(NaturalNews) Decades after being banned, cancer-causing PCBs continue to contaminate our food and our bodies, according to a study conducted by Spanish and Danish researchers and published in the journal Science of the Total Environment.

The researchers found, specifically, that the chemical PCB-153 was found in the body fat of both men and women, and that higher levels increased the risk of cancer in men.

PCBs (polychlorinated biphenyls) are synthetic chemicals that were once widely used in pesticides and plastics, as well as industrial equipment ranging from electric transformers, hydraulic systems, industrial condensers and sealing agents. Their manufacture was discontinued after evidence emerged that they cause serious damage to human and environmental health.

Pollutants accumulate in certain foods

Unfortunately, PCBs are incredibly resistant to destruction, meaning that most of the PCBs ever produced still exist today. This, along with their tendency to accumulate in living tissue (particularly fat), classifies them as persistent organic pollutants. They damage the human immune, nervous and reproductive systems, along with mimicking and disrupting the action of hormones in the body and causing cancer.

The new study was conducted by researchers from the University of Granada, the University of Granada Hospital, the Andalusian School of Public Health, CIBER in Epidemiology and Public Health, the Granada Cancer Register and Denmark's Bispebjerd University Hospital. The researchers analyzed the PCB-153 levels in the body fat of 368 adults, then followed them for nine years. In that time, men with the highest PCB-153 levels were significantly more likely to develop cancer.

"Our preliminary findings suggest a potential relationship between the historical exposure to persistent organic pollutants and the risk of cancer in men," the researchers wrote. They are planning to continue following the same participants, as cancer often takes years or even decades to develop.

According to the scientists, prior studies have suggested several mechanisms by which PCBs might cause cancer, including interactions with sex hormone receptors, free radical production or direct damage to DNA.

The researchers note that PCB levels in the bodies of the participants were significant even though the chemicals have been banned in Spain since the 1980s. Sources of exposure include not just the continuing use of obsolete equipment manufactured with PCBs, but also the chemicals' persistence in the environment, especially the food supply.

"We believe that fat food is the main source of exposure to PCBs among the general population, and consequently high levels of PCBs could be, in part, the result of a fat-rich diet," principal investigator Juan Pedro Arrebola said.

Because pollutants tend to accumulate in the ocean, a major source of PCB exposure is fatty seafood such as tuna, swordfish or farmed (but not wild) salmon.

Future generations will also be affected

Recent research has shown that in addition to directly disrupting bodily systems, PCBs can actually cause changes in gene expression that can be passed down to future generations ("epigenetic changes"). Indeed, researchers have found that PCBs and other persistent organic pollutants, such as DDT or certain pesticides, can actually cause health effects down to six generations.

For example, a 2014 study conducted by researchers from Washington State University and published in the journal PLOS ONE found that when rats were exposed to the pesticide methoxychlor, the risk of ovarian cancer, obesity and kidney disease increased in four successive generations of their offspring, even though the descendents themselves were never exposed to the chemical. Shockingly, the risk was actually higher in each generation than it had been in the last.

Although methoxychlor was banned in the United States in 2003, it has also been revealed to be a persistent organic pollutant and may persist in the environment for decades or even centuries.

Sources:

http://canal.ugr.es

http://www.sciencedirect.com/science/article/pii/S0048969714012224

https://www.naturalnews.com/023444_PCB_PCBs_toxic.html

http://www.naturalnews.com

http://www.researchgate.net/publication/259784811_Epigenetics_and_PCBs

http://www.ewg.org/research/pcbs-farmed-salmon