Much ado about nothing...... Glyphosate is broken down very rapidly, normally within days. This is one of the reasons it is popular. By the way, I live in Montana, and many of my friends are grain farmers.......NONE uses glyphosate to kill the plants to accelerate grain harvest. NOT a single one. This has a strong ring of BS to it. Where I do see it used is prior to planting to kill weeds. You can spray and plant a day or two later because it breaks down so rapidly.
H.W.
TOXICOLOGICAL EFFECTS
Acute Toxicity
Glyphosate is a moderately toxic herbicide and carries the signal word WARNING on the label. Even though the LD50 values show the compound to be relatively non-toxic it can cause significant eye irritation. The toxicity of the technical product (glyphosate) and the formulated product (Roundup) is nearly the same. The acute oral LD50 in the rat is 5,600 mg/kg. Other oral LD50 values for glyphosate are 1,538 to greater than 10,000 mg/kg for mice, rabbits mg/kg, and goats (1, 5).
In a number of human volunteers, patch tests produced no visible skin changes or sensitization.
Chronic Toxicity
Subchronic and chronic tests with glyphosate have been conducted with rats, dogs, mice, and rabbits in studies lasting from 21 days to two years. With few exceptions there were no treatment-related gross (easily observable) or cellular changes (5). In a chronic feeding study with rats, no toxic effects were observed in rats given doses as high as 31 mg/kg/day, the highest dose tested. No toxic effects were observed in a chronic feeding study with dogs fed up to 500 mg/kg/day, the highest dose tested (8). Mice fed glyphosate for 90 days exhibited reduced body weight gains. The lifetime administration of very high amounts of glyphosate produced only a slight reduction of body weight and some microscopic liver and kidney changes. Blood chemistry, cellular components, and organ function were not affected even at the highest doses.
Hens fed massive amounts over three days and again 21 days later showed no nerve related effects.
Reproductive Effects
Most of the field and laboratory evidence shows that glyphosate produces no reproductive changes in test animals. It is unlikely that the compound would produce any reproductive effects in humans.
Teratogenic Effects
In a teratology study with rabbits, the maternal NOEL was 175 mg/kg/day and no developmental toxicity was observed in the fetuses at the highest dose tested (350 mg/kg/day) (8).
Rats given doses up to 3,500 mg/kg on days 6 to 19 of pregnancy had offspring with no teratogenic effects, but other toxic effects were observed in both the mothers and the fetuses. No toxic effects to the fetuses occurred at 1,000 mg/kg/day.
Mutagenic Effects
The compound does not cause mutations in microbes. The tests on eight different kinds of bacterial strains and on yeast cells were all negative. The compound poses little mutagenic risk to humans (6).
Carcinogenic Effects
Rats and dogs and mice fed glyphosate over a wide range of doses showed no cancer related effects directly due to the compound (4). EPA has stated that there is sufficient evidence to conclude that glyphosate is not carcinogenic in humans (8).
Organ Toxicity
Glyphosate caused no changes in the rate of body weight gain, in blood, nor in kidneys or liver. The studies were conducted at doses up to 500 mg/kg (3).
Fate in Humans and Animals
Glyphosate is poorly absorbed from the digestive tract and is largely excreted unchanged by mammals. Ten days after treatment there were only minute amounts in the tissues of rats fed glyphosate for three weeks (3).
Cows, chickens, and pigs fed small amounts had undetectable levels (less than 0.05 ppm) in muscle tissue and fat. Levels in milk and eggs were also undetectable (less than 0.025 ppm). Nearly all glyphosate residues were rapidly eliminated by fish that had been exposed for 10 to 14 days once these fish were transferred to glyphosate-free water. Glyphosate has no significant potential to accumulate in animal tissue (9).
ECOLOGICAL EFFECTS
Glyphosate is only slightly toxic to wild birds. The LC50 in both mallards and bobwhite quail is greater than 4,500 ppm. The bioaccumulation factor in chicken muscle, fat, eggs, and liver was as low as 1/10,000 (4).
Glyphosate is practically non-toxic to fish. However, Roundup was more toxic to fish than was glyphosate. In rainbow trout, for instance, the 96-hour LC50 was 8.3 mg/l with Roundup and 38 ppm with glyphosate. The LC50 for glyphosate was 120 mg/l for bluegill sunfish. An additive used in the Roundup formulation (modified tallow amine used as a surfactant) is apparently more toxic to fish than many common surfactants. For this reason, the formulation for use in aquatic situations (Rodeo) omits this ingredient. The surfactant is used to allow the compound to readily dissolve in solution and to keep the compound from balling up on the leaf surface.
There is a very low potential for the compound to build up in the tissues of aquatic invertebrates or other aquatic organisms. Glyphosate is relatively non-toxic to honeybees. Its oral and dermal LD50 is greater than 0.1 mg/ bee (7).
ENVIRONMENTAL FATE
Glyphosate is highly adsorbed on most soils especially those with high organic content. The compound is so strongly attracted to the soil that little is expected to leach from the applied area. Microbes are primarily responsible for the breakdown of the product. The time it takes for half of the product to break down ranges from 1 to 174 days. Because glyphosate is so tightly bound to the soil, little is transferred by rain or irrigation water. One estimate showed less than two percent of the applied chemical lost to runoff (4). The herbicide could move when attached to soil particles in erosion run-off. Photodecomposition plays only a minor role in environmental breakdown.
In water, glyphosate is strongly adsorbed to suspended organic and mineral matter and is broken down primarily by microorganisms also. Its half-life in pond water ranges from 12 days to 10 weeks.
Glyphosate may be extensively metabolized by some plants while remaining intact in others (2). Once in the plant tissue, the chemical is translocated throughout the plant, including to the roots.
![Craft A Brew - Safale S-04 Dry Yeast - Fermentis - English Ale Dry Yeast - For English and American Ales and Hard Apple Ciders - Ingredients for Home Brewing - Beer Making Supplies - [1 Pack]](https://m.media-amazon.com/images/I/41fVGNh6JfL._SL500_.jpg)
