Cyclodiene Insecticides Highly toxic pesticides with good dermal absorption Bioconcentrated and biomagnified Aldrin is transformed to dieldrin in vivo as well as in the environment Chlordane still causes problems due to persistence and availability in NE US. Endrin-highly toxic yet short lived Heptachlor-treated grains killed wildlife, including wood pigeons and the foxes that ate them
ACh Cyclodiene Insecticides -Toxic Effects- Inhibition of the GABA GABA (gamma- aminobutyric acid) receptor,a Cl channel that stabilizes nerve cells. Loss of modulating influence in central nervous system leaves only stimulation and leads to severe convulsions +++++ Diagnosed using brain cyclodiene residue levels
Dieldrin Effects on GABA A 100 nM Diekrin in bath (7 min) 10n washou /V B 200 Dieldrin in bath 100 r100 180 1、=99.4% 160 80 n.=120 80 140 国 ICoo=15.5 nM 1.=40.0% 120 60 n.=0.64 60 100 ECn=4.4 nM 80 40 40 1 nM 10 nM 20 20 100nM 80 o-1000nM 0 0 10 10 100 1000 Time (min) [Dieldnn](nM
Dieldrin Effects on GABA
Other Organochlorines Lindane is the gamma isomer of hexachlorocyclohexane.Still used in seed treatments (being phased out internationally). Toxaphene is a complex mixture of Toxaphene chlorinated norbornanes with variable profiles in the environment.Many pelicans and other wading birds were killed in 1999 at Lake Apopka,Florida,from very old residues in“muck”(high organic matter)soils, Chlordecone and Mirex contaminated the James River (Virginia,USA)and caused neuro-and reproductive toxicity in humans PCP is used as a wood preservative
Skin Effects of Organochlorines ·DDT -Chloracne ·Lindane -Irritant reactions
Skin Effects of Organochlorines • DDT – Chloracne • Lindane – Irritant reactions