is a naturally occurring element that is found in the earth. Groundwater in the Thumb of Michigan frequently contains arsenic in levels that are hazardous to human health. This website provides easy access to a collection of online arsenic resources in order to facilitate understanding of what arsenic is, the dangers of arsenic exposure, and how to avoid arsenic poisoning. Here are a few quick answers to frequent questions residents of the Thumb may ask about arsenic:



Image of arsenopyrate (FeAsS), a naturally occuring form of arsenic. Sinclair Stammers / Science Photo Library

As a resident of the Thumb, why should I be concerned about arsenic in my water?

Arsenic is a naturally occurring element that is found in the ground in many places throughout the world. Arsenic levels in the Thumb of Michigan are particularly high and are frequently found to exceed the current EPA standard of 0.01mg/L in the groundwater. Many residents of the Thumb consume water drilled from wells in areas of the ground with high arsenic levels. Long term ingestion of this toxin can have serious health consequences. The presence of arsenic in drinking water as a health threat is often overlooked and should not be as it is ranked first on the CERCLA Priority List of Hazardous Substances.

How does arsenic in water affect my health?

Arsenic is extremely toxic and affects nearly all organs of the body if ingested, inhaled, or absorbed into the skin. If consumed in large enough quantities (~0.120mg), arsenic is lethal. Chronic exposure to smaller quantities of arsenic can cause a variety of health consequences including several types of cancers attacking the skin, lungs, kidneys, colon, and bladder. Arsenic consumption can also cause changes in the skin, such as the formation of hard patches, pigment changes, hyperkeratosis (excessive dryness), and gangrene. Cardiovascular changes can lead to Raynaud’s syndrome (hand discoloration with cold exposure), as well as noticeable blueness of the extremities. Arsenic induced neurological diseases can cause weakness and loss of sensation in the extremities. Liver disease such as jaundice and cirrhosis are also associated with chronic arsenic exposure. Recent studies have found a possible correlation between chronic arsenic exposure and type II diabetes.

How do I test my water for arsenic?

The Michigan Department of Environmental Quality’s Drinking Water Analysis Laboratory provides arsenic testing services for $16. Contact the DEQ’s Laboratory Services Section by phone (517-335-8184), or visit their website.

What is the EPA’s current standard for arsenic in water?

The acceptable level for arsenic in drinking water according to the EPA is 0.01mg/L or 10ppb. However this value is debated and levels less than 10ppb should not be disregarded.

How can I make my arsenic contaminated water safe?

The best way to avoid arsenic contaminated drinking water is to consume water that was not obtained from a well. Using bottled water obtained from a non-contaminated source is a quick alternative, however connecting to the community water supply is a recommended long term solution. Water treatment is a possible alternative if a community water supply is not available, however not all treatment solutions are effective. According to the DEQ, the best treatment solutions to remove arsenic from drinking water include reverse osmosis and distillation for faucets, and activated alumina for treatment of the entire household. These methods should be thoroughly researched prior to instillation and closely maintained if pursued. Consult NSF International for a list of certified treatment units.  


Image of a polished slab of arsenic in its native form. Sample obtained from the St. Andreasberg mines in Germany and measures 120 millimiters across. In addition to being a toxin in groundwater, arsenic, such as this specimen, is mined for industrial uses. Sirk Wiersma / Science Photo Library.

Top banner photo: Andy Harmer / Science Photo Library

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