Maine Health and Environmental Testing Lab

WATER FACTS SUMMARY SHEET
TRACE METALS
Updated 01/09/96

Trace metals may occur naturally in ground water in very small amounts and may include arsenic, barium, cadmium, chromium, lead, mercury, selenium, silver and zinc. In small amounts these are harmless and in some cases even beneficial to health. Amounts over drinking water standards may have serious health effects.

ARSENIC

DRINKING WATER STANDARDS AND HEALTH RISKS:

The primary drinking water standard for arsenic is 0.05 milligrams per liter. Arsenic accumulates in body tissues. In high concentrations, arsenic can damage the digestive tract, heart and circulation. Studies suggest that arsenic is associated with skin cancer. Studies also indicate that arsenic in small amounts may be an essential element for normal human development.

POSSIBLE SOURCE OF CONTAMINATION:

Arsenic contamination of water is most often caused by leachate from solid waste landfills, or from use of pesticides.

BARIUM

DRINKING WATER STANDARDS AND HEALTH RISKS:

The primary drinking water standard for barium is 1.0 milligrams per liter. Small doses are not harmful. Large amounts can cause increased blood pressure, nerve damage or cardiovascular disease.

POSSIBLE SOURCE OF CONTAMINATION:

Barium pollution may come from natural sources or can enter water supplies through industrial waste discharges.

CADMIUM

DRINKING WATER STANDARDS AND HEALTH RISKS:

The primary drinking water standard for cadmium is 0.01 milligrams per liter. Cadmium in high concentrations can cause short-term intestinal illness. Since cadmium tends to accumulate in the body, long-term effects may occur, including intestinal, lung and kidney damage.

POSSIBLE SOURCE OF CONTAMINATION:

Cadmium contamination may be caused by disposal of waste from photographic, metal plating or pesticide manufacturing industries. The most common source of contamination is from the corrosion by acidic water of galvanized pipes or soldered joints in copper pipes.

CHROMIUM

DRINKING WATER STANDARD AND HEALTH RISKS:

The primary drinking water standard for chromium is 0.05 milligrams per liter. Chromium in small amounts is essential to health. People who work with chromium or are exposed to amounts over the standard for a long time are at risk of damage to the skin and respiratory system, or to acute poisoning.

POSSIBLE SOURCE OF CONTAMINATION:

Chromium contamination of water is caused by disposal of industrial waste, particularly from the metal plating, tanning and textile industries.

LEAD

DRINKING WATER STANDARD AND HEALTH RISKS:

Lead in amounts over the primary drinking water standard of 0.015 milligrams per liter may cause nervous system disorders and brain or kidney damage. Since lead accumulates in body tissue, it is especially hazardous to the fetus or to children under three years old.

POSSIBLE SOURCE OF CONTAMINATION:

Most lead contamination of drinking water occurs when soft acidic water corrodes lead or galvanized pipes or corrodes solder used in pipe fittings. Lead from solder can be confirmed by testing to see if tin is also present. Lead is used in insecticides and in high octane gasolines. Lead contamination may be present in water from industrial waste disposal or landfill leachate.

MERCURY

DRINKING WATER STANDARD AND HEALTH RISKS:

The primary drinking water standard for mercury is 0.002 milligrams per liter. Mercury can cause acute poisoning in a large dose. Since mercury accumulates in body tissues, it can cause chronic effects to the nervous system, kidney or intestines at low doses over a long period of time. Mercury compounds become concentrated in the tissues of fish; therefore, fish taken from mercury polluted water should not be eaten.

POSSIBLE SOURCE OF CONTAMINATION:

Mercury contamination of water is caused by industrial or agricultural wastes.

SELENIUM

DRINKING WATER STANDARD AND HEALTH RISKS:

Selenium in small amounts is beneficial to health. Levels over the primary drinking water standard of 0.01 milligrams per liter may cause nervous system disorders, skin problems and in extreme cases may be fatal.

POSSIBLE SOURCE OF CONTAMINATION:

Selenium occurs naturally in drinking water, though in trace amounts only. It can also form in higher concentrations in some soils. Selenium is a by-product of copper refining.

SILVER

DRINKING WATER STANDARD AND HEALTH RISKS:

Amounts of silver in drinking water over the drinking water standard of 0.05 milligrams per liter may cause a permanent blue-gray discoloration of eyes, skin and mucous membranes.

POSSIBLE SOURCE OF CONTAMINATION:

Only trace amounts of silver are found naturally in drinking water. Silver contamination of water can be caused by disposal of industrial waste, including waste from metal plating and photographic processing industries.

ZINC

DRINKING WATER STANDARD AND HEALTH RISKS:

The secondary drinking water standard for zinc is 5 milligrams per liter. Zinc levels above this standard may give water a chalky appearance and bad taste. The presence of zinc in drinking water does not generally present health risks and in small amounts is essential to health.

POSSIBLE SOURCE OF CONTAMINATION:

Zinc can occur naturally in drinking water. Zinc contamination can result from corrosion of galvanized pipes by soft, acidic water. Zinc is used in fertilizers and may be found in landfill leachate or in industrial wastes.

CORRECTING THE PROBLEM OF TRACE METAL CONTAMINATION

Water contaminated with metals may be safe to drink for a short time, but over a long period is more hazardous and should not be used. Lead and cadmium caused by corroding of pipes will tend to be more concentrated in early morning because the water stands all night in the pipes. Reduce the concentrations by letting the water run for several minutes before using for cooking or drinking. Corrosion of pipes can be controlled by neutralizing the acidity of the water. Contact a water treatment specialist.

Water contaminated with metals from landfill leachates and industrial discharges are special cases and metals may or may not be able to be removed from the water. Contact a water treatment specialist. They are listed in the yellow pages under "Water Treatment".

F YOU HAVE QUESTIONS OR NEED ADVICE ON HOW TO CORRECT A PROBLEM, PLEASE CONTACT THE HEALTH AND ENVIRONMENTAL TESTING LABORATORY AT (207) 287-1716.

AGENCY INFORMATION

CORRECTING THE PROBLEM OF TRACE METAL CONTAMINATION