PCBs, or polychlorinated biphenyls, are a group of man-made organic chemicals composed of carbon, hydrogen, and chlorine atoms. They belong to the family of chlorinated hydrocarbons and were widely manufactured from 1929 until their production was banned in the late 1970s due to health and environmental concerns
. PCBs have no taste or smell and vary in consistency from oily liquids to waxy solids. Their chemical stability, non-flammability, high boiling point, and electrical insulating properties made them useful in many industrial and commercial applications, such as:
- Electrical equipment like transformers and capacitors
- Heat transfer and hydraulic fluids
- Plasticizers in paints, plastics, and rubber products
- Pigments, dyes, and carbonless copy paper
Despite the ban on manufacturing, PCBs persist in the environment because they are highly stable and resistant to degradation. They accumulate in soil, sediments, and living organisms, leading to widespread environmental contamination
. PCBs are toxic and have been linked to serious health effects, including cancer, endocrine disruption, neurotoxicity, and developmental problems in fetuses and children. They are classified as probable human carcinogens by the U.S. EPA and definite carcinogens by the International Agency for Research on Cancer (IARC)
. Exposure to PCBs can occur through ingestion of contaminated food (especially fish, meat, and dairy), inhalation, or skin contact. Because PCBs accumulate in fatty tissues and are not easily eliminated, they pose long-term health risks
. In summary, PCBs are hazardous synthetic chemicals formerly used in various industrial applications, now banned but still persistent in the environment and posing ongoing health risks
