Mirex reproductive effects

Wolfe, J.L., R.J. Esher, K.M. Robinson, and J.D. Yarbrough. 1979. Lethal and reproductive effects of dietary mirex and DDT on old-field mice, Peromyscus polionotus. Bull. Environ. Contam. Toxicol. 21 397-402. Wood, P.B., C. Vivarette, L. Goodrich, M. Pokras, and C. Tibbott. 1996. Environmental contaminant levels in sharp-shinned hawks from the eastern United States. Jour. Raptor Res. 30 136-144. 

No studies were located regarding reproductive effects in animals after inhalation exposure to mirex of chlordecone. 

The highest NOAEL and all LOAEL values from each reliable study for reproductive effects in each species and duration category are recorded for mirex in Table 2-1 and for chlordecone in Table 2-2 and plotted for mirex in Figure 2-1 and for chlordecone in Figure 2-2. 

No studies were located regarding reproductive effects in humans after dermal exposure to mirex. The available data in humans indicate that chlordecone causes male reproductive effects. Occupational exposure to chlordecone for up to 1.5 years caused oligospermia and decreased sperm motility in male workers. However, there were no reported infertility in these male subjects despite loss of sperm motility in some workers (refer to Section 2.2.1.5 for further details). 

No studies were located regarding reproductive effects in animals after dermal exposure to mirex. The only animal study that referred to reproductive effects following dermal exposure to chlordecone was conducted in rabbits by Allied Chemical. This study was not available for review. A published review of the study (Epstein 1978) indicated that chlordecone applied to shaved skin at dose levels of 5 or 10 mg/kg for 8 hours/day, 5 days/week, for 3 weeks induced testicular atrophy in two of six rabbits at 5 mg/kg and in one of six rabbits at 10 mg/kg. No other toxic effects were noted. This study is limited by the lack of dose response and lack of a NOAEL for the effect observed. 

Wolfe JL, Esher RJ, Robinson KM, et al. 1979. Lethal and reproductive effects of dietary mirex and DDT on old-field mice, Permyscus polionotus. Bull Environ Contam Toxicol 21 397-402. 

Concentrations of PCBs in fish from each of the Great Lakes currently exceed the GLWQA objectives for the protection of aquatic life. Similarly, concentrations of some substances (e.g., PCBs, Hg, mirex, toxaphene) in Great Lakes fish continue to exceed acceptable guidelines for human consumption. Documented effects in the Great Lakes include reproductive failure, congenital abnormalities and induction of tumours in various aquatic, terrestrial and avian species (23). 

Mirex has considerable potential for chronic toxicity because it is only partly metabolized, is eliminated very slowly, and is accumulated in the fat, liver, and brain. The most common effects observed in small laboratory mammals fed mirex included weight loss, enlarged livers, altered liver enzyme metabolism, and reproductive failure. Mirex reportedly crossed placental membranes and accumulated in fetal tissues. Among the progeny of mirex-treated mammals, developmental abnormalities included cataracts, heart defects, scoliosis, and cleft palates (NAS 1978 Blus 1995). 

Koenig, C.C. 1977. The effects of DDT and mirex alone and in combination on the reproduction of a salt marsh cyprinodont fish, Adinia xenica. Pages 357-376 in FJ. Vemberg, A. Calabrese, F.P. Thurberg, and W.B. Vemberg (eds.). Physiological Responses of Marine Biota to Pollutants. Academic Press, New York. 

Shannon, V.C. 1976. The Effects of Mirex on the Reproductive Performance and Behavioral Development of the Prairie vole Micropterus ochrogaster. Ph.D. thesis, Iowa State Univ., Ames. 318 pp. 

We do not know how mirex directly affects the health of people. However, animal studies have shown that eating mirex can cause harmful effects on the stomach, intestines, liver, and kidneys. Eating mirex can also cause harmful effects on the eyes, thyroid, nervous system, and reproductive system. Since these effects occur in animals, they may also occur in people. 

Chu I, Villeneuve DC, Secours VE, et al. 1981b. Effects of photomirex and mirex on reproduction in the rat. Toxicol Appl Pharmacol 60 549-556. 

Smrek AL, Adams SR, Liddle JA, et al. 1977. Pharmacokinetics of mirex in goats 1. Effect of reproduction and lactation. J Agric Food Chem 25(6) 1321-1325. 

Davison, K.L., Cox, J.H., Graham, C.K., 1975. The effect of mirex on reproduction of Japanese quail and on characteristics of eggs from Japanese quail and chickens. Arch. Environ. Contam. Toxicol. 3, 84-95. 

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