Toxicity of Cyclodienes

FIGURE 5.6 Dieldrin intoxication in hnmans and its relationship to blood levels. The hatched area represents the sublethal effects seen at 15-30% of lethal threshold concentration in blood (after Jager 1970). 

Experimental animals exposed to sublethal doses of cyclodienes show a similar picture, with changes in EEG patterns, disorientation, loss of muscular coordination and vomiting, as well as convulsions, the latter becoming more severe with increasing doses (Hayes and Laws 1991). It is clear from these wide-ranging studies that a number of neurotoxic effects can be caused by cyclodienes at levels well below those that are lethal. In the human studies described here, subclinical symptoms were frequently reported when dieldrin blood levels were in the range 50-100 pg/L, an order of magnitude below those associated with lethal intoxication. 

Some data on cyclodiene toxicity is presented in Table 5.9. Aldrin and dieldrin have similar levels of acute toxicity indeed, the toxicity of aldrin has been largely attributed to its stable metabolite, dieldrin. Dieldrin is highly toxic to fish, mammals. 

96h LCjo 330 pg/L 96h LCjo 4-18 pg/L 96h LCjo 1.2-9.9 pg/L 96h LCjo 7 pg/L Acute oral LDjo 37-87 mg/kg Acute oral LDjo 45-50 mg/kg Acute oral LDjo 40-162 mg/kg Acute oral LDjo 67 mg/kg Acute oral LDjo 4-43 mg/kg 

Organic Pollutants An Ecotoxicological Perspective, Second Edition 

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