The couples who have high body levels of PCBs and other contaminants compounds similar anomalous experience delays in achieving pregnancy, compared with other couples with lower levels of these pollutants.

This is the conclusion reached in a preliminary study by researchers at the National Institutes of Health, United States, and other institutions.

why human fertility decline

PCBs are chemicals that have been used as coolants and lubricants in electrical equipment. They belong to a class of compounds that in many cases end up being present in soil, water and, more worryingly, in the food chain itself.

These chemicals do not break down easily, and may persist in the environment for decades. Some accumulate in fatty tissues.

It is known that exposure to excessive levels of these and other pollutants has several harmful effects on human health, but their effects on human fertility and ultimately the chances of a couple to achieve pregnancy have not been studied in depth.

For the study, the team of Germaine Buck Louis epidemiologist, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, one of the U.S. National Institutes of Health, worked with 501 pairs of four counties in Michigan, and 12 counties in Texas, from 2005 to 2009.

The results obtained in the meticulous analysis suggests that some of these substances, if enough accumulate in the human body, may have a role in the abnormal delay getting pregnant.

How to avoid such compounds as far as possible? In this regard, Dr. Buck Louis said people can limit their exposure by avoiding fat from meat and fish, and limiting consumption of animal products.

She and her colleagues caution, however, that cannot be excluded that some of the abnormal delays in achieving pregnancy may be due to exposure to multiple substances, and that this will need to be confirmed by other studies.

The investigation was also worked by Specialists from Health Science Center of Texas A & M Texas in College Station, the Ohio State University in Columbus, Emory University in Atlanta, and the company EMMES Corp. in Rockville, Maryland, all these U.S. entities.