Environmental impact

Dieldrin is nonpolar and, therefore, has a strong affinity for organic matter and sorbs tightly to soil particulates based on its log Koc of 6.67. Volatilization is the principal loss process of dieldrin from soil. The process is relatively slow due to its low vapour pressure and strong sorption to soil. It may also be impeded by low soil moisture or incorporation of the compound into the soil. The volatilization rate decreases with time and increases with increasing temperature to a maximum at 25 °C.
Based on the Henry's law constant and the Koc, the volatilization halflife of dieldrin from soil has been estimated to be 2.5 years. Movement of dieldrin through the soil solution is extremely slow, indicating little potential for groundwater contamination. Analysis of environmental groundwater samples has shown that on some occasions, dieldrin has contaminated groundwater systems.
Based upon a Henry's law constant, volatilization of dieldrin from water surfaces is expected, however, may be attenuated by adsorption to suspended solids and sediment in the water column.
According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere, dieldrin, will exist in both the vapour and particulate phases in the ambient atmosphere. Dieldrin may be transported great distances in the atmosphere and be removed by wet or dry deposition.
Dieldrin has a high potential for bioaccumulation as indicated by a log Kow value that ranges from 4.32 to 6.2. This factor indicates, that dieldrin will bioconcentrate and biomagnifie in living organisms.


Structure formula of Dieldrin

3D structure of Dieldrin