What Are PCBs?
PCBs or polychlorinated biphenyls are a cluster of synthetic chemicals made up of chlorine atoms, hydrogen, and carbon. What determine the chemical and physical properties of the PCB molecule are the location and the count of chlorine atoms in a certain cluster. Like asbestos, PCBs don’t have any associated smell or taste. They are known simply for their waxy, solid or oily texture and consistency.
PCBs are identified as belonging to a group of man-made chemicals known as chlorinated hydrocarbons, which may be black and waxy, yellow and light, or plainly thin. Because they are not flammable, have the right chemical stability, have good insulating capacity, and have higher boiling points, PCBs were commonly used in different commercial and industrial applications like the following:
- Carbonless facsimile paper
- Hydraulic, heat transfer, and electrical equipment
- Paint Plasticizers
- Rubber products
- Other industrial uses
In the year 1929 until 1979, PCBs were manufactured domestically and were widely used in construction. However, they were banned in the latter part of 1979 after having been found to possess a wide range of toxic and carcinogenic properties.
Industrial Uses of PCBs
Even if PCBs are no longer produced for commercial purposes in the US, they may still be present in the environment and continue to contaminate materials that were produced before the 1979 ban.
These are examples of products that may still contain PCBs:
- Cable insulation
- Carbonless facsimile paper
- Electrical equipment
- Epoxy resin and adhesive tapes
- Floor finish
- Fluorescent light
- Hydraulic systems’ oils
- Motor oils
- Oil-based paint
- Thermal insulation
- Vintage electrical apparatuses with built-in PCB capacitors
- Voltage regulators
These materials contain PCBs that were chemically mixed to make up an assortment of chlorinated biphenyls known as congeners. Most of the commercialized forms of PCBs are known as Arochlor in the United States.
How PCBs Contaminate the Ecosystem
Currently, PCBs might still be freed into the air and into the environment from either of these sources:
- Poorly kept dangerous waste that contains PCBs.
- Prohibited or improper way of throwing away PCB rubbish.
- Leakage or discharge from old transformers that contain PCBs.
- Dumping of PCB-contaminated consumer merchandise into public landfills or landfills that are not capable of handling lethal waste.
- Burning trash in community incinerators and industrial furnaces.
Since PCBs don’t easily break down when released into the environment, they can stay for prolonged periods of time in the soil, water, or air surfaces. They can be physically moved within long distances and are found across the globe. Lighter PCB forms, which evaporated from sediments and contaminated water, were transported to places even further from the main source. Some were, in fact, found in the Antarctic and the Arctic.
Improperly disposed of PCBs are lethal to marine and aquatic resources, as they can be consumed by plankton, small fish and other small-bodied organisms. The toxic PCBs are then accumulated and stored in their body fat. As a result, the contamination can spread via the natural food web, and predators such as bigger fish and humans are at great risk of consuming high concentrations of PCBs.
In other words, experts warn that consuming contaminated fish is the main source of exposure to PCBs. The U.S. Environmental Protection Agency (U.S.EPA) rates the increase in cancer risk to be as high as 1 in every 2500 considering people consuming particular fish species taken from the Hudson River – an estimate that is a thousand times greater than the EPA’s protection goal.
Even more disturbingly, studies found high PCB levels in Inuit women – both in their blood and in their breast milk. And because they are not water-soluble, PCBs are not eliminated by the body and can be accumulated over time. It has been observed that PCBs are stored in the fat tissue. The contaminated mother then unknowingly contaminates her infant throughout pregnancy and via breastfeeding.
PCBs and Their Adverse Health Effects
Various researches and studies emphasize that PCBs, if not properly handled and disposed of, can cause a wide array of adverse health issues. In animal studies, PCB contamination and ingestion can lead to animal cancer and other non-cancerous but equally serious health effects –such as deterioration of the endocrine, nervous, reproductive and immune systems.
In humans, there is also evidence that shows both the possible non-carcinogenic and carcinogenic effects of PCBs. Such health issues are found to be interrelated among body systems, which mean that changes in an individual system might significantly affect the functioning of another system. Below are the potential adverse health effects of PCB exposure:
- Diseases of the Liver: PCB exposure can negatively impact the enzyme production process of an organ, thereby increasing cholesterol and lipid production in the liver. As a result, the body will have a reduced ability to store and process Vitamin A, which is vital for the healthy propagation and growth of cells and organs. Consequently, this may lead to severe dysfunction of the liver.
- Effects on the Endocrine System: PCB exposure can deplete the circulation of the thyroid hormone, thus leading to the development of a state called hypothyroidism. Pregnancy might also be adversely affected. One’s thyroid hormones are very important in proper and complete brain and thyroid development during a woman’s 2nd-trimester pregnancy. The adrenal glands can be adversely affected as well, wreaking havoc on the body’s adrenaline levels and leading to improper and irregular estrogen receptor-binding in the body.
- Skin Issues: PCB Exposure can lead to nail and skin pigmentation, along with skin lesions, skin irritations, severe acne, and melanomas.
- Eye Issues: Both frequent and infrequent exposure to PCBs can lead to the Meibomian gland’s hypersecretion, irregular eye pigmentation, enlarged eyelids and melanomas.
- Adverse Effects on the Immune System: In both infants and adults, exposure to PCBs can compromise an otherwise sound immune system. In infants, PCB exposure while in the mother’s womb or through breastfeeding can fatally impair the immune system. They can become susceptible to ear infections, respiratory tract infections, and other infectious diseases. On top of these, other risks to the immune system include decreased production of antibodies, lymph node changes, spleen atrophy, and thymus gland atrophy.
- Effects on the Reproductive System: In most studies, it was revealed that PCB exposure can lead to reduced sperm production in men and irregular menstrual cycle in women. Both sexes will also run the risk of suffering from reduced fertility. In pregnant women, PCB exposure can cause unborn babies to have a poor chance of survival owing to premature births.
- Effects on Fetal Development: If a pregnant woman is exposed to concentrated amounts of PCBs, there is a very high chance that the fetus will have smaller head circumference, lower birth weight, impaired thyroid functions, as well as brain development and reproductive organ malformation.
- Developmental Effects: Studies show irreparable damages in the development of the nervous system in babies and in young children born to mothers who have been exposed to PCBs regularly. Furthermore, other possible neurological impacts of PCB exposure include reduced levels of dopamine in the brain, learning difficulties due to lowered IQ, decreased spatial cognition capacities, impaired short-term memory, as well as poor performance on standardized tests on behavioral and psychomotor skills.
- Risk of Cancer: The U.S. Environmental Protection Agency (U.S.EPA) and the International Agency for Research on Cancer (IARC) have classified PCBs as a potential carcinogen, and thus people exposed to PCBs over a long period of time and in concentrated quantities are at a very high risk of developing cancer. Studies show that PCB exposure caused an increased rate in cancer cases such as liver cancer, melanomas, biliary tract cancer, gallbladder cancer, brain cancer, gastrointestinal cancer and even breast cancer.
Safe Disposal of PCBs
PCBs were once used very prevalently in the US, and more than 46 percent of private and public schools still standing today were built and renovated before the 1979 PCB ban. Given the dire health and environmental consequences of PCB exposure, it is therefore imperative that such highly toxic and harmful substances be dealt with, managed, and disposed of properly.
In 1976, the Toxic Substances Control Act (TSCA) was put into place by the U.S.EPA and in 1979, the TSCA set a ban on the public access and use of PCBs, specifying and enforcing regulations on their disposal as well as on the disposal of any material contaminated with more than 50 ppm (parts per million) of this harmful substance.
The U.S.EPA firmly enforces a strict guideline on PCB management, generously providing online resources for PCB remediation waste, bulk PCB waste, and for general PCBs.
Owing to the toxic nature of PCBs, their removal and disposal must be done by a licensed and skilled expert, especially in cases concerning renovation and demolition of decades-old houses and buildings. Your licensed PCB removal contractor will determine which parts of the property for demolition or renovation may contain high or concentrated amounts of PCBs. These contaminated tools and fixtures will then be subject to responsible abatement and proper disposal for the health and safety of the community and the generations to come.