United States
                             Environmental Protection
                             Agency
            Office of Water
            4601
                           EPA811-F-95-002n-T
                                 October 1995
                             National Primary Drinking
                             Water  Regulations
                             Thallium
  CHEMICAL/ PHYSICAL PROPERTIES
  CAS NUMBER: 7440-28-0 (metal)
  COLOR/ FORM/ODOR: Thallium is a metallic element that exists in
    nature only in as salts and other combined forms. '
  SOIL SORPTION COEFFICIENT: N/A; strongly adsorbed to some clays
    at alkaline pH.        '     '
  BIOCONCENTRATION FACTOR: Log BCFs = 5 to 5.2 in fish, inverte-
    brates; expected to bioconcentrate
      SOLUBILITIES:
        acetate
        carbonate-
        chloride-
        nitrate-
        oxide-
        sulfate-
             very soluble
             4% (w/w) cold water
             2.9g/Lat15.5degC
             39.1 g/L to 95.5 g/L at 20 deg C
             insoluble
             48.7 g/L at 20 deg C
COMMON ORES: Thallium is a trace metal associated with potas-
  sium in copper, gold, zinc, and cadmium ores.
DRINKING WATER STANDARDS
  MCLG:      O.OQ05mg/l
  MCL:       0.002 mg/l
  HAL(child):  1-to 10-day: 0.007 mg/L
             Longer-term: 0.007 mg/L

HEALTH EFFECTS SUMMARY
  Acute: EPA has found thallium to potentially cause the
following health effects from acute exposures at levels
above  the MCL: gastrointestinal. irritation; peripheral
neuropathy.
  Short-term exposures considered "safe" for a 10-kg
(22 Ib.) child consuming one liter of water per day: upto a
7-year exposure to 0.007 mg/L.
  Chronic:  Thallium has the potential to cause the
following health  effects from long-term exposures at
levels above the MCL: changes in blood chemistry;
damage to liver, kidney, intestinal and testicular tissues;
hair loss.    '
  Cancer: There is no evidence that thallium has the
potential to cause cancer from lifetime exposures in
drinking water.

USAGE PATTERNS
  There is no domestic production of thallium. Approxi-
mately 4,500 Ibs. of thallium and its .compounds were
imported in 1987. In 1984, US industry consumed thal-
lium  compounds as follows:  electronics industry, 60-
70%; the remainderwas used in Pharmaceuticals, alloys
and glass manufacture.
        Thallium compounds are used in infrared spectrom-
      eters, in crystals, in other optical systems, and for color-
      ing glass; in semiconductor research; with mercury for
      switches and closures which operate at subzero tem-
      peratures; in photoelectric cells, lamps, and, in electron-
      ics, in scintillation counters; as catalyst in organic synthe-
      sis; as a rat poison, as an  ant bait, and as a reagent in
      analytical chemistry. It was  also formerly used as a
      depilating agent by dermatologists and as a cosmetic
      depilatory cream.

      RELEASE PATTERNS
        In nature, thallium is present  as a trace compound in
      many minerals, mainly associated with potassium and
      rubidium.
        Man-made sources of thallium pollution are gaseous
      emission of cement factories, coal burning power plants,
         Toxic RELEASE INVENTORY -
         RELEASES TO WATER AND LAND:
                              1987 TO 1993
        TOTALS (in pounds)

        Top Five States
        TX
        OH
        MN
        CO
        IN
                      Water
                      2,606
                         6
                       1.500
                       1,100
                         0
                         0
         Major Industries*
         Primary copper smelting   1,856
         Petroleum refining        750
         Primary nonferrous metals     0
         Blast furnaces, steelworks     0
Land
2.770
2,020
   0
   0
  500
  250
                                        765
                                      1,255
                                        500
                                        250
October 1995
Technical Version
                            Printed on Recycled Paper

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 and metal sewers. The leaching of thallium from ore
 processing operations is the major source of elevated
 thallium concentrations in water. Thai;   < is a trace metal
 associated with copper, gold, zinc, and cadmium.
  .Water concentrations of 1 to 88 parts per billion have
 been reported in rivers draining metal mining areas.
   From 1987 to 1993, according to the Toxics Release
 Inventory thallium  releases to land and water totalled
 over 5,000 Ibs., of which about half was to water. These
 releases were primarily from copper smelting and petro-
 leum refining industries. The largest releases occurred in
 Texas and Ohio.
ENVIRONMENTAL FATE
                        i.
   In a study of thallium movement in a simple aquatic
ecosystem, concentrations of thallium decrease slowly in
the water and increase tenfold in the vegetation and fish.
Definite transport of thallium occurred among water, fish,
and vegetation, but no transport was seen between the
sand other ecosystem components.
   It was found that increasing pH decreased thallium-
inorganic interactions. Increases  in pH, however, pro-
duced extensive thallium-humic acid interaction.  It ap-
pears that thallium-organic interactions may be important
in most natural water systems.
   In reducing environments, thallous species may pre-
cipitate as a sulfide; otherwise, it will remain in solution.
   Thallium sulfate has been used  as a rodenticide in
Japan, where it was sprayed over forest areas, but was
not found to persist in water for more than a month. Since
thallium is soluble in most aquatic systems, it is readily
available to aquatic organisms and is quickly bioaccumu-
lated. Goldfish have a higher rate of uptake for thallium
than for the five most common alkali metals. Some algae
are able to concentrate thallium by a factor of 127 to 220
within one hour; in comparison, the concentration factors
of 2.7 hours exposure were 114for lead, 30 for cadmium,
80 for zinc, and 313 for copper.
   Bioconcentration factors: in freshwater fish,-factor of
100,000; in marine invertebrates, factor of 150,000; in
marine fish, factor of 100,000; in freshwater and marine
plants, factor of 100,000; in clams  (Mya arenia), factor of
17.6-18.6; in mussel (Mytilus edulis), factor of 10.9-12.4;
and in Atlantic salmon, factor of 27-1430.
         OTHER REGULATORY INFORMATION
         MONITORING:
         - FOR GROUND WATER SOURCES:
           INITIAL FREQUENCY-  1 sample once every 3 years
           REPEAT FREQUENCY-  If no detections tor 3 rounds, once every 9 years
         - FOR SURFACE WATER SOURCES:
           INITIAL FREQUENCY-  1 sample annually
           REPEAT FREQUENCY-  If no detections for 3 rounds, once every 9 years
         - TRIGGERS - If detect at > 0.002 mg/L, sample quarterly.


         ANALYSIS:
         REFERENCE SOURCE            METHOD NUMBERS
         EPA 600/4-79-020            279.2
         NTIS PB 91-231498           200.8; 200.9
         Standard Methods            3113:31138

         TREATMENT
         BEST AVAILABLE TECHNOLOGIES   .              
         Activated alumina; Ion Exchange


         FOR ADDITIONAL INFORMATION:
         4 EPA can provide further regulatory and other general information:
          EPA Safe Drinking Water Hotline - 800/426-4791
         f Other sources of lexicological and environmental fate data include:
          toxic Substance Control Act Information Line - 202/554-1404
          Toxics Release Inventory, National Library of Medicine - 301/496-6531
          Agency for Toxic Substances and Disease Registry - 404/639-6000
 October 1995
Technical Version
Page 2

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