Degradation of Pesticides - Pesticides: Evaluation of Environmental Pollution - page 51

6. Crop residue and pesticide concentration are two other factors that influence chemical
degradation.

3.2.2 Organochlorine Pesticides

Organochlorine compounds are resistant to chemical degradation in soil. Dichlobenil
and chlorothalonil undergo substitution of Cl with OH or hydration of CN group.
Dichlorodiphenyltrichloroethane (DDT) and methoxychlor undergo reductive deha-
logenation at the trichloromethyl group and hydroxylation at the tertiary carbon to form
alcohol (Pirnie et al. 2006). Cyclodiene-chlorinated compound endosulfan hydrolyzes to
endosulfan alcohol and oxidizes to endosulfan sulfate in soil and water.

OH OH

OCH 2 COOH

Cl

Cl

CH 2 COOH

Cl
2,4-D

Cl

CCl 3

CCl 3

CH

OH

C

Cl Cl

Cl

Cl

CH

Cl Cl

CCl

CCl

CH

Cl

Cl

Dichlorvos undergoes hydrolytic decomposition as (Musa et al. 2010).