MDL- Minimum Detectable Level (The smallest level that
can be detected by test).
MCL- Maximum Contaminent Level; 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. Based on this MCLG, EPA has set an
enforceable standard called a Maximum Contaminant Level. 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.
LINDANE MCL 0.2 ug/l
Lindane (gamma isomer of 1,2,3,4,5,6-hexachlorocyclohexane) is an insecticide
commercial and home use. Lindane is the active ingredient in several prescribed
shampoos used for the elimination of head lice. Lindane is slightly soluble in
water and will volatilize to the atmosphere from soil or water. It is persistent
in soils (half-life greater than 100 days), though it does undergo rapid
biotransformation under anaerobic conditions. Acute exposure of animals to
lindane results in neurological and behavioral effects. The liver and the kidney
appear to be the primary target organs for lindane toxicity. Lindane is
classified as "B2-C" (i.e., in between the lower half of the
"B" category of'probable' and the "C" category of ;possible'
carcinogen classifications) based upon evidence that lindane gives rise to
malignant liver tumors in two strains of mice, plus supportive evidence of
precancerous liver lesions in shorter term studies. Lindane, because of the
potential adverse effects and occurrence in drinking water, is regulated.
REASONABLY ANTICIPATED TO BE CARCINOGEN:
LINDANE AND OTHER HEXACHLOROCYCLOHEXANE ISOMERS
Annotated Digital Atlas of Global Water Quality