This is a fact sheet 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
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
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 (parts per billion)
Mcl: 5 ppb
Cadmium Releases to Water and Land, 1987 to 1993 (in pounds):
|Top Seven States*|
|Zinc, lead smelting
|Copper smelting, refining
|Indust. inorganic chems
|Steelworks, blast furnaces
Note: This fact sheet is part of a larger publication
adapted from U.S. EPA publication: EPA National Primary Drinking Water
* Water/Land totals only include facilities with releases greater
than a certain amount - usually 1000 to 10,000 lbs.