk are more likely to display reproductive system abnormalities.'
However, the conclusions of such studies are by no means definitive with many calling for further investigation with larger sample sizes before any significant conclusions can be drawn.