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For starters it is
consistently ranked among the top chemicals of concern
by the Agency
for Toxic Substances and Disease Registry
(currently ranked 33 out of 275.)
By any other name, lindane is the 99% pure gamma isomer
of hexachlorocyclohexane. It was introduced as a
pediculicide and scabicide in 1952 as Kwell by Reed and
Carnrick. The Pharmaceutical Manufacturing Encyclopedia
describes the manufacturing process of lindane as one in
which chlorine gas is gradually passed
into 660 parts of benzene (a known
carcinogen) until 890 parts of the gas has been
absorbed. The mixture is stirred continuously and the
temperature is maintained at 15 degrees C to 20 degrees
C.
The supply of chlorine
is then interrupted and the precipitated solid filtered
off and dried. In weight, it is found to be equivalent
of 900 parts. The mother liquid is then mixed with 330
parts of benzene and the mixture again
treated with 890 parts of chlorine in the
manner described. After filtering the reaction mixture
resulting from the second chlorination,
the filtrate is again mixed with a smaller quantity of benzene
and again chlorinated in a similar manner.
In this way, a continuous process for the preparation of
benzene hexachloride results.
This benzene
hexachloride isomer mixture is then the raw material for
lindane production.
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What does the Merck Index say
about lindane?
According to the
Centennial Edition of the Merck Index, poisoning with
lindane may occur by ingestion, inhalation, or skin
absorption; possible acute symptoms include headache,
nausea, vomiting, diarrhea, tremors, weakness,
convulsions, dyspnea, cyanosis circulatory collapse. The
Merck Index states that "Lindane and other
hexachlorocyclohexane isomers may reasonably be
anticipated to be carcinogens."
Is there a
connection between lindane and seizures?
The proconvulsant properties of repeated low
doses of lindane were reported by Joy and colleagues and
it has been since this time that lindane has been used
as a kindling agent for studying seizures in rats. M.E.
Gilbert published her work with rats and lindane in, Toxicology
and Industrial Health, Vol. 10, No. 4, 1994, Neurotoxicology
and Teratology, Vol. 17, No 2 1995. Gilbert chose
lindane for her studies because of its pharmacokinetic
and pharmacodynamic properites well characterized in the
rat. Those who think it is okay to keep prescribing
lindane need to think again!
The
United States is one of very few industrialized
countries still using lindane in agriculture
and for lice control. Sign this petition
to U.S. Surgeon General, Richard H. Carmona,
urging him to call for an immediate ban on lindane.
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