Effects of DDT and DDE on placental cholinergic receptors.

The placental cholinergic system; known as an important factor in intracellular metabolic activities, regulation of placental vascular tone, placental development, and neurotransmission; can be affected by persistent organic pesticides, particularly organochlorine pesticides(OCPs), which can influence various epigenetic regulations and molecular pathways. Although OCPs are legally prohibited, trace amounts of the persistent dichlorodiphenyltrichloroethane(DDT) are still found in the environment, making prenatal exposure inevitable. In this study, the effects of 2,4'-DDT and 4,4'-DDT; and its breakdown product 4,4'-DDE in the environment on placental cholinergic system were evaluated with regards to cholinergic genes. 40 human placentas were screened, where 42,50% (17 samples) were found to be positive for the tested compounds. Average concentrations were 10.44 µg/kg; 15.07 µg/kg and 189,42 µg/kg for 4,4'-DDE; 2,4'-DDT and 4,4'-DDT respectively. RNA-Seq results revealed 2396 differentially expressed genes in positive samples; while an increase in CHRM1,CHRNA1,CHRNG and CHRNA2 genes at 1.28, 1.49, 1.59 and 0.4 fold change were found(p<0028). The increase for CHRM1 was also confirmed in tissue samples with immunohistochemistry. In vitro assays using HTR8/SVneo cells; revealed an increase in mRNA expression of CHRM1, CHRM3 and CHRN1 in DDT and DDE treated groups; which was also confirmed through western blot assays. An increase in the expression of CHRM1,CHRNA1, CHRNG(p<0001) and CHRNA2(p<0,05) were found from the OCPs exposed and non exposed groups.The present study reveals that intrauterine exposure to DDT affects the placental cholinergic system mainly through increased expression of muscarinic receptors. This increase in receptor expression is expected to enhance the sensitivity of the placental cholinergic system to acetylcholine.

Live in same region, respond differently: Canine and human response to pollutants in placental accumulation.

Polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs) are endocrine-disrupting chemicals (EDCs). Their presence in the environment is particularly concerning in cases of fetal exposure, which is the most vulnerable period of life for both human and animals who share the same environment. Placenta, as a sample collected using noninvasive methods to screen EDCs, is a good indicator for potential fetal exposure. Although recent studies indicate that companion animal may correspond to human exposure, species-specific anatomo-morphological and metabolic differences are controversial. In this study, placenta samples of 60 women and 25 dogs living and giving birth within the same region were evaluated for the presence of PCB, OCP, PBDE, and PAH residues; where, socio-demographic factors were also assessed to identify the possible sources. Gas chromatography-mass spectrometry method was validated for the matrix, and among 45 screened and targeted pollutants, only 18 were found in human placentas. While the most frequently detected pollutants were DDTs, followed by PAHs and PCBs in decreasing order, the pollutants with the highest concentrations were PAHs, followed by PCBs and DDTs. Only five of the target contaminants were detected in the dog placentas. These results indicate that; as dogs have different bioaccumulation capacities and higher excretion rates than humans, the life-long effects of exposure to endocrine compound and possible consequences related to adverse health outcomes are expected to vary and concentrations cannot be directly correlated.

Diethylhexyl Phthalate and Bisphenol A Promote Vincristine and Tamoxifen Resistance in Vitro.

Environmental estrogen active compounds are strong determinants of estrogen receptor (ER)-positive breast cancers, and increased evidence indicates their contribution to chemotherapy resistance. In the current study, the efficacy of vincristine and tamoxifen, with the presence of diethylhexyl phthalate (DEHP) and bisphenol A (BPA) and the possible involvement of estrogen and estrogen receptor-related mechanisms, was evaluated in an ER+ mammary tumor cancer cell line, MCF-7. Chemotherapeutics tamoxifen as an estrogen receptor modulator and vincristine as an antimitotic compound were selected for evaluation against the presence of common endocrine disrupters. BPA and DEHP preincubation at their proliferative concentrations for 4 h was found to decrease the cytotoxicity of vincristine. mRNA and protein expression of ESR1 and ESR 2 were decreased by vincristine, while this decrease was reversed by DEHP and BPA. Both BPA and DEHP were able to interfere with the cytotoxic activity of vincristine against MCF-7 cells through ESR1 and ESR2. This study provides in vitro toxicological evidence for vincristine resistance and its relation to estrogen active environmental pollutants in ER+ breast cancer cells.

Effects of electrospun fiber curcumin on bisphenol A exposed Caco-2 cells.

Curcumin; the major polyphenolic compound, isolated from Curcuma longa L.; loaded polyvinylpyrrolidone K90 fibers were prepared using electrospinning method. Effectiveness was tested on human colorectal adenocarcinoma cells with the presence of the endocrine disrupter Bisphenol A. Curcumin-loaded fibers were shown to have good physicochemical properties where excellent morphology of the electrospin fibers were formed. With the presence of 8 nM Bisphenol A, 17.37 mM fibers were found to inhibit proliferation in the cells in a dose-dependent manner. Fibers induced a significant increase in malondialdehyde by Thiobarbituric Acid Reactive Substances Assay compared to the control and this effect was supported by the presence of Bisphenol A. Western blot results indicate Super Oxide Dismutase-1 levels were increased by fiber, while Bisphenol A coincubated group resulted in a decrease. Fibers increased the expression of Estrogen Receptor 2, while Estrogen Receptor 1 expression did not change. Estrogen Receptor 2 expression was increased by coincubation with Bisphenol A; indicating a possible role of Estrogen Receptor 2 in the protective effects of fiber. This study presents that fiber had enhanced bioavailability and solubility with increased anticancer effect in human colon adenocarcinoma cells in presence of Bisphenol A; where involved mechanisms are antioxidant system and estrogen receptor expression.

Multiresidues of environmental contaminants in bats from Turkey.

Bat populations have been steadily declining, most likely because of anthropogenic factors. Identification and classification of these risks have crucial importance in ensuring the survival of this species. Bats often coexist with humans in urban, industrial, and agricultural areas and are potentially exposed to a range of environmental pollutants. Two bat species widely distributed in Turkey were selected, and the residues of pesticides and organic contaminants in their carcasses were analyzed using: gas chromatography-mass spectrometry, gas chromatography-tandem mass spectrometry, and liquid chromatography-tandem mass spectrometry. Species and sex specific differences were evaluated along with their potential to be used as bioindicators. During the rigor mortis period, 23 adult Pipistrellus pipistrellus (11 female and 12 male) and 19 adult Myotis myotis (9 female and 10 male) were collected and 322 contaminants (pesticides and organic contaminants) were analyzed in whole carcasses of bats by using a validated method. Multiple pesticides and organic contaminants were detected in all collected 42 bats. The most frequent contamination was detected as 4,4-DDE, followed by ethoprophos, quinalphos, methidation, paraoxon-methyl, phosalone and tetramethrin. The least common compounds were as follows: 2,4-DDD, endrin, HCH-alpha, fenamiphos sulfoxide, parathion ethyl, bitertanol, oxycarboxin, procymidone, fluazifop-butyl, trifluralin, bifenazate, DMF, fenpyroximate, PBDE-47, benzo(a)anthracene, benzo(b)fluoranthene, and benzo(g,h,i) perylene; of these only one was found in each bat. In terms of frequency and concentration, there was no significant difference between species and sex. An average of 26.1 pollutants was found in each bat. Thus, it was concluded that bats can be used as potential bioindicators in determining environmental pollution.

In vitro effects of erythromycin and florfenicol on primary cell lines of Unio crassus and Cyprinus carpio.

The ubiquitous use of antibiotics leads exposure of these chemicals on non-target aquatic species, while the toxicity assays for these chemicals are time/labor consuming and expensive. Alternative approaches using primary cell cultures which retain the tissue functionality at its highest form have received global attention compared to cell lines. In the current study, the cytotoxic effects of two commonly used antibiotics from amphenicol (florfenicol) and macrolide (erythromycin) groups were evaluated on primary cell cultures of Unio crassus (mantle, digestive gland, gill, and gonad) and Cyprinus carpio (gill and liver) using MTT and Neutral Red assays. The highest cytotoxic effects were found on the mussel digestive gland and carp liver cells for florfenicol and erythromycin, while the lowest cytotoxic effects were found in mussel mantle cells for both drugs in the MTT test. In the NR test, the highest cytotoxic effects of erythromycin and florfenicol were found in the mussel gill, mantle, gonad, and carp gill cells; the lowest cytotoxic effect of erythromycin was found in the mussel digestive gland, while the lowest effect of florfenicol was found in the carp liver cells. The cytotoxicity of florfenicol was quite low for the carp liver, while the cytotoxicity of erythromycin was quite low in the mussel digestive tract. Thus, it was concluded that cells made from mussel tissues could be used in ecotoxicity tests, and sensitivity may vary according to the tissue.

The determination of ß-agonist residues in bovine tissues using liquid chromatography-tandem mass spectrometry.

We aimed to develop a rapid, simple and reproducible method based on LC-tandem mass spectrometry (LC-MS/MS) to analyze ß-agonist residues (clenbuterol, zilpaterol, ractopamine and isoxsuprine) in bovine tissues. The method was validated in accordance with the European Council Decision 2002/657/EC. The samples were homogenized, and then 10 mL of an acetate buffer was added to a 5-g sample. The sample was then centrifuged at 12,000 rpm and filtered. Sodium hydroxide (2 m) was added to adjust pH of the sample that was centrifuged again. The extract was filtered through a solid-phase extraction column. The residue was re-dissolved in 250 µL acetonitrile and then subjected to LC-MS/MS. The separation was done on a C18 column. The mobile phase consisted of 0.1% formic acid in deionized water and 0.1% formic acid in methanol. The mean recoveries of ß-agonists were in the range of 84.3%-119.1% with relative standard deviations (%RSDs) of 0.683%-4.05%. Decision limits and detection capabilities of the analytes ranged from 0.0960 to 4.9349 µg/kg and from 0.0983 to 5.0715, respectively. This method was used to detect four ß-agonists in 100 bovine muscle, 100 liver and 100 kidney tissues from a slaughterhouse. No residue was found above the maximum residue limit level.

Companion animals get close to the toxic aspects of antropogenic world: cytotoxicity of phthalates and bisphenol A on dog testicular primary cells.

Phthalates, which are among the most abundant plasticizers, have detrimental effects on the reproductive system. Similar to human, dogs are prominently exposed to phthalates in daily routines at low concentrations; while toys, training devices and commercial dog foods are considered as the primary sources of exposure. This study aimed to reveal and compare the cytotoxic effects of selected phthalates (Benzyl butyl phthalate (BBP), Diethyl phthalate (DEP), Bis (2-ethylhexyl) phthalate (DEHP), Di-'isobutyl' phthalate (DIBP), Di-'isodecyl' phthalate (-DIDP) Di-'isononyl' phthalate (DINP), Dimethyl phthalate (DMP), Di-n-octyl phthalate (DNOP)), and Bisphenol A (BPA) following 24 h exposure on primary testicular parenchymal cells of dog in vitro at concentrations between 0.001 and 2.5 nM. According to cytotoxicity results, DEHP was found to be the most toxic phthalate with IC50 at 22.53 µM; while DMP was the least (169.17 nM). IC50 of BPA was 161.81 nM, less than the average (61.95 nM) of phthalates. In addition, dog primary testicular cells were found more susceptible to the high molecular weight phthalates (DNOP, DEHP, DINP, DIDP) than low molecular weight phthalates (DMP, DEP, DIBP, BBP). Further studies should focus on morphological, physiological and molecular differences to comprehend the mechanisms involved as well as decreasing the risk for impaired spermatogenesis caused by environmental toxicants in companion animal medicine.

The effects of heat applications on macrocyclic lactone-structured antiparasitic drug residues in cows' milk.

The study aimed to evaluate the effects of heat on macrocyclic lactone residues in cows' milk. Ivermectin, abamectin, doramectin, eprinomectin and moxidectin were added to raw milk in three concentrations. The milk was then pasteurised (40 seconds at 74°C or 1 minute at 80°C) and boiled (10 minutes at 100°C). The analyses were performed with a validated method: LC-MS/MS. Thermal treatment resulted in a statistically significant decrease in the abamectin, eprinomectin, and moxidectin concentrations in the milk; however, the residues did not completely degrade. Boiling resulted in a greater decrease in the moxidectin concentrations than was observed with pasteurisation. The high pasteurisation and boiling processes had a greater effect on the eprinomectin residues than did the low pasteurisation process. The pasteurisation and boiling processes did not have an effect on the doramectin and ivermectin. The study concluded that the macrocyclic lactones are generally resistant to such processes.

Determination of some element levels in various kinds of cow's milk processed in different ways.

This study aimed to measure zinc (Zn), selenium (Se), copper (Cu), iron (Fe), chromium (Cr), nickel (Ni), lead (Pb), cadmium (Cd), arsenic (As), and aluminum (Al) in whole, semi-skimmed, skimmed, organic, fruit-flavored (strawberry, banana, and cocoa), pasteurized, and raw cows' milk. The samples were collected from sterilized and pasteurized milk processed in different ways in Ankara; the milk was kept in refrigerated raw milk storage tanks on dairy farms. Ninety samples were collected, and there were ten samples in each group. Analyses were performed using inductively coupled plasma-mass spectrometry. Lead and Cd were not found in any samples, while Zn was observed in all samples. The element with the highest frequency of occurrence was Zn, followed by Cr = As> Al > Se > Fe > Ni > Cu > Pb = Cd, in decreasing order. The lowest concentration among the essential elements was seen in Cu. Aluminum and As were found in 85% and 94.45% of the samples, respectively. However, the present concentrations were below the level of a probable negative effect. It was found that the concentrations of elements in milk showed statistically significant differences, depending on the milk type. It is recommended that low-quality materials not be used in the preparation of milk; the element concentrations in milk and the feed and water consumed by animals should be controlled regularly, and the animals should not be pastured near industrial and traffic sites to protect public health.

Investigation of the Metal Pollution Sources in Lake Mogan, Ankara, Turkey.

It is important to investigate the monthly level of trace metals in freshwater systems to assess environmental health. This information can be used to support effective management and control of natural areas in regard to the introduction and bioavailability of chemicals in the aquatic environment. We aimed to determine monthly changes in the levels of aluminum (Al), arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), mercury (Hg), zinc (Zn), nickel (Ni), and selenium (Se) in water, sediment, and fish samples from Lake Mogan. Five different stations were established in Lake Mogan. Water and sediment samples as well as muscle, liver, kidney, gill, and brain tissues from fish were obtained from these stations every month for 1 year. All analyses were conducted with ICP-OES. In descending order of intensity, the metals identified in the water samples were Fe, Cu, Cr, Zn, Pb, Ni, As, Se, and Hg; those identified in the sediment samples were Fe, Zn, Cu, Ni, Se, Pb, Cr, As, Al, Cd, and Hg; and those identified in fish tissues were Se, Fe, Zn, Cr, Al, Pb, Cu, Ni, As, Hg, and Cd. The most polluted station was located where waste from restaurants and tea gardens were dumped. The level of waste, and thus the level of pollution, was especially high in August. It is concluded that the metals that accumulate in water, sediment, and fish in Lake Mogan originate from anthropogenic activities.

Determination of the Polychlorinated Biphenyls Distribution in Different Fat Tissues of Cattle by Age and Gender.

Polychlorinated biphenyls (PCBs), which cause environmental pollution, are found in animal-based fatty foods. Due to their long half-life and lipophilic properties, they can accumulate in the fat tissues of cattle. The study was conducted to compare the PCB levels (PCB28, 52, 101, 118, 138, 153, and 180) in the different fat tissues (muscle, liver, kidney, spinal cord, lung, back fat, perihepatic fat, and perirenal fat) of cattle by age and gender. This information is also useful to evaluate the exposure risks for different bovine edible tissues. Therefore, 15 female and 15 male cattle under 24 months of age and 15 female and 15 male cattle over 24 months of age were used, and 480 samples were analyzed for target PCBs using gas chromatography-mass spectrometry. Of all the samples, two (50.2 µg/kg in perihepatic fat and 51.1 µg/kg in kidney) were found above the maximum residue limit; these samples were taken from the animals in the elderly female group (over 24 months). There were more PCBs in cattle older than 2 years. Muscle, kidney, and perihepatic fat presented higher PCB concentrations than other tissues, and perirenal fat presented lower PCB concentrations than other tissues. PCB101, PCB153, and PCB138 were found to have the highest contribution to the PCB concentration. Thus, it is concluded that perihepatic fat, muscle, or kidney should be sampled, particularly in routine residue monitoring, and specifically analyzed for PCB101, PCB153, and PCB138.

Effects of phthalates on bovine primary testicular culture and spermatozoa.

Among environmental endocrine-active chemicals, phthalates, commonly known as plasticizers, disrupt the development of the male reproductive tract. In this study, the effects of phthalates (DIBP, BBP, DINP, DBP, DEP, DEHP and DMP) were evaluated on cultures of bovine primary male reproductive cells (n = 3) and spermatozoa (n = 4). Epididymal (caput and corpus epididymis), testicular (parenchymal and mediastinal/tubular) and vas deferens cells (VDC) were prepared from samples collected from slaughterhouse. Second part of caput epididymis which have fewer amount of principal cells, were found to be less affected compared to the first part except DEHP; while corpus epididymis was found to be more affected with IC50 values below 0.976 ng/mL (except for DEP at 4.97 ng/mL). In testicular parenchymal cells, IC50 ranged from 0.15 to 4.11 ng/mL and for mediastinum from 0.01 to 7.31 ng/mL; where cytotoxic effects were more evident in mediastinal section. Least cytotoxic and even proliferational effects (DEHP, DMP and DEP) were observed in VDC, the muscular tube carrying sperm from epididymis to the ejaculatory duct. Least spermiotoxic phthalate was DBP (3.928 ng/mL); while DINP (0.550 ng/mL) induced highest cytotoxic effect on bovine spermatozoa. Differences in the cellular structure and/or the androgen receptor distribution effect the toxicity of phthalates. Our preliminary findings on bovine spermatozoa indicate possible morphological and motility alterations; which challenges further investigation of the transition of phthalates on semen straws used in cryopreservation. Increase of exposure to environmental contaminants raise the issue of the requirement of a new perspective on reproductive health, species and tissue specific differences should further be emphasized.

Selected persistent organic pollutants levels in the Ankara River by months.

Persistent organic pollutants (POPs) are banned in almost all countries due to their adverse health effects while they are still present in the environment due to their persistence. As the dissipation and the emission factors of POPs change by temperature and other environmental factors current study aimed to determine selected POPs, including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (OCPs) in water and sediment samples collected from 12 stations located in Ankara River, Turkey, for 12 months. C-18 solid-phase extraction technique was used to extract organic pollutants and the analysis were performed using a validated gas chromatography-mass spectrometry method. DDE was the most frequently detected contaminant in water samples. Even though no PCB residues were present in water samples, PCB101 was the most common contaminant in sediment. Although both matrices had the least load of pollutants in winter, there was an increase in presence and concentration of pollutants from late spring to autumn.

Herbal Bioenhancers in Veterinary Phytomedicine.

Herbal bioenhancers are active phytomolecules that increase the bioavailability, bioefficacy and biological activity of various drugs when coadministered at low concentrations. These valuable compounds reduce the dose, increase the treatment rate, decrease the treatment duration, drug resistance or related adverse reactions which have economical implications in livestock and pet medicine. Eventhough the concept of herbal bioenhancers are known for years through Ayurvedic medicine, the underlying mechanisms remains unclear. The main mechanisms involved are related to drug absorption (effect on solubility, drug efflux and transport proteins, increased permeability in gastrointestinal system) and drug metabolism (inhibition/induction of drug metabolysing enzymes, thermogenic effect). Due to species specific differences in these mechanisms, corresponding data on human and laboratory animal could not be attributed. As multidrug resistance is a major treat to both human and animal health, within "One Health" concept, efficient therapeutical strategies are encouraged by authorities, where focus on herbal supplements as a vast unexploited field remains to be researched within "Bioenhancement Concept." This review brings insight to mechanims involved in bioenhancing effect, examples of herbal extracts and phytoactive compounds and their potential in the veterinary medicine including different classes of drugs such as antibiotics, anticancerous, antiviral, and antituberculosis.

Determination of selected endocrine disruptors in organic, free-range, and battery-produced hen eggs and risk assessment.

An increasing amount of evidence suggests that phthalic acid esters (PAE), polychlorinated biphenyls (PCB), polybrominated diphenyl ethers (PBDE), and organochlorine pesticides (OCP) are related to mutagenic, carcinogenic, and endocrine disruptor effects (EDCs). These lipophilic compounds are highly resistant to breakdown processes, and consequently remain in the environment, followed by uptake into the food chain. Human exposure to lipophilic compounds results from the consumption of food containing EDCs, mainly foodstuffs of animal origin with a high fat content, since these contaminants accumulate in fatty tissues. Foodstuffs in which EDCs can accumulate include meat, fish, eggs, and milk. We investigated the contamination in edible eggs to determine whether relative differences in the contaminants' residue levels appeared in three types of egg production (i.e., battery, free-range, and organic). The results showed that PAEs, especially dimethyl phthalate contamination, was the most abundant in the battery eggs, and the PCBs, PBDEs, and OCPs were the most abundant in the free-range eggs. The eggs were contaminated by more than one chemical, and as many as five contaminants (PCB180, PBDE47, dimethyl phthalate, diethyl phthalate, and di-n-butyl phthalate in battery eggs, and PCB138, PCB153, PCB180, diethyl phthalate, and di-2-ethylhexyl phthalate in organic eggs) were detected in the same egg. However, none of the chemicals detected were at the maximum limit of acceptable risk.

Measurement of selected polychlorinated biphenyls (PCBs) in water via ultrasound assisted emulsification-microextraction (USAEME) using low-density organic solvents.

Despite bans and restrictions for their adverse health effects including endocrine disruption, due to their stability in the environment, polychlorinated biphenyls (PCBs) are still of concern for their residues in several matrices. This study employed low-density ultrasound-assisted emulsification-microextraction (USAEME) to measure selected PCBs (28, 52, 101, 118, 138, 153, and 180) in water samples for gas chromatography-mass spectrometry analysis. Among tested solvents (isooctane, chloroform, hexane, and cyclohexane), 200 µL isooctane resulted in the highest yield for a 10 mL sample. The optimized method was validated and yielded recoveries of 87.29-92.83% with the limit of detection and limit of quantification (LOQ) values 3-12 ng/L and 10-40 ng/L, respectively. Twelve tap water samples collected in September 2014 were screened using this simple, rapid, and validated method. PCB concentrations in two samples were above the LOQ values; one sample contained 1,380 ng/L of PCB 118, 530 ng/L of PCB 138, and 152 ng/L of PCB 153, and the other contained 444 ng/L of PCB 138. Despite the city water supply being clean and the municipality employing all available measures to ensure clean water supply, the general public must be made aware of the regular maintenance of local water pipelines and storage tanks for the prevention of PCB contamination.

In Vitro Effects of Phthalate Mixtures on Colorectal Adenocarcinoma Cell Lines.

Among endocrine-disrupting chemicals, phthalates are an important concern because of their wide-spread exposure in humans and environmental contamination. Even though the use of some phthalates has been restricted for toys, some plastics, and food contact materials, exposure to the mixture of these contaminants at very low concentrations in various matrices are still being reported. In the current research, the effects of the mixture of some phthalates were studied. Di-n-butyl phthalate (DBP), n-butyl benzyl phthalate (BBP), di-2-ethylhexyl phthalate (DEHP), diisononyl phthalate (DiNP), di-n-octyl phthalate (DNOP), and diisodecyl phthalate (DiDP) were tested on two colorectal adenocarcinoma cell lines; DLD-1 and HT29 were studied as described before. Cells were treated with increasing log concentrations (0.33 ppt to 33.33 ppb) of the phthalate mixture; cell viability/proliferation was measured by MTT and staining with neutral red and crystal violet; lactate dehydrogenase (LDH) activity was measured following 24-h exposure. Cell viability/proliferation increased from phthalate treatment at concentrations less than 33.33 ppt. The phthalate mixture induced increases in HT29 proliferation of 10.94% at 33.33 ppt and 60.87% at 3.33 ppt, whereas this proliferation relation at lower concentrations was not found for DLD1 cells. The present study demonstrates preliminary information regarding the low dose induction of proliferation of the cancer cells by phthalate mixtures. Because non-monotonic dose responses are still being debated, further studies are required to re-evaluate the reference doses defined by governments for phthalates.

Metal concentrations in tissues of the Black Sea fish Mugil auratus from Sinop-Icliman, Turkey.

Levels of five heavy metals [copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr) and nickel (Ni)] were evaluated in liver and muscle tissues of fish (Mugil auratus) collected from the Black Sea at Sinop-Icliman, Turkey. Sampling and analysis methods are described. Variations of heavy metal concentrations with seasons are discussed. Cr and Ni concentrations were below the limits of detection (< 0.05 and 0.1 microg/g dry weight) in all tissues and seasons. Cu, Pb and Cd were detected within these limits, as microg/kg dry weight, in liver tissue: 0.49-1.30, 0.60-1.21 and 0.15-0.50, and in muscle tissue: 0.30-1.00, 0.57-1.12 and 0.10-0.40, respectively. Cu, Pb and Cd concentrations in these tissues were elevated and the highest heavy metal concentrations were found in the liver. While Cu, Pb and Cd concentrations were highest in fish tissues collected in August 2000, the lowest concentrations of these metals were observed in fish tissues collected in May 2000. Pb had the highest level observed in fish tissues. According to the Turkish Food Codex Regulation's residue limits, the cadmium level determined in fish tissues was high (0.1 microg/g) and the lead level, especially in liver tissue, was high in August (1 microg/g), while other metals (Cu, Cr and Ni) were within the maximum residue limits.