Community Drinking Water and Health
The majority of health risks of arsenic exposure in the United States are long term. Although short-term exposures to high doses cause adverse effects in people, such exposures do not occur from U.S. Environmental Protection Agency (EPA)-regulated public water supplies in the United States that comply with the arsenic Maximum Contaminant Level. A high dose is about a thousand times higher than the drinking water standard.
Some people who drink water containing arsenic in excess of EPA’s standard over many years could experience health effects, including:
- thickening and discoloration of the skin;
- stomach pain;
- liver effects;
- cardiovascular effects;
- pulmonary effects;
- immunological effects;
- neurological effects, such as numbness and partial paralysis;
- reproductive effects;
- endocrine effects, such as diabetes; and
- cancers including: bladder, lungs, skin, kidney, nasal passages, liver, and prostate.
When people consume disinfection by-products (DBPs) at high levels over many years, they increase their risk of developing bladder cancer. Other health effects that may be associated with exposure to DBPs include rectal and colon cancer. Adverse developmental and reproductive effects associated with exposure to disinfection by-products during pregnancy are a concern. They have been studied with mixed results; however, the weight of evidence of the health effects data suggests a potential association.
There are several ways that disinfection by-products can get into your body:
- ingestion (through your mouth): drinking water with DPBs.
- inhalation (through your nose): Some DBPs can be released into the air in your home when you use your tap water. This can happen when you are taking a shower or washing dishes. And the hotter the water is, the more likely it is that DBPs will be released into the air. DBPs can also get into the air when you boil your tap water, such as when you make tea or soup.
- dermal (through your skin): You can be exposed to DBPs when your skin comes into direct contact with water, such as when you are bathing or showering. But for most people, only very small amounts of DBPs get into the body through the skin. However, these amounts can increase too much higher levels as your contact time with water increases, for example, if you typically take long baths or swim frequently in public pools.
Lead can cause serious health problems if too much enters your body from drinking water or other sources. It can cause damage to the brain and kidneys, and can interfere with the production of red blood cells that carry oxygen to all parts of your body.
The greatest risk of lead exposure is to infants, young children, and pregnant women. Scientists have linked the effects of lead on the brain with lower IQ scores in children. Adults, especially with kidney problems and high blood pressure, can be affected by low levels of lead.
The risks of excessive levels of nitrates apply to infants:
- short-term: Excessive levels of nitrate in drinking water have caused serious illness and sometimes death. The serious illness in infants is due to the conversion of nitrate to nitrite by the body, which can interfere with the oxygen-carrying capacity of the child’s blood. This can be an acute condition in which health deteriorates rapidly over a period of days. Symptoms include shortness of breath and blueness of the skin.
- long-term: Researchers continue to explore if there are associations with long-term exposures to nitrates, including adverse reproductive effects and some cancers. The studies are not conclusive at this time, and health standards are focused on protecting infants.