Past use of endrin as an agricultural pesticide has been the principal source of its release to soils or aquatic sediments. Emissions from endrin production and processing facilities and agricultural applications were primary sources of releases of this compound to the atmosphere.
Endrin is extremely persistent when released to the soil. It adsorbs strongly to soil particles and tends to be immobile. Endrin on soil may be transported to surface water via runoff from rain or irrigation. Since endrin in solid form is hydrophobic and sorbs strongly to soil particles, migration into groundwater would not generally be expected from normal agricultural application. However, endrin has been detected in some leachates and groundwaters suggesting that leaching may be possible in some soils under certain conditions.
Despite endrins low vapour pressure, initial volatilization of 2030% after agricultural application to soil has been reported to be rapid. Within 11 days, however, further volatilization was no longer detected.
Because of its high log Koc and log Kow values, when released to water, endrin strongly adsorbs to sediment and bioconcentrates significantly in aquatic organisms.
Based on its very small calculated Henrys law constant and its strong adsorption to sediment particles, endrin would be expected to partition very little from water into air. The halflife for volatilization of endrin from a model river, 1 m deep, flowing 1 m/sec, wind speed 3 m/sec, was estimated to be 9.6 days.
In air, endrin is expected to be associated primarily with particulate matter, based on its low vapour pressure and high Koc. However, small amounts of endrin in the atmosphere may exist in the vapour phase. Because of its low solubility endrin would not be expected to be removed significantly from the atmosphere by wet deposition.
Particleadsorbed endrin will be removed from the atmosphere by both wet and dry deposition.