- EC50: The EC50 of a graded dose response curve therefore represents the concentration of a compound where 50% of its maximal effect is observed. I.e. the researchers aren't even trying to find the killer dose like in LD50.
- LC50: The concentrations of the chemical in air that kills 50% of the test animals during the observation period is the LC50 value.
- LD50: LD50 is the amount of a material, given all at once, which causes the death of 50% (one half) of a group of test animals. The LD50 is one way to measure the short-term poisoning potential (acute toxicity) of a material.
Herbicide concentrations and toxic effects:
- Toxic effects of combined chemicals are much greater when chemicals are combined and used in the same field.
- Surfactants in the herbicide can be more toxic to animals than the herbicide itself. Surfactants help the plant absorb the chemical.
- Toxic effects could be changed by pH of the water, hardness of the water, temperature, and other factors.
- Glyphosate is generally less persistent in water than in soil, with 12 to 60-day persistence observed in Canadian ponds, although persistence of over a year has been recorded in the sediments of USA ponds. The half-life of glyphosate in water is between 12 days and 10 weeks. Wikipedia.
- When glyphosate comes into contact with the soil, it can be bound to soil particles, thereby slowing its degradation.
- Water Flea, Daphnia magna. Acute 48h EC50 is 218 mg/L (ECOTOX). That is, after 48 hours the max effect of glyphosphate was 218mg/liter.
- Fathead minnow, Pimephales promelas. Acute 96h LC50 is 97mg/L technical glyphosate and 1.0 mg/L Roundup® surfactant (Folmar et al. 1979)
- Mayfly, Ephemerella walkeri. Avoided Roundup® at 10 mg/L but not 1.0 mg/L (Folmar et al. 1979).
More studiesThe LD50 (lethal does where half the subjects die) of glyphosate is 5,000 mg/kg for rats, 10,000 mg/kg in mice and 3,530 mg/kg in goats. The acute dermal LD50 in rabbits is greater than 2 g/kg.Wikipedia.
2004, Glyphosphate poisoning from NIH.
- "Not only is glyphosate used as five different salts but commercial formulations of it contain surfactants, which vary in nature and concentration. As a result, human poisoning with this herbicide is not with the active ingredient alone but with complex and variable mixtures. Therefore, it is difficult to separate the toxicity of glyphosate from that of the formulation as a whole or to determine the contribution of surfactants to overall toxicity." We don't care about glyphosate alone, we care about the formulas we are exposed to.
- There is a reasonable correlation between the amount ingested and the likelihood of serious systemic sequelae or death.
- Gastrointestinal corrosive effects, with mouth, throat and epigastric pain and dysphagia are common.
- Renal and hepatic impairment are also frequent and usually reflect reduced organ perfusion.
- Respiratory distress, impaired consciousness, pulmonary oedema, infiltration on chest x-ray, shock, arrythmias, renal failure requiring haemodialysis, metabolic acidosis and hyperkalaemia may supervene in severe cases.
- Bradycardia and ventricular arrhythmias are often present pre-terminally (before death).
- "Glyphosate-based herbicides (e.g. Roundup) are extensively used in the aquatic environment, but there is a paucity (lack) of data on the toxicity of the formulated products and the influences by environmental factors." But it's been studied since 1979.
- "In this study, the acute toxicity of technical-grade glyphosate acid, isopropylamine (IPA) salt of glyphosate, Roundup and its surfactant polyoxyethylene amine (POEA) to Microtox bacterium (Vibrio fischeri), microalgae (Selenastrum capricornutum and Skeletonema costatum), protozoa (Tetrahymena pyriformis and Euplotes vannus) and crustaceans (Ceriodaphnia dubia and Acartia tonsa)..."
I'm reporting some of these older studies 1) So people can get some initial information about glyphosate and 2) to see if new, very different results appear in new studies. If very different results appear, that means there is something very, very wrong with the earlier studies.
If lead concentrations exceed an action level of 15 ppb ... in more than 10% of customer taps sampled, the system must undertake a number of additional actions to control corrosion. Source. In 2011, the EPA raised the amount of glyphosate allowed in food to 13ppm. Monsanto initiated the request. It is well-known that hormones in the parts per trillion (ppt) affect humans and parts per quadrillion affect fetuses.