Glossary

Type a term:

Water Samples

Water Endocrine disrupting substances are used in consumer products such as plastics, detergents, cleaning solvents, personal care products, and some over the counter and prescription drugs. After use and disposal, these substances may find their way into many water sources and sometimes, into public water supplies. It's important to be sure that the water you drink and bathe in has been appropriately purified of these substances.

What are the chemicals causing concern?

Endocrine disrupting compounds including nonylphenol, bisphenol-A, pesticides, heavy metals and phthalates have been measured in many types of water. Endocrine disrupting compounds are used in consumer products such as plastics, detergents, cleaning solvents, and personal care products and are found in discharges from commercial businesses, industry and agricultural sources. They are found in wastewater, surface water, groundwater and even drinking water.

Pharmaceuticals, including over-the-counter drugs as well as prescription drugs such as antibiotics, hormones including estradiol and synthetic estrogens, and other endocrine-disrupting drugs, are also found in various water sources. Some of these compounds enter the water system through industrial or personal disposal of unused drugs. Other sources of contamination come from excretion leading to accumulation of the compounds in sewage and wastewater.

Fortunately, many communities are cleaning up contaminated wells, rivers, and other public sources of water. Nevertheless, high levels of contaminants remain in many water sources, and clear effects on wildlife and human health have been reported. Because of the time lag between exposures to cancer-causing substances and the changes (both positive and negative) in water quality over the same many-year period, it is difficult to study directly possible effects of particular contaminated water sources and cancer rates, unless there are extremely high levels of contaminants. Yet increasingly we are coming to understand that, especially in combination with other environmental contaminants, persistent low-level exposures to many of these chemicals, may have additive effects on cellular processes, possibly leading to increased risks for breast cancer and other health problems [Payne et al., 2001; Silva et al., 2002].

How do these chemicals enter the body?

Endocrine disrupting chemicals and pharmaceuticals, including hormones, often are not filtered out through public water treatment systems and ultimately end up in the water that is used for drinking, cooking, and bathing.

What are the mechanisms by which these substances might increase the risk for breast cancer?

Endocrine disruptors are compounds that mimic or interfere with the actions of natural hormones, including estradiol. Compounds that mimic estradiol have been shown, in general, to increase the risk for breast cancer.