Glyphosat – på vej til endelig frikendelse?

For nogle dage siden snublede jeg over et indlæg, der handlede om glyphosat – et emne, der har optaget sindene mere end noget andet indenfor pesticidområdet.

Linket var til et indlæg på “American Council on Science and Health” (læs indlæg her).

I indlægget var der et link til US EPA’s vurdering af kræft. Denne vurdering er – som jeg kan læse det – den endelige vurdering af glyphosat og kræft. Det er, efter det skrevne, et i rækken af 3 dokumenter, som skal være færdige i starten af 2017 – den endelige samlede vurdering af glyphosat.

Vurderingen (læs vurderingen her) frikender glyphosat for at udgøre nogen relevant risiko for mennesker i forhold til kræft. Dette er et “sagt på almindelig dansk” udsagn for ikke at ryge ind i unyttige, akademiske og teoretiske diskussioner, der handler om irrelevanet doser, mindre egnede arter af forsøgsdyr, risiko contra fare o.m.a.

Det handler netop om risiko – ikke indbygget egenskab. Der er i linket her en fin fremstilling af blandt andet relationen mellem risiko og fare/indbygget egenskab.

Vurderingen inkluderer alle indtil nu fremkomne vurderinger inklusiv IARC’s vurdering. US EPA vurderingen indsættes her fra side 140 6.7 og frem. (NB som der står er det en “proposed” konklusion og og jeg ved ikke præcist, hvad det dækker over, men det er jeg ved at finde ud af-jeg er imidlertid overbevist om, at dette er den videnskabeligt korrekte vurdering, også fordi det var den samme konklusion, som blev fremlagt for lidt over et år siden som en endelig konklusion, men som blev trukket på mystisk vis fra EPA’s hjemmeside uden egentlig begrundelse. For ikke at nævne, at der er den konklusion, som alle andre myndigheder i tidens løb er kommet frem til minus IARC).

US EPA vurdering.

6.7 Proposed Conclusions Regarding the Carcinogenic Potential of Glyphosate Glyphosate is a non-selective, phosphonomethyl amino acid herbicide registered to control weeds in various agricultural and non-agricultural settings. Labeled uses of glyphosate include over 100 terrestrial food crops as well as other non-agricultural sites, such as greenhouses, aquatic areas, and residential areas. Following the introduction of glyphosate-resistant crops in 1996, glyphosate use increased dramatically; however, glyphosate use has stabilized in recent years due to the increasing number of glyphosate-resistant weed species. Since its registration in 1974, numerous human and environmental health analyses have been completed for glyphosate, which consider all anticipated exposure pathways. Glyphosate is currently undergoing Registration Review. As part of this process, the hazard and exposure of glyphosate are reevaluated to determine its potential risk to human and environmental health using current practices and policies. The human carcinogenic potential of glyphosate has been evaluated by the agency several times. As part of the current evaluation for Registration Review, the agency has performed a comprehensive analysis of available data from submitted guideline studies and the open literature. This includes epidemiological, animal carcinogenicity, and genotoxicity studies. An extensive database exists for evaluating the carcinogenic potential of glyphosate, including 23 epidemiological studies, 15 animal carcinogenicity studies, and nearly 90 genotoxicity studies for the active ingredient glyphosate. These studies were evaluated for quality and results were analyzed across studies within each line of evidence. The modified Bradford Hill criteria were then used to evaluate multiple lines of evidence using such concepts as strength, consistency, dose response, temporal concordance and biological plausibility. The available data at this time do no support a carcinogenic process for glyphosate. Overall, animal carcinogenicity and genotoxicity studies were remarkably consistent and did not demonstrate a clear association between glyphosate exposure and outcomes of interest related to carcinogenic potential. In epidemiological studies, there was no evidence of an association between glyphosate exposure and numerous cancer outcomes; however, due to conflicting results and various limitations identified in studies investigating NHL, a conclusion regarding the association between glyphosate exposure and risk of NHL cannot be determined based on the available data. Increases in tumor incidence were not considered treatment-related in any of the animal carcinogenicity studies. In 7 of these studies, no tumors were identified for detailed evaluation. In the remaining studies, tumor incidences were not increased at doses <500 mg/kg/day, except for the testicular tumors observed in a single study. Increased tumor incidences at or exceeding the limit dose (≥1000 mg/kg/day) are not considered relevant to human health. Furthermore, data from epidemiological and animal carcinogenicity studies do not reliably demonstrate expected dose-response relationships. For cancer descriptors, the available data and weight-of-evidence clearly do not support the descriptors “carcinogenic to humans”, “likely to be carcinogenic to humans”, or “inadequate information to assess carcinogenic potential”. For the “suggestive evidence of carcinogenic potential” descriptor, considerations could be looked at in isolation; however, following a thorough integrative weight-of-evidence evaluation of the available data, the database would not support this cancer descriptor. The strongest support is for “not likely to be carcinogenic to humans” at doses relevant to human health risk assessment.

Dansk oversættelse.

Jeg har markeret teksten i den sidste del (med en smuk og symbolsk miljøgrøn farve) og efterfølgende oversat den, da det vel er den centrale del:

Med hensyn til cancer beskrivelser understøtter de foreliggende data og “bevisvægten” ikke beskrivelserne “kræftfremkaldende hos mennesker”, “sandsynligvis kræftfremkaldende hos mennesker” eller “utilstrækkelig information til at vurdere kræftfremkaldende potentiale”. Med hensyn til “antydet evidens for kræftfremkaldende potentiale” beskrivelsen kunne overvejelser gøres isoleret set; imidlertid vil databasen ikke understøtte denne beskrivelse efter en grundig integreret “weight of the evidence” vurdering af de foreliggende data. Den stærkeste understøttelse er for “sandsynligvis ikke kræftfremkaldende for mennesker”.

5 kræftbeskrivelser.

Der foreligger 5 kræftbeskrivelser: “In the 2005 Guidelines for Carcinogen Risk Assessment, five classification descriptors are provided:

• Carcinogenic to Humans

• Likely to be Carcinogenic to Humans

• Suggestive Evidence of Carcinogenic Potential

• Inadequate Information to Assess Carcinogenic Potential

• Not Likely to be Carcinogenic to Humans

Glyposat frikendes?.

Glyphosat placeres således i den laveste af disse beskrivelser – en de facto frikendelse. Men mindre der går politik i den – det håber jeg ikke for saglighedens skyld.

Og nok så væsentligt underkendes IARC’s vurdering men undskyldes måske lidt fordi IARC ikke skelner mellem risiko og fare. Og som sagt er fare ikke relevant – det er risiko. Til dem, der er uenige heri, kan man jo nævne, at indtagelse af ethanol (alkohol) af IARC klassificeres som “sikkert kræftfremkaldende hos mennesker” – det er vist ikke dette, der afholder folk fra at indtage vin, øl eller spiritus. Selvfølgelig fordi man ikke bekymrer sig om fare men om risiko. Dette illustrerer jo også hykleriet i opstandelsen hos DN og deslige, da IARC’s klassificering af glyphosat kom frem. Og det tåbelige i Arbejdstilsynets reaktion og de deraf afledte konsekvenser.