Statute and legislative history of the federal insecticide,fungicide, and rodenticide act and its impact on agriculture

Abstract

This report discusses the responsibilities of government for the legislation of pesticides, and describes the impact of various statutes on the use of pesticides in agriculture. Governmental responsibilities for management of the economy, education, and enactment of laws and regulations are discussed, and the history of U.S. legislation of pesticides and related substances is presented. Finally, the impact of pesticide regulation on international trade is considered.     

Biopesticides: Has their time come?

Abstract

The increased tempo of developments in biopesticides is closely related to the growing awareness and emphasis on integrated pest management (IPM) and sustainable agriculture. Several economic forecasting sources predict a growth rate for the biopesticide industry at 10 to 15% per annum over the next 10 years in contrast to a 1 to 2% growth rate for synthetic chemical pesticides.

The greatest opportunity for biopesticides is in the insect pest management arena. This paper discusses several types of bioinsecticides that may have significant economic impact in the coming years.     

Effects of synthetic pyrethroids and methidation on activities of some digestive enzymes in carp (Cyprinus carpio L.)

Abstract

The effects of pyrethroid pesticides (deltamethrin, permethrin and cypermethrin) and an organophosphate ester (methidation) on the activities of carp trypsin, α‐chymotrypsin, carboxypeptidase A and lipase were studied. The enzymes were isolated from the gastrointestinal tract and the effects of the pesticides were investigated during incubation for 5 min. The activity of trypsin was influenced only slightly by the presence of deltamethrin and methidation, whereas permethrin and cypermethrin caused significant inhibition. The pyrethroid pesticides at lower concentrations resulted in a slight activation of α‐chymotrypsin. Methidation inhibited the α‐chymotrypsin activity by about 20%. These pesticides modified the lipase activity to a lesser extent; the highest inhibition was measured with cypermethrin. The carboxypeptidase A activity was inhibited by both pyrethroid pesticides and methidation. The results suggest that these pesticides might interact with the active conformation of the studied hydrolytic enzymes, resulting in changes in their activities.     

The effect of insecticides on the non-target predatory mite Kampimodromus aberrans: Laboratory studies

The side-effects of pesticides on predatory mites have been investigated at various levels and international teams (e.g., the IOBC/wprs Working Group “Pesticides and beneficial organisms”) have selected a few species of predatory mites occurring in Central and Northern Europe as representative for such studies. Key biocontrol species occurring in Southern Europe have received much less attention. Kampimodromus aberrans is the most important predator of herbivorous mites in South-European vineyards treated with selective pesticides. The impact of pesticides on K. aberrans populations has been studied in field conditions whereas few toxicological tests have been conducted in the laboratory because of difficulties in rearing this species. A method for rearing K. aberrans in the laboratory has recently been set up allowing toxicological studies to be conducted. In this paper, a toxicological method to assess the effects of pesticides on K. aberrans is described and the effects of insecticides frequently used in European vineyards on two K. aberrans strains are reported. These strains were collected from vineyards treated with organophosphates. Insecticides characterized by different modes of action were selected for trials. Among these, etofenprox and spinosad were classified as harmful to predatory mites. Chlorpyrifos reduced predatory mite fecundity, and was classified as moderately harmful for both strains. The toxicity of thiamethoxam and flufenoxuron varied with the strain (low to moderate). Indoxacarb and methoxyfenozide appeared to be harmless or slightly harmful. Implications of this study for adopting IPM tactics with a reduced risk for K. aberrans are discussed.     

Paper electrophoretic separations of some common pesticides : Determination of monocrotophos,rogor and malathion in soil samples

Abstract

Paper electrophoretic movements of a number of pesticides belonging to organophosphorus, organochlorine and pyethroid groups in various acid background electrolytes have been studied. The effect of pH and pKa of the acids on the movement of these pesticides have also been studied. It has been observed that the movement of most of the pesticides is enhanced with increase in the degree of ionisation of the acids (pKa) studied as background electrolytes. The movement also increases with increase in the pH of acids. On the basis of differential movement of pesticides towards cathode and anode, a number of separations have been achieved from binary mixtures. Monocrotophos, rogor and malathion have been determined quantitatively (28.6 ‐ 29.2 μg) in alcoholic extracts of soil samples.     

The dissipation of three fungicides in a biobed organic substrate and their impact on the structure and activity of the microbial community

Biopurification systems (BPS) have been introduced to minimise the risk for point source contamination of natural water resources by pesticides. Their depuration efficiency relies mostly on the high biodegradation of their packing substrate (biomixture). Despite that, little is known regarding the interactions between biomixture microflora and pesticides, especially fungicides which are expected to have a higher impact on the microbial community. This study reports the dissipation of the fungicides azoxystrobin (AZX), fludioxonil (FL) and penconazole (PC), commonly used in vineyards, in a biomixture composed of pruning residues and straw used in vineyard BPS. The impact of fungicides on the microbial community was also studied via microbial biomass carbon, basal respiration and phospholipid fatty acid analysis. AZX dissipated faster (t _1/2?=?30.1 days) than PC (t _1/2?=?99.0 days) and FL (t _1/2?=?115.5 days). Fungicides differently affected the microbial community. PC showed the highest adverse effect on both the size and the activity of the biomixture microflora. A significant change in the structure of the microbial community was noted for PC and FL, and it was attributed to a rapid inhibition of the fungal fraction while bacteria showed a delayed response which was attributed to indirect effects by the late proliferation of fungi. All effects observed were transitory and a full recovery of microbial indices was observed 60 days post-application. Overall, no clear link between pesticide persistence and microbial responses was observed stressing the complex nature of interactions between pesticides in microflora in BPS.     

Effects of cyclodextrin on the stereoselectivity inhibition of acetylcholinesterase by isomalathion

ABSTRACT

In attempt to evaluate the effects of cyclodextrins (CDs) on enantioselectivity of chiral pesticides toxicity, this study investigated effects of three kinds of cyclodextrins including α-CD, β-CD and randomly methylated β-CD (RAMEB) on toxicity of four enantiomers of isomalathion including (1R, 3R)-isomalathion, (1S, 3S)-isomalathion, (1S, 3R)-isomalathion and (1R, 3S)-isomalathion. Generally, the addition of α-CD and RAMEB (1.5 g/L to 3.5 g/L concentration) could lead to reduction of isomalathion toxicity in most cases, while the presence of β-CD (0.3 g/L to 1.5 g/L concentration) enhanced the toxicity of isomalathion. It was speculated that higher electronic cloud density and lower water solubility of β-CD than α-CD and RAMEB might favor to combination between acetylcholinesterase (AChE) and isomalathion included by β-CD. With respect for α-CD and RAMEB, isomalathion included by them could be easily dissolved in water because of high water solubility of the two CDs. Therefore, α-CD and RAMEB can be used as remediation regent for the pollution of isomalathion, and β-CD can act as an additive in improving bioactivity of such pesticides. In addition, the presence of CDs can alter enantioselectivity of chiral pesticides. The differences on the extent of enantioselectivity variation of isomalathion induced by α-CD, RAMEB and β-CD might be ascribe to the different cavity, electron cloud density and solubility among the three CDs. In conclusion, the above results gave researchers a possibility to change enantioselectivity of chiral pesticides from undesirable outcomes to desirable ones.     

Review of Separation Technologies for Treating Pesticide-Contaminated Soil

ABSTRACT

Pesticide contamination results from manufacturing, improper storage, handling, or disposal of pesticides, and from agricultural processes. Since most pesticides are mixtures of different compounds, selecting a remedy for pesticide-contaminated soils can be a complicated process. The various available treatment options for remediation fall into three broad categories: containment-immobilization, separation-concentration, and destruction. This paper categorizes pesticides into waste groups based on available treatment options and provides a review of separation treatment options that have been demonstrated to—or show potential to— treat pesticide-contaminated soil. Technologies include radio frequency heating, soil washing, thermal desorp-tion, and solvent extraction.     

Toxic effects of carbofuran and glyphosate on semen characteristics in rabbits

Abstract

The present study was undertaken to investigate the effect of chronic treatment with two sublethal doses of Carbofuran (carbamate insecticide) and Glyphosate (organophosphorus herbicide) on body weight and semen characteristics in mature male New Zealand white rabbits. Pesticide treatment resulted in a decline in body weight, libido, ejaculate volume, sperm concentration, semen initial fructose and semen osmolality. This was accompanied with increases in the abnormal and dead sperm and semen methylene blue reduction time. The hazardous effect of these pesticides on semen quality continued during the recovery period, and was dose‐dependent. These effects on sperm quality may be due to the direct cytotoxic effects of these pesticides on spermatogenesis and/or indirectly via hypothalami‐pituitary‐testis axis which control the reproductive efficiency.     

Degradation of atrazine,metolachlor, and pendimethalin in pesticide‐contaminated soils: Effects of aged residues on soil respiration and plant survival

Abstract

This study was conducted to determine the effects of pesticide mixtures on degradation patterns of parent compounds as well as effects on soil microbial respiration. Bioavailability of residues to sensitive plant species was also determined. Soil for this study was obtained from a pesticide‐contaminated area within an agrochemical dealer site. Degradation patterns were not affected by the presence or absence of other herbicides in this study. Atrazine concentrations were significantly lower at 21 through 160 days aging time compared to day 0 concentrations. Metolachlor and pendimethalin concentrations were not significantly different over time and remained high throughout the study. Microbial respiration was suppressed in treated soils from day 21 to day 160. Soybean and canola were the most successful plant species in the germination and survival tests. Generally, with increased aging of pesticides in soil, germination time decreased. Survival time of plants increased over time for some treatments indicating possible decreased bioavailability of pesticide residues. In some cases, survival time decreased at the longer 160‐day aging period, possibly indicating a change in bioavailability, perhaps as the result of formation of more bioavailable and phytotoxic metabolites. No interactive effects were noted for mixtures of pesticides compared to individually applied pesticides in terms of degradation of the parent compound or on seed germination, plant survival, or microbial respiration.     

Mutagenicity evaluation of chemical pesticides

Abstract

Over the last few decades, the use of chemical pesticides has increased dramatically in the U.S. This relatively sudden increase greatly concerns the U.S. Environmental Protection Agency (EPA), since it has the responsibility for ensuring the safety of all pesticides used in the U.S. In response to this concern, EPA has established a review program, the Rebuttable Presumption Against Registration (RPAR), for periodically reassessing the mutagenic and carcinogenic potential of pesticide compounds.

This paper presents a review and evaluation of the data reported in the literature on six chemical pesticides suspect for mutagenic potential. The pesticide chemicals discussed are maleic hydrazide; rotenone; monuron; diallate; triallate, and benomyl.     

Use of coal to retard pesticide movement in soil

Abstract

Three different coals and an activated carbon were mixed with prescribed amounts of a sandy loam soil and added to soil columns to test their ability to retard pesticide movement. The pesticides chosen were prometon, prometryn, 2,4‐D, carbofuran, dinoseb, fenamiphos, and two oxidation products of fenamiphos, fenamiphos sulfoxide, and fenamiphos sulfone. These compounds were chosen to represent different chemical classes of pesticides and because they were considered to have a high potential for transport in soils. All the coals were more effective in retaining the pesticides than the soil, however, some were more effective than others. One of the coals was the most effective in retaining the majority of the pesticides with an overall retention of 94.7% in a 4:1 soil/coal ratio compared to the soil only with a retention of 48.5%. The moisture content of the coal appears to have a positive correlation with the ability of the coal to retain the pesticides under the conditions used for this experiment.     

Pesticide residues in artichokes: Effect of different head shape

Abstract

Residues of three pesticides (dimethoate, parathion, and pyrazophos) in two artichoke cultivars, Masedu and Spinoso sardo, were investigated. The amount of pesticides in artichokes was greatly affected by the head shape. In the case of the calix‐shaped Masedu artichoke, the residues in whole heads at commercial ripening were on average about twice higher than those of the pagoda‐shaped Spinoso sardo artichoke. In the heart this ratio was 4 to 42 times greater. Residue decay rates were very fast, mainly owing to the dilution effect due to head growth.     

Determining the role of humic substances in the fate of pesticides in the environment

Abstract

The data presented in this paper emphasize that the behavior and fate of pesticides in the environment is influenced by humic substances. Various methods most frequently used for the characterization of humic substances are discussed. Both humic acid and fulvic acid can solubilize in water certain organic compounds and are important carriers of some pesticides in soil. Humic substances have the potential for promoting the nonbiological degradation of many pesticides. Several methods of bleaching humus color from drinking water, including chlorination, ozonation, and UV‐radiation, are described. Finally, the photochemical stability to UV‐radiation of certain pesticides in aqueous fulvic acid solution is discussed.     

Residues and dissipation kinetic of abamectin,chlorfenapyr and pyridaben acaricides in green beans (Phaseolus vulgaris L.) under field conditions using QuEChERS method and HPLC

Abstract

The current study estimated the dissipation rates of abamectin, chlorfenapyr and pyridaben acaricides in pods of green beans (Phaseolus vulgaris L.) under field conditions in Egypt. Pesticides were extracted and cleaned-up by QuEChERS method and were analyzed by HPLC. The dissipation of these acaricides followed the first order kinetics model with half-life (t_1/2) values 1.00, 3.50 and 1.50?days for abamectin, chlorfenapyr and pyridaben, respectively. The lowest residues, at different time intervals of field application rate of each pesticide, were observed with abamectin followed by pyridaben and then chlorfenapyr. Pre-harvest intervals (PHIs) were 10.00, 13.50 and 6.00?days for abamectin, chlorfenapyr and pyridaben, respectively and were below the established European maximum residue limits (EU MRLs) 10–14, 14–21 and 7–10?days after application, respectively. If the fresh pods will be consumed after harvest, it is expected that the presence of these pesticides in the food will have a negative impact on human health. Therefore, the elimination of the residues of these harmful pesticides must be carried out.     

Pacific oyster (Crassostrea gigas) hemocyte are not affected by a mixture of pesticides in short-term in vitro assays

Pesticides are frequently detected in estuaries among the pollutants found in estuarine and coastal areas and may have major ecological consequences. They could endanger organism growth, reproduction, or survival. In the context of high-mortality outbreaks affecting Pacific oysters, Crassostrea gigas, in France since 2008, it appears of importance to determine the putative effects of pesticides on oyster susceptibility to infectious agents. Massive mortality outbreaks reported in this species, mainly in spring and summer, may suggest an important role played by the seasonal use of pesticides and freshwater input in estuarine areas where oyster farms are frequently located. To understand the impact of some pesticides detected in French waters, their effects on Pacific oyster hemocytes were studied through short-term in vitro experiments. Bivalve immunity is mainly supported by hemocytes eliminating pathogens by phagocytosis and producing compounds including lysosomal enzymes and antimicrobial molecules. In this study, oyster hemocytes were incubated with a mixture of 14 pesticides and metaldehyde alone, a molecule used to eliminate land mollusks. Hemocyte parameters including dead/alive cells, nonspecific esterase activities, intracytoplasmic calcium, lysosome number and activity, and phagocytosis were monitored by flow cytometry. No significant effect of pesticides tested at different concentrations was reported on oyster hemocytes maintained in vitro for short-term periods in the present study. It could be assumed that these oyster cells were resistant to pesticide exposure in tested conditions and developing in vivo assays appears as necessary to better understand the effects of pollutants on immune system in mollusks.     

Investigation of pesticide residues in water,sediments and fish samples from Tapi River,India as a case study and its forensic significance

Abstract

This research is a case study on detection of pesticides in river water, sediment as well as fish samples from Tapi River, among the major rivers of Gujarat, India. To investigate the misuse, concentration level and occurrence patterns of persistent pesticides, samples were collected from the river. Chlorpyrifos, methyl parathion, hexachlorocyclohexane (HCH), dichloro diphenyl trichloroethane (DDT) and endosulfan were analyzed by gas chromatography technique with flame ionization detector (FID). Scanty reports are available, but after 1999, no such data are reported as some of these pesticides have been banned. Although these pesticides are still in use which we observed from the obtained results. In this river, the amount of endosulfan, chlorpyrifos, and methyl parathion was observed in surface water with concentrations of 37.56?µg/L, 0.86?µg/L and 0.43?µg/L, respectively. Endosulfan, DDT and methyl parathion detected in sediment were 38.38?ng/g, 0.65?ng/g and 0.77?ng/g, respectively. In fish samples, levels of endosulfan, chlorpyrifos, and methyl parathion detected were 101.28, 0.392, and 3.49?ng/g correspondingly. Results showed that highly toxic pesticides are still being used in the surrounding area, and there is an urgent need for enforcement of rules to control the production and application of such pesticides.     

Residues of organochlorine pesticides in fishes in Sudan

Abstract

Cotton‐producing areas of the Centrol Sudan, bordered by the Blue and the White Nile, have been subjected to repeated applications of pesticides. This region is irrigated by a series of canals, the Gezira canals, which hold large amounts of fresh water. Lake Nubia at the Sudan‐Egypt border is another important fresh water reservoir and fisheries ground. Fish from both the Gezira and Lake Nubia showed elevated concentrations of pesticides, suggesting that continued pesticides application would endanger the equatic fauna of this region and the proposed fresh water fishery.     

Comparative toxicity of some pesticides on human health and some aquatic species

Abstract

Inhibition studies have been carried on the hydrolysis reactions catalyzed by cholinesterases taken from electric eel, human and horse serums by Sevin, Aldrin and Malathion. Three esters of p‐nitrophenol have been used as substrates. The degree of inhibition has been used as a measure of the comparative toxicity of these pesticides on these cholinesterases.     

Human health effects of selected pesticides,chloroaniline derivatives.

Abstract

The health effects of two pesticides, chlordimeform and propanil, are discussed. Chlordimeform and 2‐methyl‐4‐chloroaniline, a major metabolite of chlordimeform, cause severe hemorrhagic cystitis in humans. In cats, however, only a mild effect on the bladder was noted. The herbicide propanil has produced chloracne in humans, and along with 3,4‐dichloroaniline, hyperkeratosis in rabbits. The contaminants 3,4,3’,4'‐tetrachloroazobenzene and 3,4,3’,4'‐tetrachloroazoxybenzene are responsible for the chloracnegenic characteristics of propanil, 3,4‐dichloroaniline, and methazole.