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Using the aquatic species Daphnia, commonly referred to as “water fleas,” scientists at North Carolina State University (NC State) determined that exposure to the insecticide pyriproxyfen impacted multiple generations, ultimately resulting in more male offspring, and causing reproductive problems in female offspring. Lead author Gerald LeBlanc, PhD, notes, “This work supports the hypothesis that exposure to some environmental chemicals during sensitive periods of development can cause significant health problems for those organisms later in life –and affect their offspring and, possibly, their offspring’s offspring.” The study, published in the journal PLoS One, provides the scientific community with new information on how organisms respond to the environmental signals resulting from pesticide exposure.

The goal of this study was to examine the association between urinary concentrations of dialkyl phosphate metabolites of organophosphates and attention-deficit/hyperactivity disorder (ADHD) in children 8 to 15 years of age. Cross sectional data from the National Health and Nutrition Examination Survey (2000–2004) were available for 1139 children, who were representative of the general US population. One hundred nineteen children met the diagnostic criteria for ADHD. Children with higher urinary dialkyl phosphate concentrations, especially dimethyl alkylphosphate (DMAP) concentrations, were more likely to be diagnosed as having ADHD. A 10-fold increase in DMAP concentration was associated with an odds ratio of 1.55 (95% confidence interval: 1.14–2.10), with adjustment for gender, age, race/ethnicity, poverty/income ratio, fasting duration, and urinary creatinine concentration. For the most-commonly detected DMAP metabolite, dimethyl thiophosphate, children with levels higher than the median of detectable concentrations had twice the odds of ADHD (adjusted odds ratio: 1.93 [95% confidence interval: 1.23–3.02]), compared with children with undetectable levels. These findings support the hypothesis that organophosphate exposure, at levels common among US children, may contribute to ADHD prevalence.

This video : http://www.youtube.com/watch?v=BaqPNmk1kZY&feature=share lasts 57.36 minutes. It shows the devastating effects of neonicotinoids in Japan, where they were introduced as foliar treatments on rice, fruit and vegetables in the 1990s to replace organophosphates. Because of the degree of permissiveness of Japan's Maximum Residue Limits (MRL) - compared to the EU and even to the USA (Cf. 38 minutes into the document) - high levels of exposure were inflicted on unsuspecting communities. As hives emptied or were surrounded with a thick carpet of dead honeybees, apiarists and bee scientists soon realised something very serious was amiss. The victims' stoicism, many of them in an advanced state of culture shock, is very moving. Every piece of testimony merits our attention. Of special interest (46 minutes into the document) are observations by neuroscientist Yoichiro Kuroda on the human blood-brain barrier in adults, foetuses and neonates.

The objective of the present study was to evaluate immunotoxic effects of imidacloprid in female BALB/c mice. Imidacloprid was administered orally daily at 10, 5, or 2.5 mg/kg over 28 days. Specific parameters of humoral and cellular immune response including hemagglutinating antibody (HA) titer to sheep red blood cells (SRBC; T-dependent antigen), delayed type hypersensitivity (DTH) response to SRBC, and T-lymphocyte proliferation in response to phytohemagglutinin (PHA) were evaluated. The results showed that imidacloprid at high dose, specifically suppressed cell-mediated immune response as was evident from decreased DTH response and decreased stimulation index of T-lymphocytes to PHA. At this dose, there were also prominent histopathological alterations in spleen and liver. Histopathological analysis of footpad sections of mice revealed dose-related suppression of DTH response. Imidacloprid at low dose of 2.5 mg/kg/day did not produce any significant alterations in cellular and humoral immune response and it seemed to be an appropriate dose for assessment of ‘no observable adverse effects level’ for immunotoxicity in BALB/c mice. The results also indicated that imidacloprid has immunosuppressive effects at doses >5 mg/kg, which could potentially be attributed to direct cytotoxic effects of IMD against T cells (particularly TH cells) and that long-term exposure could be detrimental to the immune system.

The present study evaluated the acute and chronic toxicity of imidacloprid to a range of freshwater arthropods. Mayfly and caddisfly species were most sensitive to short-term imidacloprid exposures (10 tests), whereas the mayflies showed by far the most sensitive response to long-term exposure of all seven arthropod species tested (28-d EC10 values of approximately 0.03 µg/L). The results indicated a high aquatic risk of chronic exposure of imidacloprid to mayflies.

In Brazil, imidacloprid is a widely used insecticide on agriculture and can harm bees, which are important pollinators. The active ingredient imidacloprid has action on the nervous system of the insects. However, little has been studied about the actions of the insecticide on nontarget organs of insects, such as the Malpighian tubules that make up the excretory and osmoregulatory system. Hence, in this study, we evaluated the effects of chronic exposure to sublethal doses of imidacloprid in Malpighian tubules of Africanized Apis mellifera. In the tubules of treated bees, we found an increase in the number of cells with picnotic nuclei, the lost of part of the cell into the lumen, and a homogenization of coloring cytoplasm. Furthermore, we observed the presence of cytoplasmic vacuolization. We confirmed the increased occurrence of picnotic nuclei by using the Feulgan reaction, which showed the chromatin compaction was more intense in the tubules of bees exposed to the insecticide. We observed an intensification of the staining of the nucleus with Xylidine Ponceau, further verifying the cytoplasmic negative regions that may indicate autophagic activity. Additionally, immunocytochemistry experiments showed TUNEL positive nuclei in exposed bees, implicating increased cell apoptosis after chronic imidacloprid exposure. In conclusion, our results indicate that very low concentrations of imidacloprid lead to cytotoxic activity in the Malpighian tubules of exposed bees at all tested times for exposure and imply that this insecticide can alter honey bee physiology.

Pesticide coated seeds are commonly used in agriculture, and may be an important source of food for some birds in times of scarcity, as well as a route of pesticide ingestion. We tested the lethal and sub-lethal effects of treated seed ingestion by the red-legged partridge (Alectoris rufa), a game bird of high socio-economic value
in Spain. One year-old partridges (n = 42 pairs) were fed for 10 days in spring (prior to breeding) with wheat treated with difenoconazole (fungicide), thiram (fungicide) or imidacloprid (insecticide), using two doses for each pesticide (the one recommended, and its double to represent potential cases of abuse of pesticides). We investigated the direct and indirect effects on the body condition, physiology, immunology, coloration and subsequent reproduction of exposed partridges. For the latter, eggs were collected, measured and incubated and the growth and survival of chicks were monitored. Thiram and imidacloprid at high exposure doses produced mortalities of 41.6 and 58.3 %, respectively. The first death was observed at day 3 for imidacloprid and at day 7 for thiram. Both doses of the three pesticides caused sublethal effects, such as altered biochemical parameters, oxidative stress and reduced carotenoid-based coloration. The high exposure doses of
imidacloprid and thiram also produced a decrease in cellular immune response measured by the phytohemagglutinin test in males. Bearing in mind the limitation of the small number of surviving pairs in some treatments, we found that the three pesticides reduced the size of eggs and imidacloprid and difenoconazole also reduced the fertilization rate. In addition, both thiram and imidacloprid reduced chick survival. These experiments highlight that the toxicity of pesticide-treated seeds is a factor to consider in the decline of birds in agricultural environments.

Neonicotinoids are widely used systemic insecticides which, when applied to flowering crops, are translocated to the nectar and pollen where they may impact upon pollinators. Given global concerns over pollinator declines, this potential impact has recently received much attention. Field exposure of pollinators to neonicotinoids depends on the concentrations present in flowering crops and the degree to which pollinators choose to feed upon them. Here we describe a simple experiment using paired yellow pan traps with or without insecticide to assess whether the commonly used neonicotinoid imidacloprid repels or attracts flying insects. Both Diptera and Coleoptera exhibited marked avoidance of traps containing imidacloprid at a field-realistic dose of 1 µg L−1, with Diptera avoiding concentrations as low as 0.01 µg L−1. This is to our knowledge the first evidence for any biological activity at such low concentrations, which are below the limits of laboratory detection using most commonly available techniques. Catch of spiders in pan traps was also slightly reduced by the highest concentrations of imidacloprid used (1 µg L−1), but catch was increased by lower concentrations. It remains to be seen if the repellent effect on insects occurs when neonicotinoids are present in real flowers, but if so then this could have implications for exposure of pollinators to neonicotinoids and for crop pollination.

In “Silent Spring" (1962) Rachel Carson wrote

"The world of systemic insecticides is a weird world, surpassing the imaginings of the brothers Grimm.
It is a world where the enchanted forest of the fairy tales has become a poisonous forest.
It is a world where a flea bites a dog and dies…where a bee may carry poisonous nectar back to its hive and presently produce poisonous honey."

Changes in arable farming practices have been identified as important factors in the decline of wildlife. Significant declines in the brown hare have been recorded, associated with changes in the availability of high quality food at certain times of year. Declines in the Pipistrelle Bat are in part likely to have resulted from lower abundance of insect prey in farmland. Information on the decline of arthropods in farmland habitats has been published by the Game Conservancy Trust’s Sussex Study In the Sussex study area, between 1972 and 1990, arthropods have declined by 4.2% per annum (excluding springtails and mites), with many groups of beneficial insects, such as aphid predators and game bird food items, declining at faster rates. Bee species are particularly threatened. A range of cornfield weeds, such as corn buttercup and shepherd’s-needle, have declined markedly this century, to the extent that some species are now extinct in the UK. These annual flowers are dependent on the arable ecosystem, which is characterised by regular soil cultivation. Declines in farmland birds have been identified for a number of species characteristic of arable and mixed farmland. These birds feed on seeds, invertebrates or both, sometimes at different times of year.