Study on distribution and behavior of dieldrin in environment

The purpose of the work reported here was to be estimated the fate of dieldrin in the environment by the present investigations and experiments. Samples investigated were sediments collected from river, sea and pond, suspended solids in river water, soils of paddy field and lumberyard, rain water and dust fall. Dust fall has been found to contain the dieldrin of 26.5ppb. The concentration in sediments has been found in range from 3.5 to 0.2ppb. This concentration was nearly equal to suspended solids collected river water. The soil of the paddy field and the lumberyard, and the rain water have been found to contain the dieldrin of 0.6ppb, 2.7ppb and 0.83ppt, respectively. The following experimenst have been carried out to elucidate the charcters of dieldrin in the environment: distribution coefficients of dieldrin on a few kinds of suspended solids and amount of dieldrin evaporated from water to atomosphere. The distribution coefficients of dieldrin determined by the batch experiment has been found in a range from 0.99X10**2 to 6.4**6X10**3. The amounts of dieldrin evaporated from water to atomsphere were related by residual value of dieldrin in water and itme while experimental water was allowed to stand at 20degC in the dark room. The relationship between reisidual value (R ; %) and time (D ; day) could be derived as follows: R=71/D**0.84. By the present investigations and experiments, the fate of dieldrin in the environment was suggested as follows: a part of dieldrin in water was adsorbed on suspended solids which were migrated and acumulated in sediments. Dieldrin in sediments was stored, and degraded slowly by was chemical reaction and microbe action. Another part of dieldrin in water was evaporated to atomsphere. Dieldrin in atomosphere was fallen on earth with the rain and dust fall.