The International Agency for Research on Cancer (IARC) met in March of this year to assess the carcinogenicity of tetrachlorvinphos, parathion, malation, diazinon and glyphosate and released a summary of their review in The Lancet Oncology.
Tetrachlorvinphos and parathion were classified as “possibly carcinogenic to humans” due to evidence from animal-based studies but inadequate examples in humans. Malation, diazinon and glyphosate were labelled “probably carcinogenic to humans” based on sufficient evidence in animals and limited evidence in humans.
The classification of glyphosate in particular has drawn attention from both proponents and detractors of the pesticide. The North American Pesticide Action Network (PAN) lauded the IARC review as “raising significant concerns about [the] widely used herbicide” while Monsanto, producer of ‘Round-up‘, the most widely-used glyphosate formulation, released a statement from Vice President Philip Miller disagreeing with the publication: “All labeled uses of glyphosate are safe for human health and supported by one of the most extensive worldwide human health databases ever compiled on an agricultural product.”
The IARC assessment emphasised the global prevalence of glyphosate, noting that it “has been detected in air during spraying, in water, and in food” and that it “has been detected in the blood and urine of agricultural workers, indicating absorption”. In a press release accompanying the Lancet publication, the IARC also highlighted inconsistencies in US Environmental Protection Agency (EPA) evaluation of glyphosate, which re-classified the pesticide as ‘evidence of non-carcinogenicity in humans’ despite statistically significant tests showing otherwise.
Though the Ecologist and PAN, among others, see the IARC review as placing additional pressure on international regulators to “re-examine the basis on which the product has been licensed”, the regulatory impacts of this latest pesticide assessment are yet to be seen.