Environmental Estrogens
by author Sherry Torkos, BScPharm

PCBs

Polychlorinated biphenyls (PCBs) are chemicals that have been used since 1929 as ingredients in industrial materials, such as sealing and caulking compounds, inks, paint additives, and to make coolants and lubricants for electrical equipment.

Due to serious health hazards (cancer risk and endocrine-disrupting activity), PCBs were banned in North America in 1977; however, they are still found in small quantities in all food commodities of animal origin and the environment (air and water).

When wood or material containing PCBs are burned at high temperatures, the process can turn them into different substances called dioxins and furans, which are far more toxic than PCBs.

PBDEs

Polybrominated diphenyl ethers (PBDEs) are commercially produced substances that are used as flame retardants in a wide variety of products, such as building material, carpet underlay, curtains, and furniture foam.

PBDEs have similar properties to PCBs. They are endocrine-disrupters and are known to cause cancers in animals. They are regarded as being environmentally persistent and can accumulate in body tissues. Measurements in animals (fish and marine mammals) and humans (milk) have indicated that levels have been increasing during the past 10 to15 years.

According to Health Canada and Environment Canada, PBDEs are considered toxic and their use is being phased out.

PFCs

Perfluorinated chemicals (PFCs) are a group of chemicals widely used in a range of consumer products such as nonstick coatings on cooking pans, and stain-repellent coatings on carpets and furniture. Two of the most well-known PFCs are perfluoro-octanesulphonic acid (PFOS) and perfluoro-octanoic acid (PFOA).

Studies on these chemicals show that they are extremely persistent and bioaccumulative and probably cause cancer, disrupt hormones, and harm reproduction and development. Many countries, including Canada, are working to phase out the use of these chemicals.

Pesticides

Pesticides are used in agriculture to protect crops and livestock, and their residues can remain after treatment. Pesticide intake may occur through dietary sources (food and water).

Pesticide exposure may also occur from their use on lawns and gardens. The application of insect repellents, flea and tick products on pets, and pesticides to control pests such as ants in homes also lead to exposure.

Organochlorine pesticides are recognized as carcinogens and reproductive and developmental toxins; they are also suspected hormone disruptors and respiratory toxins.

Phthalates

Phthalates are chemicals used in many household cleaning products and polyvinyl chloride (PVC) plastic to improve flexibility (water bottles, baby bottles, toys) and in cosmetics (nail polish and hair dye) to bind fragrance to the product. The many types of phthalates include DEHP, DBP, BBP, DIDP, DINP, and DNOP.

Because phthalates are not chemically bonded to PVC molecules they can be released into the air (called "off-gassing"). The amount released increases with mechanical stress (bending, chewing) and exposure to solvents such as oils, saliva, and temperatures over 85 F (29 C).

There are extensive reports about the adverse effects of phthalates, including early puberty in girls and premature births. The European Union and many countries have restricted the use of phthalates in children's toys and these chemicals were also recently banned in the state of California.

Source: alive Web Exclusive, July 2008