Josette Weir Pesticide Review Failure 2013: Special Review of Glyphosate Herbicides Containing Polyethoxylated Tallowamine
The applicant, Josette Wier, did not file an affidavit or attend the hearings. In response to a question from the Court as to the identity of the applicant, counsel for the applicant stated that Josette Wier was an “environmental researcher” in Smithers, BC (a town in north-central British Columbia). The applicant was a medical doctor in France but is not qualified to practice medicine in Canada.
Information Note: Reconsideration of a Request for the Special Review of Glyphosate Herbicides Containing Polyethoxylated Tallowamine
In response to a November 2011 Federal Court decision, Health Canada's Pest Management Regulatory Agency (PMRA) has now completed its reconsideration of a request for a special review of glyphosate containing the formulant polyethoxylated tallowamine (POEA). The PMRA has again found that a special review is not required. The original request was made by a member of the public in May 2009 and the original decision not to initiate this special review was made in August 2009. (The reasons for this decision can be found in Information Note: Request for a Special Review of Glyphosate Herbicides Containing Polyethoxylated Tallowamine.)
The Special Review Request and the Judicial Review of Health Canada's Decision
On 25 May 2009, a member of the public requested a special review of glyphosate pesticides containing POEA. This request involved the claim that these pesticides posed a range of unacceptable risks to human health and to the environment. After reviewing the information provided by the requester, the PMRA concluded that a special review was not warranted and on 24 August 2009 informed the requester of its decision.
On 25 September 2009, the requester filed a challenge in Federal Court of the PMRA's decision to deny the request for a special review of glyphosate. During the proceedings, however, the basis of this challenge was narrowed down from the PMRA's conclusions about a range of human health and environmental risks posed by glyphosate with POEA to its conclusions only about the risks to amphibians in small ephemeral wetlands.
On 21 November 2011 the Federal Court released its decision in this matter. In ordering a reconsideration, the Court noted some apparent inconsistencies in the documentation on which the PMRA based its decision to refuse the special review request. Because of these inconsistencies in particular, the PMRA decided not to appeal the decision and thus reconsidered the request for a special review.
The Reconsideration of the Special Review Request
On 10 January 2012, the PMRA advised the requester of the special review that it was reconsidering the request. In accordance with the Federal Court's decision, this reconsideration was confined to an assessment of the risk to amphibians in ephemeral wetlands of the aerial spraying of glyphosate with POEA in a forestry context. The PMRA invited the requester to submit additional information, which the requester did.
The PMRA completed its reconsideration of the special review request (including the additional information submitted) on 23 July 2012. It found that the particular use of glyphosate products that was the subject of the request did not pose an unacceptable risk to the environment. As a consequence, the PMRA determined that a special review of glyphosate with POEA was not required.
The PMRA found that laboratory studies suggested that glyphosate products containing POEA are indeed more toxic to amphibians than glyphosate alone. Yet, when seen in the context of all the studies available, these results did not offer credible and compelling evidence that glyphosate products created a serious possibility of an unacceptable risk to the environment. In particular, recent scientific studies under progressively more realistic conditions showed no significant adverse effects on amphibians. In addition, the initial results of ongoing field studies of breeding success of amphibians in forest wetlands following operational application of glyphosate products showed no significant effects on breeding effort, reproductive success, or abundance and fitness of wood frogs in herbicide-treated areas.
via Information Note: Reconsideration of a Request for the Special Review of Glyphosate Herbicides Containing Polyethoxylated Tallowamine.
A silviculture application of the glyphosate-based herbicide VisionMAX to wetlands has limited direct effects on amphibian larvae. Environmental Toxicology and Chemistry, 31: 2375–2383. doi: 10.1002/etc.1956
Herbicides are commonly used in agriculture and silviculture to reduce interspecific competition among plants and thereby enhance crop growth, quality, and volume. Internationally, glyphosate-based herbicides are the most widely used herbicides in both of these sectors. Laboratory and mesocosm studies have demonstrated that some formulations are toxic to amphibian larvae below concentrations that approximate predicted maximal or “worst-case” exposure scenarios. However, field studies have not found evidence of toxicity at these concentrations. The authors conducted a replicated field experiment involving 10 naturalized wetlands split in half with an impermeable plastic barrier to assess the direct toxicity of a glyphosate formulation commonly used in silviculture (VisionMAX™). The herbicide formulation was applied directly to the surface of one side of each wetland at one of two target aqueous exposure rates (high = 2,880, low = 550 µg acid equivalents [a.e.]/L), and the other side was left as an untreated control. The survival and growth of green frog larvae (Lithobates clamitans) were assessed for two years following herbicide treatment. The herbicide did not have a negative impact on survival or growth of L. clamitans larvae at either treatment level. In fact, mean larval abundance was typically greater in the treated sides than in control sides within the year of herbicide application. These results indicate that typical silviculture use of VisionMAX poses negligible risk to larval amphibians, likely because the combined effects of sorption and degradation in natural wetlands limit the exposure magnitude and duration. Environ. Toxicol. Chem. 2012; 31: 2375–2383. © 2012 SETAC
Laboratory and field exposure of two species of juvenile amphibians to a glyphosate-based herbicide and Batrachochytrium dendrobatidis
- a Department of Biology, University of New Brunswick, Saint John, New Brunswick, Canada E2L 4L5
- b Great Lakes Forestry Center, Canadian Forest Service, Sault Ste. Marie, Ontario, Canada P6A 2E5
Herbicides are commonly used in agriculture and silviculture to reduce interspecific competition among plants and thereby enhance crop growth, quality, and volume. Internationally, formulations of glyphosate-based herbicides are the most widely used herbicides in both these sectors. A large amount of work has focused on the effects of these herbicides on amphibians. Several laboratory and mesocosm studies have demonstrated that various formulations of glyphosate herbicides can be acutely toxic to larval and juvenile amphibians at concentrations at the upper end of environmental realism. However, to date there has been little work done investigating such effects in natural systems, limited work on juvenile amphibians, and only a few studies have investigated interactions with other stressors. We conducted a 16 day field experiment in which juveniles of two amphibian species (Lithobates clamitans and Lithobates pipiens) were exposed to the herbicide Roundup WeatherMax™ at four application rates (0, 2.16, 4.32 and 8.64 kg a.e./ha) to investigate effects on survival, liver somatic index (LSI), body condition, and incidence of disease caused by Batrachochytrium dendrobatidis (Bd). In a separate 16 day laboratory experiment, we exposed juvenile L. clamitans to both the herbicide and Bd. Results of our studies showed that this particular herbicide formulation had no effect on juvenile survival, LSI, body condition, or disease incidence, nor was there an interaction between exposure to herbicide and exposure to the disease in tests which closely mimic real world exposure scenarios. These experiments suggest that Roundup WeatherMax as typically used in agriculture is unlikely to cause significant deleterious effects on juvenile amphibians under real world exposure conditions.