Arsenic

1.   What is arsenic?
2.   How can my family be exposed to arsenic?
3.   How can arsenic affect my family's health ?
4.   How can I tell if my family is exposed to high levels of arsenic?
5.   What can I do to reduce my family's exposure to arsenic?
6.   References

What is arsenic?

Arsenic is a naturally occurring heavy metal, which may be associated with several types of cancer, skin disorders, cardiovascular disease, diabetes, and some neurological problems. In the past, Arsenic has been used in pesticides, a broad range of consumer products, such as cosmetics and medical treatments. [1] Today, the sources of arsenic exposure include both anthropogenic- meaning arsenic released into the environment as a result of human activity- and natural sources. Anthropogenic sources of exposure may include:
  • burning of coal;
  • wood preservation,
  • smelting;
  • waste incinerators; and
  • release of industrial wastes into air or water
In addition to these sources, small amounts of arsenic are added to other metals to form mixtures, or alloys. These alloys may be used to make automobile batteries, semiconductors, and electrical diodes. However, in areas without significant industrial activity or waste facilities, the most relevant source of arsenic from natural sources. This is because minerals, soils, and bedrock in some areas of the U.S. naturally contain high levels of arsenic. As a result of erosion and leaching, arsenic may be released from soil and bedrock and contaminated groundwater, which is eventually used for drinking and agriculture. [2]

In addition to understanding how arsenic may be released into the environment, it is important to realize that individuals may be exposed to several different forms of arsenic, which vary in their ability to be absorbed by the body and toxicity. These forms include organic arsenic and inorganic arsenic. We are generally more concerned with exposure to inorganic arsenic, since it is typically more toxic at lower levels. [2]
How can my family be exposed to arsenic?

Arsenic is tasteless and odorless, which may contaminate water, food, air, and soil. Given that elevated levels of arsenic are naturally found in some regions of the U.S. and arsenic is also released through human activity, it often important to consider geographic location and proximity to facilities releasing arsenic when evaluating potential exposure. Each of these exposure pathways is described in the sections below.
  • In water:

    In 2001, U.S. EPA revised its drinking water standard from 50 parts per billion (ppb) to 10 ppb after determining that exposure to lower levels of arsenic may be a health concern. [3] Some areas of the U.S. have relatively high natural levels of inorganic arsenic in rock. As a result, groundwater is far more likely than surface water to have higher levels of arsenic. Therefore, if you are on a private well or living in an area with high levels of naturally occurring arsenic, you may be at risk of elevated arsenic exposure.

    In general, the Western and Northeastern regions of the U.S. tend to have higher levels of arsenic in groundwater. However, in the Southeast region of the U.S., the U.S. Geologic Survey (USGS) also has found elevated levels of arsenic. In particular, parts of Florida, Tennessee, and North Carolina may have levels that exceeds U.S. EPA’s standard of 10 mg/L (Click here to see a map of arsenic levels in drinking water across the U.S.).

    Some hazardous waste sites may release higher levels of inorganic arsenic into various sources of surface water.
  • In food:

    In areas without naturally high levels of arsenic, food may be the largest source of arsenic. Seafood typically tends to have the highest concentrations of arsenic, followed by grains, mushrooms, and poultry. Most of the arsenic found in these foods contains arsenobetaine, which is an organic form of arsenic that is generally considered non-toxic. [2]
  • In air:

    Although, natural sources of arsenic may contaminate the air, emissions from industrial facilities is generally a greater concern. For example, one study estimated that anthropogenic sources of arsenic represent 90% to 93% of worldwide annual arsenic emissions. [4] As a result, you may be exposed to higher levels of inorganic arsenic if you live near these facilities. More detailed information is provided in a U.S. EPA called the National-Scale Air Toxics Assessment (EPA, 2006). The program’s most recent analysis of air pollution was conducted in 1999. (Click here for a map indicating where the greatest quantities of arsenic are released into the air).

    In addition, some occupations involve arsenic-treated wood. Exposure to inorganic arsenic in the air can occur through inhaling the sawdust of treated wood. Also, when arsenic-treated wood is burned, arsenic-containing smoke may be inhaled.
  • In soil:

    Some people living in agricultural areas where inorganic arsenic was formerly used may be exposed to higher levels of arsenic in the soil.

    Children may also be exposed to higher levels of arsenic by eating contaminated dirt or from playing in contaminated dirt.

How can arsenic affect my family's health?

As stated above, arsenic is generally less toxic in its organic form and more toxic in its inorganic form. The health effects associated with acute, high-level and chronic, low-level exposure to inorganic arsenic are discussed below.

Acute, high-level exposure to inorganic arsenic:

Acute, low-level exposure is unlikely a result of environmental contamination of water, air, food, and soil, since the levels of arsenic exposure in the environment are generally low. This type of exposure is much more likely in certain occupational settings involving inorganic arsenic. In addition, some commercial products, such as older pesticides and wood preservatives may contain arsenic, which could be a source of acute exposure if accidentally ingested. Arsenic poisoning may cause:
  • nausea/vomiting
  • severe abdominal pain
  • severe diarrhea
  • impaired production of red and white blood cells
  • damage to blood vessels
  • abnormal heart rhythms
  • possibly death
Chronic exposure to inorganic arsenic:

In many cases, chronic, low-level exposure is the most relevant type of exposure because there are low levels of arsenic contamination found in the environment. Much of The health effects from this type of exposure are not as clearly established as those from higher levels of inorganic arsenic. Chronic inorganic arsenic exposure may cause:
  • darkening of skin [6]
  • abnormal thickening of skin in palms and soles. [6] These may appear as “warts” or “corns.”
  • “Blackfoot disease”. This condition is a disease in which the blood vessels to the feet are badly damaged and may lead to poor oxygen supply to the feet. This condition has been demonstrated on the southwest coast of Taiwan. [2,7,8]
  • increased risk of skin, liver, kidney, bladder, and lung cancer [2, 7-14] kidney problems. One human study has also associated chronic arsenic exposure with increased risk of kidney dysfunction among males. [15]
  • heart disease. One human study has suggested arsenic exposure may increase risk of heart disease.[15]
Although research has shown that there are many adverse health effects are associated with low-level, chronic exposure, it is less clear if this relationship exists at the low levels most commonly found in the U.S. This is because many of the studies on chronic arsenic exposure were conducted outside the U.S. including Argentina, Chile and Taiwan. These countries have much higher levels of arsenic contamination in drinking water. Furthermore, there may be dietary, genetic, or lifestyle differences, which make it difficult to draw inferences on populations in the U.S. However, the weight-of-evidence suggests that there adverse health effects are associated with low-level exposure in the U.S., which is the U.S. EPA’s basis for lowering the standard to 10 ppb. [3]
How can I tell if my family is exposed to high levels or arsenic?

The federal government sets standards for public water systems known as minimum contaminant levels (MCLs). By law, public water systems must report any water contaminant that exceeds its MCL to the EPA. The Safe Drinking Water Act (revised in 1996) requires that water utilities provide Consumer Confidence Reports(CCRs) to those using public drinking water supplies. You can check your CCR to see if your drinking water meets federal standards for arsenic levels. CCRs only report water quality data from the previous calendar year. They do not necessarily reflect current drinking water conditions.

For more current information on arsenic levels in local and regional drinking water supplies, contact:
  • Your regional EPA office. You may obtain specific water quality information in your state at www.epa.gov/ow/states.html.
  • You can also obtain local water information at EPA’s “Surf Your Watershed” database, www.epa.gov/surf.
  • Call the U.S. EPA’s Safe Drinking Water Hotline at 800-426-4791 and ask for the state certification officer who can give you the names of labs in your area that can do the testing.
There are medical tests that can measure arsenic levels in urine, blood, fingernails, and hair. However, these tests are not routinely performed in a clinician’s office. The urine test is generally considered the most useful of these tests, but only indicates exposure within the previous few days. [2]

Unlike urine tests, hair and fingernail testing are generally not useful in detecting lower levels of arsenic. However, they may be able to indicate exposure to high levels of arsenic over the past 6-12 months. [2]
What can I do to reduce my family’s exposure to arsenic?

If you suspect that your public water supply is contaminated with arsenic, check with the previously mentioned agencies for more information on arsenic contamination of state and local water supplies. Work with local political representatives to have any problem with the water supply corrected.

If you suspect arsenic contamination of your private well, consult your local health or environmental department for more information on how to have the well tested for arsenic. In addition, you may also call the U.S. EPA’s Safe Drinking Water Hotline at 800-426-4791 and ask for the state certification officer who can give you the names of labs in your area that can do the testing.

If you use arsenic-treated wood for home projects, be sure to use protective equipment such as a dust mask and gloves. Do not burn arsenic-treated wood near the home.

Discourage your children from eating dirt, which may be contaminated with arsenic or other pollutants.

Encourage all family members to wash their hands before meals.

If any adult in the household works with arsenic be sure they change from their work clothes and work shoes before entering the house.

Additional Resources
ATSDR’s ToxFAQs™ for Arsenic
U.S. EPA’s Arsenic in Drinking Water
U.S. EPA’s National-Scale Air Toxics Assessment
References

[1] Etzel R, Balk S. Handbook of Pediatric Environmental Health. American Academy of Pediatrics Committee on Environmental Health Affairs 1999: 284-88.

[2] Smith A, Arroyo A, et al. Arsenic-induced skin lesions among Atacameno people in Northern Chile despite good nutrition and centuries of exposure. Environmental Health Perspectives 2000;108(7):617-20.

[3] Chen C. Blackfoot disease. Lancet 1990;2:442.

[4] Lu F. Blackfoot disease: arsenic or humic acid? Lancet 1990;336:115-116.

[5] Lewis D, Southwick J, et al. Drinking water arsenic in Utah: A cohort mortality study. Environmental Health Perspectives 1999; 107(5):359-65.

[6] Haupert T, Wiersma J, Goldring J. Health effects of ingesting arsenic-contaminated groundwater. Wisconsin Medical Journal 1996;95(2):100-4.

[7] ATSDR ToxFaq's. Arsenic. http://www.atsdr.cdc.gov/tfacts2.html.

[8] Bates M, Smith A, et al. Arsenic ingestion and internal cancers: a review. American Journal of Epidemiology 1992;135:462-76.

[9] Chiou H, Chiou S, et al. Incidence of transitional cell carcinoma and arsenic in drinking water: a follow-up study of 8,102 residents in an arseniasis-endemic area in northeastern Taiwan. American Journal of Epidemiology 2001;153(5):411-418.

[10] Lubin J, Pottern L, et al. Respiratory cancer in a cohort of copper smelter workers: results from more than 50 years offollow-up. American Journal of Epidemiology 2000;151(6):554-65.

[11] Kurttio P, Pukkala E, et al. Arsenic concentrations in well water and risk of bladder and kidney cancer in Finland. Environmental Health Perspectives 1999;107(9):705-10.

[12] Tsai S, Wang T, Ko Y. Mortality for certain diseases in areas with high levels of arsenic in drinking water. Archives of Environmental Health 1999;54(3):186-93.

[13] Hopenhayn-Rich C, Biggs M, Smith A. Lung and kidney cancer mortality associated with arsenic in drinking water in Cordoba, Argentina. International Journal of Epidemiology 1998;27(4):561-9.

[14] Buchet J, Lison D. Mortality by cancer in groups of the Belgian population with a moderately increased intake of arsenic. International Archives of Occupational & Environmental Health 1998; 71(2):125-30.