HexaclorocyclohexaneThe Effects of Long Term Exposure

What is Hexaclorocyclohexane?

• Grouped as an Organochlorine Insecticide.• Colorless, Crystal Compound• Chemical Name: gamma- 1,2,3,4,5,6-

hexachlorocyclohexane• Used as: an insecticide on fruit and vegetable crops, seed

treatment, in forestry, as well as livestock treatment.• Initially produced after the photochloronation of

benzene.• Hexachlorocyclohexane’s insecticidal properties were

discovered in 1942.

Uses• Lindane has been used on a wide range of soil-dwelling

and plant-eating insects.• Commonly used on crops, but also in warehouses.• As a fungicide.• For public health.

Currently Used• In lotions, creams, and shampoos.

HCH Metabolism

• Lindane is readily absorbed by the gastrointestinal tract, skin, and lungs.• HCH metabolism in the body is very complex, occurring

in different pathways but also rapid.• The main pathways eliminate chlorines, conjugating with

sulfates or gluconuronides for elimination.• Other pathways form water-soluble mercapturates,

which are excreted through the urine.

Case Study 1:• Sheep owners in Iceland used to dip their sheep in HCH to

prevent incidents of ectoparasites.• The correlation of sheep owners and Non- Hodgkin's

Lymphoma was near unity compared to the general public.

Case Study 1: Results

• The odds ratio for NHL was 3.86 with a 95% confidence interval for those having 100 sheep or more as compared to those who had less than 100 sheep, adjusted for age.• With age, a continuous variable was associated with the

risk of NHL.• With the number of sheep owned, serving as a proxy for

exposure to HCH, the odds of risk ratio was high and the 95% confidence intervals, did not include unity in the sample studied.

Case Study 2:

• A study was conducted between organochlorine insecticides and fungicides and association to Non-Hodgkin’s Lymphoma, as well as its subtypes.• The sample was taken from a cohort of farmers and

commercial pesticide applicators in North Carolina and Iowa.• The analysis sample was a total 54,306 participants.

Information on cancer incidence was taken by regular association to the population-based cancer registry files in Iowa and North Carolina.

Case Study 2: Results

Case Study 2: Results Cont’d

• Pesticides from different chemical and functional classes showed association with excess risk of NHL and its subtypes.• A significant exposure–response trend for total Non-

Hodgkin’s Lymphoma was observed with use for two organochlorine insecticides, Lindane and DDT.• There was a total of 523 incident cases of NHL, including

148 cases from subtypes and 99 cases of Multiple Myeloma.

HCH Today…• Lindane was restricted by the EPA due to its potential to

cause cancer and birth defects in animals.• Production of lindane was terminated in the U.S. in 1976.• As of today, in the U.S. imported lindane is now used to

treat lice and scabies.• Residues of Lindane in diets are gradually decreasing and

are no longer considered a health concern in the U.S.

References• Risk of non-Hodgkin’s lymphoma and exposure to hexachlorocyclohexane, a

nested case-control study. Vilhjalmur Rafnsson. Eurpean Journal of Cancer. 42, 16, 2781-2785

• Occurrence and distribution of hexachlorocyclohexane isomers in vegetation samples from a contaminated area. P.C. Abhilasha, Sarah Jamila, Vandana Singha. Chemosphere. 2008. 01. 79-86

• Non-Hodgkin Lymphoma Risk and Insecticide, Fungicide and Fumigant se in the Agricultural Health Study. Alavangja, MCR., Hofmann, J.N., Lynch, C.F. Public Library of Science. 2014. 10. 1371

• Life after lindane in California: water concentrations, poison control calls drop following ban. Brown, Valerie. Environmental Health Perspectives. 2008. 116.3, pA128.