General information about environmental health research.
Bisphenol A (BPA) is a chemical produced in large quantities for use primarily in the production of polycarbonate plastics and epoxy resins.
Where is BPA found?
Polycarbonate plastics have many applications including use in some food and drink packaging, e.g., water and infant bottles, compact discs, impact-resistant safety equipment, and medical devices. Epoxy resins are used as lacquers to coat metal products such as food cans, bottle tops, and water supply pipes. Some dental sealants and composites may also contribute to BPA exposure.
How does BPA get into the body?
The primary source of exposure to BPA for most people is through the diet. While air, dust, and water are other possible sources of exposure, BPA in food and beverages accounts for the majority of daily human exposure.
Bisphenol A can leach into food from the protective internal epoxy resin coatings of canned foods and from consumer products such as polycarbonate tableware, food storage containers, water bottles, and baby bottles. The degree to which BPA leaches from polycarbonate bottles into liquid may depend more on the temperature of the liquid or bottle, than the age of the container. BPA can also be found in breast milk.
Last Updated: 09/2010
Bisphenol S (BPS) is one of the most widely used BPA replacements. A 2012 analysis of urine samples taken in the United States, Japan, China and five other Asian countries confirmed that humans are widely exposed to BPS from drinking from containers or cans lined with the chemical or contamination through the water supply.
However, BPS may not be safer than BPA. Two recent studies have found that BPS is as hormonally active as BPA and, like BPA, it interferes with the endocrine (hormone) system in ways that may produce harmful effects, such as obesity, cancer and neurological disorders. In a paper published last month, we showed that both of these endocrine-disrupting chemicals alter normal development of the reproductive system.
A pesticide is any substance used to kill, repel, or control certain forms of plant or animal life that are considered to be pests. Pesticides include herbicides for destroying weeds and other unwanted vegetation, insecticides for controlling a wide variety of insects, fungicides used to prevent the growth of molds and mildew, disinfectants for preventing the spread of bacteria, and compounds used to control mice and rats. Because of the widespread use of agricultural chemicals in food production, people are exposed to low levels of pesticide residues through their diets. Scientists do not yet have a clear understanding of the health effects of these pesticide residues. The Agricultural Health Study, an ongoing study of pesticide exposures in farm families, also posts results online. Other evidence suggests that children are particularly susceptible to adverse effects from exposure to pesticides, including neurodevelopmental effects. People may also be exposed to pesticides used in a variety of settings including homes, schools, hospitals, and workplaces.
Formaldehyde is a colorless, flammable, strong-smelling chemical widely used to make home building products. Most formaldehyde produced in the United States is for the manufacture of resins, such as urea-formaldehyde, used to make the adhesives for pressed wood products, such as particleboard, furniture, paneling, cabinets, and other products. Formaldehyde is also commonly used as a preservative in medical laboratories, mortuaries, and consumer products, including some hair smoothing and straightening products. It is also a by-product of automobile combustion and is produced in small amounts by most living organisms, including humans.
How are people exposed to formaldehyde?
People are exposed to formaldehyde in the workplace and in their home environment, but the highest levels are found in work settings where formaldehyde is used or produced. Exposure to formaldehyde can occur in numerous industries and professions, such as manufacturers of formaldehyde and formaldehyde-based resins, woodworking, and furniture making. Morticians and laboratory workers may also be exposed to formaldehyde.
The general population is exposed to formaldehyde by breathing contaminated indoor or outdoor air and from tobacco smoke. Automobile and other combustion sources, such as woodstoves, incinerators, refineries, forest fires, and fumes released from new construction or home-finishing products, are some of the major sources of airborne formaldehyde. Other consumer goods, including some hair smoothing and straightening products used in salons, cleaning agents, glues, and adhesives, may contain formaldehyde. Formaldehyde levels can be higher in indoor air than in outdoor air.
Since the release of the 12th Report on Carcinogens, several companies that use formaldehyde in their products, have been making efforts to remove or reformulate the chemical so it is less harmful.
Acrylamide is a chemical widely used during the manufacturing of paper, dye, and other industrial products. It can also be formed when certain foods are cooked at high temperatures. Frying, baking, or roasting certain foods, such as potatoes or grains, can create acrylamide. French fries and potato chips, for example, may have measurable acrylamide levels. Acrylamide is also found in cigarette smoke.
Last Updated: 06/2011