Herbicides

Pestizide − eine Gefahr für die biologische Vielfalt

In Deutschland sind 70 Prozent der natürlichen Lebensräume bestandsgefährdet, zwei Drittel der Amphibien- und Reptilienarten als gefährdet eingestuft oder vom Aussterben bedroht, 30 Prozent der Farne und Blütenpflanzen sind bestandsgefährdet. Ebenso stehen zwei Drittel der Tier- und Pflanzenarten des Offenlandes auf den Roten Listen der bedrohten Arten. In Deutschland ist für die Erhaltung der biologischen Vielfalt insbesondere die Art und Weise der praktizierten Landwirtschaft ausschlaggebend, fast die Hälfte der Landesfläche ist Agrarfläche (Europäische Union: 43 Prozent). Die nationale Biodiversitätsstrategie trägt dieser Bedeutung Rechnung, Ziele zur Erhöhung des Anteils an Grünland oder Streuobstwiesen wurden vereinbart. Die Zusagen aber werden nicht eingehalten. Die Landwirtschaft in der Bundesrepublik muss, um einen signifikanten Beitrag zur Sicherung der Biodiversität zu leisten, im Rahmen einer Agrarwende weg von der intensiven Landwirtschaft hin zu einer nachhaltigen extensiven Landwirtschaft transformiert werden. Dies beinhaltet eine umfassende Veränderung der Art zu wirtschaften, speziell aber den Stopp des Einsatzes von chemisch-synthetischen Pestiziden.

Ecologically relevant concentrations of atrazine and nitrates have immunosuppressive effects

Pathogenic diseases and environmental contaminants are two of the leading
hypotheses for global amphibian declines, yet few studies have examined the influence of contaminants on disease susceptibility. In this study, we examined effects of ecologically relevant doses of atrazine (0, 1.6, 16, and 160 ug/L), sodium nitrate (0, 6.8, 68 mg/L), and their interactions on susceptibility of four laboratory-bred tiger salamander families to Ambystoma tigrinum virus (ATV), a pathogen implicated in global amphibian die-offs.

Agrochemicals increase trematode infections in a declining amphibian species

We show that the widely used herbicide, atrazine, was the best predictor (out of more than 240 plausible candidates) of the abundance of larval trematodes (parasitic flatworms) in the declining northern leopard frog Rana pipiens. The effects of atrazine were consistent across trematode taxa. The combination of atrazine and phosphate—principal agrochemicals in global corn and sorghum production—accounted for 74% of the variation in the abundance of these often debilitating larval trematodes (atrazine alone accounted for 51%). Analysis of field data supported a causal mechanism whereby both agrochemicals increase exposure and susceptibility to larval trematodes by augmenting snail intermediate hosts and suppressing amphibian immunity. A mesocosm experiment demonstrated that, relative to control tanks, atrazine tanks had immunosuppressed tadpoles, had significantly more attached algae and snails, and had tadpoles with elevated trematode loads, further supporting a causal relationship between atrazine and elevated trematode infections in amphibians. These results raise concerns about the role of atrazine and phosphate in amphibian declines, and illustrate the value of quantifying the relative importance of several possible drivers of disease risk while determining the mechanisms by which they facilitate disease emergence.

Herbicides and insecticides can both affect the abundance of insect prey available to bats

Bats are intriguing animals – the world’s only true flying mammals and one of the most diverse mammal groups on Earth – second only to the rodents in number of species, they occur on every continent except Antarctica. Throughout Great Britain and Northern Ireland – as elsewhere in western Europe – bat populations have declined dramatically in recent years. Several species of bats are now seriously threatened, and in the last decade one species – the greater mouse-eared bat – became extinct as a UK breeding species. Even the more common bats have suffered dramatic declines. Pipistrelle numbers, for example, are estimated to have dropped by about 70% during the 15-year period 1978-1993. In the UK, bats eat only insects and changes in agricultural practices appear to be an important factor in declining bat numbers. Herbicides and insecticides can both affect the abundance of insect prey available to bats. Hedgerows and ponds, both widely used by bats, have been lost from the countryside at an alarming rate – even in recent years. For example 23% of hedgerows and 75% of ponds were lost during the period 1984 to 1990. Woodland habitats, including old trees, have declined also.

The Scientific American: Doubt is their product (Twijfel is hun product)

Weinig wetenschappelijke uitdagingen zijn complexer dan het begrijpen van de gezondheids- of milieurisico's van een chemische stof. Onderzoekers kunnen nu eenmaal giftige verbindingen niet aan mensen toedienen om te zien welke doses kanker veroorzaken. In plaats daarvan vertrouwen laboratorium onderzoekers op dierproeven, en epidemiologen onderzoeken de humane blootstelling die in het veld kan optreden. Beide soorten studies hebben veel onzekerheden, en wetenschappers moeten extrapoleren om oorzakelijke gevolgtrekkingen te kunnen maken en beschermende maatregelen aan te bevelen. Omdat absolute zekerheid zelden een optie is, zouden regelgevingprogramma's niet effectief zijn als een dergelijk bewijs vereist zou zijn. Overheidsfunctionarissen moeten de beste beschikbare gegevens gebruiken om grenswaarden voor schadelijke chemische stoffen vast te stellen en de veiligheid van geneesmiddelen te bepalen. Onzekerheid is een inherent probleem van de wetenschap, maar gefabriceerde onzekerheid is een heel andere kwestie. In de afgelopen drie decennia is de industrie vaak betrokken geraakt bij het ​​ wetenschappelijk onderzoek wanneer hun belangen werden bedreigd. Als, bijvoorbeeld, studies aantonen aan dat een bedrijf de bevolking of het milieu blootstelt aan gevaarlijke niveaus van een bepaalde chemische stof, reageert het bedrijf meestal met het inhuren van eigen onderzoekers om deze studies in twijfel te trekken. Eclatante voorbeelden van deze strategie zijn de wetenschappelijke controverses die zijn ontstaan over de relaties tussen roken en longkanker en tussen bestrijdingsmiddelen en bijensterfte.

Jeff Lowenfels: Ik droom van een Kerstmis zonder bestrijdingsmiddelen

Meer dan 300 ziekten zijn gekoppeld aan het gebruik van pesticiden. Niet als gevolg van dierproeven of laboratoriumonderzoek. Nee, gebaseerd op epidemiologische studies van de mens. Van de top 25 bestrijdingsmiddelen die gebruikt worden voor "voorzieningen" en de 13 voor "landschapsbeheer," zijn er 11 gekoppeld aan kanker, 5 aan geboorteafwijkingen, 10 aan lever-of nierschade, en veroorzaken er 12 neurologische problemen en de lijst gaat maar door. Natuurlijk zijn kinderen het meest gevoelig voor letsel door blootstelling aan pesticiden, omdat hun lichamen nog in ontwikkeling zijn. Veel pesticiden zijn hormoonontregelaars, dus de ontwikkeling die wordt verondersteld te gebeuren, gebeurt "verkeerd." Er is zelfs nu een koppeling met een lager intelligentiequotiënt bij blootgestelde kinderen. Dit is geen gelukkige gang van zaken. Bloedmonsters van volwassenen geven aan dat 95 procent van ons ten minste 1 residue van een bestrijdingsmiddel in de bloedsomloop heeft. Dit kan niet goed zijn. Het zit op het voedsel dat we eten, als het al niet in de lucht of het water zit.

Jeff Lowenfels: Dreaming of a pesticide-free Christmas

More than 300 diseases have been linked to pesticide use. These are not as a result of lab rat tests and studies either. They are based on real-life, epidemiological studies of humans around the country. Of the top 25 pesticides used to manage "facilities" and the 13 used in "landscape management," 11 are linked to cancer, five cause birth defects, 10 cause liver or kidney damage, 12 are linked to neurological problems and the list goes on. Of course, children are the most susceptible to injury from pesticide exposure because their systems are still developing. Many pesticides are endocrine disrupters, so the development that is supposed to happen happens "wrong." There is even now link to lower I.Q. in children when exposed. This is not a happy state of affairs.

Potential developmental neurotoxicity of pesticides used in Europe

Pesticides used in agriculture are designed to protect crops against unwanted species, such as weeds, insects, and fungus. Many compounds target the nervous system of insect pests. Because of the similarity in brain biochemistry, such pesticides may also be neurotoxic to humans. Concerns have been raised that the developing brain may be particularly vulnerable to adverse effects of neurotoxic pesticides. Current requirements for safety testing do not include developmental neurotoxicity. We therefore undertook a systematic evaluation of published evidence on neurotoxicity of pesticides in current use, with specific emphasis on risks during early development.

People who have suffered a traumatic brain injury and lived in areas with exposure to pesticides may be three times more likely to develop Parkinson's disease

According to a recent study by researchers at University of California, Los Angeles, people who have suffered a traumatic brain injury and lived in areas with exposure to pesticides may be three times more likely to develop Parkinson's disease. In UCLA's recent study, researchers compared a group of 357 people with Parkinson's to 754 people without the disease. All respondents lived in an agricultural area in central California. Using records of pesticide applications dating back to 1974, researchers tracked exposure to paraquats in the study. The research participants were also asked to report any head injuries suffered in their pasts that caused loss of consciousness longer than five minutes. The examination found that 42 of the 357 people with Parkinson's reported having had a traumatic brain injury compared to 50 of the 754 people without the disease. Moreover, those with Parkinson's were 36 percent more likely to report exposure to pesticides than those without the disease. Ultimately, the research suggests that while brain injuries and pesticides are individually associated with an increased risk of Parkinson's, the combination is associated with a greater threat of developing the disease.

Are Israelis eating a mouthful of pesticides for breakfast?

If there’s one food group that Israelis love, it’s vegetables. In fact, all over the Middle East, vegetables are treated with love and presented at table in infinite artful ways. But health hazards lurk on the well-loved produce. According to Haaretz, 11% of produce tested by the Israel Health Ministry showed unacceptably high levels of pesticide residues. Of over 5000 samples taken from 108 kinds of foods, 56% had traces of different pesticides. A scary tomato yielded 50 kinds of residues, while a cucumber showed 30 types. 46 kinds of pesticides were found on parsley. Those are the main ingredients of the famous Israeli salad. Are Israelis indeed eating pesticides with every bite of salad? Studies like the one showing how pregnant Jerusalemite women have higher pesticide levels in their bodies than pregnant New Yorkers support this suspicion.