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Consumer Factsheet on: CADMIUM
List of
Contaminants
As part of the Drinking Water and Health pages, this fact
sheet is part of a larger publication: National Primary Drinking Water
Regulations
This is a factsheet about a chemical that may be found in some public or
private drinking water supplies. It may cause health problems if found in
amounts greater than the health standard set by the United States Environmental
Protection Agency (EPA).
What is Cadmium and how is it used?
Cadmium is a metal found in natural deposits as ores containing other
elements. The greatest use of cadmium is primarily for metal plating and
coating operations, including transportation equipment, machinery and baking
enamels, photography, television phosphors. It is also used in nickel-cadmium
and solar batteries and in pigments.
Why is Cadmium being regulated?
In 1974, Congress passed the Safe Drinking Water Act. This law requires EPA
to determine safe levels of chemicals in drinking water which do or may cause
health problems. These non-enforceable levels, based solely on possible health
risks and exposure, are called Maximum Contaminant Level Goals.
The MCLG for cadmium has been set at 5 parts per billion (ppb) because EPA
believes this level of protection would not cause any of the potential health
problems described below.
Based on this MCLG, EPA has set an enforceable standard called a Maximum
Contaminant Level (MCL). MCLs are set as close to the MCLGs as possible,
considering the ability of public water systems to detect and remove
contaminants using suitable treatment technologies.
The MCL has also been set at 5 ppb because EPA believes, given present
technology and resources, this is the lowest level to which water systems can
reasonably be required to remove this contaminant if it occurs in drinking
water.
These drinking water standards and the regulations for ensuring these
standards are met, are called National Primary Drinking Water Regulations. All
public water supplies must abide by these regulations.
What are the health effects?
Short-term: EPA has found cadmium to potentially cause the following health
effects when people are exposed to it at levels above the MCL for relatively
short periods of time: nausea, vomiting, diarrhea, muscle cramps, salivation,
sensory disturbances, liver injury, convulsions, shock and renal failure.
Long-term: Cadmium has the potential to cause the following effects from a
lifetime exposure at levels above the MCL: kidney, liver, bone and blood
damage.
How much Cadmium is produced and released to the environment?
2.9 million lbs. of cadmium were produced in the US in 1986, and nearly
twice that amount was imported in the same year. Cadmium occurs naturally in
zinc, lead, copper and other ores which can serve as sources to ground and
surface waters, especially when in contact with soft, acidic waters. Major
industrial releases of cadmium are due to waste streams and leaching of
landfills, and from a variety of operations that involve cadmium or zinc. In
particular, cadmium can be released to drinking water from the corrosion of
some galvanized plumbing and water main pipe materials.
From 1987 to 1993, according to EPAs Toxic Chemical Release Inventory,
cadmium releases were primarily from zinc, lead and copper smelting and
refining industries, with the largest releases occurring in Arizona and
Utah.
What happens to Cadmium when it is released to the environment?
Some cadmium compounds are able to leach through soils to ground water. When
cadmium compounds do bind to the sediments of rivers, they can be more easily
bioaccumulated or re-dissolved when sediments are disturbed, such as during
flooding. Its tendency to accumulate in aquatic life is great in some species,
low in others.
How will Cadmium be detected in and removed from my drinking water?
The regulation for cadmium became effective in 1992. Between 1993 and 1995,
EPA required your water supplier to collect water samples once and analyze them
to find out if cadmium is present above 5 ppb. If it is present above this
level, the system must continue to monitor this contaminant every 3 months.
If contaminant levels are found to be consistently above the MCL, your water
supplier must take steps to reduce the amount of cadmium so that it is
consistently below that level. The following treatment methods have been
approved by EPA for removing cadmium: Coagulation/Filtration, Ion Exchange,
Lime Softening, Reverse Osmosis.
How will I know if Cadmium is in my drinking water?
If the levels of cadmium exceed the MCL, the system must notify the public
via newspapers, radio, TV and other means. Additional actions, such as
providing alternative drinking water supplies, may be required to prevent
serious risks to public health.
This is a factsheet about a chemical that may be found in some public or
private drinking water supplies. It may cause health problems if found in
amounts greater than the health standard set by the United States Environmental
Protection Agency (EPA).
Drinking Water Standards:
MCLG: 5 ppb
MCL: 5 ppb
Cadmium Releases to Water and Land, 1987 to 1993 (in pounds):
|
Water |
Land |
TOTALS |
31,487 |
2,059,574 |
|
Top Seven States *
| |
AZ |
503 |
433,035
|
UT |
1,750 |
372,010
|
MT |
0 |
315,965
|
TN |
2,700 |
288,781
|
ID |
250 |
225,761
|
MO |
2,361 |
189,914
|
WI |
0 |
106,000
|
|
Major Industries*
| |
Zinc, lead smelting |
5,061 |
831,948
|
Copper smelting, refining |
2,253 |
805,045
|
Indust. inorganic chems |
250 |
225,761
|
Electroplating, anodizing |
0 |
106,000
|
Steelworks, blast furnaces |
5 |
13,000
|
Inorganic pigments |
5,140 |
7,000
|
* Water/Land totals only include facilities with releases greater than a
certain amount - usually 1000 to 10,000 lbs.
Learn more about your drinking water!
EPA strongly encourages people to learn more about their drinking water, and
to support local efforts to protect and upgrade the supply of safe drinking
water. Your water bill or telephone books government listings are a good
starting point.
Your local water supplier can give you a list of the chemicals they test for
in your water, as well as how your water is treated.
Your state Department of Health/Environment is also a valuable source of
information.
For help in locating these agencies or for information on drinking water in
general, call: EPAs Safe Drinking Water Hotline: (800) 426-4791.
For additional information on the uses and releases of chemicals in your
state, contact the: Community Right-to-Know Hotline: (800) 424-9346.
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