Arsenic is an element found in nature, and in man-made products, including some pesticides. 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. In 2001, the Environmental Protection Agency lowered the drinking-water standard from 50 parts per billion of arsenic to 10 parts per billion. Below is a map with levels of where arsenic is. Consuming high levels of arsenic has been known to cause a variety of cancers as well as being linked to heart disease, strokes and diabetes. Recent research has also found an association between arsenic below 10 parts per billion and IQ deficits in children. Because arsenic is colorless and odorless it can go undetected in your drinking water. If you drink from a private well you should have your water tested. If high levels of arsenic are detected they can be removed with a reverse osmosis drinking water system.