By Jessica Domel
Multimedia Reporter
A new report from the Environmental Protection Agency (EPA) reveals popular weedkiller glyphosate is not likely to cause cancer in humans.
EPA issued the draft human health and ecological risk assessment for glyphosate Friday.
“The agency’s assessment found no other meaningful risks to human health when the product is used according to the pesticide label,” a release from EPA said.
The review evaluated dietary, residential/non-occupational, aggregate and occupational exposures to glyphosate.
EPA reports it also performed an in-depth review of the glyphosate cancer database, including data from epidemiological, animal carcinogenicity and genotoxicity studies.
“In response to concern from segments of the general public related to the presence of glyphosate in human milk, the EPA Biological and Economic Analysis Division Analytical Chemistry Branch (BEAD-ACB) analyzed human milk samples collected by the National Children’s Study for residues of glyphosate and the glyphosate metabolites,” the report states.
Thirty-nine samples were taken from mothers and analyzed. Glyphosate was not found in the milk.
The study noted residential exposure to glyphosate may occur as a result of use on golf courses, residential lawns and aquatic applications.
“Based on the registered turf and aquatic use patterns, there is a potential for short-term dermal and inhalation exposure to residential handlers (mixing, loading and applying) and short-term dermal, inhalation and incidental oral exposure from post-application activities,” the report states.
Some people may face a short-term risk of oral exposure if they touch a recently-treated lawn or crop and then touch their mouth or face, but the report states the margins of exposure don’t exceed levels of concern.
According to the report, oral exposure is considered the primary route of concern for glyphosate.
The maximum absorption rate for glyphosate in the GI tract is estimated at 30 to 40 percent. That’s based upon radiolabel detected in the urine.
“In general, the amounts of glyphosate detected in tissues were negligible indicating low tissue retention following dosing,” the report states.
In the dose ranges tested by EPA, glyphosate was essentially out of the system within 24 hours.
“Glyphosate is categorized as having low acute toxicity following oral, dermal and inhalation exposure,” the report states.
Glyphosate is a mild eye irritant, slight skin irritant and is not a dermal sensitizer.
EPA also studied glyphosate’s effect on drinking water.
“The groundwater monitoring data with high glyphosate concentrations provided (in a table on page 21 in the report) are associated with subsurface drains and, therefore, they are not representative of groundwater sourced drinking water,” the report states.
The ground water concentrations in the table in the report, per EPA, are the worst case scenarios used when considering all uses of a product.
The ecological risk assessment indicates a potential effect for birds, mammals, terrestrial plants and aquatic plants.
“In rats, maternal and developmental toxicity was observed only at or above the limit dose. In rabbits, maternal toxicity was comprised mainly of clinical signs (diarrhea, few and/or soft feces) and no developmental toxicity was observed,” the report states. “In one of the two generation rat reproductive toxicity studies, no adverse effects were seen in the parental animals including reproductive toxicity. While there was an increased postnatal quantitative susceptibility, offspring effects were observed only at the limit dose (1000 mg/kg/day) and consisted of delayed age and increased weight at attainment of preputial separation (PPS).”
According to the report, glyphosate showed no evidence of increased susceptibility following in utero exposure to rats and rabbits.
The draft risk exposure document is available in EPA’s glyphosate registration review document EPA-HQ-OPP-2009-0361 on Regulations.gov.
A 60 day comment period will be available after the assessment and documents are posted online.