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SELENIUM
FACT SHEET ON A DRINKING WATER CHEMICAL CONTAMINANT
GENERAL INFORMATION
Synonyms:
•	None
Chemical Description:
•	Naturally occurring inorganic chemical (metal)
found in abundance in combined form in
rocks and soils around the world, usually with
sulfide-type ores of heavy metals
Properties:
•	Solubility of selenium compounds is chemical-
specific
Production and Use:
•	Used in electronics, photocopy components,
the manufacture of glass, chemicals, drugs,
and as a fungicide and feed additive
ENVIRONMENTAL PROFILE
Occurrence:
•	Occurs naturally as a low level conatminat of
drinking water as a result of weathering of soils
and rocks, and as a by-product of copper
mining and smelting
•	Present in coal and fuel oil
•	Present in food
Releases:
•	Released to the environment primarily from
coal combustion, copper mining and smelting,
and industrial wastes
Environmental Fate:
•	In alkaline soils and oxidizing conditions, it may
be oxidized sufficiently to maintain the avail-
ably of its biologically active form, and cause
plant uptake of the metal to be increased
•	In acidic or neutral soils, it tends to remain
relatively insoluble and the amount of bio-
logically available selenium should • steadily
decline
HEALTH EFFECTS
Humans:
•	An essential nutrient at low levels (inadeauate
dosage results in Keshan disease)
•	Short-term toxic effects of high-dose exposure
include hair and fingernail changes, damage
to the peripheral nervous system, fatigue, ana
irritability
•	Long-term toxic effects of high-dose exposure
include hair and fingernail loss, and damage
to the kidney, liver, and nervous and
circulatory systems
Experimental Animals:
•	Long-term, high-dose exposures cause
damage to the kidney, liver, and nervous and
circulatory systems
•	Little evidence of mutagenic or carcinogenic
potential
REGULATORY PROFILE
Existing Standards:
•Clean Air Act (CAA): Not regulated
•Clean Water Act (CWA):
Criteria established
•Resource Conservation and Recovery Act
(RCRA):
Not regulated
•Superfund (CERCLA):
•Hazardous waste
•SARA: Toxic waste
•Federal Insecticide, Fungicide, and
Rodentlcide Act (FIFRA):
Registered
•Toxic Substances Control Act (TSCA):
Regulated

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HEALTH INFORMATION
WATER TREATMENT
Maximum Contaminant Laval Goals (MCLG):
•	Non-enforceable levels based solely on an
evaluation of possible health risks and
exposure, and talcing into consideration a
margin for public safety
•	Set at 0.05 mg/L to protect against damage to
the nervous system
MCLG for Selenium = 0.05 mg/L
(effective July 1992)
Maximum Contaminant Levels (MCL):
•	Legally enforceable levels for contaminants in
public drinking water supplies
•	Based on health risks associated with the
contaminants, analytical methods for their
assay, and water treatment feasibility and
practicality aspects
•	Exceedance of the MCL in drinking water may
result in adverse effects which will depend
upon the contaminant concentration in water,
amount of water/contaminant ingested,
length of exposure, and other biological
parameters
•	Current MCL = 0.01 mg/L
MCL for Selenium = 0.05 mg/L
(effective July 1992)
EPA Health Advisories (HA):
•	Short-term HAs: Provide acceptable
concentrations of contaminants in water for
up to 10 day exposures, primarily to evaluate
the public health risk resulting from an
accidental spill or an emergency
contamination situation
•	Longer-term HAs: Provide guidance for
persistent water contamination situations to
cover a period of up to 7 years
•	Lifetime HAs: Derived in the same way as an
MCLG
Health Advisories:
Permanent Treatment:
•	Best Available Technology (BAT):
•	Electrodialysis Reversal
•	Coagulation/Filtration
•	Activated Alumina
•	Lime Softening
•	Reverse Osmosis
SHORT-TERM HAZARD ELIMINATION
•	If the drinking water standards are exceeded,
install BAT or use an alternative drinking water
supply such as bottled water
ADDITIONAL HELP
•	State or county health officials can indicate a
certified laboratory for testing
•	Experts in the state Department of
Environmental Protection or Natural Resources
may also be of help
•	The EPA has toll-free numbers for further
information on drinking water quality,
treatment technologies, for obtaining Health
Advisories, and for other regulatory information
•	EPA Hotlines are available Monday through
Friday
•Safe Drinking Water	800-426-4791
•National Pesticides:	800-858-7378
•Superfund/RCRA:	800-424-9346
•	For information on the Clean Water Act, call
(202) 260-7301
•	For information on the Toxic Substances
Control Act, call (202) 554-1404
•	For information on the Clean Air Act, call
(919) 541-2777
A Heaitti Advisory does not exist at this time
ANALYTICAL METHODS
~	Gaseous Hydride Atomic Absorption
EPA Method 270.3
•	Graphite Furnace Atomic Absorption
EPA Method 270,2

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