Ratten

The Battle Over the Most Used Herbicide Heats Up as Nearly 100 Scientists Weigh In

One year ago, an agency of the World Health Organization’s International Agency for Cancer Research (IARC) declared that glyphosate (or Roundup), the world’s most widely used herbicide, probably causes cancer. Then, in the fall, the European Food Safety Agency’s (EFSA) responded with an assessment that disagreed with the WHO’s findings. In response, 94 scientists came out in support of the IARC’s original findings. This week, the group—which includes scientists from around the world—released their article in the peer-reviewed Journal of Epidemiology and Community Health saying: The most appropriate and scientifically based evaluation of the cancers reported in humans and laboratory animals as well as supportive mechanistic data is that glyphosate is a probable human carcinogen. On the basis of this conclusion and in the absence of evidence to the contrary, it is reasonable to conclude that glyphosate formulations should also be considered likely human carcinogens. And their endorsement is no small matter. In fact, as the U.S. Environmental Protection Agency (EPA) reassesses the safety of glyphosate, and the U.S. Food and Drug Administration (FDA) plans to begin testing food for its residue, this volley has important implications.

Neurotoxiciteit studie met Imidacloprid van Bayer CropScience toont mogelijk schadelijke werking op de ontwikkeling van de hersenen aan

Bij neurotoxiciteit studies wordt onder andere onderzocht of pre- of postnatale blootstelling aan een giftige stof invloed heeft op de ontwikkeling van het zenuwstelsel. Bayer Crop Science (BCS) heeft in 2001 een dergelijke studie uitgevoerd met imidacloprid. Imidacloprid werd toegediend via het dieet aan zwangere Sprague Dawley ratten van zwangerschapsdag 0-20 tot en met lactatiedag 21 in doseringen van 0, 100, 250 en 750 ppm, overeenkomend met een gemiddelde dagelijkse dosis van 0, 8, 19 en 54,7 mg / kg / dag . Het nageslacht werd indirect blootgesteld aan imidacloprid over een totaal van 41 dagen (20 dagen in de baarmoeder en 21 dagen via lactatie). Na het spenen op postnatale dag 21 werd onbehandeld voedsel gegeven. De hersenen van 10 dieren / geslacht / groep werden geanalyseerd op postnatale dagen 11 en 75. Op postnatale dag 11 vertoonden vrouwelijke dieren van de 750 ppm groep een verminderde omvang van caudate putamen (-5.5%) en een aanzienlijke vermindering van de omvang van het corpus callosum (-27,6%). Morfometrische hersen metingen werden niet uitgevoerd in de intermediaire en lage dosis groepen. Het EFSA-panel voor gewasbeschermingsmiddelen en residuen (PPR) heeft bezorgdheid geuit over deze resultaten, vooral gelet op de omvang van de daling van het corpus callosum. Het belangrijkste punt van onenigheid tussen BCS en het PPR-panel is de interpretatie van de morfometrische data. BCS betoogt dat imidacloprid geen morfometrische effecten in hun studie heeft veroorzaakt, alhoewel BCS erkent dat hun morfometrisch onderzoek werd beperkt tot de hoge dosis en de controlegroep. Daarentegen ziet het PPR-panel de morfometrische gegevens een bron van zorg door het ontbreken van intermediaire en lage dosis gegevens. Met de beschikbare gegevens is het onmogelijk om een ​​dosis-werkingsrelatie van de morfometrische veranderingen te beoordelen. Er bestaat volgens het PPR-panel grote onzekerheid over de potentiële neurotoxiciteit van imidacloprid. Ook de Amerikaanse EPA had kritiek op het ontbreken van intermediaire en lage dosis gegevens.

EFSA PPR panel expresses concern about a Bayer developmental neurotoxicity study with imidacloprid

Developmental neurotoxicity (DNT) studies are designed to investigate whether pre- or post-natal exposure to a toxicant affects neural development. Bayer conducted such a study with imidacloprid. Imidacloprid was administered in the diet to mated Sprague Dawley rats. The females were treated from gestation day 0 to 20 and then continued through the lactation day 21 at doses of 0, 100, 250 and 750 ppm, corresponding to an average daily intake of 0, 8, 19 and 54.7 mg/kg/day during gestation. The pups were indirectly exposed to imidacloprid for a total of 41 days (20 days in utero and 21 days via lactation). After weaning on postnatal day 21 pups were given untreated feed. Brain tissue from 10 pups/sex/group were analyzed on postnatal days 11 and 75. On post-natal day 11, female pups from the 750 ppm group had a decreased caudate putamen width (-5.5%) and a substantial reduction in the thickness of the corpus callosum (-27.6%). Morphometric brain measurements were not performed in the intermediate and low dose groups. The EFSA Panel on Plant Protection Products and their Residues (PPR) expressed concern about this pattern and although it does not directly demonstrate neurotoxicity, it cannot be dismissed, especially considering the magnitude of decrease in corpus callosum dimension. The major point of disagreement between Bayer Crop Science (BCS) and the PPR Panel is the interpretation of morphometric data. BCS contends that imidacloprid caused no morphometric effects in their DNT study; meanwhile BCS recognizes that their morphometric investigations were limited to the high dose and control groups. By contrast, the PPR Panel considered the morphometric data a source of concern and the lack of intermediate and low dose data as important missing information. Using the available data it is impossible to assess a dose-response relationship for morphometric changes. The level of uncertainty identified in brain morphometry precludes a robust characterization of the DNT potential of imidacloprid.

De stad Antwerpen voert op 1 januari 2015 een verbod in op het gebruik van pesticiden op openbare plaatsen en rond openbare gebouwen

Zowel de stadsdiensten als externe partners zullen er vanaf dan geen pesticiden meer mogen inzetten. De hoeveelheid gebruikte pesticiden was de voorbije jaren al sterk gedaald uit milieuoverwegingen, maar nu zal de stad er dus volledig mee stoppen. Het verbod is deels een gevolg van het decreet dat de Vlaamse overheid begin vorig jaar opstelde. Antwerpen had de hoeveelheid gebruikte pesticiden op openbaar terrein al verminderd van meer dan 800 kilogram in 2000 naar nog amper 13 kilogram vorig jaar. "We zullen in de toekomst allerlei milieuvriendelijke alternatieven hanteren om het openbaar domein van onkruid en ongedierte te verlossen", zegt schepen voor Leefmilieu Nabilla Ait Daoud (N-VA). "Daarnaast zal het groen in de stad ook intensiever beheerd worden." Op de nieuwe regel blijven voorlopig wel nog twee uitzonderingen mogelijk. Enerzijds voor het bestrijden van een wespenplaag of een bruine rattenplaag en anderzijds voor het terugdringen van agressieve invasieve soorten zoals de Japanse duizendknoop.

The fungicide carbendazim is a reproductive/developmental toxicant altering key events of spermatogenesis

This study aimed to better elucidate reproductive and possible hormonal effects of the fungicide carbendazim (CBZ) through a review of published toxicological studies as well as an evaluation of this fungicide in the Hershberger and uterotrophic assays, which are designed to detect in vivo effects of the sex hormones. The literature review indicates that CBZ induces reproductive and developmental toxicity through alteration of many key events which are important to spermatogenesis. The lower dose of CBZ (100 mg/kg) evaluated in the Hershberger test increased prostate weight compared to control group but did not alter the weight of other testosterone-dependent tissues. In the uterotrophic assay, CBZ did not induce an estrogenic or an antiestrogenic effect. In the literature, it has been reported that CBZ may: 1) alter the levels of various hormones (testosterone, LH, FSH, GnRH); 2) negatively influence testicular steroidogenesis; 3) have androgenic effects acting directly in the androgenic receptors and/or increasing the expression of androgen receptors. Despite the contradictory results reported by the different studies that investigated a possible endocrine mode of action of CBZ, it seems that this fungicide may influence the hypothalamus-pituitary-gonad axis in addition to being a testicular toxicant.

Editor of Food and chemical Toxicology is obliged to give Prof. Séralini’s team right of reply after retracting NK603 and Roundup study

The editor of Food and Chemical Toxicology (FCT) uses double standards when it comes to publishing in favour of the industry, Prof. Séralini’s team say. Now the journal’s publisher Elsevier has compelled him to publish a right of reply by the Séralini team. More than a year after its publication, the editor of Food and Chemical Toxicology (FCT), Dr A. Wallace Hayes, retracted the long-term toxicity study on two Monsanto products, the NK603 GM maize and its associated herbicide Roundup by Séralini et al. He did so despite the fact that he found neither fraud nor conscious misinterpretation in the study. In a new article published in FCT, following pressure from the journal’s publisher Elsevier, the scientists explain why they do not accept Dr Hayes’ conclusion. They denounce the lack of scientific validity of the reasons given for the reatraction, explain why the Sprague-Dawley rat strain used is appropriate, and describe the statistical results in depth concerning the blood and urine parameters affected, proving that the liver and kidney pathologies and the mammary tumours are solidly based.

Disposition and acute toxicity of imidacloprid in female rats after single exposure

Single dose of imidacloprid (IMI-20 mg/kg bodyweight) was orally administered in female rats. Its disposition along with two metabolites 6-chloro nicotinic acid (6-CNA) and 6-hydroxy nicotinic acid (6-HNA) was monitored in organs (brain, liver, kidney, and ovary) and bodily fluids (blood, urine) at 6, 12, 24 and 48 h and faeces at 24 and 48 h. Maximum concentration (Cmax) of IMI and metabolites in each organ and bodily fluid occurred after 12 h. Area under curve (AUC) of IMI ranged from 35 to 358 μg/ml/h; 6-CNA: 27.12–1006.42 μg/ml/h and 6-HNA: 14.98–302.74 μg/ml/h in different organs and bodily fluids. Clearance rate of IMI was maximum in ovary followed by kidney, liver, brain, faeces, blood and urine. Percent inhibition of acetyl-cholinesterase (AChE) was comparable in brain and Red Blood Cells (RBC) at 6–48 h which suggests the RBC-AChE as valid biomarker for assessing IMI exposure. It is evident that IMI was absorbed, metabolized, and excreted showing increased level of serum enzymes like Glutamic oxaloacetic transaminase (GOT), Glutamic pyruvic transaminase (GPT) and biochemical constituents like billirubin and Blood Urea Nitrogen (BUN) at 48 h. These data suggest that IMI is widely distributed, metabolized and induced toxicology effects at 20 mg/kg bodyweight to female rats.

Early-life permethrin exposure imparts long-lasting consequences on the hippocampus such as impairment of long-term memory storage and synaptic morphology

During the neurodevelopmental period, the brain is potentially more susceptible to environmental exposure to pollutants. The aim was to determine if neonatal exposure to permethrin (PERM) pesticide, at a low dosage that does not produce signs of obvious abnormalities, could represent a risk for the onset of diseases later in the life.

Volgens een Braziliaanse wetenschapper kunnen ratten bij een kleine dosis Roundup hersenschade oplopen

In een recent onderzoek laat de Braziliaanse wetenschapper Cattani zien dat ratten, bij een kleine dosis Roundup, hersenschade (in de hippocampus) kunnen ondervinden. De beestjes in het laboratorium van Cattani kregen op gezette tijden één procent Roundup in hun drinkwater gemengd. Na deze dosis trad er neurotoxiciteit op. Het onderzoek van Cattani is op 15 maart 2014 gepubliceerd in de wetenschappelijke journal Toxicology en werd gefinancierd door het Conselho Nacional de Desenvolvimento, een organisatie van het Braziliaanse ministerie van Wetenschap en Techniek. Vorige maand werd Monsanto’s Roundup ook al uit academische hoek onder vuur genomen. Dokter Channa Jayasumana constateerde in zijn paper, die op 20 februari in de International Journal of Environmental Research and Public Health werd gepubliceerd, een verband tussen het aantal nierziektes onder boeren in Sri Lanka en het gebruik van de onkruidverdelger Roundup.

Roundup® (a glyphosate-based herbicide) leads to neurotoxicity in hippocampus of immature rats

The aim of this study was to investigate whether Roundup® (a glyphosate-based herbicide) leads to neurotoxicity in hippocampus of immature rats following acute (30min) and chronic (pregnancy and lactation) pesticide exposure. Maternal exposure to pesticide was undertaken by treating dams orally with 1% Roundup® (0.38% glyphosate) during pregnancy and lactation (till 15-day-old). Hippocampal slices from 15 day old rats were acutely exposed to Roundup® (0.00005-0.1%) during 30min and experiments were carried out to determine whether glyphosate affects 45Ca2+ influx and cell viability. Moreover, we investigated the pesticide effects on oxidative stress parameters, 14C-α-methyl-amino-isobutyric acid (14C-MeAIB) accumulation, as well as glutamate uptake, release and metabolism. Results showed that acute exposure to Roundup® (30min) increases 45Ca2+ influx by activating NMDA receptors and voltage-dependent Ca2+ channels, leading to oxidative stress and neural cell death.