Knows About Thallium
Notes about Thallium
from Environmental Health
Criteria document 182 by World Health Organisation
Allan Gow was an active
contributor to the North Lake Macquarie Environmental Health Liaison Meetings held near
Newcastle in NSW, until the meetings were cancelled by the Health Department in early
1999. Allan was a neighbour of the Pasminco Lead Smelter at Boolaroo who discovered that
0.6 tonnes of Thallium was stored on the site of the smelter. He summarised the World
Health Organisation (WHO) Criteria Document on Thallium, for the benefit of other
residents. We reproduce his notes here also because thallium has been found in ceiling
dust in Sydney homes that have been tested. Only the results from one of the 40 homes
tested has been published (see LEAD Action News vol 7 no 2, 1999). The results were
Thallium in the Flue Dust (dust sitting inside the flue pipe that vented from a coal gas
burner into the ceiling cavity) Sample: 3 mg/kg (milligrams per kilogram) and Thallium in
the Ceiling Dust Sample: <0.5 mg/kg. "Normal" soil range: 0.1 - 0.8 mg/kg.
Notes about THALLIUM:
Rapidly absorbed via Stomach,
Lungs & Skin & affects all internal organs progressively.
Thallium 1 carbonate induces
chromosomal aberrations plus Gene mutation.
0.5 gram is a fatal dose in 1 to
At 10-15 mg/Kg of Body Weight
(Daily) = Dead in 10-12 days.
Leaves the body through Urine
(non-cumulative) (30 days?) if you're not dead.
Above background levels it is
recommended that Bio monitoring of population living in the vicinity of the source be
World production 10?15 tonnes.
Pasminco = 0.6 tonne at Boolaroo suggests Blood, Urine, Hair Testing and Saliva is
U.S.A. stopped production in
Average daily intake for adults
is estimated to be 0.005 mg/Day (= 5 µg/Day)
1 µg/Day can be tolerated by
Vast Majority of Humans. Exposure to small amounts ? eat more potassium foods.
Speeds up ingestion of selenium
in kidneys and liver where thallium is released significantly.
1.0 µg/Litre in water can
deliver effects. Detection limit in 1987 was 5µg/Litre. Better analysis techniques are
0.01 µg/Litre can be found in
some "unpolluted" fresh water.
5mg/kg has been found in
Pale Blue in Colour. Fumes are
Odourless * Colourless * Tasteless.
In research laboratories, for
amounts greater than 0.01 mg (= 10 µg) - storage containers are to be sealed and clearly
Access to rooms where used
should be restricted.
Has high specific gravity (Heavy
metal). Has 2 isotopes:- 203 and 205.
Increased levels were found
around H2S04 (sulphuric acid) plant.
Flue dust is a source of
thallium as it is released in concentrations of the smallest particles that pass through
Even wool is not a satisfactory
Vapours and dust similar texture
to Lead and melts at 303°C, that is 1/2 the melting point of aluminium (Al).
Melted thallium accumulates in
top levels of soil, decreases at depth.
The weather side of a hill
opposite a smokestack is a Collector.
Accumulates in the chlorophyll as it is taken up by Plants. Uptake by plants increases as
soil pH decreases.
Thallium in soil and vegetables
from "acid rain" areas should be determined.
Does leak from soil into local
water. Easily soluble in Acid soil. Trees can be a long-term reservoir of thallium.
Plant uptake increases with
increased use of sewage sludge and Potash Fertilizers.
Waste material from mining
mercuric oxide and coal containing 25-106 mg/kg resulted in chronic poisoning in China
Prussian blue used as treatment
N.B. Cadmium: One of the most
toxic of heavy metals in the "Freshwater environment."
Editor's note: perhaps cadmium
will be Allan's next project. It is also found in ceiling dust. Thallium is no longer used
in developed countries due to concerns about its toxicity - however it is still used in
developing countries as a rodenticide (rat poison) due to its cheapness.