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Arsenic in Drinking Water is a Serious Concern

January 31st, 2013

The topic of arsenic in drinking water has been in the news lately. Earlier this month, the water supplier in the small town of Tacna, Arizona was cited for numerous violations of high arsenic levels in the drinking water. Elsewhere in the country, local wells have been found to have extremely high levels of arsenic in Hinkley, California, a community already well-known for having contaminated groundwater. Even if you have read these news stories, you, like most Americans, may not know what arsenic is, where it comes from, and how harmful it can be if consumed at high levels for a long period of time. It is worthwhile for you to take a moment to learn a little bit more about this drinking water contaminant.

What is arsenic?

Arsenic is a tasteless, odorless semi-metal. It can be released into the groundwater via several sources, including mining and smelting operations, agricultural applications, and processes used to ma7167445_snufacture products like glass, electronics, paints, drugs, soaps, and dyes. Unfortunately for certain regions of the country, arsenic can also enter the groundwater through natural weathering of soil and rocks. Arsenic is a regulated drinking water contaminant and the EPA has declared that 0.010 milligrams per liter (mg/L) or 10 parts per billion (ppb) is the maximum contaminant level that can be present in drinking water.

Where is arsenic found?

In most regions of the country, drinking water supplies contain less than 2 ppb of arsenic. Approximately 12% of groundwater sources in the western US and 12% of surface water sources in the North Central region, however, have levels that exceed 20 ppb. A few individual wells in the West were found to have levels up to an unbelievable 3,400 ppb.The majority of the high arsenic concentrations are found in the West, the Midwest, the Northeast, and parts of Texas. This is most likely due to local geology. These regions tend to have volcanic rock and sulfide-containing mineral deposits that are high in arsenic which release the contaminant to the water through natural processes.  The US Geological Survey (USGS) provides a map of arsenic concentrations in groundwater which clearly shows a pattern of higher concentrations in the western United States.  This map was created in 2000 but still provides a good representation of current concentrations.

How can arsenic affect your health?

If you drink water that is contaminated with higher levels of arsenic for a long period of time you may experience certain health effects. Changes in the skin such as thickening, discoloration, or “warts” on the palms, soles, and torso, are the most common health effects. Arsenic can also cause circulatory system problems such as decreased red and white blood cells, abnormal heart rhythm, and bruising from blood vessel damage. Irritation of the stomach and intestines may also occur, causing nausea, vomiting, and diarrhea.

The EPA, Department of Health and Human Services, and the International Agency for Research on Cancer have all classified arsenic as a human carcinogen (cancer-causing agent). Skin tumors are the most common type of cancer caused by arsenic but if you regularly consume high levels of this contaminant you also increase your risk of cancer in the bladder, lungs, liver, kidney, and prostate.

Is arsenic in your water?

With its relatively widespread distribution and long list of potential health effects, arsenic is a water contaminant that you should take seriously. If your drinking water comes from a municipal water supply, the arsenic level should not exceed the maximum contaminant level however you can contact your local water supplier to find out if it is present in your water supply and if any violations ever occurred. If you have a private well, experts recommend that you have the well water tested by a state-certified laboratory if you suspect arsenic contamination. If arsenic is present in your drinking water supply, rest assured that water filters are available that can remove this contaminant. Do not risk your health or that of your family – take the time to determine if arsenic is in your drinking water and, if necessary, find a way to reduce the contamination as soon as possible.


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