An analysis of the toxicity of organic insecticides and their effect on the environment

Marc Brazeau Genetic Literacy Project May 25, A quick note in my news feed highlighted a new data set from the World Bank that shows that while the US has one of the most productive agriculture sectors in the world, it also has some of the lowest rates of pesticide and fertilizer use. His write up was about pesticide and fertilizer use, and while high yields, with low pesticide and fertilizer rates are very commendable and surprising to manypesticide and fertilizer use is hardly the last word in sustainability in agriculture. And among the biggest impacts of agriculture:

An analysis of the toxicity of organic insecticides and their effect on the environment

Published online Jan 8. Schmehl2 Christopher A. Mullin1 and James L. The authors have declared that no competing interests exist. Conceived and designed the experiments: Provided suggestions and comments on the manuscript: Received May 10; Accepted Sep This article has been cited by other articles in PMC.

Associated Data Table S1: Some pesticide formulations that disclose in msds the percentage of the solvent NMP. Pesticide detections in wax and pollen samples collected —12 from North American honey bee colonies.

An analysis of the toxicity of organic insecticides and their effect on the environment

A larval rearing method was adapted to assess the chronic oral toxicity to honey bee larvae of the four most common pesticides detected in pollen and wax - fluvalinate, coumaphos, chlorothalonil, and chloropyrifos - tested alone and in all combinations.

All pesticides at hive-residue levels triggered a significant increase in larval mortality compared to untreated larvae by over two fold, with a strong increase after 3 days of exposure. Among these four pesticides, honey bee larvae were most sensitive to chlorothalonil compared to adults.

The addition of coumaphos significantly reduced the toxicity of the fluvalinate and chlorothalonil mixture, the only significant non-additive effect in all tested ternary mixtures.

We have shown that chronic dietary exposure to a fungicide, pesticide mixtures, and a formulation solvent have the potential to impact honey bee populations, and warrants further investigation. We suggest that pesticide mixtures in pollen be evaluated by adding their toxicities together, until complete data on interactions can be accumulated.

Introduction Recently, one hundred and twenty one different pesticides and metabolites were identified in the hive with an average of seven pesticides per pollen sample, including miticides, insecticides, fungicides, herbicides, and insect growth regulators [1][2].

Feeding on pollen and nectar in the larval diet directly exposes honey bee larvae transdermally, orally and internally [3] ; therefore, the potential for chronic toxicity and synergistic interactions at the brood stage seems likely to occur, especially considering the fact that early life stages might be much more sensitive to certain contaminants relative to the adult stage.

Several studies have demonstrated that insecticides ranging from insect growth regulators and encapsulated organophosphate formulations to systemic insecticides are more toxic to larvae than to adult bees [4] — [8].

Moreover, because beebread serves as an absolute requirement for developing bee larvae, pesticide disruption of the beneficial mycofloral community in the colony may thwart the processing of pollen into beebread and allow undesirable pathogens to thrive, therefore indirectly impacting the brood health [9][10].

Conceivably, these impacts on the larval phase could lead to weakening of the colony structure over time. To date, only a few peer-reviewed pesticide toxicity studies assess the risks of oral toxicity of pesticides to honey bee larvae.

Therefore, a goal of our study was to assess the chronic and mixture effects of common pesticides at realistic exposure concentrations on larval honey bee survival. In order to mimic realistic exposure scenarios of honey bee larvae to contaminated pollen food, we chose the four most frequently detected pesticides in the hive - fluvalinate, coumaphos, chlorothalonil, and chlorpyrifos, and tested them alone and in all combinations via chronic dietary exposure, at concentrations found in pollen and beebread.

The pyrethroid tau-fluvalinate and the organophosphate coumaphos have been used widely for Varroa mite control, and found highly persistent in the hive with an estimated half-life in beeswax of about 5 years [12].Synthetic Pyrethroids: Toxicity and Biodegradation.

A.J. Thatheyus Chronic sequelae to pyrethroids exposure include cerebro-organic disorders, Though they are said to have rapid rate of degradation in the environment, their adsorption to sediments increases their persistence by rendering them unavailable to SP-degraders which are.

In denying their own pesticide use, while playing up the use in conventional agriculture, the organic industry has played a big role in shaping public perception on the issue, and not for the better.

An organochloride, organochlorine compound, chlorocarbon, or chlorinated hydrocarbon is an organic compound containing at least one covalently bonded atom of chlorine that has an effect on the chemical behavior of the molecule.

If there are specific combinations of pesticides that account for these most extreme deviations, then these specific combinations are important to further examine with regard to their toxicity and their frequency of occurrence in the environment.

Their toxicity is not limited to the acute phase, however, and chronic effects have long been noted. Neurotransmitters such as acetylcholine (which is affected by organophosphate pesticides) are profoundly important in the brain's development, and many organophosphates have neurotoxic effects on developing organisms, even from .

Children's Health and the Environment WHO Training Package for the Health Sector World Health Organization Their mode of action is by targeting systems or enzymes in the pests which may be identical Insecticides are mostly used in developing countries and fungicides/herbicides in developed.

Insecticide - Wikipedia