Mirex in the Southeastern

Between 1961 and 1975, about 400,000 kg of mirex were used in pesticidal formulations, of which approximately 250,000 kg were sold in the southeastern U.S. for control of native and imported fire ants (Solenopsis spp.) most of the rest was exported to Brazil for use in fire ant control in that country. Mirex was also used to control big-headed ant populations in Hawaiian pineapple fields, Australian termites. South American leaf cutter ants. South African harvester termites, and, in the U.S., western harvester ants and yellow jackets. Chemical control measures for imported fire ants began in the southeastern U.S. during the 1950s with the use of heptachlor, chlordane, and dieldrin. The large mounds built by ants in cultivated fields were believed to interfere with mowing and harvesting operations, the vicious sting of the insects presented a hazard to workers 

Widespread use of mirex may lead to altered population structure in terrestrial systems, with resurgence or escalation of nontarget pests due to selective mirex-induced mortality of predators. For example, populations of immature horn flies and rove beetles, two species of arthropods normally preyed upon by fire ants, were higher in mirex-treated areas than in control areas. Conversely, other species, such as crickets, ground beetles, and various species of oil-loving ants, were directly affected and populations were still depressed or eliminated 14 months post-treatment, whereas fire ants recovered to higher than pretreatment 

Mirex concentrations in muscle and liver of mammalian wildlife in Alabama and Georgia during the period 1973-76 from reference 

A 10-5 bait formulation containing 0.1% mirex was designed to make more of the toxicant available to the fire ant and less to nontarget biota. In one study, the 10-5 formulation was applied to a previously untreated 8000-ha area near Jacksonville, Florida, infested with fire ants. The bait was applied by airplane at 1.12kg/ba, or 1.12 g mirex/ha. Insects accumulated mirex to the greatest extent during the first 6 months after application, and most of 

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Kutz FW, Strassman SC, Stroup CR, et al. 1985. The human body burden of mirex in the southeastern United States. J Toxicol Environ Health 15(3-4) 385-394. 

Mirex and chlordecone are no longer made or used in the United States. Mirex and chlordecone were most commonly used in the 1960s and 1970s. Mirex was used as a pesticide to control fire ants mostly in the southeastern part of the United States. It was also used extensively as a flame retardant additive under the trade name Dechlorane in plastics, rubber, paint, paper, and electrical goods from 1959 to 1972 because it does burn easily. Chlordecone was used to control insects that attacked bananas, citrus trees with no fruits, tobacco, and ornamental shrubs. It was also used in household products such as ant and roach traps. Chlordecone is also known by its trade name Kepone . All registered products containing mirex and chlordecone were canceled in the United States between 1977 and 1978. 

Uses Mirex is used in North America and in the southeastern United States for the control of fire and ants. Mirex is also effective against the hamster ant, the yellow-jacket, the Texas leaf-cutting ant, and the Hawaiian mealy bug. A ban on the use of mirex for pest control with exemptions was brought in on June 30, 1978. It has its use as a fire retardant in plastics, rubber, paint, paper, and electrical goods from 1959 to 1972 due to its high melting point and high chemical stability.14,48... 

Mirex (dodecachlorooctahydro-l,3,4-metheno-2H-cyclobuta [tv/] pentalene) has been used extensively in pesticidal formulations to control the red imported fire ant (Solenopsis invicta), and as a flame retardant in electronic components, plastics, and fabrics. One environmental consequence of mirex was the severe damage recorded to fish and wildlife in nine southeastern states and the Great Lakes, especially Lake Ontario. In 1978, the U.S. Environmental Protection Agency banned all further use of mirex, partly because of the hazards it imposed on nontarget biota. These included ... 

Mirex was detected in 18% of the 1980 samples (maximum concentration, 210 pg/kg [ppb] mean concentration, 0.01 pg/g) and in 13% of the 1984 samples (maximum concentration, 440 pg/kg [ppb] mean concentration, 10 pg/kg). The highest mirex concentrations were detected in whole fish taken from Lake Ontario, the St. Lawrence River, and the southeastern United States, all areas where mirex had been manufactured or used (Schmitt et al. 1990). In the recent EPA National Study of Chemical Contaminants in Fish, mirex was detected at 38% of 362 sites sampled. The mean mirex concentration was 3.86 pg/kg (ppb) and the maximum concentration was 225 pg/kg (ppb). The highest concentrations of mirex were detected in fish collected in the Lake Ontario area of New York State (EPA 1992a). 

Limited data are available on mirex worldwide except in the United States. The levels of mirex found in birds that were collected in the United States, except of those from the southeastern United States and the Great Lakes, were low and were considered nonhazardous in the 1970s (Cain Bunck, 1983). White (1979) investigated the wings of mallards and American black ducks (Anas rubripes) that were collected from four major flight pathways between 1976 and 1977 (Eisler, 1985 and the references therein). The results showed that Atlantic mallards had the highest detection frequencies of occurrence at 50% and the highest concentration of mirex (0.14 pg g-1 wet wt.). They were followed by Mississippi mallards at 29% and 0.03 pg g-1 wet wt., Central mallards at 14% and 0.06 pg g-1 wet wt., and Pacific mallards at 4% and 0.03 pg g-1 wet wt. (Eisler, 1985). 

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