Certain components present in shampoo, detergents and other household cleaning agents can make water from sewage treatment plants carcinogenic.

The research throws light on possible environmental sources of this poorly understood water contaminant, known as nitrosodimethylamine, a semi-volatile organic chemical, which is highly toxic and is a suspected human carcinogen.

William Mitch, chemical engineer from Yale University, says that researchers have known that NDMA and other nitrosamines can figure in small quantities in the disinfection of wastewater and water with chloramine.

Although nitrosamines are found in a wide variety of sources - including processed meats and tobacco smoke - scientists know little about their precursors in water.

Earlier researches with cosmetics detected that substances called quaternary amines that are also ingredients in household cleaning agents, may play a role in the development of nitrosamines.

Their lab test indicated that when mixed with chloramine, some household cleaning products produced NDMA.

The report notes that sewage treatment plants may take away some of the quaternary amines, which gives birth to NDMA, said a release of the American Chemical Society (ACS).

But, quaternary amines are used in such big amounts, which some still may persist and have a potentially harmful effect on the effluents from sewage treatment plants.

The study findings were published in the ACS' Environmental Science & Technology. (With Inputs from Agencies)