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Toxicokinetics and Biomarkers/Environmental Sources of Exposure Biomonitoring Levels

Biomarkers TM General Populations Toxicokinetics . ToxGuide . Endrin is a man-made chemical used as a . Toxic effects following oral, inhalation, Levels of endrin and endrin metabolites pesticide. It has not been produced or or dermal exposure indicate that the body can be measured in blood, fatty tissue, used in the United States since 1991. absorbs endrin via all routes; however, urine, feces, and breast milk. data regarding absorption rates are very for . Environmental exposure is expected to . Measurements of endrin in blood are best limited. be low. suited for detecting recent exposures . Endrin is rapidly metabolized and because endrin is cleared rapidly from . The general population may be exposed excreted in urine and feces. blood. Endrin to endrin through ingestion of imported contaminated food or from contaminated . Low concentration of endrin may remain . Hair has been shown to be a sensitive water, soil, or air near waste disposal and be distributed in fat. Endrin can also target to detect prior endrin exposure. sites. cross the placenta. . The major biotransformation product of endrin is anti-12-hydroxyendrin and the C12H8Cl6O

corresponding sulfate and glucuronide Occupational Populations metabolites. Environmental Levels (CAS # 72-20-8) . Occupational exposures to endrin may . There are no recent monitoring data for March 2021 occur among workers involved in the environmental levels of endrin in air. handling and treatment of materials at water, or soil.

hazardous waste sites, and among NHANES Biomonitoring . Monitoring data at hazardous waste sites agricultural workers at sites formerly are available. The geometric mean levels . Serum endrin levels in the National treated with endrin. were 0.0024 ppbv in air (4 National Health and Nutrition Examination Priorities List [NPL] sites), 0.651 ppb in U.S. Department of Health and Survey (NHANES) (2001–2004) were water (13 NPL sites), and 1,160 ppb in Human Services below the level of detection. No other soil (24 NPL sites). Public Health Service data are available. Agency for Toxic Substances

and Disease Registry www.atsdr.cdc.gov

Reference Agency for Toxic Substances and Disease Registry (ATSDR). 2021. Toxicological Profile for Endrin. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Services.

Chemical and Physical Information Routes of Exposure Relevance to Public Health (Health Effects) Health Effects Endrin is a Solid . Inhalation – Not likely an exposure route Health effects are determined for the general or occupational by the dose (how much), the . In animal studies, inhalation, oral and . dermal exposure resulted in neurological Endrin is a solid, white, almost odorless population. duration (how long), and the substance. . effects (altered activity, convulsions). and Oral – Most likely route of exposure for route of exposure. hepatic toxicity. . Endrin’s principal use was as an the general population through ingestion . With the exception of increased insecticide, rodenticide, and avicide of contaminated imported foodstuffs and locomotor activity in rat offspring, beginning in 1951. water. Minimal Risk Levels (MRLs) developmental effects were only Inhalation . Dermal – Not likely an exposure route of observed at doses that caused significant . Endrin’s production and use has been concern for the general or occupational discontinued since 1991 mostly due to its . No acute-, intermediate-, or chronic maternal mortality and/or toxicity. population. duration inhalation MRLs were derived toxicity on nontarget populations of birds . The U.S. Environmental Protection for endrin. such as raptors (birds of prey) and Agency (EPA) has classified endrin in migratory birds. Endrin in the Environment Group D, not classifiable as to Oral . . There is potential for endrin to be carcinogenicity in humans. The Endrin aldehyde and endrin ketone occur International Agency for Research on as impurities of endrin or as degradation released into the environment from . An acute-duration (≤14 days) oral MRL hazardous waste sites, unregistered use, of 0.0006 mg/kg/day was derived for Cancer (IARC) has classified endrin in products. Group 3, not classifiable as to its or inappropriate disposal. endrin. . . carcinogenicity in humans. Endrin is generally not found in the air The acute-duration oral MRL of except when it was applied to the fields in 0.0006 mg/kg/day was adopted as an the past during agricultural application. intermediate-duration (15–364 days) oral . Endrin adsorbs strongly to soil particles MRL for endrin. Children’s Health and sediment and tends to be immobile. . A chronic-duration (≥365 days) oral . It is not known if children are more . The estimated half-life of endrin in soil is MRL of 0.0003 mg/kg/day was derived sensitive to endrin toxicity than adults. approximately 14 years. for endrin. . It is not expected to migrate significantly from soil to groundwater; however, at waste sites where endrin may become Health Effects mixed with organic solvents, migration may be increased. . The central nervous system is the most sensitive target to endrin in humans. . Endrin may be transported to surface water via runoff from rain or irrigation. . Exposure to high levels of endrin can cause harmful neurologic effects, . Endrin transformation products can be including convulsions, jerking of arms detected in plants grown in soils treated and legs, twitching facial muscles, clonic at least 16 years prior to planting. contractions, changes in electro- . Endrin has the potential to significantly encephalogram (EEG) patterns, sudden bioconcentrate in aquatic organisms. collapse, and death in humans.