Study Links Male Infertility to Use of SolventFeb 27, 2003 | The Globe And Mail
In a major finding, a team of Canadian and U.S. researchers has linked male infertility to a widely used industrial and household solvent, providing a possible clue to the decline in male sperm counts that has been observed in many countries.
The researchers suspect that trichloroethylene, a solvent used in industry to strip grease from metals and frequently found in such consumer products as paint thinners, spot removers and rug-cleaning fluids, concentrates in the male reproductive system, where it impedes the growth of healthy and viable sperm.
Although TCE, as the chemical is commonly known, is a suspected carcinogen that also causes liver, kidney and lung damage, the new research is the first to link it to male reproductive disorders.
The use of TCE in workplaces and its dispersal into the environment is a likely explanation for some of the decline in male sperm levels, said Poh-Gek Forkert, one of the researchers who conducted the study, based on infertile Ottawa-area auto mechanics.
"From our study, it certainly supports that premise," said Ms. Forkert, a Queen's University toxicologist and lead author of the paper that will appear in next month's issue of the journal Drug Metabolism and Disposition.
TCE is one of the most widespread environmental contaminants in Canada; traces have been found in the drinking water of an estimated one million people, primarily those who rely on groundwater polluted by industrial sites or landfills. The chemical is also used in thousands of workplaces.
In December, the federal government ordered companies to reduce their usage of TCE by 65 per cent because of concerns that it is toxic, but the cut doesn't take effect until 2007.
The finding that TCE is linked to damage of the male reproductive system is likely to intensify calls from environmentalists for an outright ban on TCE. There are safer substitutes for most of its uses.
Ms. Forkert concluded that men can be damaged by the solvent based on a review of car mechanics, a trade that uses TCE to clean grease from auto parts.
The researchers tested eight car mechanics from the Ottawa area who had been diagnosed with infertility because of low sperm counts or high numbers of damaged sperm.
All the men had used TCE for at least two years on the job, and all had the solvent or metabolic breakdown products from the chemical present in sperm samples they provided to researchers.
The researchers also tested five men who did not use TCE and didn't find any of the chemical in their sperm.
The study was based on a small number of samples. The researchers said they were unsuccessful in getting additional semen samples from fertile men who were also exposed to TCE.