The Michigan Department of Environment, Great Lakes, and Energy (EGLE) recommends that homeowners have their well water tested for arsenic. Arsenic is a chemical element that naturally occurs in the earth’s mineral deposits and dissolves in groundwater. Michigan has naturally higher arsenic levels in groundwater. Arsenic in drinking water may have harmful health effects depending on how much you consume and how sensitive you are to it. Since arsenic cannot be seen or tasted in water, a laboratory analysis specifically designed for detecting arsenic is the only way to determine the arsenic level in drinking water wells.
Arsenic exposure
A few areas in Michigan have naturally higher arsenic levels in groundwater. Exposure to inorganic arsenic typically occurs through groundwater used for drinking and cooking. However, exposure is possible in the following ways:
- A large source of total arsenic comes from the food we eat. However, most of the arsenic in food is in an organic (carbon containing) form which is much less harmful than the inorganic arsenic found primarily in groundwater. Some foods also contain inorganic arsenic but the main exposure to inorganic arsenic is normally from consuming water.
- Arsenic may be inhaled by breathing in dust from industrial processes or smoke from burning arsenic-treated wood. Tobacco smoke also contains small amounts of arsenic.
- Work-related exposures to arsenic may occur in certain occupations.
- Arsenic is not readily absorbed by the skin; contact with water (showering, laundering, washing dishes, etc.) is not a risk
Health risk factors
If you have been exposed to arsenic, the following factors will determine your health risk:
- Dose – The amount of arsenic in your body
- Duration – How long and how often your body has been exposed to arsenic
- Type of arsenic – Whether your body has been exposed to inorganic or organic arsenic
- General health, age, lifestyle, and diet – Some people may be affected by lower levels of arsenic while others remain unaffected at the same levels. Young children, the elderly, people with long-term illnesses, and unborn babies are at greater risk, as they can be more sensitive to exposure.
Human health effects of arsenic exposure
The way arsenic affects our bodies is not fully understood. Long-term exposure to low levels of inorganic arsenic in drinking water is known to cause human health problems including: cancer, thickening and discoloration of the skin, problems with blood vessels, high blood pressure, heart disease, nerve effects including numbness and/or pain, and interference with some important cell functions.
Short-term exposure to very high levels of arsenic may cause stomach pain, nausea, vomiting, diarrhea, headaches, weakness, and even death; but, groundwater in Michigan has not been shown to have this high a level of arsenic. There is some evidence that suggests that long-term exposure to low levels (≥0.005 milligrams/liter (mg/L)) of arsenic from drinking water may result in lower IQ scores in children.
If you have concerns about health problems that may be related to arsenic in your well water, discuss them with your doctor. A urine test will indicate if you have been exposed to arsenic at levels of concern.
