Table 1: Residues of organochlorine hydrocarbon insecticides in freshwater from Alexandria Citya.
| Pesticide | Concentration (ppb) | |||
| Canals raw water | Plants treated water | Tap water | wastewater | |
| HCB | 0.39 | ND | 0.1 | 0.19 |
| Lindane | 0.34 | 0.19 | 0.29 | 0.63 |
| Heptachlor | 0.7 | 0.1 | 0.12 | 0.19 |
| p,p'-DDT | 0.65 | 0.47 | 0.47 | 0.95 |
| o,p'-DDT | 0.95 | ND | 0.95 | 0.25 |
ND = Not detected; aAdapted from El-Sebae and Abu El-Amayem [29].