Concentrations Of Organophosphate Pesticides Research Articles

Purple acid phosphatase promoted hydrolysis of organophosphate pesticides in microalgae

When organophosphate pesticides (OPs) are not used and handled in accordance with the current rules and standards, it results in serious threats to the aquatic environment and human health. Phaeodactylum tricornutum is a prospective microalgae-based system for pollutant removal and carbon sequestration. Genetically engineered P. tricornutum, designated as the OE line (endogenously expressing purple acid phosphatase 1 [PAP1]), can utilize organic phosphorus for cellular metabolism. However, the competencies and mechanisms of the microalgae-based system (namely the OE line of P. tricornutum) for metabolizing OPs remain to be addressed. In this study, the OE line exhibited the effective biodegradation competencies of 72.12% and 68.2% for 30 mg L−1 of dichlorvos and 50 mg L−1 of glyphosate, accompanied by synergistic accumulations of biomass (0.91 and 0.95 g L−1) and lipids (32.71% and 32.08%), respectively. Furthermore, the biodiesel properties of the lipids from the OE line manifested a high potential as an alternative feedstock for microalgae-based biofuel production. A plausible mechanism of OPs biodegraded by overexpressed PAP1 is that sufficient inorganic P for adenosine triphosphate and concurrent carbon flux for the reduced form of nicotinamide adenine dinucleotide phosphate biosynthesis, which improved the OP tolerance and biodegradation competencies by regulating the antioxidant system, delaying programmed cell death and accumulating lipids via the upregulation of related genes. To sum up, this study demonstrates a potential strategy using a genetically engineered strain of P. tricornutum to remove high concentrations of OPs with the simultaneous production of biomass and biofuels, which might provide novel insights for microalgae-based pollutant biodegradation.

Residual Dialkyl Phosphate Metabolite Concentrations of Organophosphate Pesticides Among Indian Farmworkers: Implication of Exposure and Hazard Assessment.

Biomonitoring of urinary dialkyl phosphate (DAP) metabolites, a sensitive biomarker to assess pesticides exposure and also to study the impact of the use of personal protective equipment (PPE). A preintervention-postintervention study to biomonitor dimethylphosphate, diethylphosphate, diethylthiophosphate, and diethyl-dithiophosphate using liquid chromatography with tandem mass spectrometry among Indian farmworkers (n = 120). Dimethylphosphate was detected in all samples at a mean concentration of 74.91 μg · L -1 (17.616 μg · g -1 creatinine), whereas diethylthiophosphate and diethyl-dithiophosphate were detected in 88% and 82% of samples, respectively, among farmworkers who adopted unsafe pesticide-handling practices. Intervention studies showed a significant reduction in the urinary DAP metabolites detected among the farmworkers using PPE provided to them ( P < 0.01). Study confirms the exposure to pesticides among farmworkers and highlights the importance of the use of PPE to minimize exposure.

Organophosphate pesticides in South African eutrophic estuaries: Spatial distribution, seasonal variation, and ecological risk assessment

The seasonal variation, spatial distribution, and ecological risks of thirteen organophosphate pesticides (OPPs) were studied in the Sundays and Swartkops estuaries in South Africa. Ten pesticides were detected in surface water samples from both estuaries, while all OPPs were detected in sediments. The highest concentration of OPPs (18.8 μg pyrazophos L−1) was detected in surface water samples from Swartkops Estuary, while 48.7 μg phosalone kg−1 dw was the highest in sediments collected from Sundays Estuary. There was no clear seasonal pattern in OPPs occurrence in surface water from both systems. However, their occurrence in sediments was in the following order: winter > autumn > summer > spring, perhaps indicating major pesticide input in the winter seasons. Results from ecological risk assessment showed that pyraclofos and chlorpyrifos (CHL) in surface water from both systems are respectively likely to cause high acute and chronic toxicity to fish (risk quotient – RQ > 1). For sediments of both estuaries, the highest acute and chronic RQs for fish were calculated for isazophos and CHL respectively. The majority of the detected OPPs in sediments posed potential high risks to Daphnia magna from both systems. These results suggest that these aquatic organisms (fish, and Daphnia), if present in the studied estuaries, can develop certain forms of abnormalities due to OPP exposure. To this end, proper measures should be taken to reduce OPP input into the estuarine systems.

Integrating multiple lines of evidence to assess freshwater ecosystem health in a tropical river basin

Degradation of freshwater ecosystems by uncontrolled human activities is a growing concern in the tropics. In this regard, we aimed at testing an integrative framework based on the IFEQ index to assess freshwater ecosystem health of river basins impacted by intense livestock and agricultural activities, using the Muchacho River Basin (MRB) as a case study. The IFEQ combine multiple lines of evidence such as riverine hydromorphological analysis (LOE 1), physicochemical characterization using ions and pesticides (LOE 2), aquatic macroinvertebrate monitoring (LOE 3), and phytotoxicological essays with L. sativa (LOE 4). Overall, results showed an important reduction in streamflow and an elevated increase in ion concentrations along the MRB caused by deforestation and erosion linked to agricultural and livestock activities. Impacts of the high ion concentrations were evidenced in macroinvertebrate communities as pollution-tolerant families, associated with high conductivity levels, represented 92 % of the total abundance. Pollution produced by organophosphate pesticides (OPPs) was critical in the whole MRB, showing levels that exceeded 270-fold maximum threshold for malathion and 30-fold for parathion, the latter banned in Ecuador. OPPs concentrations were related to low germination percentages of Lactuca sativa in sediment phytotoxicity tests. The IEFQ index ranged from 44.4 to 25.6, indicating that freshwater ecosystem conditions were “bad” at the headwaters of the MRB and “critical” along the lowest reaches. Our results show strong evidence that intense agricultural and livestock activities generated significant impacts on the aquatic ecosystem of the MRB. This integrative approach better explains the cumulative effects of human impacts, and should be replicated in other basins with similar conditions to help decision-makers and concerned inhabitants generate adequate policies and strategies to mitigate the degradation of freshwater ecosystems.

Monitoring of pesticides in surface water, pesticides removal efficiency in drinking water treatment plant and potential health risk to consumers using Monte Carlo simulation in Behbahan City, Iran

Excessive application of pesticides to control pests and weeds leads to contaminating bodies of water and health problems for consumers. The present study was designed to investigate the concentration of pesticides in raw water originated from the Marun River as well as the treated water of the drinking water treatment plant in Behbahan City. The efficiency of each treatment process was evaluated. Moreover, the health risks caused by detectable pesticides for consumers of treated water were assessed. The target pollutants were extracted using droplet liquid-liquid microextraction and detected by a gas chromatograph-mass spectrophotometer. The results showed relatively high mean concentrations of organophosphate pesticides ranging from 0.87 to 3.229 μg/L in the river water and low concentrations of organochlorine pesticides, except for 1,3-dichloropropene with the concentration of 3.58 μg/L. Alachlor had a rather high concentration (2.44 μg/L) in the river water. The concentration of pesticides in the drinking water had been reduced to an acceptable amount. The major part of pesticides removal occurred in coagulation-flocculation and rapid sand filtration units (87 %) due to the hydrophobic nature of pesticides and the use of GAC in the filtration unit. Based on the risk assessment estimates, the total hazard quotient (THQ) for all the pesticides was much less than one. The value of THQ was higher in younger individuals and children for all the given pesticides. The highest value of THQ in children was 0.2 which was attributed to aldrin. Similarly, the carcinogenic risk (CR) of aldrin for children and teenagers was in the unsafe range (more than 10−4) while the CR for other target compounds in all the age groups was negligible (10−4-10−6 or less). The high concentration of pesticides in the river water might be concerning and therefore selling and using pesticides, especially the banned ones, should be more regulated.

A translocation analysis of organophosphate pesticides between surface water, sediments and tissues of common reed Phragmites australis

This study investigated the ability of common reed, Phragmites australis to take up organophosphate pesticides (OPPs). The study site was the agriculturally polluted Sundays Estuary in South Africa. Surface water, leaves, roots, and deep-rooted-sediments of P. australis were collected along the length of the estuary and analysed for 13 different OPPS. The extraction of OPPs in plant tissues was performed by QuEChERS method followed by GC-MS analysis. The highest concentration of OPPs was found in leaves (16.41–31.39 μg kg−1 dw), followed by roots (13.92–30.88 μg kg−1 dw), and sediments (3.30–8.07 μg kg−1 dw). Of the 13 targeted OPPs, only one compound was not detected across the four sample matrices, thus reflecting widespread contamination in the Sundays Estuary. The biota sediment accumulation factor (BSAF) values of pyraclofos, quinalphos, fenitrothion, phosalone, EPN, diazinon, chlorpyrifos, pyrazophos, and isazophos were higher than one implying that P. australis possesses the ability to bioaccumulate these compounds. The root-leaf translocation factors (TFr-l) of these pesticides were higher than 1, suggesting that P. australis possesses the capacity to move these pesticides from roots to leaves. The insignificant correlation observed between log BSAF and log Kow and log TFr-l and log Kow implies that OPPs uptake by P. australis tissues were not dependent on log Kow. Our study demonstrates that P. australis possesses the potential to effectively remove OPPs from contaminated water and sediment.

Dual-mode detection of organophosphate pesticides in pear and Chinese cabbage based on fluorescence and AuNPs colorimetric assays

Herein, a dual-mode method based on fluorescent and colorimetric sensor was developed for determination of organophosphate pesticides (OPs). In this study, indoxyl acetate (IDA) was hydrolyzed by esterase into indophenol. Indophenol leads to changes in fluorescence signal and aggregation of gold nanoparticles (AuNPs); ultimately changing the color from red to blue. When OPs exist, the formation of indophenol was inhibited. With increasing the concentrations of OPs, the enhancement rate of fluorescence signal decreases, and the color change of AuNPs weakened gradually. The assay was applied for determination of dichlorvos, trichlorfon, and paraoxon, and the limits of detection (LODs) were 0.0032 mg/kg, 0.0096 mg/kg, and 0.0074 mg/kg (fluorometric assay), and 0.0120 mg/kg, 0.0224 mg/kg, and 0.0106 mg/kg (colorimetric assay), respectively. Finally, such a convenient and sensitive sensing assay was successfully applied for quantification of OPs in pear and Chinese cabbage with good recoveries ranged between 80.19 and 116.93%.

Assessment of Microplastic and Organophosphate Pesticides Contamination in Fiddler Crabs from a Ramsar Site in the Estuary of Guayas River, Ecuador.

We assessed the concentration of organophosphate pesticides (OPs) and microplastics (MPs) in water and sediments from the burrows, and tissues of the fiddler crabs Leptuca festae and Minuca ecuadoriensis, from Isla Santay, a Ramsar site in the estuary of the Guayas River, Ecuador. MPs concentrations in the burrows were 660 ± 174.36 items kg-1 (w.w.) and 26 ± 1 items L-1 in collected sediments and water, respectively. Regarding OPs, water and sediment concentrations were up to 26 times above the USEPA thresholds for chronic exposure, indicating environmental risk. MPs were found in tissues collected from both species. The highest abundance was in the gills followed by the digestive tract and hepatopancreas. OPs concentrations in tissues were below the detection limits. Because fiddler crabs are chronically exposed to environmental contamination, they are suitable bioindicators to monitor Isla Santay and to comprehend human impacts in coastal environments of Ecuador.

The contamination of filter feeder mussel Perna viridis Linnaeus, 1758 (Bivalvia: Mytilidae) by organophosphate pesticide at Brebes marine waters Central Java, Indonesia

In the last five years, organophosphate pesticides have been introduced in red onions fields in Brebes. This will broadly impact to the ecosystem, including the filter feeder marine organisms such as green mussel P. viridis. This article presents the occurrence level of organophosphate pesticides residues in marine waters and green mussel which has collected on Brebes marine areas. Some selected organophosphate pesticides compounds (Chlorpyrifos, Profenofos, Diazinon, Fenitrothion, Malation and Methidathion) of contaminant have been determined. The samples were analyzed by using gas chromatography and followed by using the method of Standard Method Examination. The results showed that average of six residues (Chlorpyrifos, Profenofos, Diazinon, Fenitrothion, Malation and Methidathion) in marine water were undetected (<0.0004 ppm). The merely concentration of PPOs detected was Chlorpyrifos 0.31 µg/L detected in green mussel. The concentration of organophosphate pesticides in these areas might contribute by the usage of organophosphate pesticide from red onion fields

A new configuration of polar organic chemical integrative sampler with nylon membranes to monitor emerging organophosphate ester contaminants in urban surface water

Organophosphate ester contaminants, including organophosphate pesticides (OPPs) and organophosphate flame retardants (OPFRs) are ubiquitous in surface water and pose a significant risk to aquatic organisms, thus it is important to develop effective methods for long-term monitoring of these emerging compounds. Polar organic chemical integrative sampler (POCIS) has become a promising monitoring tool for waterborne contaminants, yet recent studies found that the commonly used polyethersulfone (PES) membrane strongly sorbed some moderately hydrophobic compounds, resulting in long lag-phase for chemical accumulation in POCIS. In the present study, 0.45-μm nylon membranes was selected as POCIS diffusion-limiting membrane to design a new POCIS-Nylon configuration for analyzing moderately hydrophobic OPPs and OPFRs in water. The POCIS-Nylon had negligible lag-phase due to low sorption of OPPs and OPFRs to nylon membrane. Meanwhile, linear accumulation time and sensitivity for target contaminants using POCIS-Nylon retained similar to the traditional POCIS. Water velocity and chemical concentration had little impact on sampling rate (Rs), validating that the POCIS-Nylon was suitable for various water conditions. Finally, the occurrence of OPPs and OPFRs in urban waterways of Guangzhou, China was evaluated using the POCIS-Nylon with Rs values that were calibrated in the laboratory. The average concentration of OPPs was 4.97 ± 1.35 ng/L (range: 2.64 ± 1.28–6.54 ± 0.18 ng/L) and the average concentration of OPFRs was 400 ± 88 ng/L (range: 316 ± 24–615 ± 36 ng/L) across nine sampling sites. The present study provides a way to resolve the inherent challenge of accumulating hydrophobic substances by POCIS.

Carbon dots co-doped with nitrogen and chlorine for "off-on" fluorometric determination of the activity of acetylcholinesterase and for quantification of organophosphate pesticides.

Nitrogen and chlorine dually-doped carbon dots (N,Cl-CDs) were hydrothermally prepared starting from 4-chloro-1,2-diaminobenzene and dopamine. The N,Cl-CDs exhibit strong orange fluorescence, with excitation/emission maxima at 420/570nm and a relative high quantum yield (15%). The N,Cl-CDs were employed to detect acetylcholinesterase (AChE) activity and organophosphate pesticides (OPs) which are enzyme inhibitors. Acetylthiocholine is enzymatically split by AChE to produce thiocholine which triggers the decomposition of Ellmans's reagent to form a yellow colored product (2-nitro-5-thiobenzoate anion). The product causes an inner filter effect (IEF) on the fluorescence of the N,Cl-CDs. Fluorescence decreases linearly in the 0.017 to 5.0 Unit·L-1 AChE activity range, and the detection limit is 2 mUnit·L-1. If organophosphates are present, the activity of AChE becomes increasingly blocked, and this leads to a less expressed IFE and an increasing recovery of fluorescence. This was used for the quantification of OPs. Response is linear in the 0.3-1000μg·L-1 OP concentration range with a 30ng·L-1 detection limit. Graphical abstractSchematic representation of the synthesis of nitrogen and chlorine dually-doped carbon dots (N,Cl-CDs) and the recognition of organophosphate pesticides by N,Cl-CDs.

Integrating Target-Responsive Hydrogels with Smartphone for On-Site ppb-Level Quantitation of Organophosphate Pesticides.

Precise on-site profiling of organophosphate pesticides (OPs) is of significant importance for monitoring pollution and estimating poisoning. Herein, we designed a simple and convenient portable kit based on Ag+-responsive hydrogels for accurate detection of OPs. The newly developed hydrogels employed o-phenylenediamine (OPD) and silicon quantum dots (SiQDs) as indicator, which possessed ratiometric response. In this sensor, OPs as inhibitor of acetylcholinesterase prevented the generation of thiocholine, which blocked the formation of metal-polymer with Ag+, further triggered the oxidation of OPD to yield yellow 2,3-diaminophenazine (DAP) with fluorescence emission at 557 nm. The fluorescence intensity of SiQDs (444 nm) was quenched by DAP through inner filter effect (IFE) process, emerging a typical ratiometric response. Interestingly, the ratiometric signal of kit, which was recorded by smartphone's camera, can be transduced by ImageJ software into the hue parameter that was linearly proportional to the concentration of OPs. The simplicity of portable kit combined with smartphone operation, which possessed high sensitivity (detection limit <10 ng mL-1) and rapid sample-to-answer detection time (45 min) in agricultural sample, indicating that the methodology offered a new sight for portable monitoring of food safety and human health.

Ecological risk and estimates of organophosphate pesticides loads into the Central Mediterranean Sea from Volturno River, the river of the “Land of Fires” area, southern Italy

The organophosphate pesticides pollution in the Volturno River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) were estimated. Eight selected organophosphate pesticides (diazinon, dimethoate, malathion, chlorpyrifos, pirimiphos-methyl, fenitrothion, methidathion and tolclofos-methyl) were determined in the water dissolved phase, suspended particulate matter and sediment samples collected from 10 sites in different seasons. Total organophosphate pesticides concentrations ranged from 0.12 to 65.09 ng L−1 in water (as the sum of the water dissolved phase and suspended particulate matter) and from 1.19 to 23.17 ng g−1 in sediment samples. It has been calculated that the discharge of pollutants from the Volturno river into the Tyrrhenian Sea was about 71.815, 31 g year−1; for this reason the river is to be considered one of the main mouths of organophosphate pesticides in the Tyrrhenian Sea. In relation to environmental risk assessment, the concentrations of most OPPs in water and sediments from the Volturno River and its estuary were lower than guideline values, but the mean concentration of chlorpyrifos (5.41 ng L−1) in the Volturno River and Estuary has been shown that the ecological integrity of the river watercourse is possibly at risk.

The Preliminary Investigation of Organophosphate Pesticide Residues on Green Mussel Perna viridis (bivalvia: Mytilidae, linnaeus, 1758) at Demak Coastal Waters Central Java Indonesia

The organophosphate pesticides pollution in the Demak coastal waters and their impact on green mussel were estimated. The paper presents the occurrence level of organophosphate pesticides residues in marine waters and green mussel which were collected from marine coastal areas. Six selected organophosphate pesticides compounds (Chlorpyrifos, Profenofos, Diazinon, Fenitrothion, Malation and Methidathion) of contaminant have been determined in the marine water and green mussel of Demak coastal waters. The samples were then analyzed by using gas chromatography and followed by using the method of Standard Method Examination. The result showed that the average concentration of organophosphate pesticides Chlorpyrifos, Profenofos, Diazinon, Fenitrothion, Malation and Methidathion in green mussel were 0.22 µ g/L, below detected, below detected, 0.413 µ g/L, below detected, below detected, respectively. But all of organophosphate pesticides residues in marine waters were below detected. The highest concentration of organophosphate pesticide in green mussel showed on Fenitrothion (0.413 µ g/L) and than Chlorpyrifos (0.22 µ g/L). The concentration of organophosphate pesticides in these areas might contribute four paddy and red onion agriculture.

Environmental monitoring and risk assessment of organophosphate pesticides in aquatic ecosystems of north-west Bangladesh

The use of organophosphate pesticides (OPPs) to protect a variety of crops has increased in Bangladesh. OPPs may contaminate surrounding aquatic environments through several routes including spray drift, surface runoff and groundwater leaching. Since it is unknown how much OPP end ups in aquatic environment in Bangladesh, the objectives of the present study were to quantify the residues of ten most commonly used OPPs in water and sediment of water bodies of north-west Bangladesh and to assess their ecological risks for aquatic organisms. The risks of the pesticides in surface water and sediment were assessed using a first-tier risk quotient (RQ) approach. The higher-tier PERPEST model was used to refine the ecological risks of pesticides when RQ indicated a potential risk. Results showed the most frequently detected pesticides that appeared in high concentrations were chlorpyrifos, diazinon and quinalphos in surface water and sediment. The highest concentration of OPPs measured in water was 9.1 μg chlorpyrifos/L (median of 1.95 μg/L), while this was 51 μg diazinon/kg dw (median of 11 μg/kg dw) for sediment. Furthermore, results showed high acute and/or chronic RQs (RQ > 1) in surface water and sediment for chlorpyrifos, diazinon, quinalphos, malathion and fenitrothion. The higher-tier PERPEST model confirmed risks of chlorpyrifos, diazinon, quinalphos and fenitrothion for aquatic insects, micro- and macro-crustaceans which were previously derived by RQ-based risk assessment for aquatic organisms. Furthermore, the results of the PERPEST model also indicated possible indirect effects of these pesticides on algae and macrophytes, community metabolism, rotifers and other macro-invertebrates.

Human Health Risk Assessment Through Consumption of Organophosphate Pesticide-Contaminated Water of Peshawar Basin, Pakistan

In this study, the concentrations of organophosphate pesticides (OPPs) were determined in drinking water samples collected from Peshawar Basin (Charsadda, Nowshera, Peshawar, Mardan, and Swabi districts), Khyber Pakhtunkhwa, Pakistan. The selected OPPs such as methamidophos, dichlorvos, and chlorpyrifos were extracted through liquid–liquid extraction procedure and quantified using gas chromatography–mass spectrometry. The results revealed that among OPPs, the highest contamination was observed for methamidophos, while the lowest for dichlorvos. The OPP concentrations were compared with their respective permissible limits set by European Union (EU in Council Directive 98/83/EC on the quality of water intended for human consumption. European Union, 1998), Australia (NHMRC in Australian drinking water guidelines. Agricultural and Resource Management Council of Australia and New Zealand Commonwealth of Australia, Canberra, 1996), and World Health Organization (WHO in Guidelines for drinking water quality, 2nd edn, WHO, Geneva 1998). In majority samples (94.4%), methamidophos concentrations exceeded its respective permissible limit set by EU. The concentrations of dichlorvos exceeded the limit set by Australia and EU in 17.2 and 69% samples, respectively. However, the concentrations of chlorpyrifos exceeded the EU limit in only 2.3% samples, while found within the safe limits set by WHO. The concentrations of studied OPPs were also used to assess the health risk including chronic risk such as average daily dose (ADD), hazard quotient (HQ), and carcinogenic risk or cancer risk (CR). The ADD values for OPPs showed a great variation in the study area. The values of HQ were > 1 for methamidophos in drinking water samples of Peshawar Basin. Moreover, the CR values through consumption of dichlorvos in drinking water exceeded US-EPA safe limit. Among all drinking water sources, the shallow water sources along agriculture productive zones revealed higher contamination and serious health risk. Therefore, this study recommends to stop the use of shallow drinking water and use the deep groundwater at depths > 98 m that showed comparatively less contamination.

Distributions and determinants of urinary biomarkers of organophosphate pesticide exposure in a prospective Spanish birth cohort study

BackgroundPrenatal exposure to organophosphate pesticides (OPs) has been associated with impaired child development. Pesticide exposure determinants need to be studied in order to identify sources and pathways of pesticide exposure. The aim of this paper is to describe prenatal exposure to OPs and evaluate the associated factors in pregnant women.MethodsThe study population consisted of pregnant women (n = 573) who participated in the INMA birth cohort study in Valencia (Spain, 2003–2006). OP metabolites were analyzed in maternal urine at the 32nd week of gestation using a liquid chromatography-high resolution mass spectrometry method. The analysis included non-specific (diethyl phosphate [DEP], diethyl thiophosphate [DETP], dimethyl thiophosphate [DMTP], dimethyl dithiophosphate [DMDTP]) and specific metabolites (2-diethylamino-6-methyl-4-pyrimidinol [DEAMPY], 2-isopropyl-4-methyl-6-hydroxypyrimidine [IMPY], para-nitrophenol [PNP], and 3,5,6-trichloro-2-pyridinol [TCPY]). Information about the sociodemographic, environmental, and dietary characteristics was obtained by questionnaire. The association between log-transformed OPs and covariates was analyzed using multivariable interval censored regression.ResultsThe detection frequencies were low, DMTP and TCPY being the most frequently detected metabolites (53.8% and 39.1%, respectively). All the OP metabolites were positively associated with maternal intake of fruits and vegetables. Other maternal characteristics related to the OPs were body mass index (BMI) before pregnancy and smoking habit during pregnancy. Women with lower BMI and those who did not smoke presented higher OP concentrations. Moreover, mothers who had a yard or garden with plants at home or who lived in an urban area were also more exposed to OPs.ConclusionsThe OP detection frequencies and the concentrations observed in our study population were low, compared with most of the previously published studies. Given the high vulnerability of the fetus to neurotoxicant exposure, further research on the determinants of the body burden of OPs during pregnancy would be necessary. The knowledge gained from such studies would enhance the effectiveness of public health control and future recommendations in order to reduce the risk to both the health of pregnant women and the health and development of their children.

Ultrasensitive electrochemiluminescence biosensor for organophosphate pesticides detection based on carboxylated graphitic carbon nitride-poly(ethylenimine) and acetylcholinesterase

A signal on electrochemiluminescence (ECL) biosensor was designed for sensitive organophosphate pesticides (OPs) detection based on a novel composite of carboxylated graphitic carbon nitride-poly(ethylenimine) (C-g-C3N4-PEI) and acetylcholinesterase (AChE). The C-g-C3N4-PEI nanocomposite which was prepared through covalent bonding between the COOH of C-g-C3N4 and the NH2 of PEI exhibited significantly enhanced ECL efficiency and stability. K2S2O8 as the coreactant of C-g-C3N4-PEI could be consumed by thiocholine, produced by the hydrolysis of acetylthiocholine (ATCl) in the presence of AChE. Since OPs are one of AChE inhibiter, the consumption of coreactant K2S2O8 decreased with the increasing concentration of OPs, thus enhancing ECL signal. Under the optimum conditions, the proposed biosensor for OPs detection (using ethyl paraoxon as a model OPs) exhibited a wide linear ranging from 1.0 pM to 5.0μM with a low detection limit of 0.3 pM. The novel strategy has the advantages of fine practicality, good stability and reproducibility, which might provide a new promise for OPs detection in real-life samples.

Estimates of Tiber River organophosphate pesticide loads to the Tyrrhenian Sea and ecological risk

The organophosphate pesticides pollution in the Tiber River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) were estimated. Eight selected organophosphate pesticides (diazinon, dimethoate, malathion, chlorpyrifos, pirimiphos-methyl, fenitrothion, methidathion, tolclofos-methyl) were determined in the water dissolved phase, suspended particulate matter and sediment samples collected from 21 sites in different seasons. Total organophosphate pesticides concentrations ranged from 0.40 to 224.48ngL−1 in water (as the sum of the water dissolved phase and suspended particulate matter) and from 1.42 to 68.46ngg−1 in sediment samples. Contaminant discharges of organophosphate pesticides into the sea were calculated in about 545.36kgyear−1 showing that this river should be consider as one of the main contribution sources of organophosphate pesticides to the Tyrrhenian Sea. In relation to the eco-toxicological assessment, the concentrations of most OPPs in the water and sediments from the Tiber River and its estuary were lower than guideline values.

Olfactory Transcriptional Analysis of Salmon Exposed to Mixtures of Chlorpyrifos and Malathion Reveal Novel Molecular Pathways of Neurobehavioral Injury.

Pacific salmon exposed to sublethal concentrations of organophosphate pesticides (OP) have impaired olfactory function that can lead to loss of behaviors that are essential for survival. These exposures often involve mixtures and can occur at levels below those which inhibit acetylcholinesterase (AChE). In this study, juvenile Coho salmon were exposed for 24 h to either 0.1, 0.5, or 2.5 ppb chlorpyrifos (CPF), 2, 10, or 50 ppb malathion (MAL), or binary mixtures of 0.1 CPF:2 ppb MAL, 0.5 CPF:10 ppb MAL, or 2.5 CPF:10 ppb MAL to mimic single and binary environmental exposures. Microarray analysis of olfactory rosettes from pesticide-exposed salmon revealed differentially expressed genes involved in nervous system function and signaling, aryl hydrocarbon receptor signaling, xenobiotic metabolism, and mitochondrial dysfunction. Coho exposed to OP mixtures exhibited a more pronounced loss in detection of a predatory olfactory cue relative to those exposed to single compounds, whereas respirometry experiments demonstrated that exposure to OPs, individually and in mixtures, reduced maximum respiratory capacity of olfactory rosette mitochondria. The observed molecular, biochemical, and behavioral effects occurred largely in the absence of effects on brain AChE. In summary, our results provide new insights associated with the sublethal neurotoxic effects of OP mixtures relevant to environmental exposures involving molecular and cellular pathways of injury to the salmon olfactory system that underlie neurobehavioral injury.