Scientists warn about the dangers of SDHI fungicides

Scientists are alarmed by the use of fungicides. In a tribune published in Liberation Monday, April 16, 2018 a group of researchers, oncologists, doctors and toxicologists of CNRS, Inserm and Inra ] call for the suspension of the use of the SDHI, succinate dehydrogenase inhibitors. These are used in large proportion in the French agriculture and on lawns, especially those of golf courses, to kill fungi and molds. SDHIs prevent the development of fungi by blocking their respiration, which is provided by succinate dehydrogenase (SDH). SDHI fungicides are used extensively on many crops. For example, 70% of soft wheat surfaces and 80% of winter barley were treated with this product in 2014. The researchers explain that after spraying on crops, the fungicide ends up in the soil. , in water and in animal and human nutrition. But this passage in the human food chain can seriously damage their health .

All concerned

" Universal cellular respiration and SDH enzyme function in all living species. How not to feel concerned by the presence of the SDHI in our plates through the contamination of food? How could such pesticides be placed on the market with the assurance of having no impact on human health, but also on the entire ecosystem? ", s' ask the authors of the platform.

Thus, the cells of all living beings breathe, from fungi through micro-organisms and of course man. " Our research on the SDH enzyme has revealed a very particular mechanism of cellular disruption: the blocking of this enzyme leads to the accumulation of a small molecule, succinate. This will lead to a long-term change in the structure of our DNA: these are epigenetic modifications phenomena.These epigenetic abnormalities linked to the blocking of SDH will deregulate thousands of genes, explaining the occurrence of tumors and cancers, without causing mutations in genes, as is often the case with carcinogens, and these modifications, unlike mutations, are not detected or tested during toxicity tests conducted before the pesticides are placed on the market [19659005] ", explain the scientists, because the long-term toxicity of SDHI fungicide to humans has never been seriously studied. However, The effects of SDH enzyme " can lead to cell death by causing severe encephalopathies, or uncontrolled cell proliferation, and leading to cancer ". In addition, Pierre Rustin, geneticist and research director at the CNRS-Inserm, ensures, in the gallery, that these fungicides " block well the human SDH, we tested it in the laboratory. However, we know that it is extremely dangerous to block this enzyme . "

Suspension of authorization

The fungicide was set up by major industrialists among which the now famous ] Monsanto and Bayer. The use of the SDHI was authorized in 2009 as a substitute for other pesticides previously manufactured and since abandoned because of their dangerousness, their reduced effectiveness and / or the appearance of resistance. " It is now very difficult to access the information that gave rise to the marketing authorizations for these molecules, but, to our knowledge, only a few tests on the toxicity at the human were made by the firms themselves ", say the authors of the forum.

ANSES, the National Agency for Food Safety, the Environment and Labor, and INRA, the National Institute for Agricultural Research, have both noticed that fungi and mold begin to develop resistance to SDHI. In addition to being potentially dangerous for humans, this product would have become equally inefficient.

The collective, author of the tribune, calls for " to suspend the use (of the SDHI) as long as an estimate of the dangers and the risks will not have been carried out by public bodies independent of the industrialists distributing these compounds and agencies that previously gave the marketing authorizations of the SDHI ". The association Générations Futures for its part, asked ANSES, in a communiqué the " urgent review of the evaluation of these SDHI fungicides and that an immediate suspension of their authorizations ".

Scientists accidentally create a plastic-eating enzyme

American and British scientists accidentally devised an enzyme that could destroy plastic, which could help solve the global problem of this type of pollution, according to a study released on Monday.

More than eight million tons of plastics end up in the world's oceans every year, raising concerns about the toxicity of this petroleum derivative and its impact on the health of future generations and the environment.

Despite efforts to recycling, the vast majority of these plastics can last for hundreds of years. Scientists are looking for a better way to eliminate them

Scientists at the Portsmouth University of the United Kingdom and the National Renewable Energy Laboratory of the US Department of Energy have focused their efforts on a bacterium discovered in Japan a few days ago. years: Ideonella sakaiensis.

It feeds only on one type of plastic, polyethylene terephthalate (PET), which is used in many plastic bottles.

Japanese researchers believe that bacterium has evolved quite recently in a recycling center, because plastics were invented only in the 1940s.

The goal of the US-UK team was to understand the functioning of one of its enzymes called PETase, discovering its structure

"But they went a step further by accidentally designing an enzyme that is even more effective at breaking down the s PET plastics, "according to the findings published Monday in the Proceedings of the American Academy of Sciences (PNAS).

Scientists from the University of South Florida and the Brazilian University Campinas also participated in the experiments which led to the mutation by chance of a much more efficient enzyme than natural PETase.

Scientists are now busy improving their performance in hopes of eventually being able to use it in an industrial process. destruction of plastics.

"Luck is often an important part of basic scientific research and our discovery is no exception," said John McGeehan, a professor at the School of Biological Sciences in Portsmouth.

"Although the advance is modest, this unexpected discovery suggests that there is room to further improve these enzymes, to bring us even closer to a recycling solution. growing mountain of discarded plastics, "he continued.