A two-year, oral, long-term toxicity and carcinogenicity study was carried out on 60 male and 60 female F-344 rats per group fed diets fumigated with methyl bromide (Mitsumori et al., 1990).
8.4.1 Oral 220.127.116.11 Rat Rats were fed for 7-8 months on wheat grain or peanuts fumigated with methyl bromide having residual bromide levels of 20 and 22-46 mg/kg, respectively.
For comparison, samples of natural Br- concentrations in surface water were taken from a region where methyl bromide fumigation was not carried out.
Fallico & Ferrante (1991) measured bromide concentrations in greenhouse soil before, and after, the application of methyl bromide (80 g/m2).
The concentrations of methyl bromide and bromide-ion were measured in irrigation water, drainage water, and surface water during the leaching periods in two Netherlands glasshouse soils after fumigation with methyl bromide (Wegman et al., 1981).
A study was carried out in 1980 in Metaponto, in southern Italy, where methyl bromide was used to control nematodes and other plant pathogens in the soil (Basile & Lamberti, 1981).
5.1.2 Water 18.104.22.168 Seawater In 1975, samples of seawater from near the shore at Dorset, England were analysed for halomethanes and methyl bromide was detected at levels ranging from 2.0 to 3.9 x 10-9 ml gas/ml water [apprx.
USA tolerancesa Br in, or on, the following raw agricultural commodities, which have been fumigated with the antimicrobial agent and insecticide methyl bromide after harvest (with the exception of strawberries) (mg/kg) corn (pop) 240 almonds, brazil nuts, bush nuts, 200 butternuts, cashews, chestnuts, cottonseed, filberts, hickory nuts, peanuts, pecans, pistachio nuts, soybeans, walnuts asparagus, copra, cumin (seed), 100 ginger (roots), pomegranates avocados, coffee beans, potatoes, 75 sweet potatoes alfalfa (hay), barley, beans, 50 beans (green), benas (lima), beans (snap), cabbage, cippolini (bulbs), cocoa beans, corn, corn (sweet), garlic, oats, peas, peas (blackeyed), rice, rye, sorghum (grain), timothy (hay), wheat artichokes (Jerusalem), garden beets 30 (roots), sugar beets (roots), carrots, citrus citron, cucumbers, grapefruit, horseradish, kumquats, lemons, limes, okra, oranges, parsnips (roots), peppers, pimentos, radishes, rutabagas, salsify (roots), squash (summer), tangerines, turnips (roots) apricots, blueberries, cantaloupes, 20 cherries, eggplant, grapes, honeydew melons, mangoes, muskmelons, nectarines, onions, papayas, peaches, pineapples, plums, pumpkins, squash (winter), squash (zucchini), tomatoes, watermelons apples, pears, quinces 5 a From: US EPA (1988b; CFR 180.124).
No methyl bromide was found in excess of the detection limit (0.01 mg/kg); all samples contained inorganic bromide, but at levels of 4 mg/kg or less, which is given as the level naturally present in wheat as a result of uptake from the soil (Heuser & Scudamore, 1970; Osborne et al., 1989).
Investigations by Netherlands Institutes (TNO and RIVM) showed that the hourly average concentrations within a 20-m distance from the green-houses in 1981 (after the introduction of gas-tight film) during the first hours was 5.9 mg/m3 after fumigation with methyl bromide at a dose of 700 kg/ha.
Trials carried out on a commercial scale showed that CT (concentration x time) products for methyl bromide generally lay in the range of 50-2000 mg.h/litre (Scudamore, 1987).
Stacks of bags containing stored grains and pulses (wheat, lentils, maize, barley, chick-peas, peas, and sorghum) were covered with PVC sheets and exposed to methyl bromide fumigation for 48 h (Urga, 1983).
22.214.171.124 Release of methyl bromide to the outside air from greenhouses During 1986, 400 000 kg methyl bromide were emitted into the air in the Westland area of the Netherlands (Van Doorn et al., 1989).