Consumer Factsheet on: THALLIUM
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 Thallium and how is it used?
Thallium is a metal found in natural deposits as ores containing other
elements. The greatest use of thallium is in specialized electronic research
equipment.
Why is Thallium 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 thallium has been set at 0.5 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 been set at 2 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 should it occur 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 thallium to potentially cause the following health
effects when people are exposed to it at levels above the MCL for relatively
short periods of time: gastrointestinal irritation; nerve damage.
Long-term: Thallium has the potential to cause the following effects from a
lifetime exposure at levels above the MCL: changes in blood chemistry; damage
to liver, kidney, intestinal and testicular tissues; hair loss.
How much Thallium is produced and released to the environment?
Thallium is not produced in the US. Approximately 4,500 lbs. of thallium and
its compounds were reportedly imported in 1987. Man-made sources of thallium
pollution are gaseous emission of cement factories, coal burning power plants,
and metal sewers. The leaching of thallium from ore processing operations is
the major source of elevated thallium concentrations in water. Thallium is a
trace metal associated with copper, gold, zinc, and cadmium.
What happens to Thallium when it is released to the environment?
Thallium does not long persist if released to water, but does have a strong
tendency to accumulate in aquatic life. If released to land, it may bind to
alkaline soils, but may otherwise migrate to ground water.
How will Thallium be detected in and removed from my drinking water?
The regulation for thallium became effective in 1994. Between 1993 and 1995,
EPA required your water supplier to collect water samples once and analyze them
to find out if thallium is present above 2 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 thallium so that it is
consistently below that level. The following treatment methods have been
approved by EPA for removing thallium: Activated alumina; Ion Exchange.
How will I know if Thallium is in my drinking water?
If the levels of thallium 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: 0.5 ppb
MCL: 2 ppb
Thallium Releases to Water and Land, 1987 to 1993 (in pounds):
|
Water |
Land |
TOTALS |
2,606 |
2,770 |
Top Five States |
TX |
6 |
2,020
|
OH |
1,500 |
0
|
MN |
1,100 |
0
|
CO |
0 |
500
|
IN |
0 |
250
|
Major Industries* |
Primary copper smelting |
1,856 |
765
|
Petroleum refining |
750 |
1,255
|
Primary nonferrous metals |
0 |
500
|
Blast furnaces, steelworks |
0 |
250
|
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.
|