Pesticides In Fish Research Articles

New method based on combining ultrasonic assisted miniaturized matrix solid-phase dispersion and homogeneous liquid–liquid extraction for the determination of some organochlorinated pesticides in fish

In this study, ultrasonic assisted miniaturized matrix solid-phase dispersion (US-MMSPD) combined with homogeneous liquid–liquid extraction (HLLE) has been developed as a new method for the extraction of organochlorinated pesticides (OCPs) in fish prior to gas chromatography with electron capture detector (GC-ECD). In the proposed method, OCPs (heptachlor, aldrin, DDE, DDD, lindane and endrin) were first extracted from fish sample into acetonitrile by US-MMSPD procedure, and the extract was then used as consolute solvent in HLLE process. Optimal condition for US-MMSPD step was as follows: volume of acetonitrile, 1.5 mL; temperature of ultrasound, 40 °C; time of ultrasound, 10 min. For HLLE step, optimal results were obtained at the following conditions: volume of chloroform, 35 μL; volume of aqueous phase, 1.5 mL; volume of double distilled water, 0.5 mL; time of centrifuge, 10 min. Under the optimum conditions, the enrichment factors for the studied compounds were obtained in the range of 185–240, and the overall recoveries were ranged from 39.1% to 81.5%. The limits of detection were 0.4–1.2 ng g −1 and the relative standard deviations for 20 ng g −1 of the OCPs, varied from 3.2% to 8% ( n = 4). Finally, the proposed method has been successfully applied to the analysis of the OCPs in real fish sample, and satisfactory results were obtained.

Levels of polychlorinated biphenyls (PCBs) and three organochlorine pesticides in fish from the Aleutian Islands of Alaska.

BackgroundPersistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs) and chlorinated pesticides, have been shown to have many adverse human health effects. These contaminants therefore may pose a risk to Alaska Natives that follow a traditional diet high in marine mammals and fish, in which POPs bioaccumulate.Methods and FindingsThis study examined the levels of PCBs and three pesticides [p, p′-DDE, mirex, and hexachlorobenzene (HCB)] in muscle tissue from nine fish species from several locations around the Aleutian Islands of Alaska. The highest median PCB level was found in rock sole (Lepidopsetta bilineata, 285 ppb, wet weight), while the lowest level was found in rock greenling (Hexagrammos lagocephalus, 104 ppb, wet weight). Lipid adjusted PCB values were also calculated and significant interspecies differences were found. Again, rock sole had the highest level (68,536 ppb, lipid weight). Concerning the PCB congener patterns, the more highly chlorinated congeners were most common as would be expected due to their greater persistence. Among the pesticides, p, p′-DDE generally dominated, and the highest level was found in sockeye salmon (Oncorhynchus nerka, 6.9 ppb, wet weight). The methodology developed by U.S. Environmental Protection Agency (USEPA) was used to calculate risk-based consumption limits for the analyzed fish species. For cancer health endpoints for PCBs, all species would trigger strict advisories of between two and six meals per year, depending upon species. For noncancer effects by PCBs, advisories of between seven and twenty-two meals per year were triggered. None of the pesticides triggered consumption limits.ConclusionThe fish analyzed, mainly from Adak, contain significant concentrations of POPs, in particular PCBs, which raises the question whether these fish are safe to eat, particularly for sensitive populations. However when assessing any risk of the traditional diet, one must also consider the many health and cultural benefits from eating fish.

Characterization of certified reference material for quantification of polychlorinated biphenyls and organochlorine pesticides in fish

Fish certified reference material (CRM), NMIJ CRM 7404-a, for the analysis of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) was developed by the National Metrology Institute of Japan, part of the National Institute of Advanced Industrial Science and Technology. Fish samples (Japanese seabass) used for the preparation of the CRM were collected from Tokyo Bay, and the edible part was freeze-dried, pulverized, sieved, homogenized, and sterilized by gamma-irradiation. This sample is in the form of a powder comprising approximately 10 g stored in a brown glass bottle. The certification was carried out using multiple analytical methods such as pressurized liquid extraction, Soxhlet extraction, saponification, and homogenization to ensure the reliability of analytical results; the certified values of target PCBs (PCB 28, PCB 70, PCB 105, PCB 153, and PCB 170) and OCPs (trans-nonachlor, dieldrin, p,p'-DDE, p,p'-DDT, and p,p'-DDD) were 1.05-14.0 microg kg(-1) and 1.57-18.0 microg kg(-1) for PCBs and OCPs, respectively. This is the first fish powder CRM in which PCBs and OCPs were determined by isotope dilution mass spectrometry.

Sample Preparation Based on Matrix Solid-Phase Dispersion and Solid-Phase Extraction Cleanup for the Determination of Organochlorine Pesticides in Fish

A method based on matrix solid-phase dispersion (MSPD) and SPE to determine 20 organochlorine pesticides (OCPs) in fish tissues (muscle and liver) was optimized in terms of the sorbents and elution solvents used for the analysis. The following analytical components were evaluated: ENVI-CarbTM and ENVI-18 as dispersing agents, Florisil and Florisil over alumina as cleanup adsorbents, and hexane and hexane-ethyl acetate (80 + 20) as elution solvents. The pesticides were determined by GC with electron capture detection. The best results were obtained with ENVI-Carb as a dispersing agent and an ENVI-Florisil co-column using 40 mL hexane-ethyl acetate (80 + 20) as the elution solvent. Analytical recoveries ranged between 75 and 130% except for beta-HCH in fish liver, and the RSD values were < 15% for most of the pesticides studied. Furthermore, sensitivity was sufficient (LOD of < 300 microg/kg) for all OCPs under study, in compliance with the tolerance limits of the U.S. Food and Drug Administration for OCPs in fish. The results were compared with those obtained by microwave-assisted extraction (MAE) and pressurized liquid extraction (PLE) in order to evaluate the performance of the MSPD procedure. The MPSD methodology was shown to be easy to use and fast, with a clear advantage relative to cost, because it does not need the expensive equipment required for MAE and PLE.

Regression models for explaining and predicting concentrations of organochlorine pesticides in fish from streams in the United States

Empirical regression models were developed for estimating concentrations of dieldrin, total chlordane, and total DDT in whole fish from U.S. streams. Models were based on pesticide concentrations measured in whole fish at 648 stream sites nationwide (1992-2001) as part of the U.S. Geological Survey's National Water Quality Assessment Program. Explanatory variables included fish lipid content, estimates (or surrogates) representing historical agricultural and urban sources, watershed characteristics, and geographic location. Models were developed using Tobit regression methods appropriate for data with censoring. Typically, the models explain approximately 50 to 70% of the variability in pesticide concentrations measured in whole fish. The models were used to predict pesticide concentrations in whole fish for streams nationwide using the U.S. Environmental Protection Agency's River Reach File 1 and to estimate the probability that whole-fish concentrations exceed benchmarks for protection of fish-eating wildlife. Predicted concentrations were highest for dieldrin in the Corn Belt, Texas, and scattered urban areas; for total chlordane in the Corn Belt, Texas, the Southeast, and urbanized Northeast; and for total DDT in the Southeast, Texas, California, and urban areas nationwide. The probability of exceeding wildlife benchmarks for dieldrin and chlordane was predicted to be low for most U.S. streams. The probability of exceeding wildlife benchmarks for total DDT is higher but varies depending on the fish taxon and on the benchmark used. Because the models in the present study are based on fish data collected during the 1990s and organochlorine pesticide residues in the environment continue to decline decades after their uses were discontinued, these models may overestimate present-day pesticide concentrations in fish.

Evaluation of Microwave-Assisted Extraction for the Analysis of Polychlorinated Biphenyls and Organochlorine Pesticides in Fish

The efficiency of microwave-assisted extraction (MAE) was evaluated for the analysis of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in fish. An isotope dilution method was used for quantification via analysis of the samples by gas chromatography and mass spectrometry. MAE solvent, temperature, and time were optimized, and observed concentrations were compared. The MAE results were also compared to those of other extraction techniques (Soxhlet extraction, pressurized liquid extraction, saponification, and homogenization). Concentrations of PCBs and OCPs obtained by MAE at 120 degrees C for 10 min were comparable to those by the other techniques. The results suggest that MAE can be used for the analysis of PCBs and OCPs in fish.

Genotoxic pressure of vineyard pesticides in fish: Field and mesocosm surveys

The present study deals with the genotoxicity assessment of vineyard pesticides in fish exposed in the field or in mesocosm conditions. Primary DNA damage was quantified as strand breaks using the single cell gel electrophoresis assay (Comet assay) applied to fish erythrocytes. In a first experiment, a significant genotoxic effect was observed following an upstream–downstream gradient in early life stages of brown trout ( Salmo trutta fario) exposed in the Morcille River contaminated by a mixture of vineyard pesticides during three consecutive years. The pronounced response in terms of DNA damage reported in the present study could argue for a high sensitivity of fish early life stage and/or a high level of exposure to genotoxic compounds in the Morcille River. This stresses the interest in using trout larvae incubated in sediment bed to assess genotoxic compounds in the field. In a second experiment, adult European topminnow ( Phoxinus phoxinus) were exposed in water running through artificial channels to a mixture of diuron and azoxystrobin, two of the main pesticides detected in the Morcille watershed. As compared with the unexposed channel, a 3–5-fold increase in the DNA damage was observed in fish exposed to chronic environmental pesticide concentrations (1–2 μg L −1 for diuron and 0.5–1 μg L −1 for axoxystrobin). A single 6 h pulse of pesticide (14 μg L −1 of diuron and 7 μg L −1 of azoxystrobin) was applied to simulate transiently elevated chemical concentrations in the river following storm conditions. It did not increase genotoxicity. After a 1-month recovery period, DNA damage in exposed fish erythrocytes recovered to unexposed level, suggesting possible involvement of both repair mechanisms and cellular turnover in this transient response. This work highlights that vineyard treatment by pesticides and in particular diuron and azoxystrobin can represent a genotoxic threat to fish from contaminated watershed rivers.

Organochlorine pesticides in fish from the southern Baltic Sea: Levels, bioaccumulation features and temporal trends during the 1995–2006 period

The levels of HCH isomers, HCB and ∑ DDTs were determined in five species of Baltic fish collected during 1995–2006. Some downward time trends of HCH isomer, pp′-DDE and pp′-DDD concentrations in Baltic fish were observed; in contrast, HCB and DDT concentrations did not exhibit any obvious trend. Concentrations of ∑ HCHs expressed on a lipid weight basis were very similar in all species studied. In contrast, concentrations of ∑ DDTs varied in tested species. The most abundant HCH isomer was β-HCH and among DDT-related compounds, pp′-DDE prevailed. In our investigations the sampling sites were not a crucial factor for organochlorine pesticide concentrations and patterns observed in fish, but the occurrence of several inter-species differences in the bioaccumulation features of OC pesticides were observed. For cod there was a positive correlation between fish size (length) and ∑ DDT concentration. In herring, sprat and salmon samples, ∑ DDT concentrations were negatively correlated with fat content.

Persistent organochlorine pesticides, polychlorinated biphenyls, polybrominated diphenyl ethers in fish from coastal waters off Savannah, GA, USA

Contamination profiles of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined in six fish species from three selected regions along coastal waters off Savannah, GA, USA. Concentrations of PCBs were predominant (12–493 ng g−1 lw) followed by PBDEs (10–337 ng g−1 lw), OCPs such as DDTs (2.7–153 ng g−1 lw), chlordanes (3.8–34 ng g−1 lw), cyclodienes (<0.1–35 ng g−1 lw), mirex (<0.1–8.6 ng g−1 lw), γ-hexachlorocyclohexane (<0.1–1.4 ng g−1 lw), and hexachlorobenzene (<0.1–0.68 ng g−1 lw). The results indicated no region-specific difference in the contaminants however inter-species as well as intra-species differences were evident. Comparison of DDTs, PCBs, and PBDEs profiles in fish with those from other countries revealed that fish from coastal waters off Savannah contained relatively less concentrations of PCBs and chlorinated pesticides, while PBDE concentrations were comparable or even higher than fish samples from other regions. Polychlorinated biphenyl congeners and chlorinated pesticide tempoal trend data exhibited no increase of contamination levels. The levels of PCBs and chlorinated pesticides in fish from Savannah coastal waters were below the Food and Drug Administrations (FDA) established limits for human consumption.

ＧＣ／ＭＳによる魚介類中の農薬一斉分析法の検討

A simple pretreatment of sample and comprehensive analysis method has been developed for the GC/MS determination of 29 pesticides in fish and shellfish. For the pretreatment, the pesticides in the sample were extracted with acetonitrile and the lipid in the sample extract was eliminated by partitioning between hexane and acetonitrile. After Sep-Pak Plus Florisil or Florisil PR column clean-up, the sample extract was analyzed by GC/MS (SIM). Recovery tests were performed by use of Sep-Pak Plus Florisil and Florisil PR for fish and shellfish. On the whole, recoveries (%) and CV (%) by Florisil PR were better than those by Sep-pak Plus Florisil in both of Japanese smelt (fish) and corbicula (shellfish). However, Sep-Pak Plus Florisil had better results in pyrokiron, fenthion, etc., so selection of clean-up procedure in agreement with the purpose was recommended. The quantification limits were 0.002∼0.005μg/g for most of the 29 pesticides.

Tissue distribution of organochlorine pesticides in fish collected from the Pearl River Delta, China: Implications for fishery input source and bioaccumulation

Fish tissues from different fishery types (freshwater farmed, seawater farmed and seawater wild) were analyzed for organochlorine pesticides (OCPs), with the aim to further our understanding of bioaccumulation, and reflect the state of different fishery environments. Significantly higher SigmaOCP levels were found in seawater farmed fish than others, and among three freshwater farmed species, the lowest levels occurred in filter-feeding fish (bighead carp). Liver contained the highest SigmaOCP levels, while no significant differences were found among other tissues. Among DDT components, p,p'-DDT was abundant in seawater fish, while for freshwater fish, p,p'-DDE was the predominant congeners, except for northern snakehead (34% for p,p'-DDE and 30% for p,p'-DDT). The new source of DDTs to freshwater fish ponds was partly attributed to dicofol, whereas sewage discharged from the Pearl River Delta and anti-fouling paint were likely the DDTs sources to seawater farmed fish.

Simultaneous determination of residual polychlorinated biphenyls and organochlorine pesticides in fish and fish products by gas-liquid chromatography

A procedure is developed for the simultaneous determination of polychlorinated biphenyls and organochlorine pesticides in fish and fish products by gas-liquid chromatography with an electron capture detector on a capillary column DB-1701 (30 m × 0.25 mm × 0.25 μm) under temperature-programming conditions. The detection limit is 0.06 μg/kg of the test sample. Polychlorinated biphenyls and organochlorine pesticides were extracted from the samples using a hexane-acetone mixture (1 : 1). Lipids were removed by treatment with H2SO4. Eighteen samples were analyzed; the concentrations of pollutants were found to be below the prescribed values.

Effects of Diazinon on Mummichog (Fundulus heteroclitus) Larvae Produced from Eggs Differentially Treated with PCB126

During their formation, fish eggs receive a load of contaminants including polychlorinated biphenyls (PCBs) from their mother and then, after spawning, are exposed to pesticides present in water. This is the first study investigating the interaction between PCBs and organophosphorous pesticides in fish. The effect of diazinon was evaluated in mummichog (Fundulus heteroclitus) larvae produced from eggs differentially treated with 3,3',4,4',5 pentachlorobiphenyl (PCB126). A few hours after fertilization, eggs were treated topically with a solution of PCB126 (100 pg/microl) in dimethyl sulfoxide (DMSO) (Group P), DMSO (Group D), or not treated (Group N). Newly hatched larvae from Groups P and D were exposed to diazinon (125-12,900 ng/L) in saltwater and Group N larvae to saltwater alone. Diazinon caused a dose-responsive inhibition of cholinesterase (ChE) activity at environmentally realistic concentrations (> or =361 ng/L), with up to 85% inhibition at 12,900 ng/L. Body length was also inversely related to diazinon at concentrations > or =361 ng/L and was significantly reduced (by 4%) at 12,900 ng/L compared to controls. Mummichog larvae were highly sensitive to PCB126 with an eightfold induction of the activity of ethoxyresorufin-O-deethylase at a dose of 710 pg PCB126 or 3.6 pg TCDD-TEQ/g wet weight. Treatment with PCB126 also caused a slight reduction in body length but no effect on ChE activity. This study indicates that the effects of PCB126 and diazinon on body length are cumulative because no significant synergistic or antagonistic interactions were observed. Longer term studies with several doses of PCB126 are needed to fully assess the overall impact of joint exposure to diazinon and PCB126 on growth and survival of fish larvae.

Residues of Organochlorine Pesticides in Fish from the Gomti River, India

This study reports the levels and distribution patterns of some organochlorine pesticides (OCPs) in fish samples of the Gomti river, India, collected from three sites. In the fish muscles Sigma OCPs ranged between 2.58-22.56 ng g(-1) (mean value: 9.66 +/- 5.60 ng g(-1)). Neither spatial nor temporal trends could be observed in distribution of the OCPs. Aldrin was the predominant OCP, whereas, HCB and methoxychlor could not be detected. alpha-HCH and beta-HCH among the isomers of HCH and pp-DDE among the metabolites of DDT were the most frequently detected OCPs. The results revealed that the fish of the Gomti river are contaminated with various OCPs.

Acetylcholinesterase inhibition and gill lesions in Rasbora caverii, an indigenous fish inhabiting rice field associated waterbodies in Sri Lanka

The present study was aimed at applying condition factor (CF), brain acetylcholinesterase (AChE) and gill histology as biomarkers for detecting possible exposure/effect induced by pesticides in fish residing rice field associated waterbodies in Sri Lanka. Biomarkers of an indigenous fish, Rasbora caverii collected from five sampling sites including canals near rice fields, a river and a reservoir (the reference site) were evaluated at four sampling stages covering pesticide application periods during rice cultivation season in 2004. Results indicated that CF of the fish did not show significant alterations regardless of the sampling sites or sampling stages. Site specific differences in AChE activities of the fish were not evident either prior to application of pesticides or at 7 days after Paraquat application to the rice fields. Two days after the application of a mixture of Fenthion and Phenthoate to the rice fields, AChE activity of the fish collected from canals near rice fields was significantly depressed (65-75%) compared to the fish in the reference site. The activities remain depressed to 50-56% even at 65 days after the insecticides application. Laboratory studies showed that prior exposure of R. caverii to Paraquat (2 microg l(-1), 7 days) enhanced the extent of inhibition of brain AChE activity induced by Fenthion (3 microg l(-1)) or a mixture of Fenthion (3 microg l(-1)) and Phenthoate (5 microg l(-1)). Gills of fish collected from canals near rice fields exhibited abnormal multiple divisions at the tips of some secondary lamellae in addition to hyperplasia, hypertrophy and club shaped deformities. Results indicate that application of pesticides in rice culture could manifest a threat to native fish populations residing rice field associated waterbodies. The response of brain AChE and histological changes in the gills of R. caverii allowed differentiating sampling sites after insecticide applications to the rice fields. Hence, R. caverii may be considered as a surrogate species in ecotoxicological risk evaluation of agrochemicals in the region.

Determination of organochlorine pesticide residues in water, sediment, and fish samples from the Meriç Delta, Turkey

This study had been carried out between May 2002 and August 2003 in Meriç Delta, Turkey which is located at a site where the Meriç River falls to the Agean Sea. Residues of organochlorine pesticides (OC) in surface water, sediment, and fish (Cyprinus carpio) samples from Meriç Delta were analysed by gas chromatography. The results of the study showed that all analysed 20 organochlorine pesticides and their residues have been widespread throughout the study area. According to the results, it was found that the concentrations of these selected organochlorine pesticides in fish (Cyprinus carpio) samples were higher than in water and sediment samples. Because of the low water solubility of the organochlorine compounds, it is expected that any organochlorine pesticides present in the study area, will be preferably adsorbed to sediment or bioaccumulated in fish. The α- and β-HCH were the predominant HCH isomers in all analysed fish samples and ranged between 319.5 and 968.15 ng g−1 and between 397.5 and 876.4 ng g−1, respectively. The concentration levels of p,p′-DDT (ranging from 2.68 to 52.45 ng g−1) in all analysed fish samples were consistently higher than its metabolite p,p′-DDE, indicating a recent use of this organochlorine pesticide in the area. We have analysed the distribution characteristics of individual organochlorine pesticide and found that α-, β-HCH, p,p′-DDT p,p′-DDE, β-endosulphan, heptachlore epoxide, and endrin ketone were the most common organochlorine pesticides contaminants in the study area.

A solid-phase microextraction method for the chromatographic determination of organophosphorus pesticides in fish, water, potatoes, guava and coffee

Este trabalho descreve um metodo de Microextracao em Fase Solida (SPME-CG) para a determinacao de pesticidas organofosforados em amostras de peixes de agua doce, agua e outros alimentos por cromatografia em fase gasosa com detector de nitrogenio e fosforo. As amostras foram coletadas entre outubro de 2002 e abril de 2003 nos afluentes e subafluentes do rio Paranaiba que abastecem a cidade de Patos de Minas, Minas Gerais, Brasil. A determinacao dos pesticidas co-ral (O,O-dietil-O-(3-cloro-4-metil-2-oxo-2H-1-benzopiran-7-il) fosforotioato)), DDVP (2,2-dicloroetenil dimetilfosfato), di-siston (O,O-dietil S-[2-(etiltio) etil] fosforoditioato), etion (O,O,O',O'-tetraetil S,S'-metilenobisfosforoditioato), forato (O,O-dietil-S-etiltiometilfosforoditioato), fosdrin (O,O-dimetil-1-carbometoxi-1-propen-2-il-fosfato), gution (O,O-dimetil-S-(4-oxo-1,2,3-benzotrizina-3-metil) fosforoditioato)), malationa (O,O-dimetil-S-(etil-1,2-dicarboetoxi) fosforoditioato) e parationa metilica (O-dimetil-O-4-nitrofenilfosforotioato) em amostras de peixes, agua e outros alimentos, com o procedimento de SPME-CG utilizando uma microfibra de PDMS de 100 µm, e simples, facil manuseio, economica e livre de solvente. As condicoes otimizadas para a extracao dos pesticidas com o metodo SPME-CG foram: amostras sob agitacao, absorcao a temperatura ambiente durante 40 min, dessorcao a 220°C durante 10 min e volume de amostra no frasco de 16,0 mL. Utilizando-se estas condicoes foram obtidas curvas analiticas lineares em diferentes faixas de concentracao (dependendo de cada pesticida) com coeficientes de correlacao entre 0,997 a 0,999. A precisao estava adequada com desvios padrao relativos variando de 4,40 a 15,13%. O limite de deteccao variou de 0,05 µg L-1 a 8,37 µg L-1 e o limite de quantificacao de 0,09 µg L-1 a 8,70 µg L-1. O metodo foi empregado para detectar e quantificar pesticidas em 24 amostras de peixes de tres especies diferentes e tambem em agua, batatas, goiaba e cafe. As amostras analisadas mostraram residuos de seis pesticidas organofosforados diferentes.

Modelling bioconcentration of pesticides in fish using biopartitioning micellar chromatography

Ecotoxicity assessment is essential before placing new chemical substances on the market. An investigation of the use of the chromatographic retention (log k) in biopartitioning micellar chromatography (BMC) as an in vitro approach to evaluate the bioconcentration factor (BCF) of pesticides in fish is proposed. A heterogeneous set of 85 pesticides from six chemical families was used. For pesticides exhibiting bioconcentration in fish (experimental log BCF > 2), a quantitative retention-activity relationships (QRAR) model is able to perform precise log BCF estimations of new pesticides. Considering the present data, the results based on log k seem to be more reliable than those from available software (BCFWIN and KOWWIN) and from log P (quantitative structure-activity relationships (QSAR)). It is also possible to perform risk assessment tasks fixing a threshold value for log k, which substitute two common threshold values, log P and experimental log BCF, avoiding the experimental problems related with these two parameters.

Rapid determination of chlorinated pesticides in fish by freezing-lipid filtration, solid-phase extraction and gas chromatography–mass spectrometry

An analytical method has been developed for measuring 24 chlorinated pesticides in fish tissue samples. Extraction of chlorinated pesticides was carried out by ultrasonication using an acetone– n-hexane (5:2, v/v) mixture. Most of the lipids in the extract were eliminated by freezing-lipid filtration, prior to solid-phase extraction (SPE) cleanup. During freezing-lipid filtration, about 90% of the lipids extracted from the fish samples were easily removed without any significant losses of chlorinated pesticides. For purification, SPE using Florisil was shown to be more effective than silica. Quantification was performed using gas chromatography–mass spectrometry in the selected ion monitoring mode. Spiking experiments were carried out to determine the recovery, precision, and limits of detection (LODs) of the method. The overall recovery was above 80% in the spiked fish tissue sample at 100 ng/g level. The detection limits for chlorinated pesticides were ranged from 0.5 to 5 ppb, except for endosulfan I and II which was 20 ppb. The newly developed method is demonstrated to give efficient recoveries and LODs for detecting chlorinated pesticides spiked into fish tissue with high lipid content.

Assessment of persistent toxic substances in the environment of Egypt

The objective of this review is to provide a comprehensive assessment of the threats posed by persistent toxic substances (PTS) to the environment and human health in Egypt and to identify priorities, data gaps and recommendations for future intervention to control, reduce or eliminate releases of PTS. Data on available concentrations of persistent toxic substances in the different environmental compartments and their impacts on the ecosystem, and humans have been assembled and summarized. Despite extensive studies, most of the data available deal with limited studies or hot spot situations. Localized inputs of PTS have been identified from freshwater discharges in coastal areas (e.g., Nile estuaries and coastal lakes) and near sewage outfalls from highly industrialized and populated cities. Data are often missing for certain contaminants and in some compartments and geographical areas. The lack of standardized methodologies makes it difficult to compare and use existing data to provide exact conclusions on spatial and temporal trends. In spite of these restrictions, available data indicate that it is unlikely that present levels of cyclodiene pesticides would adversely affect marine organisms. Compounds which are proven to be of concern are DDT, PCBs, γ-HCH, PAHs, HCB and organotin compounds. Other compounds are suspected to be ubiquitous but data are lacking. Based on few recent data, the reported levels of organochlorine pesticides in fish and human milk samples suggest a concentration decline during the 1990s consistent with the regulatory restrictions on the use of these compounds. It is essential to activate monitoring programs to fill data gaps in appropriate abiotic and biotic. Monitoring programs should be follow standard procedures and include improved QA/QC protocols.