Insecticides

This report reviews dozens of recent studies that examine the impact of pesticides on children’s health. Our analysis reveals the following:
• Compelling evidence now links pesticide exposures with harms to the structure and functioning of the brain and nervous system. Neurotoxic pesticides are clearly implicated as contributors to the rising rates of attention deficit/hyperactivity disorder, autism, widespread declines in IQ and other measures of cognitive function.
• Pesticide exposure contributes to a number of increasingly common health outcomes for children, including cancer, birth defects and early puberty. Evidence of links to certain childhood cancers is particularly strong.
• Emerging science suggests that pesticides may be important contributors to the current epidemic of childhood asthma, obesity and diabetes.
• Extremely low levels of pesticide exposure can cause significant health harms, particularly during pregnancy and early childhood.

The aim of this study was to provide EFSA with information relating to assessment of the risk to amphibians posed by pesticide exposure. In the first part of the study the European amphibian species associated with agricultural habitats were identified with the aim of collating information for representative species such as body size and life-cycle. Also collated were the results of studies of amphibians in European agricultural habitats to provide information on activity in areas where they may be at risk of exposure to pesticides.

Human exposure to imidacloprid is likely to occur during its use as an acaricide or an ectoparasiticide. Accordingly, the developmental immunotoxic potential of imidacloprid was investigated. Oral exposure was initiated in timed pregnant female Wistar rats on gestation day 6 (GD 6) till GD 21. On GD 20, half of the gravid dams were sacrificed, and in utero fetal development was assessed. In the other half of the dams, administration was continued till weaning on postnatal day 21 (PND 21) and maternal toxicity was investigated. A subgroup of weaned pups was sacrificed to assess immunotoxicity parameters. The other half of the pups were exposed to imidacloprid till PND 42, and immunotoxicity was assessed. The findings revealed post-implantation loss in the highest dose group, indicating the risk of abortion. Soft tissue abnormalities and skeletal alterations were observed in the highest dose group. Humoral immunity was assessed by estimating hemagglutination titer and immunoglobulin production. Cell mediated immunity was assessed by Delayed Type Hypersensitivity, whereas, non-specific immunity was assessed by phagocytic index, and other phenotypic parameters. These data revealed that imidacloprid caused age-dependent adverse effects on the developing immunity which was aggravated when exposure continued throughout development, leading to a compromised immune system.

Deze week is het nieuwe boek van Universiteitshoogleraar Louise Fresco verschenen, getiteld 'Hamburgers in het paradijs. Voedsel in tijden van schaarste en overvloed'. Fresco stelt daarin veel belangwekkende vragen en kaart wezenlijke maatschappelijke kwesties aan zoals de verspilling van voedsel. Maar, Fresco is beter in het analyseren van het probleem, dan in het bedenken van duurzame oplossingen. De inleiding begint als volgt: "Voedsel is vandaag de dag een bron van intense verwarring." Bionext is van mening dat Fresco zelf nogal eens verwarring bij de consument veroorzaakt door haar uitspraken over biologisch en duurzaamheid.

Het stond al een tijdje vast dat vanaf 1 januari 2015 geen chemische pesticiden meer gebruikt mogen worden op terreinen die door openbare diensten worden onderhouden. Maar met een bijkomend decreet wil de Vlaamse regering het gebruik van insectenwerende middelen nog strenger inperken. Het nieuwe decreet, dat er kwam op voorstel van Vlaams minister van Leefmilieu Joke Schauvliege (CD&V) en is goedgekeurd door de Vlaamse regering, is de omzetting van een Europese richtlijn uit 2009.

Steeds meer boeren en consumenten sluiten zich aan bij de opvatting dat het Europees landbouwbeleid anders moet. De bodem- en waterkwaliteit worden door grootschalige landbouw en pesticiden aangetast. Europarlementariër Bas Eickhout: “Dat willen wij anders: Landbouwbeleid mag niet ten koste gaan van gezondheid en milieu. We moeten met belastinggeld niet méér problemen veroorzaken, maar juist strenge eisen stellen ter bescherming van milieu en gezondheid.”

Im Sommer 2008 starben am Oberrhein innerhalb weniger Stunden Millionen Bienen. Verantwortlich war offiziell ein technischer Fehler an Saatgutmaschinen, durch den große Mengen eines neuartigen Pflanzenschutzmittels aus der Gruppe der so genannten Neonikotinoide in die Umwelt gelangten. Ein einmaliges Ereignis, sagen die einen. Die Logik eines extrem gefährlichen Pestizids, sagen die anderen. Schon lange stehen die Neonikotinoide im Verdacht, nicht nur akut toxisch zu wirken, sondern auch in geringen Dosen das Immun- und Navigationssystem der Nektarsammler zu stören. Im Frühjahr konnten Wissenschaftler des französischen staatlichen Agrarforschungsinstitut INRA diesen Effekt nachweisen - mit der Folge, dass ein Verbot des Pestizids sehr wahrscheinlich ist.

Im Zusammenhang mit dem durch Pestizide verunreinigten Korneuburger Grundwasser ist nun ein unabhängiges Expertenteam am Wort, das die Sanierungsmaßnahmen leiten wird. Die Herkunft der Verunreinigung sei durch Probennahmen und Überprüfungen auf das Werksgelände der Kwizda Agro GmbH eingeengt worden, teilte die Bezirkshauptmannschaft am Donnerstag mit. Als wahrscheinliche Ursache gilt ein undichter Abwassersammelbehälter. Univ.-Prof. Werner Wruss, der das Expertenteam leitet, sprach von einem mehrstufigen Konzept, das umgesetzt werden soll. Eine Sofortmaßnahme sei die Wasserhaltung auf dem Kwizda-Werksgelände, damit es zu keinen weiteren Emissionen komme. Außerdem gehe es um die Quellsanierung und die Inbetriebnahme bzw. Aktivierung von Sperrbrunnen, die nachgerüstet werden müssten, um auch das zuletzt entdeckte Herbizid Clopyralid zurückzuhalten. Dass derartige Grundwasserreinigungen selbst Jahrzehnte dauern könnten, ließ Wruss nicht unerwähnt. Darüber hinaus sei mit "einigen Millionen" Euro an Kosten zu rechnen.

An injection study and a field study were used to investigate the hypothesis that environmental xenobiotics have the potential to alter the immune function of northern leopard frogs (Rana pipiens). Three assays, IgM-specific antibody response to keyhole limpet hemocyanin linked to dinitrophenyl (KLH-DNP), zymozan induced chemiluminescence (CL) of whole blood and the delayed-type hypersensitivity (DTH), were used to assay humoral, innate and cell-mediated immune endpoints. Sublethal doses of DDT (923 ng/g wet wt), malathion (990 ng/g wet wt), and dieldrin (50 ng/g wet wt) were used in the injection study. In all pesticide-injected groups, antibody response was dramatically suppressed, DTH reactions were enhanced, and respiratory burst was lower. When the order of administration of pesticides and antigens was reversed, no differences in immune function between the control and dosed groups were apparent, indicating that frogs exposed to pathogens prior to pesticide exposure can still respond. A field study found significant differences in immune function between frog populations in pesticide-exposed and pesticide-free locations. The antibody response and CL were suppressed and the DTH enhanced in frogs from Essex County (ON, Canada).
Overall, the results suggest that exposure to these pesticides can cause both stimulatory and suppressive immune changes in adult frogs and is doing so in wild populations.

Recently, a decrease in the populations of marine toads (Bufo marinus) and whistling frogs (Eleutherodactylus johnstonei and E. gossei) has been noted on the island of Bermuda. In the current study, we investigated whether this decline was related to altered immune functions. During August 1998, a significant proportion (25%) of the toads exhibited deformities. Analysis of soil samples revealed presence of chlorinated pesticides and polychlorinated biphenyls (PCBs). Spleen cells from toads collected from more polluted areas of Bermuda exhibited a decrease in B-cell proliferative response to lipopolysaccharide when compared to the responsiveness of B cells from toads collected from less polluted areas. In contrast, the T-cell responsiveness to mitogens in these two groups was not significantly altered. Histological examination of major parenchymatous organs in marine toads and whistling frogs showed alterations in hepatic and splenic morphology, indicative of exposure to toxicants. Together, the current study suggests that the immune functions of toads from contaminated sites of Bermuda are significantly altered, which may contribute to the decline in their population.