PCBs and Human Health

Polychlorinated biphenyls (PCBs) are considered “persistent organic pollutants;” fat-soluble compounds that bioaccumulate in individuals and biomagnify in the food chain. PCBs were the first industrial compounds to experience a world-wide ban on production because of their potent toxicity. PCB bioaccumulation can lead to reduced infection fighting ability, increased rates of autoimmunity, cognitive and behavioral problems, and hypothyroidism.


Polychlorinated biphenyls (PCBs) are a category of industrial chemicals historically used as coolants or heat transfer agents in electrical transformers. They have also been used in microscope immersion oils, carbonless copy paper, cutting oils, and as an inert ingredient in pesticides.


Production of PCBs in the United States ceased in 1979 because of findings that these compounds were accumulating in the environment and were being associated with severe health problems.


Some consumer products made before 1977, including old fluorescent lighting fixtures, electrical devices, or appliances containing PCB capacitors, may still contain PCBs and can be a source of exogenous exposure. Widespread use, large-scale environmental contamination events (spills), and slow biodegradation, all combine to make PCBs a ubiquitous environmental contaminant.


34 of the 38 PCBs were found in virtually all persons tested.


Potential Adverse Effects of Polychlorinated Biphenyls in Humans


Immune System


Testing indicates that PCBs are potent inducers of cell death for monocytes and thymocytes.


Apoptosis of thymocytes appears to be secondary to mitochondrial damage by PCBs. Increased apoptosis of monocytes and thymocytes results in lower numbers of white blood cells (WBCs) to initiate an immunological defense. In order to determine if dietary intake of PCBs leads to immunological problems, mice were fed diets with either PCB-contaminated whale blubber or beef fat that was not contaminated with PCBs.


Because PCBs can cause more serious health problems in the case of in uteroexposure, it is highly recommended women be tested for these compounds before trying to conceive. If levels are high, exposure reduction and toxin elimination can commence prior to conception.


PCBs – How to Protect Your Family.wmv

PCBs were domestically manufactured from 1929 until their ban in 1979 and were used in hundreds of industrial and commercial applications. PCBs have been dem…

Benzene may seem innocuous – it is clear, colorless, and has a slightly sweet odor. But it’s one bad actor.

It’s a carcinogen, and you don’t want to be breathing it. Traditionally, people have thought of industrial facilities as the main threat. Data from the U.S. Environmental Protection Agency shows that the top major emitters in Pennsylvania and New Jersey are the refineries in South Philadelphia and Paulsboro.


New research out of Emory University in Atlanta suggests that how close you live to one of these facilities may affect your chances of getting a particular kind of cancer, non-Hodgkin’s lymphoma. But the qualifier is that the EPA and the Emory study looked only at major stationary sources. The big “wow” is that, in Philadelphia, the refinery isn’t the biggest source of benzene overall.


It’s traffic. An EPA assessment of Philadelphia’s air toxics, based on 2005 data, the latest available, shows that the area with the highest risk of cancer from benzene exposure is roughly along the Vine Street Expressway, near the Schuylkill Expressway. Overall, only about 7 percent of the city’s benzene comes from “major risks,” such as the refinery. Traffic accounts for more than triple that – 26 percent, the largest piece of the city’s benzene pie.


To Joseph O. Minott, head of the Clean Air Council in Philadelphia, this means “it really makes sense in urban areas to promote alternatives to the automobile, such as public transit, walking, and biking.” Other sources of benzene include the airport, construction equipment, and gas stations. About 22 percent of the benzene in the city blows in from somewhere else.


Beyond that, cigarettes are considered the dominant lifestyle-related source of benzene exposure. In the human body, benzene causes cells to not work correctly. It can lead to anemia and damage the immune system, says the Centers for Disease Control and Prevention. Non-Hodgkin’s lymphoma, which the Emory study tracked, starts in the immune system. The National Cancer Institute estimates it will kill nearly 20,000 Americans this year.


Since the 1970s, diagnoses have increased by 3 to 4 percent a year. Researchers think part of the increase is due to things such as changes in the classification system, better diagnoses, and increases of HIV, which also attacks the immune system. But that would account for only half the additional cases, they say. The other half? Increased diagnoses also appear to parallel expanded industrial production, which has prompted suspicion of occupational exposures. The Emory study was one of the first to look at the risk for people who, while they may not work at a facility, live near it. This matters. EPA statistics show that nearly 3,000 people live within a mile of the Philadelphia refinery – most of them white, most with no more than a high school diploma. Fewer than half the households have incomes topping $25,000 a year. In a recent study in the journal Cancer, the Emory researchers found that a person’s risk for the disease falls a third of a percent for every mile between the home and a major facility.


This doesn’t necessarily mean you should move. Christopher Flowers, an epidemiologist at Emory who led the study, said the risk is based on mean distance calculations, and there’s no way people could be sure that in moving away from one site, they’re not moving toward another. Plus, the study pointed simply to an association, not a cause. Many other factors could also increase your risk of lymphomas. But, Flowers said, “it is something provocative that merits further exploration.”