High Concentrations Of Pesticides Research Articles

Cocktails of pesticide residues in Prochilodus lineatus fish of the Salado River (South America): First record of high concentrations of polar herbicides

Muscle and viscera (gills-liver) of the fish Prochilodus lineatus were obtained from four sites of lower course of Salado river and one site at Santa Fe river near to its confluence with Salado river from Santa Fe (Argentina) between December 2021 and February 2022. Sediment samples were also obtained from the same sites. All samples were analyzed for pesticide residues following the QuEChERS method to quantify 136 compounds by UHPLC-ESI-MS/MS and GC-EI-MS/MS. Overall, muscle fish tissue showed very high concentrations (maximum concentrations detected) of the insecticide cypermethrin (204 μg/kg), polar herbicides (glyphosate; 187 μg/kg and its degradation product (aminomethylphosphonic acid) AMPA; 3116 μg/kg, and glufosinate-ammonium; 677 μg/kg), and the fungicide pyraclostrobin (50 μg/kg). In viscera samples, high values of cypermethrin (506 μg/kg), chlorpyrifos (78 μg/kg), and lambdacyhalothrin (73 μg/kg) were the main pesticides found. Mean residues concentrations detected among sites were not significantly different neither in muscle nor viscera of P. lineatus in most of the cases. Exceptionally, the southernmost studied site of the Lower Salado river showed significant differences in concentration of residues found in muscle, due to high concentrations of glyphosate and glufosinate-amonium (KW = 11.879 and KW = 13.013, respectively, P < 0.05). Other norther Lower Salado river site showed significant higher AMPA concentration in fish viscera than in the rest of the studied sites (KW = 12.86 P < 0.05). Some sediment samples showed low levels of herbicides such as glyphosate (24 μg/kg) and fungicides. However, the world highest levels of polar herbicides were recorded in fish muscle. The results of this study highlight the need for periodic monitoring due to the high concentration of pesticides and its potential risk in a very important commercial freshwater fish from Argentina, which is consumed locally and exported to other countries for human consumption.

Characterizing the adult exposome in men and women from the general population: Results from the EHES-LUX study

Throughout life individuals are exposed to a large array of diverse environmental exposures (exposome). Hair analyses can assess chronic exposure to a large number of chemicals with less intra-variability than urine and blood. This is essential for studies that aim to achieve a global vision of the exposome. We aimed at characterizing the adult exposome by describing 175 environmental exposures and correlation patterns between and within exposure groups. A subsample of participants of the European Health Examination Survey, covering information on exposure to chemical pollutants in hair samples, were included in the present analysis (N = 442). Concentrations of micronutrients, lifestyle, home environment and socioeconomic information completed the exposome description and were obtained through blood analyses and questionnaires. We detected 29 persistent and non-persistent chemical pollutants in more than 70% of hair samples. Compared to women, men had higher concentrations of pesticides, lower concentrations of micronutrients (with the exception of vitamin A), and presented higher alcohol consumption. Across all exposures, a low median absolute correlation was found, 0.05 (5th − 95th centiles = 0.10, 0.20). We observed higher correlations and median correlations within exposure groups than between groups of exposure. The highest median correlation was observed between plasticizers (bisphenol A and S) in both men (0.50) and women (0.31). A 70% and 95% of cumulative variance was explained by 37 and 73 principal components respectively. We found a wide range of chemical exposures in hair samples of men and women. The adult exposome was complex and multidimensional. Future exposome studies should include hair as a matrix for characterizing exposure to multiple environmental chemicals.

Risk assessment of persistent pesticide pollution: Development of an indicator integrating site-specific characteristics

Detection of high pesticide concentrations in sediments and water often leads to prioritizing a site as being ‘at risk’. However, the risk does not depend on pesticide concentration alone, but on other site-specific characteristics also. We developed an indicator that identifies the ‘Level of Concern’ by integrating five such characteristics: (i) pesticide concentrations in surface and groundwater causing risks to ecological health (ii) impacts on human health, (iii) water scarcity, (iv) agricultural production, and (v) biodiversity richness. We applied this framework in an agricultural region of the Lower Ganges Basin in West Bengal, India. We measured concentrations of selected organochlorine pesticides (OCPs) in surface and groundwater within an 8 km2 area in 2019. Of 20 banned and restricted OCPs, 11 were detected as causing high risk to ecological health and 10 at concentrations above the Accepted Carcinogenic Risk Limit (ACRL) for humans. In the pre-monsoon, the mean concentrations of ΣOCPs in groundwater and surface water were 126.9 ng/L and 104 ng/L, in the monsoon they were 144.7 ng/L and 138 ng/L, and in the post-monsoon 122.1 ng/L and 147 ng/L respectively. In groundwater, no significant seasonal difference was observed in most pesticides. In the surface water, 7 pesticides were significantly higher in the monsoon and post-monsoon, which may be attributed to increased runoff as well as post monsoon application of OCPs. In September 2022 we again measured OCP concentrations in surface water and sediment. The mean concentration of 14 of the 20 measured OCPs were found to be significantly lower in the post-pandemic period compared to the pre-pandemic time. These lower pesticide concentrations may indicate a reduced use of OCPs in agricultural practices during the pandemic. This area was identified as being at the highest Level of Concern, even though the OCP concentrations alone conformed to general guidelines.

Monitoring of Pesticide Residues in Lebanese Vegetables and Agricultural Soils and Their Impact on Soil Microbiological Properties

The practice of pesticide application in agriculture done in Lebanon deviate from standard agricultural disciplines, raising awareness of their contamination of soil and vegetables as well as their repercussions on microbial communities. To this end, soil and vegetable samples from different pesticide-treated sites were quantified for chlorpyrifos (C) and methomyl (M) residues using Gas Chromatography-Mass Spectrometry. Moreover, clear soil specimens were treated with different concentrations of C, M, and CM assortment to assess their repercussion on the microbial population. High pesticide concentrations were recovered ranging between 31.13 and 53.74 mg/kg in eight agricultural fields, which abate gradually with time. After 20 days of pesticide implementation, their residues were above the maximum residual levels for lettuce, cabbage, tomato, and corn. Soil altered with pesticides showed fluctuation in its microbial community by suppressing some groups while favouring the propagation of tolerant species. Our data indicate the need for the requirement of strict laws to minimise pesticide usage and reduce their impact on soil quality, human health, and non-target organisms.

Degradation of seven pesticides and two metabolites before and during aquifer storage transfer and recovery operation

Degradation of 7 common pesticides (bentazon, boscalid, chloridazon, fluopyram, flutolanil, imidacloprid, and methoxyfenozide) and 2 metabolites of chloridazon (desphenyl-chloridazon, and methyl-desphenyl-chloridazon) was studied in an anoxic and brackish sandy aquifer before and during Aquifer Storage Transfer and Recovery (ASTR) operation. Fresh tile drainage water was injected and stored for later re-use as irrigation water. We hypothesized that electron acceptors (O2, NO3), dissolved organic carbon (∼24.7 mg/L), nutrients (NO3: ∼14.1 mg/L, NH4: ∼0.13 mg/L, PO4: ∼5.2 mg/L), and biodegrading bacteria in tile drainage water could stimulate degradation of the pesticides and metabolites (ranging between 0.013 and 10.8 μg/L) introduced in the aquifer. Pesticide degradation was studied at 6 depths in the aquifer using push-pull tests lasting ±18 days before the onset of ASTR operation. Degradation was too limited to quantify and/or could not be assessed because of the potential occurrence of pesticide retardation. Utilizing push-pull tests to obtain degradation constants should only be considered in future studies for non-retarding pesticides with relative low half-lives (here <20 days). During ASTR operation, pesticide degradation was studied at the same depths during 3 storage periods equally spread over 1.5 years of ASTR operation. Overall, trends of degradation were observed, although with relatively high half-lives of at least 53 days. Microbial adaptation of the aquifer and/or bioaugmentation by the injected biodegrading bacteria did not result in enhanced degradation during consecutive storage periods. Operational monitoring data over longer periods and distances yielded half-lives of at least 141 days. The slow degradation mostly agrees with previous studies. The injected tile drainage water composition did therefore not notably stimulate pesticide degradation. The relatively persistent behavior of the studied pesticides/metabolites implies that ASTR abstracted water will have generally high pesticide concentrations, and non-abstracted water may form a contamination risk for the surrounding native brackish groundwater.

Pesticide screening and health risk assessment of residential dust in a rural region of the North China Plain.

Pesticides that have accumulated in arable soil could be easily transported by wind erosion, thereby potentially threating air quality and human health in surrounding areas. The risks this poses to farmers exposed to pesticide-associated dust is still unknown, especially in rural areas of China. In this study, we screened pesticide residues in dust (indoor and outdoor) collected from the homes and yards of pesticide sprayers (21 participants) and farm workers (14 participants) living in Quzhou County located in the North China Plain to assess health risks by exposed to pesticide-contaminated dust. The results showed that multiple pesticide residues were detected in the dust samples and more than 90% of the samples contained over 10 pesticide residues. The maximum detected number of residues was 23, out of the 25 pesticides currently used in the farming area. There was a wide range of pesticide concentrations with the geometric mean values measuring between 0.03 and 0.86mgkg-1. More residues and higher concentrations of pesticides were detected in indoor dust compared to outdoor dust. Over the monitoring period, the pesticide application has not caused significant pesticide accumulation in dust. The measured concentrations of carbendazim, dimethomorph, dimethomorph and pendimethalin paired indoor-outdoor dust samples were significantly correlated (p<0.05). The health risks were assessed using the hazard index (HI) and highest HI was found for children under indoor exposure (HI=0.82). In addition, based on the survey and statistics, pesticide preparation in the home was significantly correlated with the pesticide indoor exposure level. Therefore, farmers should take measures, such as preparing pesticides outside of the house or in the open fields with protection, in order to avoid the exposure risk of pesticides associated with dust.

Producing food sustainably

Producing food sustainably

ORGANOCHLORINE AND ORGANOPHOSPHORUS PESTICIDE RESIDUES IN GRAINS, VEGETABLES AND FRUITS: A REVIEW

Organochlorin and organophosphorus pesticides are broadly applied in agriculture, primarily to boost crop yields and protect crops from pests to reach the needs of a growing global population. This review aims to assess levels of pesticide residues in grains, fruits, and vegetables from already established secondary data from different authors or journals. The data obtained adequately confirmed the presence of concentrations of Organochlorin and organophosphorus residues in vegetables, grains and fruits. Both high and low concentration levels of pesticide residue were documented based on data obtained which showed application of the synthetic pesticides by farmers. The high or minute concentration of synthetic pesticides poses adverse health effect on human. This review suggest that consumers of these type of pesticides contaminated food are liable to contact diseases associated with pesticides. Pesticides have been related to damage to the kidneys, liver, and nervous system, birth defects, cancer, immunodeficiency, reproductive process disruption, and altering or interfering with normal endocrine system function. Thereby, the use of natural pesticides as an alternative to synthetic pesticides for pest control is highly recommended for food security and sustainable environmental practices.

Pengolahan Air Sungai Menggunakan Slow Sand Filter Sistem Downflow dalam Menurunkan COD dan BOD

The raw water used as drinking water is currently contaminated with industrial, domestic, and agricultural waste, resulting in high concentrations of nitrogen, phosphate, detergent, COD and pesticides. Slow sand filters can be used as an effort to treat drinking water. This study aims to determine the effect of the variables used on the reactor performance for the removal of COD and BOD nutrients. In this study, the variation of gravel (with and without gravel) is used, so that the performance of each type of reactor can be seen. While the parameters to be measured are COD and BOD. The results showed that SSF gave a good reduction performance in reducing BOD up to 60% and COD up to 68.33% on the 6th day.

The Effect of Residual Pesticide Application on Microbiomes of the Storage Mite Tyrophagus putrescentiae.

Arthropods can host well-developed microbial communities, and such microbes can degrade pesticides and confer tolerance to most types of pests. Two cultures of the stored-product mite Tyrophagus putrescentiae, one with a symbiotic microbiome containing Wolbachia and the other without Wolbachia, were compared on pesticide residue (organophosphate: pirimiphos-methyl and pyrethroid: deltamethrin, deltamethrin + piperonyl butoxide)-containing diets. The microbiomes from mite bodies, mite feces and debris from the spent mite diet were analyzed using barcode sequencing. Pesticide tolerance was different among mite cultures and organophosphate and pyrethroid pesticides. The pesticide residues influenced the microbiome composition in both cultures but without any remarkable trend for mite cultures with and without Wolbachia. The most influenced bacterial taxa were Bartonella-like and Bacillus for both cultures and Wolbachia for the culture containing this symbiont. However, there was no direct evidence of any effect of Wolbachia on pesticide tolerance. The high pesticide concentration residues in diets reduced Wolbachia, Bartonella-like and Bacillus in mites of the symbiotic culture. This effect was low for Bartonella-like and Bacillus in the asymbiotic microbiome culture. The results showed that the microbiomes of mites are affected by pesticide residues in the diets, but the effect is not systemic. No actual detoxification effect by the microbiome was observed for the tested pesticides.

Reducing MCPA herbicide pollution at catchment scale using an agri-environmental scheme

In river catchments used as drinking water sources, high pesticide concentrations in abstracted waters require an expensive treatment step prior to supply. The acid herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA) is particularly problematic as it is highly mobile in the soil-water environment following application. Here, an agri-environmental scheme (AES) was introduced to a large-scale catchment (384 km2) to potentially reduce the burden of pesticides in the water treatment process. The main measure offered was contractor application of glyphosate by weed wiping as a substitute for boom spraying of MCPA, supported by educational and advisory activities. A combined innovation applied in the assessment was, i) a full before-after-control-impact (BACI) framework over four peak application seasons (April to October 2018 to 2021) where a neighbouring catchment (386 km2) did not have an AES and, ii) an enhanced monitoring approach where river discharge and MCPA concentrations were measured synchronously in each catchment. During peak application periods the sample resolution was every 7 h, and daily during quiescent winter periods. This sampling approach enabled flow- and time-weighted concentrations to be established, and a detailed record of export loads. These loads were up to 0.242 kg km−2 yr−1, and over an order of magnitude higher than previously reported in the literature. Despite this, and accounting for inter-annual and seasonal variations in river discharges, the AES catchment indicated a reduction in both flow- and time-weighted MCPA concentration of up to 21% and 24%, respectively, compared to the control catchment. No pollution swapping was detected. Nevertheless, the percentage of MCPA occurrences above a 0.1 μg L−1 threshold did not reduce and so the need for treatment was not fully resolved. Although the work highlights the advantages of catchment management approaches for pollution reduction in source water catchments, it also indicates that maximising participation will be essential for future AES.

Safety Evaluation of Chemical Insecticides to Tetrastichus howardi (Hymenoptera: Eulophidae), a Pupal Parasitoid of Spodoptera frugiperda (Lepidoptera: Noctuidae) Using Three Exposure Routes.

Simple SummarySpodoptera frugiperda is an important pest in many crops worldwide, causing substantial economic losses. The main control strategies are biological control and chemical control. However, pesticides also have varying degrees of toxicity to parasitic wasps in the field. In this study, we evaluate the safety of insecticides for Tetrastichus howardi, an important pupal parasitoid of S. frugiperda. We tested the toxicity of six major control insecticides against the parasitic wasps. Indoxacarb was the less toxic pesticide to T. howardi due to its toxicity’s low-risk quotient (7.43). Furthermore, we used three methods to simulate the side effects of different concentrations of indoxacarb on T. howardi. The exposure of adults to pesticide residues on the glass tube was the most significant in inhibiting development and fecundity. Moreover, T. howardi had a lower parasitism rate and emergence rate with the higher pesticide concentrations. Overall, our study showed that different exposure patterns and concentrations of pesticides have varying degrees of side effects on T. howardi. Even if the pesticide residues are low, such exposures can affect the life cycle of parasitic wasps, affect their population establishment, and thus affect pest control. This study guides a more scientific and comprehensive pesticide application and releases natural enemies.Spodoptera frugiperda has become a major pest in many crops worldwide. The main control strategies are biological and chemical controls. However, pesticides have varying degrees of toxicity to parasitic wasps in the field. To integrate chemical and biological controls, we evaluated the safety of insecticides to Tetrastichus howardi, an important pupal parasitoid of S. frugiperda. This study assessed the toxicity of six major control insecticides (emamectin benzoate, chlorfenapyr, indoxacarb, chlorantraniliprole, bisultap, and lufenuron) to T. howardi based on risk quotient. The results showed that indoxacarb had the lowest risk quotient (RQ = 7.43). Then the side effects of three sublethal concentrations (LC20, LC30, LC40) of indoxacarb were tested using three methods (1. Adult exposure to pesticide residues on the glass tube; 2. Adult exposure to pesticide residues on the host; 3. Larval exposure to pesticides through host exposure). Overall, T. howardi had a lower parasitism rate and emergence rate with the higher pesticide concentrations. Furthermore, among three methods, the adult exposure to pesticide residues on the glass tube was the most efficient in inhibiting the parasitism rate, and impairing the emergence rate and the offspring female/male ratio. This study guides a more scientific and comprehensive application of pesticides and releases natural enemies in the field.

Survival analysis of African catfish and Nile tilapia briefly exposed to complex pesticide mixtures

BackgroundPulse exposures are the consequences of the intermittent release of pollutants in the environment. Brief exposure of aquatic organisms to high concentrations of pesticides simultaneously occurs, particularly in small watercourses during high flows. The effects of pulse exposure often include effects occurring during and after the exposure. Despite this, routine toxicity tests procedures often ignore brief exposure scenarios and the role of time in toxicity. We conducted a pulse toxicity test by briefly exposing African catfish and Nile tilapia fingerlings to pesticide mixtures of atrazine, mancozeb, chlorpyrifos, and lambda-cyhalothrin. The study aimed to estimate pesticide mixture interaction in pulse-exposed fish and elucidate the influence of species differences on the response of fish to the pesticide mixture.ResultsDespite the similarity in fingerlings weight, African catfish had a significantly higher survival probability than Nile tilapia after exposure to atrazine-mancozeb mixture. However, the survival probability of African catfish and Nile tilapia fingerlings were similar after exposure to atrazine-chlorpyrifos, atrazine-lambda cyhalothrin, mancozeb-chlorpyrifos, mancozeb-lambda cyhalothrin, chlorpyrifos-lambda cyhalothrin, and quaternary mixture (p > 0.05). The survival probability of exposed fingerlings was significantly lower for continuous than pulse exposure to the mixtures (p < 0.01). Nevertheless, the survival probability of 60 min of pulse exposure to 13.49 mg/L mancozeb-lambda cyhalothrin was similar to continuous exposure for 96 h. Atrazine-mancozeb, atrazine-chlorpyrifos, atrazine-lambda cyhalothrin, mancozeb-chlorpyrifos, mancozeb-lambda cyhalothrin, and the quaternary pesticide mixture were antagonists in African catfish but not in Nile tilapia. At the same time, chlorpyrifos-lambda-cyhalothrin was antagonistic in Nile tilapia but not African catfish.ConclusionsPesticide mixture interaction was antagonist but specie-dependent. Innate intrinsic and extrinsic deterministic factors and, to a limited extent, stochastic processes may have influenced the survival probability of African catfish, and Nile tilapia pulsed exposed to complex pesticide mixtures. Pulse toxicity assessment using survival analysis is relevant in ecotoxicology as it enables the study of factors that can influence pulse toxicity.

Levels of Pesticides in Sediment of Hor Al-Hammar Marshes, Iraq

The present study was included limitation, distribution, spread and resources of pesticides in water (Dissolved and suspended), sediments from three stations Al-harrir, Al-sulal and Al-burga). This study was extended from January, 2009 to December, 2009 during low tide times. The highest concentrations of pesticides in sediments was recorded for Lindane pesticides in February 497.5 μg/ kg and lowest concentrations 0.01 μg/ kg was found for Dialdrin in March at Al-harrir station and in November at Al-sulal station. Percentage ratio of total organic compounds (TOC) and grain size analysis of sediments was measured and Significant correlation (r = 0.98) were recorded between TOC% and total average of pesticides at tree stations and no Significant correlation were found between silts and total average of pesticides.

Chlorpyrifos pesticide reduction in soybean using cold plasma and ozone treatments

To meet market demands, soybean is predominantly grown with the excess use of harmful pesticides like chlorpyrifos, which leaves poisonous residues on the seeds' surfaces. In this study, we have treated chlorpyrifos (1, 2 and 3 mg/kg) infused soybean with ozone (300–550 mg/l) and low pressure (2 mbar) cold plasma (CP: 1.0–2.0 kV) for up to a period of 30 min to reduce the pesticide residues. However, it was found that at higher pesticide concentrations, ozone treatment can only cause 50% pesticide reduction after 30 min exposure, even at 550 mg/l concentration. In contrast, CP treatment took only 6 min to achieve the same at 2.0 kV voltage level but caused a significant reduction (P ≤ 0.05) in moisture content and seed coat integrity. However, the water absorption of CP treated samples was higher (∼230%) than ozone-treated samples (∼200%). Furthermore, increased pesticide concentration reduced the pesticide degradation rate for ozone (0.078–0.0643 min−1) and cold plasma (0.160–0.143 min−1) treatments even at higher treatment intensities. Nevertheless, CP was effective against chlorpyrifos than ozone treatment and caused minor quality changes in soybeans.

Pesticide trends in a tailwater recovery system in the Mississippi Delta

AbstractTailwater recovery (TWR) systems are an important best management practice (BMP) used to address both water quality and quantity issues in the Mississippi Delta region. Tailwater recovery systems are surface water capture‐and‐irrigation reuse systems using a combination of ditches to capture surface water, an on‐farm storage (OFS) reservoir to store captured surface water, and pumps to move surface water from ditches to the reservoir and from the reservoir to irrigate nearby fields. It is anticipated that TWR systems improve water quality by allowing agricultural contaminants to settle out in ditches and reservoirs rather than being transported during irrigation to nearby fields and downstream aquatic systems. To determine if TWR systems are an effective way to reduce downstream pesticide transport, water samples from a ditch‐and‐reservoir TWR system in Sunflower County, MS, were routinely collected and analyzed for 5 yr. Objectives of this study were to assess seasonal pesticide and pesticide metabolite concentrations throughout the different components of the TWR system and identify any trends that may exist. Atrazine‐desethyl, atrazine‐desisopropyl, atrazine, clomazone, propanil, fipronil desulfinyl, metolachlor, fipronil, p,p'‐DDT, bifenthrin, beta‐cyfluthrin, and zeta‐cypermethrin were found in every season in both ditch and reservoir samples. Several pesticides that have not been used in the United States for decades were detected including DDT and its metabolites as well as dieldrin, heptachlor, lindane, and methyl parathion, demonstrating their environmental persistence. The reservoir featured more types and higher concentrations of pesticides, indicating a possible risk of cross‐crop injury from the recycling of the water from the reservoir for irrigation.

Neke od karakterističnih supstanca u reci Devoli, Albanija

This preliminary study presents first data on organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) concentrations in water and sediment samples of Devolli River. It is located in Southeast Albania, in Korca field, which is the second agricultural area in Albania. Sampling stations water of Devolli River were selected in eight different stations, starting from its stream (Gramozi Mountain) to the end of Korca field, near Banja hydropower (Gramshi region). Sampling of water and sediments were done in the same stations, in December 2018. Pesticides were used in the past in this area for many years mainly for agricultural purposes. Also, basin of Devolli River is affected from industrial activity and urban pollution, too. Water irrigation and rainfall contribute on their transport from soil to underground and surface waters. Organochlorine pesticides and PCB are very stable compounds that can be found in the environment for many years after their application. Liquid-liquid extraction was used for isolation of OCPs and PCBs in water samples while ultrasonic extraction was used for their extraction in sediment samples. The simultaneous analysis of organochlorine pollutants in water samples was performed by gas chromatography technique using electron capture detector (GC/ECD). Rtx-5 capillary column (30 m x 0.33 mm x 0.25 um) was used for separation of 17 organochlorine pesticides according EPA 8081A and 7 PCB markers. Relatively high concentrations of organochlorine pesticides were detected in water and sediment samples of Devolli River compare with other rivers of Albania. Their presence can be due to their previous use in Korca field. Volatile PCBs were found in higher concentration in water samples because of atmospheric deposition. Levels of some individual pesticides in surface water samples of Devolli River were found to be higher than permitted levels according to Albania and EU norms. Responsible authorities should be done continues monitoring in water samples of this river.

Route of Exposure and Impact of Pesticides Pollution on Human Health and Aquatic Ecosystem

Pesticides have been found in aquatic ecosystems such as groundwater, lakes, rivers and oceans through clogged storm drains, improper disposal, unplanned discharges and accidental spills. Pesticide exposure results in a variety of abnormalities in the human body, including mutagenic or genotoxic impacts. Pesticide-exposed organisms exhibit a wide range of developmental abnormalities, including genital deformities. Herbicides have a direct negative impact on the population size of primary producer. Pesticides accumulate in rivers and fresh water because of the high concentration of pesticides in the agricultural environment. Toxicants produced by humans have been identified as a severe threat to freshwater ecosystems. Pesticide use has led to the drastic decline of the populations of certain fish species. Insecticides, herbicides and fungicides have all been associated with a decrease in several animal species. Pesticides accumulate in the bodies of fish and have an impact on human health as a result of biological cycling and bio-magnification. Not only can pesticides affect fish, but they can also affect the food webs that support them. Pesticides enter the human body through a variety of ways, including the food chain, air, soil, water, flora and fauna and the environment. In pesticide applicators, farmers and farm workers in general, abnormalities and illnesses of the skin have been documented

Systematic Underestimation of Pesticide Burden for Invertebrates under Field Conditions: Comparing the Influence of Dietary Uptake and Aquatic Exposure Dynamics.

Pesticides used in agriculture can end up in nearby streams and can have a negative impact on nontarget organisms such as aquatic invertebrates. During registration, bioaccumulation potential is often investigated using laboratory tests only. Recent studies showed that the magnitude of bioaccumulation in the field substantially differs from laboratory conditions. To investigate this discrepancy, we conducted a field bioaccumulation study in a stream known to receive pollutant loadings from agriculture. Our work incorporates measurements of stream pesticide concentrations at high temporal resolution (every 20 min), as well as sediment, leaves, and caged gammarid analyses (every 2-24 h) over several weeks. Of 49 investigated pesticides, 14 were detected in gammarids with highly variable concentrations of up to 140 ± 28 ng/gww. Toxicokinetic modeling using laboratory-derived uptake and depuration rate constants for azoxystrobin, cyprodinil, and fluopyram showed that despite the highly resolved water concentrations measured, the pesticide burden on gammarids remains underestimated by a factor of 1.9 ± 0.1 to 31 ± 3.0, with the highest underestimations occurring after rain events. Including dietary uptake from polluted detritus leaves and sediment in the model explained this underestimation only to a minor proportion. However, suspended solids analyzed during rain events had high pesticide concentrations, and uptake from them could partially explain the underestimation after rain events. Additional comparison between the measured and modeled data showed that the pesticide depuration in gammarids is slower in the field. This observation suggests that several unknown mechanisms may play a role, including lowered enzyme expression and mixture effects. Thus, it is important to conduct such retrospective risk assessments based on field investigations and adapt the registration accordingly.

Growth, respiratory activity and chlorpyrifos biodegradation in cultures of Azotobacter vinelandii ATCC 12837

This study aimed to evaluate the growth, respiratory activity, and biodegradation of chlorpyrifos in cultures of Azotobacter vinelandii ATCC 12837. A strategy based on the modification of culture media and aeration conditions was carried out to increase the cell concentration of A. vinelandii, in order to favor and determine its tolerance to chlorpyrifos and its degradation ability. The culture in shaken flasks, using sucrose as a carbon source, significantly improved the growth compared to media with mannitol. When the strain was cultivated under oxygen-limited (5.5, 11.25 mmol L−1 h−1) and no-oxygen-limited conditions (22 mmol L−1 h−1), the growth parameters were not affected. In cultures in a liquid medium with chlorpyrifos, the bacteria tolerated a high pesticide concentration (500 ppm) and the growth parameters were improved even under conditions with a reduced carbon source (sucrose 2 g L−1). The strain degraded 99.6% of chlorpyrifos at 60 h of cultivation, in co-metabolism with sucrose; notably, A. vinelandii ATCC 12837 reduced by 50% the initial pesticide concentration in only 6 h (DT50).Graphical