Polychlorinated Biphenyls (PCBs) were (and still are) powerful carcinogens. A carcinogen is any substance or agent that tends to produce a cancer. PCBs are found in things such as asbestos and radon; however, we are also forced to consume it in our foods – many unaware of its presence! We are exposed to many substances at any given time, including those we encounter at work, school, or home; in the food we eat and in the air we breathe.
But it’s very unlikely (almost impossible!) anyone could know precisely what they’ve all been exposed to. PCBs are toxic. They can provoke serious health effects that go beyond cancer. They can also play a role in:
- Hormone disruption
- Reduced ability to reproduce
- Skin toxicity
- Immune system disorders
Short period of exposure are not considered to have adverse effects on health unless levels are extremely high – a rare occurrence. (Source: Food Safety Authority of Ireland)
In spite of all the unavoidable exposure, both Canada and the United States did ban the use of PCBs in food back in 1970. But agreement on how much is too much is difficult to come by. The United States Environmental Protection Agency states that levels as low as fifty parts per billion are associated with an increased risk, while Health Canada and the United States Food and Drug Administration argue that foods with less than two thousand parts per billion (ppb) of PCBs are fine to eat.
The truth is, no one really knows.
PCBs In Our Food
It is estimated that up to 90% of human exposure to dioxins and PCBs results from the consumption of food containing these contaminants, mainly those of animal origin. Fruit and vegetables provide only a minor contribution to human intake.
PCBs are notorious for being found in salmon, other types of farmed fish, in chicken, beef, pork, eggs, and even milk. A carcinogen called Acetaldehyde is in every beverage you consume that contains alcohol. Salmon accounts for about 6 percent of PCBs ingested by humans.
This graph shows the absolute amount of PCBs in various foods. It is taken from a FDA market basket study.
We should be concerned about the level of PCBs in our daily diet, and should know where to look for ways to reduce our consumption that make sense, while not compromising other significant health benefits, such as that of omega-3 in salmon.
Free download: A List of Known Chemicals Containing PCBs