Arsenic and Drinking Water
The levels of arsenic in your drinking water could affect your health. The levels of
concern are lower than previously thought and, as a result, the EPA is lowering its
drinking water standard for arsenic. Levels above the new standard have been found in
groundwater at various locations in Iowa. This fact sheet has been prepared by the Iowa
Department of Natural Resources and the Iowa Department of Public Health to provide
you with facts on arsenic and what you can do to determine if your well water has
arsenic in it.
What is arsenic?
Arsenic is a naturally occurring, common element found in the earth’s crust. Very
low levels of arsenic are also present in plants and foods such as fish as well as
in the air. Arsenic is typically found in combination with other elements – arsenic
compounds – and has no distinctive taste or smell. Many of these compounds
occur naturally but some are man-made.
Arsenic compounds have had number of uses including medicines,
manufacturing, pesticides and even livestock feed additives, but most of these
uses have been discontinued. Today, the main use is for a wood preservative,
chromated copper arsenate or CCA, although small amounts are still used for
pesticides, as a metal alloy, and for electronic components. Since 1985, arsenic
used in the U.S has been imported.
Why the concern over arsenic if it occurs in nature?
At very low levels, there is relatively little concern. The body may even need very
small amounts of arsenic. However, new evidence shows the amount of arsenic
that can cause health problems is lower than previously thought. Most people
consume small amounts of arsenic in the food they eat, but drinking water with
even low to moderate levels of arsenic can provide more than is safe. And the
most toxic form of arsenic, known as inorganic arsenic, is the form typically found
in groundwater. Studies have shown that people drinking well water with
elevated levels of arsenic have higher risks of some diseases.