Pesticides Captan Research Articles

Inhibitory effects of captan on growth of Escherichia coli and Bacillus coagulans

As the world’s population increases, so does the need for the availability of clean fruits and vegetables. In order to comply with these demands, an increase in the usage of pesticides, such as captan, has also emerged. This study aimed to determine the effect that captan has on the gut microbiome, specifically by using Bacillus coagulans and modeling strains of Escherichia coli by using Escherichia coli K-12. To do this, we mixed a pesticide dilution into melted nutrient agar, while the control groups only contained distilled water. After they had re-hardened, we streaked the plates and placed the E. coli and the B. coagulans into an incubator. Following incubation, we found a significant difference in bacterial growth between the control and the captan-containing plates. Therefore, we concluded that the pesticide captan has a negative effect on the growth of these bacteria, and, potentially, on the human microbiome. The information found during this experiment could possibly warn regular produce consumers of the potential dangers of not washing their products before consumption.

Multiple Myeloma in an Agricultural Worker Exposed to Pesticides

Multiple myeloma (MM) is a neoplastic disorder characterized by the monoclonal proliferation of plasma cells in the bone marrow. It is estimated to account for only 1% of neoplastic diseases, and there is still a great deal of uncertainty about its precise etiology. Common risk factors with a proven association with MM include ionizing radiation exposure, age greater than 65, male gender, and the presence of monoclonal gammopathy of unknown significance (MGUS).More recently, research has shown that occupational exposures to pesticides also have a significant association with the development of MM. We present the case of an adult male who presented with rib pain, back pain, fevers, and progressive shortness of breath and was ultimately found to have multiple myeloma thought to be associated with occupational exposure to the pesticide captan.

Impact of Fungicide Residues on Polymerase Chain Reaction and on Yeast Metabolism

ABSTRACT The indiscriminate use of pesticides on grape crops is harmful for consumers´ healthin “in natura” consumption and in the ingestion of wine and grape juice. During winemaking, a rapid and efficient fermentation stage is critical to avoid proliferation of contaminating microorganisms and to guarantee the product´s quality. Polymerase chain reaction (PCR) has the advantage of detecting these contaminants in the early stages of fermentation. However,this enzymatic reaction may also be susceptible to specific problems, reducing its efficiency. Agricultural practices, such as fungicide treatments, may be a source of PCR inhibiting factors and may also interfere in the normal course of fermentation.The action of the pesticides captan and folpet on PCR and on yeast metabolism was evaluated, once these phthalimide compounds are widely employed in Brazilian vineyards. DNA amplification was only observed at 75 and 37.5 µg/mL of captan concentrations, whereas with folpet, amplification was observed only in the two lowest concentrations tested (42.2 and 21.1µg/mL).Besides the strong inhibition on Taq polymerase activity, phthalimides also inhibited yeast metabolism at all concentrations analyzed.Grape must containing captan and folpet residues could not be transformed into wine due to stuck fermentation caused by the inhibition of yeast metabolism. Non-compliance with the waiting period for phthalimide fungicides may result in financial liabilities to the viticulture sector.The use of yeasts with high fungicide sensitivity should be selected for must fermentation as a strategy for sustainable wine production and to assure that products comply with health and food safety standards.

Effects of pesticides on community composition and activity of sediment microbes – responses at various levels of microbial community organization

A freshwater sediment was exposed to the pesticides captan, glyphosate, isoproturon, and pirimicarb at environmentally relevant and high concentrations. Effects on sediment microorganisms were studied by measuring bacterial activity, fungal and total microbial biomass as community-level endpoints. At the sub-community level, microbial community structure was analysed (PLFA composition and bacterial 16S rRNA genotyping, T-RFLP). Community-level endpoints were not affected by pesticide exposure. At lower levels of microbial community organization, however, molecular methods revealed treatment-induced changes in community composition. Captan and glyphosate exposure caused significant shifts in bacterial community composition (as T-RFLP) at environmentally relevant concentrations. Furthermore, differences in microbial community composition among pesticide treatments were found, indicating that test compounds and exposure concentrations induced multidirectional shifts. Our study showed that community-level end points failed to detect these changes, underpinning the need for application of molecular techniques in aquatic ecotoxicology.

Acrylonitrile content as a predictor of the captan permeation resistance for disposablenitrile rubber gloves

AbstractThe aim of this study was to determine whether the acrylonitrile (ACN) content influences the permeation resistance of disposable nitrile rubber (NBR) gloves to aqueous solutions of the pesticide captan. Attenuated total reflectance/Fourier transform infrared (ATR–FTIR) spectrophotometry at 2237 ± 5 cm−1 was used to measure the ACN contents of seven different NBR gloves. The ACN contents of the gloves ranged from 12.7 to 29.9%. Permeation was conducted according to American Society for Testing and Materials (ASTM) Method F 739‐99a with a gas chromatography/mass spectrometry analysis of captan in the hexane collection liquid. Significant correlations were found between (1) the ACN content and mass‐to‐area ratio and the logarithm of the steady‐state permeation rate (SSPR; Pearson correlation coefficient = 0.9227, p ≤ 0.05), and (2) the ACN content and mass‐to‐area ratio and the ASTM normalized breakthrough detection time (NBT) at 0.25 μg/cm2 (Pearson correlation coefficient = 0.9471, p ≤ 0.05). On average, the NBT increased 120 min for every 5% increase in the ACN content. The average SSPR ranged from 0.002 to 0.40 μg/cm2/min, a 200‐fold difference. Increasing the ACN content resulted in decreased SSPR. ATR–FTIR was useful in determining the NBR polymer ACN content, surface homogeneity, and potential glove chemical resistance. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2057–2063, 2007

Analytical method for assessing potential dermal exposure to captan, using whole body dosimetry, in small vegetable production units in Argentina

An analytical method has been developed that can be used to determine the potential dermal exposure (PDE) of workers to the pesticide captan in small-scale horticultural production units. The methodology is based on the whole body dosimetry technique, using a cotton coverall and cotton gloves as sampling media, with protective clothing worn beneath the cotton media to protect the operator. The quantitative determination of captan was done by gas chromatography-electron capture detector (GC-ECD), with the analytical method validated by measuring limits of detection and quantification, linear ranges, sample recovery and precision. Special emphasis is placed on factors that affected the stability of captan during chromatographic determination. The data generated for potential dermal exposure are presented separately for mixing/loading and application activities. These data are compared with values obtained with visible tracers using a similar field technique. Margin of safety (MOS) values are also calculated for the agricultural procedures studied.

Effects of the pesticides captan, deltamethrin, isoproturon, and pirimicarb on the microbial community of a freshwater sediment.

In three microcosm experiments, we exposed microbial communities of a natural sediment to environmentally relevant concentrations of the fungicide captan, the herbicide isoproturon, and the insecticides deltamethrin and pirimicarb. Exposure concentrations were estimated negligible concentrations (NCs), maximum permissible concentrations (MPCs), and 100 times MPC (100MPC). Experimental endpoints were microbial community respiration and biomass, bacterial activity, and denitrification. All four pesticides inhibited bacterial activity by 20 to 24% at MPC, which corresponded to concentrations in the range of microg/kg dry-weight sediment. Treatments with deltamethrin and isoproturon showed inhibiting effects on bacterial activity at NC exposures. Surprisingly, for captan, deltamethrin, and isoproturon, this inhibiting effect was not observed at 100MPC treatments. Microbial biomass was negatively effected in MPC treatments with deltamethrin and in NC treatments with isoproturon. The tested pesticides did not affect community respiration and denitrification rates. These results show that exposure to the tested pesticides may induce toxic responses in sediment microbial communities at concentrations that are predicted to be environmentally safe.

Kuwait's Total Diet Study: Dietary Intake of Organochlorine, Carbamate, Benzimidazole and Phenylurea Pesticide Residues

The State of Kuwait in cooperation with the U.S. Food and Drug Administration (FDA) conducted a Total Diet Study (TDS) to estimate intakes of pesticide residues by the population. The levels of organochlorine (OC) pesticides, carbamates, benzimidazoles, and phenylureas in the TDS core list are reported here. The TDS core list was established through a national food consumption survey. All food items (140 for the Kuwaiti adult) were prepared as eaten and analyzed for the pesticides mentioned above. The FDA's multiresidue methods in Volume I of the Pesticide Analytical Manual were used in gas, liquid, and gel permeation chromatographic analyses. Only vegetable and fruit samples contained pesticide residues (mg/kg), including the carbamates 1-naphthol (1.4) and 3H-carbofuran (0.94) in carrots; the OC pesticide vinclozolin (0.47), 3H-carbofuran (0.66), and fenuron (0.6) in kiwi fruit; the OC pesticide procymidone (0.32) and carbendazim (0.5) in grapes; 3H-carbofuran (5.0) in apricots; the OC pesticides captan (0.013) and thiabendazole (0.63) in pears; captan (0.035) in plums; and carbendazim (0.4) in mandarin oranges. The levels of 3H-carbofuran found in both apricots and kiwi fruit exceeded the maximum residue limits (MRLs) of the Food and Agriculture Organization/World Health Organization (FAO/WHO) of the United Nations. The daily intakes of pesticides by the different population groups are discussed in light of the FAO/WHO acceptable daily intakes.

Incomplete removal of the pesticide captan from skin by standard handwash exposure assessment procedures.

The dermal route of exposure is often the primary route of occupational exposure to pesticides, and several investigators have reported that over 60% of the total absorbed dose was contributed by the dermal route (Durham et al. 1972; Fenske and Elkner 1990). Although handwashing procedures to assess occupational dermal exposure have been standard practice for several decades (Durham and Wolfe 1962), the validity of these results are not typically addressed. As a significant quantity of pesticide may remain sorbed to the skin on the hands, handwashing procedures probably underestimate exposure. Moreover, for those pesticides that most sorb to skin, handwashing exposure assessment procedures result in the most significant underestimates of the physiologically relevant dose.

The effect of ph on fungitoxic interactions between a solvent and pesticide

The effect of pH on interactions between combinations of the solvent acetone and the pesticide captan was determined using the fungiPythium ultimum, Sclerotinia homeocarpa, andPestalotia sp.. Seven concentrations of the solvent acetone, ranging from 0.1 to 3.0 % (v/v), were interacted with four concentrations of the fungicide captan, ranging from 1.0 to 10.0 ppm (mg L−1). This interaction procedure was repeated at pH 4.5, 5.5, 6.5, and 7.5, using a temperature of 30 °C. Acetone and captan interacted synergistically towardsP. ultimum andS. homeocarpa, and antagonistically towardsPestalotia sp., regardless of the pH. However, the solvent concentration at which synergism or antagonism was first observed usually decreased as pH increased. The actual pH response obtained was dependent upon both the captan level and culture used. As pH increased from 4.5 to 7.5, the toxicity of captan decreased by up to 40% withS. homeocarpa andPestalotia sp., and 80% withP. ultimum. WithS. homeocarpa andPestalotia sp., the magnitude of synergism or antagonism increased as the captan concentration was raised from 1.0 or 2.5 ppm up to 7.5 or 10.0 ppm. With P. ultimum, the degree of synergism decreased at pH 4.5 and 5.5, but increased at pH 6.5 and 7.5, as the captan concentration was raised from 2.5 to 10.0 ppm. The lowest interaction magnitudes were recorded at pH 4.5 forP. ultimum, but was variable for the other cultures. The greatest interaction magnitudes were obtained at pH 4.5 forS. homeocarpa, 5.5 forPestalotia sp., and 6.5 or 7.5 forP. ultimum.

Effects of the pesticides Captan, Folpet, Guthion®, and Dichlorvos on recombination in maize ( Zea mays L.)

This study was designed to determine if commercial preparations of the pesticides Folpet, Captan, Guthion®, and Dichlorvos, have a significant effect on genetic recombination in maize ( Zea mays L.). The pesticides were applied in aqeous solutions of 1.5% dimethyl sulfoxide with 0.04% X-77 Spreader®. Premeiotic treatment s to heterozygous females were applied as a foliar spray. Testcrosses were analyzed for changes in frequencies of recombination between loci 1 g− g12 and a- et on chromosomes 2 and 3, respectively. Sib-crosses were analyzed for changes in frequencies of recombination between the 1 g− g12 loci and the a2− bt loci on chromosomes 2 and 5, respectively. Between the a- et markers, significant increases in genetic recombination were produced by the 0.17 M level of Folpet, the 0.50 M level of Captan, the 0.50 M level of Guthion®, and the 0.66% v/v and 1.00% v/v levels of Dichlorvos. Between the a2− bt markers, significant increases in recombination were produced by the 0.33 and the 0.50 M levels of Guthion®. Analysis of variance for simple regression was conducted on each pesticide/marker group combination to determine possible linear dose responses. Significant increases in genetic recombination were induced linearly in the a− et linkage group with increasing levels of Captan, Guthion®, and Dichlorvos. Genetic recombination also was increased linearly in the a2− bt linkage group with increasing concentrations of Captan and Guthion®. The conclusion from this study is that commercial preparations of the pesticides Captan, Guthion®, Dichlorvos, and possibly Folpet, have the ability to increase the frequency of genetic recombination between markers of maize. This study therefore supports the consensus that certain pesticides, at abnormally high rates of application, are genetically active, environmental recombinagens.

Modulatory effect on the pesticide captan on the immune response in rats and mice.

The effect of short-term oral administration of captan, [N-(trimethylthio)-4-cyclohexene-1,2-carboximide] on the immune response was studied in rats and mice. Animals were fed a diet with or without 0.3% (w/w) of captan for 7, 14, 21 and 42 days. The SRBC-antibody formation was depressed by about 70% in both species after 14 days of treatment. A release of inhibition occurred in mice at day 42. In a parallel manner, the lymphoblastic stimulation of splenic cells by PHA and by LPS was studied in captan-treated mice and their controls. The stimulation by PHA of splenic cells that were mainly T cells was clearly inhibited (45%) by day 14 of captan ingestion. Thereafter, the inhibition was only partially released until day 42. B cells, stimulated by LPS, presented a decrease in stimulation in captan-treated mice, during the first week of diet (20%). Then an important increase in the stimulation of these cells occurred at day 21 (85%) followed by a return to the normal value at day 42. These results pointed out a clear depressive effect of captan-diet on the immune response of the animals. The inhibition of SRBC-antibody formation during the first stage of the treatment may be correlated to the inhibitory effect of captan on T cells, which were cooperative with B cells for the expression of SRBC-antibody synthesis. These effects were obtained at a level of captan which was considerably lower than the toxic dose.