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What is Arsenic?

Arsenic is a naturally occurring element in the earth's crust. It is widely distributed throughout rocks and soil. It can also be released into the environment from agricultural and industrial activities, such as copper and lead smelting, and wood treatments. In our environment, it can enter the air and water, and can concentrate in some foods we eat.

Arsenic in Private Wells, New Mexico

Arsenic levels in water samples from private wells vary between New Mexico counties and even within the same county. There appears to be higher arsenic levels in central New Mexico counties based on the data that are available. The groundwater system in New Mexico is very complex. This complexity can lead to large arsenic concentration variability even among neighboring wells. Therefore, to know the arsenic concentration in your water from your own well, you need to test.

The safe drinking water concentration for arsenic is 10 mcg/L and some of the water samples from wells in counties (with greater than 20 samples) appear to exceed this this Environmental Protection Agency (EPA) Safe Drinking Water standard. Based on data available, counties without water samples that exceed the EPA drinking water standard include: Curry, Chaves, Mora, and Quay counties.

The information available in this section, including the maps, demonstrates arsenic found in tested private wells in New Mexico based on the data available from various sources.

Arsenic distribution interpolated groundwater arsenic concentrations (mcg/L) from private wells data Nov. 1973- Oct. 2018
Average arsenic distribution in groundwater by county (mcg/L) from private wells data Nov. 1973- Oct. 2018
Percentage of samples exceeding the EPA MCL of 10 mcg/L for arsenic: private wells data Nov. 1973- Oct. 2018.

Where Arsenic is Found

Arsenic is found in:

  • Some drinking water sources, especially ground water sources in areas known to have high levels of arsenic in the rocks and soil.
  • Low levels of arsenic are commonly found in food; the highest levels are found in seafood, meats, poultry, and grains. Some examples include: Seafood, especially shellfish and seaweed; Food prepared with water containing high levels of arsenic and food crops irrigated with high-arsenic water (e.g., rice).
  • Some pressure-treated wood in outdoor structures and especially sawdust or smoke from these woods. Arsenic-treated wood for residential/community uses was phased out in 2004.
  • Tobacco and cigarette smoke.
  • Some medicines, such as: Folk and naturopathic remedies and anti-parasitic drugs.

Arsenic and Health

Inorganic arsenic in both drinking water and food are the primary sources of environmental exposure for the general population. Organic arsenic compounds, which are abundant in seafood, are less harmful to health. Potential health concerns from long-term exposure to high levels typically are associated with long term exposure may cause urinary bladder, lung, and skin cancers.

Other health problems associated with arsenic include:

  • Peripheral vascular disease
  • Peripheral nerves changes (symptoms may initially include numbness in the hands and feet that may progress into a painful sensation of "pins and needles").
  • Liver injury, which may progress to cirrhosis.
  • Tobacco and cigarette smoke. Skin changes, including pigmentation and hard patches on the palms and soles of the feet, which may lead to skin cancer.

Reducing Excessive Exposure to Arsenic

If your water comes from a private well, have it tested for arsenic. If arsenic levels are high, consider arsenic removal using an appropriate treatment/filtration system or consuming water from a different (low-arsenic) source. (If your water comes from a public water supply, it will regularly be tested for arsenic).

These are some possible things you can do to reduce excessive exposure to arsenic:

  • Maintain a balanced diet for you and your family.
  • Do not burn pressure-treated wood manufactured before 2004 and avoid using it for home projects.
  • Have your children wash their hands after playing on or around wooden play structures or decks.
  • If your deck was built around or before 2004, apply a protective sealant or coating every few years.
  • If you work with arsenic, take all precautions to avoid bringing arsenic-containing dust home one your clothing, skin, hair, or tools.

How to find water quality information for public water systems

If you get your water from a public drinking water system, contact:

  • Your community water system by telephone
  • Look up your community water system online through the New Mexico Environment Department (NMED) Drinking Water Watch
  • Call the NMED Drinking Water Bureau, TOLL FREE 1-877-654-8720

Arsenic, Well Water, and Biomonitoring

The New Mexico Department of Health, through its programs in the Environmental Health Epidemiology Bureau, work on various projects to collect data about drinking water quality and arsenic exposure to help New Mexicans better understand potential exposure. See Related Topics and Downloads and Resources below for more information.

Notifiable Diseases or Conditions in New Mexico (N.M.A.C

Arsenic in urine greater than 50 micrograms/liter is reportable to the New Mexico Department of Health. Report to Epidemiology and Response Division, NM Department of Health, P.O. Box 26110, Santa Fe, NM 87502-6110; or call 505-827-0006.