Some organochlorine pesticide residues in fish species in Konya, Turkey

Pesticides in fish from the Uruguay River and markets in Argentina and health risk assessment

Organochlorine, organophosphate, triazole, and strobilurin pesticides were determined in fish samples. Relative standard deviations lower than 9.3% were obtained for organochlorine pesticides and 10.8% for other pesticides. Accuracy ranged from 73% to 119% for organochlorine pesticides and 80.4% to 116% for organophosphate, triazole, and strobilurin pesticides. A total of 28 pesticides were analysed and 7 of them were detected (exceeding 10 µg/kg) in some samples, with the highest concentration recorded at 68.5 µg/kg, corresponding to heptachlor epoxide A. The pesticide most frequently detected was β HCH, found in 30 of the 100 analysed samples. Hazard Quotient values were estimated for men, women, and children. These values exceeded 1 for heptachlor epoxide in women and children, as well as for endrin in children. These findings emphasise the need for stricter controls to reduce fish contamination and mitigate health risks.

Recent advances in clay minerals for groundwater pollution control and remediation

Clay minerals are abundant on Earth and have been crucial to the advancement of human civilization. The ability of clay minerals to absorb chemicals is frequently utilized to remove hazardous compounds from aquatic environments. Moreover, clay-based adsorbent products are both environmentally acceptable and affordable. This study provides an overview of advances in clay minerals in the field of groundwater remediation and related predictions. The existing literature was examined using data and information aggregation approaches. Keyword clustering analysis of the relevant literature revealed that clay minerals are associated with groundwater utilization and soil pollution remediation. Principal component analysis was used to assess the relationships among clay mineral modification methods, pollutant properties, and the Langmuir adsorption capacity (Qmax). The results demonstrated that pollutant properties affect the Qmax of pollutants adsorbed by clay minerals. Systematic cluster analysis was utilized to classify the collected data and investigate the relationships. The pollution adsorption mechanism of the unique structure of clay minerals was investigated based on the characterization results. Modified clay minerals exhibited changes in surface functional groups, internal structure, and pHpzc. This review provides a summary of recent clay-based materials and their applications in groundwater remediation, as well as discussions of their challenges and future prospects.

Persistent Organic Pollutants (POPs) in Sardine (Sardinella brasiliensis): Biomonitoring and Potential Human Health Effects

Organochloride (OC) and polychlorinated biphenyl (PCB) concentrations were determined in the muscle tissue of fifty sardine samples (Sardinella brasiliensis) sampled off the south-east Brazilian shelf. The aim herein was to investigate OCs and PCBs composition profile, bioaccumulation potential and human risks. The concentrations of 18 organochlorine pesticides (OCPs) were below the method limit of quantification in most samples (ca. 94%), with few detected, namely δ-HCH, γ-HCH, Endosulfan I and II, Endosulfan Sulphate, DDE, Dieldrin, Endrin, Endrin Aldeide, Endrin Cetone and Metoxyclor. The median concentration for the Σ41 PCBs was 2.32 ng g^-1, ranging from values below the limit of quantification (<LOQ) to 37.2 ng g^-1. Based on the analyzed samples, the concentrations reported herein do not represent a risk for human consumption according to both national and international guidelines, nor do OC and PCB bioaccumulation in sardines appear to be a concern at the moment. These findings, although preliminary, represent a baseline for future comparisons of the quality of an important source of protein available to the poorest Brazilian population strata.

Aptamer-based NanoBioSensors for seafood safety

Chemical and biological contaminants are of primary concern in ensuring seafood safety. Rapid detection of such contaminants is needed to keep us safe from being affected. For over three decades, immunoassay (IA) technology has been used for the detection of contaminants in seafood products. However, limitations inherent to antibody generation against small molecular targets that cannot elicit an immune response, along with the instability of antibodies under ambient conditions greatly limit their wider application for developing robust detection and monitoring tools, particularly for non-biomedical applications. As an alternative, aptamer-based biosensors (aptasensors) have emerged as a powerful yet robust analytical tool for the detection of a wide range of analytes. Due to the high specificity of aptamers in recognising targets ranging from small molecules to large proteins and even whole cells, these have been suggested to be viable molecular recognition elements (MREs) in the development of new diagnostic and biosensing tools for detecting a wide range of contaminants including heavy metals, antibiotics, pesticides, pathogens and biotoxins. In this review, we discuss the recent progress made in the field of aptasensors for detection of contaminants in seafood products with a view of effectively managing their potential human health hazards. A critical outlook is also provided to facilitate translation of aptasensors from academic laboratories to the mainstream seafood industry and consumer applications.

Health risk assessment of organochlorine pesticide residues in edible tissue of seafood

Fish is one of the most valuable foods with high-quality animal protein. However, aquaculture, or ingesting contaminated food, allows organochlorine pesticides (OCPs) to enter the fish's body, and therefore, it negatively impacted public health. One-hundred and twenty random samples of Clupea harengus (C. harengus), Mugil cephalus (M. cephalus), Sardinella aurita (S. aurita), Oreochromis niloticus (O. niloticus), Neptunus pelagicus (N. pelagicus) and Sepia savigngi (S. savigngi) (n = 20 each) were collected from local markets in Mansoura city, Egypt. Samples were checked to see whether any residues of OCPs with the application of risk assessment due to their consumption by Mansoura citizens. The findings indicated that summation hexachlorocyclohexane (∑HCH) in examined seafood samples ranged from 0.27 ± 0.13 in N. pelagicus to 61.61 ± 52.03 μg.kg-1 in S. aurita. Also, the γ-HCH isomer was considered the more prominent among isomers. Hexachlorobenzene (HCB) was found in five different species, with mean values of 2.03 ± 1.85, 1.5.7 ± 1.17, 0.94 ± 0.87, 0.35 ± 0.06, and 0.18 ± 0.06 μg.kg-1 in C. harengus, S. aurita, M. cephlaus, O. niloticus, and S. savigngi. Moreover, summation of Heptachlors (∑HPTs) was 10.19 ± 7.63, 1.27 ± 0.26, 2.58 ± 0.11, 0.95 ± 0.12, 0.21 ± 0.11 and 0.32 ± 0.03 μg.kg-1 of wet weight in examined C. harengus, M. cephlaus, S. aurita, O. niloticus, N. pelagicus, and S. savigngi. Aldrin and dieldrin residues were 3.75 ± 1.31 and 4.86 ± 1.33 μg.kg-1 in C. harengu, meanwhile they were 1.61 ± 0.77 and 0.78 ± 0.04 μg.kg-1in M. cephalus. Dichlorodiphenyldichloroethylene (pp-DDE) was dominant in all examined species within different concentrations 5.08 ± 4.12, 0.98 ± 0.10, 3.07 ± 0.91, 0.93 ± 0.27, 0.08 ± 0.01 and 0.35 ± 0.02 μg.kg-1 in C. harengus, M. cephlaus, S. aurita, O. niloticus, N. pelagicus and S. savigngi, respectively. We concluded that all examined seafood samples were lower than the recommended maximum residue limit. Also, the estimated daily intake was less than the permitted daily intake. Non-carcinogenic indices of target hazard quotient and hazard index for OCPs in all examined species were less than 1.

Freely dissolved organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) along the Indus River Pakistan: spatial pattern and risk assessment

Freely dissolved OCPs and PCBs were measured by using polyethylene passive samplers at 15 sites during 2014 throughout the stretch of the Indus River to investigate the spatial pattern and risk assess. Levels (pg/L) of dissolved ∑OCPs and ∑PCBs ranged from 34 to 1600 and from 3 to 230. Among the detected OCPs, dissolved DDTs (p,p'-DDE, followed by p,p'-DDT) predominated with levels of 0.48 to 220 pg/L. The order of occurrence for other studied OCPs was as follows: HCB, endosulfans, chlordanes, and HCHs. Spatially, dissolved (pg/L) ∑OCPs varied (p < 0.05) as the following: surface water of the alluvial riverine zone (ARZ) showed the highest levels (114) followed by the frozen mountain zone (FMZ) (52.9), low-lying zone (LLZ) (28.73), and wet mountain zone (WMZ) (14.43), respectively. However, our zone-wise PCB data did not exhibit significant differences (p > 0.05). Principal component analysis/multilinear regression results showed pesticide usage in the crop/orchard fields and health sector, electric and electronic materials, and widespread industrial activities as the main source of OCPs and PCBs along the Indus River. Our results showed that OCPs and PCBs contaminated water intake, playing an important role towards the considerable cancer/non-cancer risk (HI and CR values) along the Indus River Flood-Plain.

Health risk assessment of hexachlorocyclohexane in soil, water and plants in the agricultural area of Potohar region, Punjab, Pakistan

In this study analysis of soil, water and plant residue samples is presented to evaluate the contamination levels and possible health risks. Hexachlorocyclohexane (HCH) is a persistent organic pollutant used as a pesticide in agricultural sector for pest control in order to obtain higher productivity. For analysis soil, water and crop residue samples were collected from different agricultural areas of the northern Punjab region of Pakistan. The investigation of the samples shows significant levels of HCH residues in all types of samples. Gas chromatography-mass spectrometry analysis was used to assess the higher residue levels of HCH in the samples. The concentration of HCH residues detected in samples ranged from 2.43 to 8.88 µg/g in soil, nd -5.87 µg/l in water and nd - 4.87 µg/g in plants. The presence of HCH residues in soil, water and plant samples was beyond the recommended quality guidelines. Human health risk was evaluated for cancer and non-cancer risks through dietary and non-dietary exposure routes. The hazard index was HI > 1 in children and HI < 1 in adults, while the non-dietary incremental lifetime cancer risks (ILCR) were beyond the internationally acceptable limit of 1 × 10^-5. Hence, results of the present investigation concluded the presence of high levels of HCH residues in samples and pose high health risk to the inhabitants. These findings are alarming and apprise the concerned departments for the remediation of contamination and proper implementation of environmental laws in the area.

Hexachlorocyclohexane toxicity in water bodies of Pakistan: challenges and possible reclamation technologies

Pakistan is an agro-economy country where hexachlorocyclohexane (HCH) pesticides are being used to improve crop productivity, as a result the risk of contamination of soil and sediment has been increased. HCH exhibits all the characteristics of persistent organic pollutants (POP), and was therefore added to the list of 'new POPs' in 2009. This review report revealed that the major rivers of Pakistan such as the Indus Basin, River Ravi, River Chenab and their tributaries all are contaminated with HCH and the highest residual concentration (4,090 ng/g) was detected in a pesticide burial ground in Hyderabad city. Major sources of HCH contamination were identified as agricultural runoff, discharge of untreated industrial effluents and surface runoff. In order to manage HCH pollution, various ex-situ and in-situ remediation techniques along with their merits and demerits are thoroughly reviewed. Among these, microbial bioremediation is a low cost, environment friendly, effective in-situ remediation technique for remediation of HCH. Overall, the information provided in this manuscript will provide a future reference to the scientific community and bridge the knowledge gap between HCH release in the environment and their mitigation through proper treatment methods.

Expression of estrogen-, progesterone-, and androgen-responsive genes in MCF-7 and MDA-MB-231 cells treated with o,p'-DDT, p,p'-DDT, or endosulfan

Endocrine disruptors are a major concern due to their possible association with hormone-dependent carcinogenesis. Some examples of compounds with such properties are organochlorine pesticides (OCPs). OCPs are persistent pollutants with high lipophilicity, long half-life, and bioaccumulation potential. In the past, some of the most commonly used OCPs were dichlorodiphenyltrichloroethane (DDT) and endosulfan. Here, we investigated the effects of o,p'-DDT, p,p'-DDT, and endosulfan and of hormones estradiol, testosterone, and progesterone on the expression of estrogen, progesterone, and androgen receptors (ER, PR, and AR) and of their target genes (KLF4, VEGFA, CCND1, PRLR, CDKN1A, and BCL6) in MCF-7 and MDA-MB-231 cells. The results confirmed that under the action of the insecticides, there are dose- and time-dependent changes in the expression of these receptors and target genes. As corroborated by an experiment with ER, PR, and AR negative MDA-MB-231 cells, the change in the expression of KLF4, VEGFA, CCND1, and PRLR in MCF-7 cells treated with o,p'-DDT and the change in CDKN1A and PRLR expression in MCF-7 cells treated with p,p'-DDT are likely mediated by ER, PR, and AR pathways. In conclusion, we have identified some targets of DDT and endosulfan and confirmed that the effects of insecticides on the expression of these target genes differ for breast cancer cell lines with different receptor statuses.

Electrochemical Detection of Endosulfan Using an AONP-PANI-SWCNT Modified Glassy Carbon Electrode

This report narrates the successful application of a fabricated novel sensor for the trace detection of endosulfan (EDS). The sensor was made by modifying a glassy-carbon electrode (GCE) with polyaniline (PANI), chemically synthesized antimony oxide nanoparticles (AONPs), acid-functionalized, single-walled carbon nanotubes (fSWCNTs), and finally, the AONP-PANI-SWCNT nanocomposite. The electrochemical properties of the modified electrodes regarding endosulfan detection were investigated via cyclic voltammetry (CV) and square-wave voltammetry. The current response of the electrodes to EDS followed the trend GCE-AONP-PANI-SWCNT (-510 µA) > GCE-PANI (-59 µA) > GCE-AONPs (-11.4 µA) > GCE (-5.52 µA) > GCE-fSWCNTs (-0.168 µA). The obtained results indicated that the current response obtained at the AONP-PANI-SWCNT/GCE was higher with relatively low overpotential compared to those from the other electrodes investigated. This demonstrated the superiority of the AONP-PANI-SWCNT-modified GCE. The AONP-PANI-SWCNT/GCE demonstrated good electrocatalytic activities for the electrochemical reduction of EDS. The results obtained in this study are comparable with those in other reports. The sensitivity, limit of detection (LoD), and limit of quantification (LoQ) of AONP-PANI-SWCNT/GCE towards EDS was estimated to be 0.0623 µA/µM, 6.8 µM, and 20.6 µM, respectively. Selectivity, as well as the practical application of the fabricated sensor, were explored, and the results indicated that the EDS-reduction current was reduced by only 2.0% when interfering species were present, whilst average recoveries of EDS in real samples were above 97%.

Activity concentrations of 210Po and 210Pb in fish and mussels in İzmir, Turkey, and the related health risk assessment (dose assessment and pesticide levels) to the consumers

The activity concentrations of natural radionuclides (²¹⁰Po and ²¹⁰Pb) and residual pesticide levels were determined from the fish (red mullet, common sole, anchovy, horse mackerel, gray mullet, and sardine) and mussel samples collected in İzmir Bay seasonally from October 2012 and July 2013. The ²¹⁰Po and ²¹⁰Pb concentrations varied between 5.7 ± 4.0 Bq kg^-1 dry weight (dw) to 353.7 ± 45.0 Bq kg^-1(dw) and 0.7 ± 0.2 Bq kg^-1 (dw) to 4.3 ± 0.8 Bq kg^-1 (dw), respectively. From a public health point of view, the fish and mussel collected from the İzmir Bay are not harmful to consumers.

Determination of Heavy Metals and Pesticides in Different Types of Fish Samples Collected from Four Different Locations of Aegean and Marmara Sea

Heavy metals and pollutants cause serious damage to the ecological environment and accumulate in marine species in the seas. These pollutants and heavy metals accumulating in living species are a serious source of danger for human health. For this purpose, in this study, heavy metal (lead, mercury, copper, zinc, arsenic, cadmium, silver, manganese, and nickel) and pesticide (p-p′-DDE, α-BHC, endosulfan, endosulfan sulfate, endrin, aldrin, heptachlor, heptachlor epoxide, methoxychlor, p-p′-DDD, p-p′-DDT, β-BHC, cypermethrin, and dieldrin) analyses of four different fish species (Pomatomus saltatrix, Dicentrarchus labrax, Mugil cephalus, and Sparus aurata) collected from the Aegean and Marmara seas were carried out by gas chromatography-mass spectroscopy and using an inductively coupled plasma-mass spectrometer. We observed serious and remarkable arsenic, lead, and cadmium concentrations in the muscle meat of fish sample. p-p′-DDE and endosulfan were determined in every fish sample of each region. Heptachlor concentration was determined as 0.0598 μg/g in Dicentrarchus labrax sample from Marmara Sea, which is nearly nine thousand times more than the maximum allowable concentration of environmental quality standards biota of heptachlor listed in 2013/39/EU. The results show an indication of the significant health risks associated with the consumption of these contaminated fish in the Aegean and Marmara seas. In the Turkish food codex and in the 2013/39/EU directive, some heavy metals that do not have the maximum allowable concentration limits should be urgently indicated.

Efficacy of nanoencapsulated pelargonidin in ameliorating pesticide toxicity in fish and L6 cells: Modulation of oxidative stress and signalling cascade

Removal of bio-accumulated pesticides in edible fish is a global problem. In this study, we tested protective capability of a phytochemical pelargonidin-loaded non-toxic, biodegradable poly-lactide-co-glycolide nano-particles (NPG) against toxicity induced by a pesticide cypermethrin (CM) in a fish model (Oreochromis mossambica) in vivo and also in L6 muscle cell line, in vitro. First we assessed potential sustainable release of nanoparticles following oral administration of NPG to fish, their ability to cross sub-cellular membranes in several tissues and efficacy to cross blood-brain-barrier. Next, protective ability of NPG, if any, against CM in fish was evaluated deploying parameters like % cell viability, DNA damage in muscle cells and modulation of anti-oxidative-enzymes like superoxide dismutase, catalase and lipid peroxidase. Modulation of reactive oxygen species generation, nuclear condensation and alteration in stress related protein signalling cascade were assessed in L6 cells. Results revealed that NPG had nano-size range (~10-12 nm) and negative zeta potential (-17 mV). Bioavailability and distribution of NPG could be followed by spectrophotometric absorbance of pelargonidin at 293 nm from 6 h onward till 24 h in all important tissues including the brain. Thus, 0.5 mg/g b.w. NPG could demonstrate protective ability in CM-intoxicated fish muscle cells in respect of % cell viability, DNA damage and stress related enzymes. Similar alterations could also be found in signalling protein cascade in L6 cells in response to treatment of 5 μg/ml NPG against CM-induced toxicity and depletion of overall ROS generation and nuclear condensation. Therefore, NPG could be used as a potential drug in management of pesticide toxicity in cultured edible fish.

Biochars reduced the bioaccessibility and (bio)uptake of organochlorine pesticides and changed the microbial community dynamics in agricultural soils

Biochar is considered as a universal sorbent used for soil amendment but its impacts on organochlorine pesticides (OCPs) and microbial communities associated with soil and vegetables are unclear. The effects of different biochars (derived from sewage sludge biochar (SSBC), soybean straw biochar (SBBC), rice straw biochar (RSBC) and peanut shells biochar (PNBC)), on bioaccessible fractions of OCPs in a contaminated soil and their subsequent bioaccumulation into vegetables (Chinese cabbage and spring onion) were investigated in this research work. The influence of these amendments on vegetable yields and soil microbial community using Illumina next generation sequencing technology was also assessed. The application of selected biochars significantly (p < 0.01) reduced the bioaccessibility of ∑OCPs in contaminated soil: SSBC (52%), PNBC (51%), RSBC (60%), and SBBC (47%), as compared to the control. The results indicated that following biochar additions, the bio-uptake of ∑OCP bio-uptake was considerably (from 86 to 85%) reduced in grown vegetables. Risk assessment showed that biochar amendments markedly (p < 0.01) decreased the hazard quotient (HQ) indices and incremental lifetime cancer risk (ILTR) values for OCPs associated with the consumption of vegetables. In addition, the results of high-throughput sequencing showed significant differences in microbial community structure between the treatments, which was driven by differences in the relative abundances of soil microbes. The relative abundances of Acidobacteria, Chloroflexi, Nitrospirae and Verrucomicrobia decreased following biochar additions. However, biochar amendments increased the relative abundances of Actinobacteria, Proteobacteria, Planctomycetes, Bacteroidetes, Firmicutes, and Gemmatimonadetes, though the increase in relative abundances of these phyla was strongly dependent on the type of biochar used.

Environmental contaminants in fish species from a large dam reservoir and their potential risks to human health

The residue levels of antibiotics, metals and organochlorine pesticides (OCPs) were investigated in six fish species from the Karakaya Dam Reservoir, Turkey. Among monitored antibiotics, only enrofloxacin and ofloxacin were detected in muscle of fish species. Enrofloxacin levels in positive samples ranged from 0.0034 to 0.0073 mg/kg. It was detected in four fish species (trout barb, common carp, chub and Euphrates barbell), while ofloxacin was only found in common carp with the concentration of 0.0072 mg/kg. Both enrofloxacin and ofloxacin levels were below the maximum residue levels. No detectable residues of any OCPs were found in fish species. The highest toxic metal (As, Cd and Pb) content was detected in Euphrates barbell (0.103 mg/kg). Arsenic, Cd, Cr, Cu, Pb and Zn levels were well below the maximum permissible limits. The levels of antibiotics and metals found in fish species in the present study were generally lower than or comparable to those reported in other water bodies. According to estimated daily intake and hazard quotient values, antibiotics and metals detected in these wild fish species do not appear to pose a serious risk to public health.

Assessment of organochlorine pesticides in the Himalayan riverine ecosystems from Pakistan using passive sampling techniques

Organochlorine pesticides (OCPs) pose a considerable threat to human and environmental health. Despite most OCPs have been banned, they are still reported to be used in developing countries, including Pakistan. We aimed to identify the distribution, origin, mobility, and potential risks from OCPs in three major environmental compartments, i.e., air, water, and soil, across Azad Jammu and Kashmir valley, Pakistan. The sums of OCPs ranged between 66 and 530 pg/g in soil, 5 and 13 pg/L in surface water, and 14 and 191 pg/m3 in air, respectively. The highest sum of OCPs was observed in the downstream zone of a river that was predominantly influenced by peri-urban and urban areas. The OCP isomers ratios (α-HCH/γ-HCH and o,p'-DDT/p,p'-DDT) indicate use of lindane and technical DDTs mixture as a source of HCH and DDT in the riverine environment. Similarly, the ratios of DDE and DDD/the sum of DDTs, α-endosulfan/β-endosulfan, and cis-chlordane/trans-chlordane indicate recent use of DDTs, endosulfan, and chlordane in the region. The air-water exchange fugacity ratios indicate net volatilization (fw/fa > 1) of α-endosulfan and trans-chlordane, and net deposition (fw/fa < 1) of β-endosulfan, α-HCH, γ-HCH p,p'-DDD, p,p'-DDE, and p,p'-DDT. Based on the risk quotient (RQ) method, we consider the acute ecological risks for fish associated with the levels of OCPs as negligible. However, more studies are recommended to evaluate the chronic ecological risks to other riverine-associated aquatic and terrestrial species as well as human health risks to the POPs exposure through food chain transfer in forthcoming years.

Persistent Organochlorine Contaminant Residues in Tissues of Hedgehogs from Turkey

The residues of persistent organochlorinated pollutants (POPs), namely polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) (HCHs, CHLs, HCCPs, DDTs, and dicofol congeners) were investigated in the hair and muscle of road-killed Erinaceus roumanicus and E. concolor in Turkey. Mean residue levels were as follows: in hair, PCBs = 7.43 ± 4.88 ng/g and OCPs = 9.21 ± 1.27 ng/g; in muscle, PCBs = 30.73 ± 2.51 ng/g and OCPs = 145.04 ± 16.59 ng/g. There was no significant difference between species and sex, while there was significant difference between habitats and regions in terms of either total PCB and OCP levels, or POP levels (p < 0.05). Age was a determinative factor for the bio-accumulation of POPs. The contaminant levels were high in the species, sample areas, and habitats. The data also showed that tissues of hedgehogs are suitable for monitoring and evaluating the bioaccumulation of POP levels in Turkey.

Pesticide residues in muscles of some marine fish species and seaweeds of Iskenderun Bay (Northeastern Mediterranean), Turkey

Pesticide residues in muscles of nine marine fish and four seaweed species of Iskenderun Bay (Northeastern Mediterranean) have been investigated. In sampled fish species, two herbicides, three insecticides, two fungicides, and one synergist were identified and quantified. Metribuzin DADK, propamocarb HCl, and piperonyl butoxide (PBO) were detected in all the muscles of sampled fish species. Metribuzin DADK was the most abundant pesticide residue in fish muscles and the highest metribuzin DADK concentration was found in sardine (311.20 μg/kg). Propamocarb HCl concentrations varied greatly among species; from 0.530 ± 0.020 μg/kg in striped sea bream to 34.170 μg/kg in sea bass. The level of PBO ranged from 0.001 μg/kg for fourlined terapon to 0.013 μg/kg for sardine. No measurable oxamyl residue was found in any of the muscles of sampled fish species (except sardine). In seaweeds, two herbicides and two insecticides were identified and quantified. Metribuzin DADK was the most abundant and found in Cystoseira corniculata (5.01 mg/kg), Corallina elongata (0.703 mg/kg), and Jania rubens (3.85 mg/kg). Molinate was a minor contaminant and only found in Corallina elongata (0.002 mg/kg). Pyrethrin I was determined only in Padina pavonia to be 0.567 mg/kg. Pyrethrine II was found in Padina pavonia and Corallina elongate to be 1.214 and 0.229 mg/kg, respectively. The most hazardous pesticide residues of organochlorines and organophosphorus were not detected in both sampled fish muscles and seaweeds. There are no clear maximum residue limits for the detected eight pesticide residues declared for fish muscle by European Union MRL (2017). In conclusion, it can be considered that observed concentrations of pesticides in sampled nine marine fish species do not have a potential health risk for consumers. Some of the detected pesticide residues can be toxic for algae and aquatic life and regular monitoring studies are therefore essential to control the pesticide concentrations of aquatic biota in the region.

Organochlorine pesticide, antibiotic and heavy metal residues in mussel, crayfish and fish species from a reservoir on the Euphrates River, Turkey

This study investigated the residues of 19 organochlorine pesticides, 37 antibiotics and 5 heavy metals in biota samples (one mussel species, one crayfish species, six wild fish species and one farmed fish species) from the Keban Dam Reservoir on the Euphrates River, Turkey. Among monitored OCPs, only p,p'-DDE was detected in biota samples. It was found only in mussel, fish muscle and fish gill samples. The highest concentration of p,p'-DDE (0.032 mg/kg ww) was determined in the gill of common carp, which was found to be below the maximum residue limit (MRL). Only sulfadimethoxine was detected among antibiotics in biota samples. Its maximum concentration (0.0044 mg/kg ww) did not exceed the MRL of 0.1 mg/kg. Sulfadimethoxine was found only in muscle and gill of common carp collected from site S6, where there are many rainbow trout cage farms. However, no detectable residue of sulfadimethoxine was found in farmed rainbow trout. The highest concentrations of As, Cd and Pb were detected in mussels, while the highest concentrations Cu and Zn were determined in crayfish. Metal concentrations in biota samples did not exceed the maximum permissible levels. According to these results, the consumption of biota samples from the Keban Dam Reservoir is safe for human health.

Optimized Multiresidue Analysis of Organic Contaminants of Priority Concern in a Daily Consumed Fish (Grass Carp)

The organic contaminants, including polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs), are of priority concern because of their persistence, toxicity, and long-distance transportation in global environment. Their residues in a daily consumed fish (grass carp) pose potential threat to human health and aquatic ecosystems. The present study optimized an analytical protocol of microwave-assisted extraction (MAE), lip-removal by gel permeation chromatography (GPC), cleanup by solid phase cartridge (SC) or adsorption chromatography column (CC), and gas chromatography-mass spectrometry (GC/MS). Besides traditional statistical parameters, some indicators were calculated to judge the performances of extraction by various methods. The optimization experiment showed that n-hexane/acetone was the best MEA extraction solvent; an optimal fraction time of 10-39 min could simultaneously elute all the target chemicals in a single GPC run. Both CC and SC showed good recoveries. However, CC performed better than SC (p < 0.05) for OCPs, and SC performed better than CC for PBDEs (p < 0.05). We also emphasized the limitations and advantages of SC and CC and finally proposed SC as the promising cleanup method because of its low-cost materials, time-saving steps, being free of manual filling, and operation by automated SPE system.

4,4'-DDE and Endosulfan Levels in Agricultural Soils of the Çukurova Region, Mediterranean Turkey

Mediterranean Turkey has long been at the forefront of Turkish agriculture and the use of organochlorinated pesticides (OCPs) in this area rose considerably between the 1940s and 1980s. This study aimed to determine OCP residue levels in agricultural soils collected from the Mersin and Adana Districts, Çukurova Basin in Mediterranean Turkey. Most soil samples were contaminated with one, or both, of two OCP metabolites; 4,4'-dichlorodiphenyldichloroethylene (4,4'-DDE) and endosulfan sulfate. 4,4'-DDE occurred in 27 of the 29 samples and ranged from 6 to 1090 µg kg(-1)-dry soil (ds)(-1), while six samples contained endosulfan sulfate ranging between 82 and 1226 µg kg(-1)-ds(-1). Generally, horticultural and corn-planted soils contained only 4,4'-DDE, whereas greenhouse cultivation appeared to accumulate both residues. This study indicated that 4,4'-DDE occurred above acceptable levels of risk in agricultural soils of Mersin District and further studies on the qualitative and quantitative assessment of OCPs in other agricultural regions with intensive pesticide use are necessary to fully understand the impact of OCPs on agricultural soil in Turkey.

Distribution and health risk assessment of organochlorine pesticides (OCPs) residue in edible cattle tissues from northeastern part of Egypt: High accumulation level of OCPs in tongue

Food consumption is an important route of human exposure to organochlorine pesticides (OCPs). In order to assess the potential human health risks associated with OCPs, edible cattle tissues (liver, kidney and tongue) were collected from three slaughter houses in Mansoura, Zagazig and Ismailia cities, Egypt. Levels of 22 OCPs such as hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), aldrin, dieldrin and endrin (Drins), chlordanes (CHLs), heptachlors (HPTs) and hexachlorobenzene (HCB) residues were investigated. Among the investigated OCPs, HCHs represented the most dominant group with high proportions of γ-HCH isomer (53-91% of total HCHs). Mansoura city had the highest OCPs contamination load ranged from 0.1 to 2827 ng g(-1) lw (lipid weight). Surprisingly, tongue samples collected from Mansoura showed the highest concentration of HCHs (448 ng g(-1) lw) in comparison to liver (152 ng g(-1) lw) and kidney (266 ng g(-1) lw). Generally, contamination pattern of OCPs was in the order of HCHs > Drins > CHLs > DDTs ≅ HCB and HPTs. Estimated daily intakes (EDIs) through dietary consumption of cattle tissues were lower than the recommended acceptable daily intakes (ADIs) established by FAO/WHO. However, the hazard ratios (HRs) based on cancer risk were greater than 1.0 for HCHs based on the average and 95th centile concentrations, indicating carcinogenic effects to consumers through cattle tissues consumption.

Pesticides in Ichkeul Lake-Bizerta Lagoon Watershed in Tunisia: use, occurrence, and effects on bacteria and free-living marine nematodes

This study aimed to identify the most commonly used agricultural pesticides around Ichkeul Lake-Bizerta Lagoon watershed. First survey of pesticide use on agricultural watershed was performed with farmers, Regional Commissioner for Agricultural Development, and pesticide dealers. Then, sediment contamination by pesticides and response of benthic communities (bacteria and free-living marine nematode) were investigated. The analysis of 22 active organochlorine pesticides in sediments was performed according to quick, easy, cheap, effective, rugged, and safe (QuEChERS) method, biodiversity of indigenous bacterial community sediment was determined by terminal restriction fragment length polymorphism (T-RFLP), and free-living marine nematodes were counted. The results of the field survey showed that iodosulfuron, mesosulfuron, 2,4-dichlorophenoxyacetic acid (2,4 D), glyphosate, and fenoxaprops were the most used herbicides, tebuconazole and epoxiconazole the most used fungicides, and deltamethrin the most used insecticide. Sixteen organochlorine pesticide compounds among the 22 examined were detected in sediments up to 2 ppm in Ichkeul Lake, endrin, dieldrin, and hexachlorocyclohexane being the most detected molecules. The most pesticide-contaminated site in the lake presented the higher density of nematode, but when considering all sites, no clear correlation with organochlorine pesticide (OCP) content could be established. The bacterial community structure in the most contaminated site in the lake was characterized by the terminal restriction fragments (T-RFs) 97, 146, 258, 285, and 335 while the most contaminated site in the lagoon was characterized by the T-RFs 54, 263, 315, 403, and 428. Interestingly, T-RFs 38 and 143 were found in the most contaminated sites of both lake and lagoon ecosystems, indicating that they were resistant to OCPs and able to cope with environmental fluctuation of salinity. In contrast, the T-RFs 63, 100, 118, and 381 in the lake and the T-RFs 40, 60, 80, 158, 300, 321, and 357 in the lagoon were sensitive to OCPs. This study highlighted that the intensive use of pesticides in agriculture, through transfer to aquatic ecosystem, may disturb the benthic ecosystem functioning of the protected area. The free-living marine nematodes and bacterial communities represent useful proxy to follow the ecosystem health and its capacity of resilience.

Human health risk assessment of pesticide residues in snappers (Lutjanus) fish from the Navachiste Lagoon complex, Mexico

Organochlorine pesticides (OCPs) residues were determined in fillets of Lutjanus colorado, L. argentiventris, and L. novemfasciatus. Fillet samples were collected bimonthly from February 2012 to February 2013. OCPs average concentrations do not differ significantly according to size, weight, or season, nor do they relate with the physico-chemical parameters of the sea water. The highest concentration and most frequently encountered OCPs were endosulfan sulfate, δ-HCH, and heptachlor epoxide, which indicates their use in the recent past and confirms their persistence. Average concentrations of ∑HCHs, ∑chlordane, and ∑heptachlor in samples were above cancer MRLs according to data from monthly consumed portions. HCHs and heptachlor are listed in Appendix III of the Rotterdam Convention of chemicals placed on a prior informed consent procedure for import and export purposes; they are considered illegal in Mexico. The OCPs concentrations above cancer MRLs in Lutjanus spp. turn its frequent consumption into a human health risk.

Organochlorine pesticides accumulated by SPMD-based virtual organisms and feral fish in Three Gorges Reservoir, China

Organochlorine pesticides (OCPs) accumulated by semipermeable membrane device (SPMD) -based virtual organisms (VOs) and local feral fish were studied in Three Gorges Reservoir (TGR), China. VOs were deployed at seven sites in TGR for two periods in 2009 and 5 species of fish with different living habitats and feeding habits collected in the same periods from two counties in TGR. 28 OCPs were analyzed and the concentration and profile of OCPs in fish were quite different from those in VOs. The lipid-based concentrations of OCPs in fish ranged from 225.7 ng/g lw to 1996.4 ng/g lw which were much higher than those in VOs which ranged from 17.3 to 112.4 ng/g lw. Dichlorodiphenyltrichloroethanes (DDTs) were the prevalent OCPs in the investigated fish, while hexachlorobenzene (HCB) was the dominant compound in VOs. DDT in the few fish sample analyzed was not of concern based on chemical contaminant limits of non-carcinogenic effect.

Organochlorine pesticide levels in Clarias gariepinus from polluted freshwater impoundments in South Africa and associated human health risks

There are increasing concerns regarding the safe human consumption of fish from polluted, freshwater impoundments. The aim of this study was to analyse the muscle tissue of the sharptooth catfish Clarias gariepinus for selected organo-chlorine pesticides (OCPs) and to perform a human health risk assessment using a standard protocol described by the United States Environmental Protection Agency (US EPA). Fish were collected from the polluted Roodeplaat-(RDPD), Rietvlei-(RVD) and Hartbeespoort (HBPD) Dam impoundments located in the north-eastern regions of South Africa. GC-MS analyses showed levels of various OCPs in fish muscle samples from all three impoundments. For fish collected from the RDPD, p,p'-DDE, endosulfan, lindane and β- and δ-HCH were the most prevalent OCPs detected, while p,p'-DDE and endosulfan were the most predominant in fish from the RVD. Lindane and β- and δ-HCH were the main OCPs detected in fish from the HBPD. Dieldrin was the only OCP detected at concentrations for which a cancer risk and a hazard index above the acceptable risk levels were estimated. This was the case for fish from both the RDPD and RVD impoundments. No toxic risk was estimated should fish from the HBPD be consumed.

Determination of organochlorine pesticide concentrations in flathead mullet (Mugil cephalus) caught from the western Black Sea coast of Turkey

The objective of this study was to determine the levels of 14 organochlorine pesticides (OCPs) in flathead mullet (Mugil cephalus) caught from the western Black Sea coast of Turkey. The fish samples were caught from five different locations of the western Black Sea coast of Turkey in August 2009. Organochlorine pesticides were extracted from the liver tissues, and then the levels of OCPs were measured using gas chromatography with an electron capture detector. Organochlorine pesticides were detected in all locations. The levels of total OCPs in fish samples ranged between 0.224 and 1.103 μg g(-1) dry weight in the western Black Sea coast of Turkey. DDT, beta-HCH, and endosulfan I were the dominant OCPs in the fish samples. The levels of DDT in fish samples ranged between 0.081 and 0.186 μg g(-1) dry weight. The levels of total HCH in fish samples ranged between 0.007 and 0.376 μg g(-1) dry weight in the western Black Sea coast of Turkey. Although the usage of OCPs was banned in Turkey, the results of this study clearly indicated the presence of OCPs in the western Black Sea coast of Turkey and exposure of living organisms to these chemicals.

Cattle egrets as a biosentinels of persistent organic pollutants exposure

We investigated selected chlorinated pollutants (β-HCH, γ-HCH, DDDs, DDEs, o,p'-DDT, p,p'-DDT, heptachlor, aldrin, dieldrin, and endrin) in the Lahore and the Sialkot districts of Pakistan, using eggs of cattle egret (Bubulcus ibis) collected during May and June 2007. The pollutant with highest level and frequency was ΣDDT, followed by β-HCH, γ-HCH, heptachlor, aldrin, dieldrin, and endrin in descending order. The concentration(s) were significantly higher in Sialkot heronry for all the pollutants (except p,p'-DDT) than in Lahore. The values for DDTs, β-HCH, γ-HCH, and heptachlor were significantly higher (p < 0.05) in the egg(s) than in sediment(s) and in the chicks' diet, due to biomagnification. Among DDTs analogues, p,p'-DDD was the major contaminant with >60 % of total DDT burden, reflecting the widespread aged as well as recent use of DDT as well as anaerobic degradation (DDD/DDE > 1 in many cases) in the nearby paddy soils. In few samples, p,p'-DDT/(DDD + DDE) > 0.5 suggested the recent emission patterns from surrounding contaminated areas of demolished DDT units and obsolete pesticide stores. The higher levels of HCHs (i.e., β-HCH) in the samples collected from Sialkot indicate exposure from long-term agricultural use. Overall, concentrations of all studied POPs were less than the threshold levels known to affect reproduction. Nevertheless, total DDTs and/or HCHs burdens in some eggs contained concentrations of greater than what would educe adverse effects on birds. This is among few studies on OCPs exposure to avian species, which provide the evidence of Pakistan's contribution toward the Global POPs emission.

Polychlorinated biphenyls (PCBs) in air, soil, and cereal crops along the two tributaries of River Chenab, Pakistan: concentrations, distribution, and screening level risk assessment

This study reports the first systematic data on PCB levels and their risk assessments by consumption of cereal food crops from Pakistan. Polychlorinated biphenyls (PCB) including dioxin-like PCBs (dl-PCBs) were analyzed in wheat (n=28), rice (n=28), air (n=6), and soil (n=28) samples to assess the levels, spatial distribution pattern, and their risk assessments along with the two tributaries of River Chenab, Pakistan. ∑33PCB concentrations ranged between 0.15-2.22 ng g(-1)dW, 0.05-9.21 ng g(-1)dW, 0.70-30.5 ng g(-1)dW and 41-299 pg m(-3) in the wheat, rice, soil, and air samples, respectively. In the current study, comparatively lower dioxin toxicity equivalency (TEQ) values were calculated from the previously reported data. Hazardous ratio (HR) for human health risk assessment allied to non-cancer was found lower than integrity.

Bioaccumulation and tissue distribution of organochlorine pesticides (OCPs) in freshwater fishes: a case study performed in Poyang Lake, China's largest lake

Concentrations and tissue distribution of organochlorine pesticides (OCPs) in different tissues of freshwater fish, silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis), collected from Poyang Lake, China's largest shallow lake, and were studied. OCPs were detected with the observed concentrations ranging from 280.67 to 1,006.58 ng/g wet weight (ww) for bighead carp and from 67.28 to 930.06 ng/g ww for silver carp. Composition analysis demonstrated OCPs in both fish were from the same polluted environment, and then, the species-specific bioaccumulation might be mainly due to the different fish age as well as the different feeding habits elucidating from the stable carbon (δ(13)C) and nitrogen (δ(15)N) isotope analysis. Tissue distribution indicated that dietary intake was the major exposure route of OCPs for both fish and higher accumulation potency of OCPs by the hepatobiliary-related tissues (such as liver, kidney, bile, and heart). The higher metabolic activities of these tissues elucidating from the higher values of δ(15)N might be the potential-determined factor responsible for the tissue-specific accumulation.

Residual levels, tissue distribution and risk assessment of organochlorine pesticides (OCPs) in edible fishes from Taihu Lake, China

Tissue distribution and bioaccumulation of organochlorine pesticides (OCPs) in edible fishes collected from Taihu Lake, Cyprinus carpio (C. carpio) and Ctenopharyngodon idellus (C. idellus), were studied. OCPs were detected in all samples with hexachlorocyclohexanes (HCHs), aldrins (including aldrin, dieldrin, endrin, endrin aldehyde, and endrin ketone), heptachlors (heptachlor and heptachlor epoxide) and dichlorodiphenyltrichloroethanes (DDTs) being the predominant compounds for both fish species. Gill and gonad were found to be the dominant tissues for OCP bioaccumulation followed by liver, while muscle showed the least affinity of OCPs for both fishes. Tissue distribution indicated the exchange of contaminants between water and gill, as well as the food intake from environment were the dominant pathways for OCP bioaccumulation in gill-breathing fish, and the following tissue distribution was affected by both the physiological properties of target tissues and physicochemical characteristics of pesticides. OCP residues in fish were species-specific (45.63-1575.26 ng/g dry weight (dw) for C. idellus; 8.40-60.23 ng/g dw for C. carpio) mainly due to the growth rate of individuals as well as the metabolic capacity difference among species. HCHs and DDTs observed in fishes from Taihu Lake were comparable and moderate with other reported places in China. Human exposure risk assessment performed with the estimated daily intake values demonstrated the consumption of target fish species in Taihu Lake at present was safe.

The residual levels and health risks of hexachlorocyclohexanes (HCHs) and dichloro-diphenyl-trichloroethanes (DDTs) in the fish from Lake Baiyangdian, North China

The tissue and organs (muscle, brain, liver, and gill) of four species of freshwater fish from Lake Baiyangdian were analyzed for hexachlorocyclohexanes (HCHs) and dichloro-diphenyl-trichloroethanes (DDTs). The distribution characteristics were analyzed for HCHs and DDTs in various tissue and organs, which determined the health risks for humans. The research results showed that the wet weight content of all HCHs (∑HCHs) ranged from 0.05 ∼ 14.53 ng g(-1), with a mean of 3.47 ng g(-1). The wet weight content of all DDTs (∑DDTs) ranged from ND to 8.51 ng g(-1), with a mean of 2.41 ng g(-1). For the various species of fish, the residual level of ∑HCHs was relatively higher in chub and grass carp and lowest in snakehead. The residual level of ∑DDTs was the highest in snakehead and did not exhibit a significant variance in the other three species. For the various tissues and organs, the contents of HCHs and DDTs were both highest in the fish liver, second highest in the fish gill, and lowest in the fish brain and muscle. Among the four types of isomers, the residual level of γ-HCH was relatively higher, while the residual level of α-HCH was the lowest. The content of p,p'-DDE was significantly greater to other forms of DDT and its isomer. The residual levels of HCHs and DDTs in fish were both below the national standard. However, the carcinogenic risk from the HCHs in parts of the tissue and organs of four fish species in Lake Baiyangdian exceeded the screen value threshold set by USEPA.

Uptake of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) by river water fish: the case of River Chenab

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were investigated in eleven edible fish species (5 herbivorous and 6 carnivorous) collected from the River Chenab, Pakistan, during 2007-2009. Total OCP and PCB concentrations (ng g(-1) wet weight, ww) ranged between 13-107 (mean: 38) and 3.1-93.7 (mean: 20) for five herbivorous fish species and 21.6-365 (mean: 148) and 2.5-108 (mean: 30) for six carnivorous species, respectively. The trends of detected organochlorine pesticides (OCPs) in fish samples were: DDTs>PCBs>chlordanes>HCHs. The mean concentration(s) (ng g(-1) ww) of OCPs were relatively higher in all fish species collected near industrial areas followed by urban and agricultural areas. Risk assessment of OCPs and PCBs indicated that fish intake may pose health risk to humans with a consumption rate of >8 g/person/day. The hazardous ratios for the 50th and 95th percentile data of OCPs and PCBs in fish exceeded the value of 1, suggesting that the daily exposure to OCPs and PCBs yield a lifetime cancer risk greater than 1 in 10,000.

Studies on organochlorine pesticide residue in fishes from the Densu river basin, Ghana

The study was carried out to determine the levels of organochlorine pesticide residue in five fish species Chrysichthys nigrodigitatus, Hepsetus odoe, Tilapia zilli, Heterotis niloticus and Oreochromis niloticus from the Densu river basin (Weija) in Ghana. The fishes sampled from the Weija fish landing site were selected on the basis of their importance to local human fish consumption. The detectable organochlorine pesticides were γ-Hexachlorocyclohexane (HCH), δ-Hexachlorocyclohexane, aldrin and dieldrin. Others investigated were alpha endosulfan, endosulfan sulfate, p,p'-DDT and its metabolite p,p'-DDE, endrin and its metabolite endrin aldehyde and endrin ketone. The total contamination levels of the individual fishes varied in the decreasing order of 9.19 ng g(-1) (O. niloticus), 4.16 ng g(-1) (T. zilli), 3.69 ng g(-1) (C. nigrodigitatus), 3.68 ng g(-1) (H. odoe) and 3.09 ng g(-1) (H. niloticus). The highest organochlorine pesticide residue recorded in the study was alpha-endosulfan while dieldrin was the least pesticide observed. Analysis of variance indicated significant statistical differences for most organochlorine pesticide residues in the samples. The levels of organochlorine pesticides found in fish samples in the study were below maximum residue limit for food safety stipulated by EU, US FDA, FAO, Italy and Australia and thus safe for human consumption.

The source of DDT and its metabolites contamination in Turkish agricultural soils

The concentration and impact of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)-ethane (DDT) and its metabolites (DDE: 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene) on the environment was expected to decrease after its ban in the mid-1980s. Unfortunately, DDT contamination via its presence as an impurity in dicofol (2,2,2-trichloro-1,1-bis(4-chlorophenyl)ethanol) has led to a new source of contamination. This is particularly true especially in cotton production in Söke Plain, Turkey, where difocol-based pesticides are being used. The aim of this research was to investigate the extent and source of DDT contamination in cotton soils. Söke Plain soil samples were collected from 0-30, 30-60, and 60-90-cm depth and analyzed by GC/MS/MS. o,p'-DDT and p, p'-DDE were detected at 16.2 % and 17.6 % of the sites in the 0-30-cm depth of soils. In the 30-60 cm, p, p'-DDT (14.9 %), o, p'-DDE (8.1 %) and p, p'-DDE (2.7 %) were found in soil samples, and p, p'-DDT was the most prevalent with 9.5 % of the sampling sites. The dominant source of DDT particularly in the 60-90-cm depth was due to historic use of DDT. The presence of p, p'-DDE, o, p'-DDE and p,p'-DDT in the topsoil was attributed to recent dicofol applications.

A review of endosulfan, dichlorvos, diazinon, and diuron--pesticides used in Jamaica

The global agricultural sector is the primary user of pesticides, consuming more than three billion kilograms of pesticides annually. Although pesticides are beneficial in controlling the proliferation of pests, they have been associated with adverse human and ecological impacts. Approximately 87% of the annually imported pesticides in Jamaica are applied within agricultural or household settings. However, in Jamaica, the potential impact on humans, their property, and the environment is unknown, as the fate of many of the locally applied pesticides has not been established. This review discusses four pesticides extensively applied in agricultural practices in Jamaica - endosulfan, diazinon, diuron, and dichlorvos. The information presented is essential for the development of fate and transport models of these chemicals. Consequently, health and ecological impact assessments may be conducted from the generated models.

Seasonal variation of organochlorine contaminants in bonito (Sarda sarda L. 1758) and anchovy (Engraulis encrasicolus L. 1758) in Black Sea region, Turkey

The concentrations of indicator polychlorinated biphenyls (PCBs) and organochlorine insecticides were determined in bonito (Sardasarda L. 1758) and anchovy (Engraulisencrasicolus L. 1758) from the Black Sea, Turkey. Concentrations of total indicator PCBs ranged between <1-17.0 in bonito, and <1-17.5 ng/g fresh weight in anchovy, and total of 1,1,1-trichloro-2,2-bis-chlorophenyl-ethane and its metabolites' (DDTs) concentrations ranged between 13.4-26.3, and 2.96-19.0 ng/g fresh weight in bonito and anchovy respectively. PCB 52, p,p'-DDE and endosulfan (α+β) were found dominant in both of the fish species. Except endosulfan, and some DDT metabolites, none of the studied organochlorine pesticides was detected in the fish samples. Concentrations of PCBs in anchovy were found higher than those in bonito, whereas DDT and endosulfan concentrations were found similar in both of the fish species. All of the fish samples had residue concentrations below the maximum residue limits (MRL) recommended by FAO/WHO Codex Alimentarius Commission.

Sampling-rate calibration for rapid and nonlethal monitoring of organic contaminants in fish muscle by solid-phase microextraction

Solid-phase microextraction (SPME) is a promising technique for determining organic contaminants within biotic systems. Existing in vivo SPME-kinetic calibration (SPME-KC) approaches are unwieldy due to the necessity of predetermining a distribution coefficient for the analyte of interest in the tissue and the preloading of a calibrating compound to the fiber. In this study, a rapid and convenient SPME alternative calibration method for in vivo analysis, termed SPME-sampling rate (SPME-SR) calibration, was developed and validated under both laboratory and field conditions to eliminate such presampling requirements. Briefly, the SPME probe is inserted into tissue, in this study fish dorsal-epaxial muscle, for 20 min allowing the concentrations of target analytes in the fish muscle to be determined by the extracted amount of analyte and the predetermined sampling rates. Atrazine, carbamazepine, and fluoxetine were detected nonlethally in the low ppb levels within fish muscle, with both laboratory and field-derived results obtained by in vivo SPME-KC comparable (within a factor of 1.27) to those obtained by lethal sampling followed by tissue liquid extraction. The technique described in this study represents an important advance which broadens the application of SPME in vivo sampling technology.

Biochemical effects induced by the hexachlorocyclohexanes

The hexachlorocyclohexanes (HCHs) are synthetic compounds that have been widely used for the control of pests. The most common HCH isomers are the α-, β-, δ-, and γ-HCH. Although the have the same chlorine substitution pattern, the spatial orientation of chlorine atoms is different on each one of them, resulting in unique structures that have distinct molecular properties. Humans are exposed to individual HCH isomers through various routes, including ingestion of contaminated water or food, absorbed through the skin or by inhalation, and because of their liposolubility, these chemicals are mostly stored in fat-containing tissues. The isomer-specific spectrum of biochemical actions for these compounds has been wee characterized for different endpoints such as enzyme activation, calcium homeostasis, gap junctional intercellular communication, endocrine disruption, and cancer, among others. The interaction with the GABA reception has been one of the most extensively studied properties of the HCHs. For instance, γ-HCH acts as a GABAA channel blocker, whereas α- and δ-HCH potentiate currents , all working as allosteric modulators of the receptor. The changes in calcium homeostasis elicited by HCHs are both isomer and cell type specific. For example, in neurons, both the δ- and γ-isomers of HCH stimulate Ca²+ influx through different voltage-gated Ca²+ channels. In human neutrophils, α-,δ-, and γ-HCH, but not β-HCH, increase intracellular Ca²+ concentrations. This isomer-dependent behavior is also similar to that observed for phospholipase A2 activation and also correlates with oxidative stress generation. On the other hand, there are several lines of evidence suggesting that HCHs alter genomic integrity, and, therefore, these compounds have been classified as possibly carcinogenic to humans . Finally, HCHs have been reported to be endocrine disrupters. In fact, γ- and β-HCH have been shown to have weak estrogenic activity, and together with the α- and the δ-isomer, also interfere with steroidogenesis. In short, the HCH isomers are good examples of structurally related chemicals, for which the geometrical patterns present in each one of the different conformers create structures that possess specific mechanisms of action and toxicological properties.

Herbicide contamination of live armclad rockfish, clam and pen shell by moss-control agents used in aquariums of seafood restaurants in Korea

Determination of simazine and diuron by high-performance liquid chromatography-ultraviolet detection (HPLC-UV) in moss-control agents, seawater and fish in aquariums was investigated and validated. The detection limits are 0.2 (simazine) and 0.4 µg l(-1) (diuron) in blank seawater, and 0.20 (simazine) and 0.30 µg kg(-1) (diuron) in blank fish homogenate, while the recoveries ranged from 93.9% to 102.4% with a relative standard deviation ≤ 9.8% for simazine and diuron. The method was successfully used in the study of simazine and diuron contamination in live fish stored in seafood restaurant aquaria in Korea. It was found that 0.4-2.3% of simazine and <0.10-3.8% of diuron were included the in moss-control agents tested. Of the 66 sampled aquarium seawaters, simazine was found to be present in four samples (3.8-42 µg l(-1)) while diuron was detected in two samples (1.3-1.6 µg l(-1)). For fish homogenates used in a bioconcentration study, simazine content ranges from 0.17 to 1.8 mg kg(-1).