Comparative effects of synthetic insecticides--endosulfan, phosalone and permethrin--on Chlamydomonas reinhardtii algal cells.

Presence of insecticide-endosulfan, phosalone or permethrin in the growth medium caused concentration dependent inhibition in the vegetative growth of Chlamydomonas reinhardtii algal cells. The rate of inhibition produced by endosulfan was two-fold higher than that of phosalone or permethrin. Endosulfan affected the cell growth completely at 100 times less concentration as compared to that of phosalone or permethrin. Non-dividing cell populations encountered significant losses in cells during their exposure (2 h) to endosulfan and did not show further loss in the 72 h post-treatment period. The populations treated with phosalone exhibited losses of considerable magnitude in the post-treatment period. Permethrin treated non-diving cell populations did not lower the cell number, either after the treatment period (2 h) or the post-treatment period (72 h). However, these populations showed reduced levels of chlorophyll following the exposure of the insecticide and did not display recovery or further reduction in the levels in the post-treatment period. The chlorophyll levels of endosulfan or phosalone treated cell populations remained unaffected. The cells remaining intact after the treatment (2 h) of endosulfan or phosalone exhibited significant decreases in their post treatment vegetative growth abilities. The growth ability of such permethrin exposed cells was similar to that of untreated cells.