of organochlorine compounds (references in Neilson
et al., 1991): in contrast to the compounds noted
above, however, these are not deliberately
synthesized but are by-products. The introduction
of alternative technologies however, and in
particular those that do not use chlorine in any form
will essentially eliminate this source of
organochlorine compounds in the future.
Serious concern has been expressed over the
massive introduction of synthetic chemicals into the
environment, and the potentially adverse effects of
DDT, PCBs and aliphatic organohalogen compounds
used as solvents and as refrigerants have
become notorious. The reasons for this concern
originate in the properties of many organochlorine
compounds. In assessing their environmental
impact, three factors are of primary importance:
(1)
(2)
(3)
their recalcitrance to degradation - both
biotic and abiotic;
their toxicity;
their potential for partition into biota, and
soil and sediment.