Volatile compounds in flavor-tainted fish from the Upper Wisconsin River

Fillets from Walleye pike (Stizostedion vitreum) and Northern pike (Esox lucius) captured from the Upper Wisconsin River were analyzed for volatile components using simultaneous steam distillation-extraction and GC-MS techniques. Based on comparative odor assessments of eluting GC fractions and GC-MS analysis between control and tainted fish, trace amounts (ppb) of alkylphenols (2-isopropyl-, 4-isopropyl-, 2,4-diisopropyl-, 2,5-diisopropyl-, 2,6-diisopropyl-, 3,5-diisopropyl-, 5-methyl-2-isopropyl-, and 2-methyl-5-isopropyl-) and thiophenol were identified as the principal contributors to flavor-tainting found in fish during the spring of the year. Geosmin and 2-methylisoborneol were major contributors to mustiness flavor-tainting occurring in fish captured in the late summer and were more abundant in downstream fish than in upstream control fish.     

Effect of pesticide use in fruit production orchards on shallow ground water

As a part of landscape-scale study, ground water samples were collected from 30 wells located in fruit production farms belonging to the valley of Neuquen river during the period 1995-1998 and analyzed for organophosphate pesticides. As a consequence of the leaching process, ground water from the Valley of Neuquen River frequently contained concentrations of organophosphorus pesticides that exceeded acute toxicity risk ratios established to protect aquatic life. It was found that some pesticides, as azinphos methyl, had a high detection frequency, 66% of the samples, with concentrations varying from no detection to 48.9 ppb. Dimethoate, metidathion and phosmet were also detected with frequencies of 14.1, 13.6 and 10.8% and with concentration ranks from no detection to a maximum value of 10.9, 2.0 and 15.5 ppb, respectively. Seasonal variations and temporal trends were found for these compounds in ground water.     

EROD induction and PCDD/F levels in fish liver from the Biobio River in Chile

The Biobio River basin, located in central Chile, is one of the most important freshwater resources for a population of 1 million inhabitants. The river receives discharges of pulp mills, sewage treatment plants and there is a diffuse input of materials coming from the drainage basin. Previous studies reported high levels of etoxyresorufin-O-deethylase (EROD) induction in fish from the lower stretch of the river, mainly due to polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) exposure. The present study investigates polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzo-furans (PCDFs) levels as well as EROD induction in fish livers from Central Chile's Biobio River. Dioxin and furan levels in fish livers are reported for the first time in three areas of the Basin. In all samples the highest concentrations were found for the octachlorodibenzo-p-dioxin (OCDD) and PCDD/F TEQ concentrations ranged from 2.83 to 6.33 ppt (wet weight). The results indicate a clear induction of EROD activity in different fish species as the river mouth is approached, although this induction is not clearly related with dioxin and furan levels found in the fish livers. Our results clearly show that other pollutants might be acting as EROD inductors in the Biobio Basin.     

A method for quantitative analysis of flavor-tainting alkylphenols and aromatic thiols in fish

Simultaneous steam distillation-extraction (SDE) of fortified rainbow trout tissue resulted in greater than 95% recovery of 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol, 2,4-diisopropylphenol, 2,5-diisopropylphenol, 3,5-diisopropylphenol, carvacrol and thymol. Lower recoveries were obtained for 2,6-diisopropylphenol (81%), thiophenol (55%), and thiocresol (85%). Analysis of concentrated extracts by gas chromatography/mass spectrometry operated in the selected ion monitoring mode allowed quantitative detection of these compounds down to 0.5 ppb based on 20 g of initial sample.     

Uptake and enantioselective elimination of chlordane compounds by common carp (Cyprinus carpio, L.)

An analytical method involving supercritical fluid extraction (SFE) followed by a two-dimensional gas chromatography (2D-GC) analysis was developed to determine the concentration (first GC) and enantiomeric ratio (second GC) of cis- and trans-chlordanes at the ppb (ng/g) level in fish tissue. The SFE method allowed concentration of the compounds of interest, and reduced the number of extraction and sample clean-up manipulations as compared to classical solvent extraction techniques. Four hundred common carp fingerling (Cyprinus carpio, L.) were exposed for three days to water containing 5 ppb (5 ng/g) technical grade chlordane containing about 1 ppb of chlordane isomers. The fish concentrated the pesticides more than 200 times (162 and 312 ng/g of cis- and trans-chlordane, respectively). However, the uptake is not enantioselective. The concentration of the principle constituents and their enantiomeric ratio was followed during a fifty days growth period in chlordane free water. The first order decay of concentration was observed with a half time of about 18 days for both the cis- and trans-chlordane isomers. However it was found that the enantiomeric ratio of the trans-chlordane was significantly altered during this short period of time, decreasing from ER=1 to ER=0.7, while no enantiomeric changes were observed for the cis-chlordane. It seems that the (-)-trans-chlordane is metabolized significantly faster (t(1/2-)=15 days) in the river carp fish than the (+)-trans-enantiomer (t(1/2+)=20 days).     

The occurrence of xenoestrogens in the Elbe river and the North Sea

The xenoestrogens Bisphenol A (BPA), p-alkylphenols and p-alkylphenol ethoxylates were determined in water samples of the North Sea, the Elbe river, and its tributaries Schwarze Elster, Mulde, Saale and the Weisse Elster. The sampling sites of the Elbe river reached from Schmilka at the German-Czech border to Cuxhaven at the estuary. Samples of the North Sea were taken in the German Bight. Additionally, freshly deposed sediments of the River Elbe and its tributaries were analyzed. Partitioning coefficients of these compounds for the distribution between suspended particulate matter (SPM) and the aqueous phase were calculated for samples of the River Elbe at sampling site Geesthacht. The analytical procedure consisted of liquid-liquid extractions of the acidified water samples using dichloromethane. Sediments and SPM samples were extracted by Accelerated Solvent Extraction with n-hexane/acetone. Following a clean-up by HPLC, the analytes were derivatized with heptafluorobutyric acid anhydride and quantified using GC-MSD. The concentration ranges of the compounds analyzed in water samples of the Elbe river were as follows (in ng l(-1)): BPA 9-776, alkylphenols 10-221 and alkylphenol ethoxylates 18-302. In sediment samples the concentrations were (in microg kg(-1) dry mass): BPA 66-343, alkylphenols 17-1378 and alkylphenol ethoxylates 30-1797. In samples of the North Sea the concentrations were generally about 1 order of magnitude lower. As shown by the concentration profiles following the River Elbe into the North Sea, the Elbe river must be considered as a major pollution source for the North Sea concerning the compounds analyzed. The SPM/water-partitioning coefficients calculated (mean values) amounted to: BPA 4.50, alkylphenols 5.52-5.58 and alkylphenol ethoxylates 5.60-6.38. A comparison of the results with data from other surface waters showed that concentrations of these xenoestrogens in the River Elbe and its tributaries were relatively low. The evaluation of the data based on the lowest observable effect concentration (LOEC) for alkylphenols (endpoint: vitellogenin synthesis in male trout) indicated that the concentrations were well below the effectivity threshold.     

Organic mercury levels among the Yanomama of the Brazilian Amazon Basin

The Catrimani River basin in northern Brazil is the home of the Yanomama and has been the site of renegade gold mining since 1980. Gold-mining operations release inorganic mercury (Hg) into the environment where it is organified and biomagnified in aquatic ecosystems. Ingestion of mercury-contaminated fish poses a potential hazard to fish-eating populations such as the Yanomama. We surveyed Hg levels in Yanomama villagers living near mined and unmined rivers in 1994 and 1995, and analyzed Hg levels in piranha caught by villagers. In 1994, 90 Yanomama Indians from 5 villages and in 1995, 62 Yanomama Indians from 3 villages participated in the studies. Four villages surveyed in 1994 were located directly on the Catrimani River, approximately 140-160 km downstream from past gold-mining activities. The other village surveyed in 1994 was situated on the unmined Ajaraní River. In 1995, 2 of the Catrimani River villages were revisited, and a third Yanomama village, on the unmined Pacu River, was surveyed. Blood organic mercury levels among all villagers surveyed ranged from 0 to 62.6 microg L(-1) (mean levels in each village between 21.2 microg L(-1) and 43.1 microg L(-1)). Mercury levels in piranha from the mined Catrimani River ranged from 235 to 1084 parts per billion (ppb). Nine of 13 piranhas, measuring 30 cm or longer had total mercury levels which exceeded mercury consumption limits (500 ppb) set by both the World Health Organization and the Brazilian Ministry of Health. Unexpectedly, high mercury levels were also observed in fish and villagers along the unmined Ajaraní and Pacu Rivers suggesting that indirect sources may contribute to environmental mercury contamination in the Amazon basin.     

Levels and distribution of DDT in the Cinca River (Spain).

The evolution over time of the levels and distribution of dichlorodiphenyltrichloroethane (DDT) in water, surface sediments, and fish from the River Cinca (Spain), a tributary of the River Ebro, during the period 1999 to 2004, was investigated by means of gas chromatography coupled with mass spectrometry. The sampling site corresponded to a point downstream from Monzón, a heavily industrialized town with drainage into the river. This river has historically been a source of emissions of DDT and its metabolites. The highest levels were found in 1999 and 2000, although the concentrations of organic compounds in sediments and fish have decreased since then. The levels of DDT in water were below the quantification limit during the period of study. The average composition of DDT isomers measured in sediments and fish showed the prevalence of p,p'-DDE, the product of aerobic degradation of p,p'-DDT. Concentrations in fish were compared with sediment samples, and high quotients indicate that they are highly bioavailable.     

Search for chlorobornanes in river sediments and in influents and effluents

In 1997, we collected nine river sediment samples, including one duplicate, from above and below three pulp and paper mills on the Wisconsin River in Wisconsin, USA, and one mill on Beaver Dam Creek in Ontario, Canada. We also obtained twenty split sediment samples from the Wisconsin River that were collected by the US EPA in collaboration with Indiana University. Finally, we collected influent and effluent samples from eight pulp and paper related industries in the US and Canada. We analyzed all sediment and water samples for hexa- through decachlorobornanes. We did not detect any chlorobornanes in most of the sediments. When chlorobornanes were detected, the concentration in sediments below pulp mills were similar to or less than in those from above the same mills. Chlorobornanes could not be detected in any of the influent or effluent samples. Thus, pulp and paper mills and relate facilities are not a source of chlorobornanes.     

Pesticide and PCB levels in fish from Alberta (Canada)

Pesticide and PCB analyses were completed on fat and muscle samples of 750 fish collected from 11 major lakes and rivers in Alberta. Although phenoxy and organophosphate residues were always below detectable limits, traces of chlorinated pesticides and their derivatives, particularly DDE, DDD and chlordane, were detected in most fat samples. Methoxychlor was frequently found in goldeye from the North Saskatchewan River but not recorded in fish from any other lake or river. Its presence in goldeye, a highly migratory species, was probably a result of biting-fly control programs in the Saskatchewan part of the river. PCB levels exceeded 25 mg/kg in the fat of several species from the North Saskatchewan River but were generally lower in the other systems. Analysis of 160 sediment samples from the North Saskatchewan River revealed no point source of PCB contamination, with residues always <0.01 mg/kg dry weight.     

The flame retardant tetrabromobisphenol-A and its metabolite found in river and marine sediments in Japan

Tetrabromobisphenol-A (TBBP), used as a flame retardant, was detected in river sediments collected in Osaka, Japan, at a concentration range from 22 to 140 μg/kg (ppb), as determined on a dry weight basis. TBBP was also found in marine sediments collected at Osaka Bay, though the TBBP levels of these samples were much lower than those from river sediments. Dimethyl ether derivative of TBBP (TBBP-DM), thought to be a decomposition product from microbial methylation, was found in the river sediments but in none of the marine sediments. TBBP-DM residues were about one-hundredth of the TBBP levels.     

Residues of organochlorine pesticides in environmental samples from the Shatt al-Arab River, Iraq

Application of high resolution gas chromatography has confirmed relatively low residue levels of sumDDT, endrin and dieldrin in the Shatt al-Arab River. Thus, average concentration of these compounds in the edible portion of the cyprinid (Barbus xanthopetrus) were 21, 4 and 2 microg kg(-1) wet weight respectively. Mean values of sumDDT, endrin and dieldrin in surface sediments were 5, 40 and 20 microg kg(-1) dry weight respectively. Shrimps sampled from the Shatt al-Arab River were found to contain residues of o, p'-DDD only (average concentration was 2 microg kg(-1) wet weight). However, comparison of these samples with those from an area affected directly by a point source of organochlorine pesticides has shown that the cyprinid of the same age group contained significantly higher residue levels (average concentrations of sumDDT, endrin and dieldrin were 166, 20 and 7 microg kg(-1) wet weight respectively). Thus, it may be concluded that there was no direct input of organochlorine pesticides to the Shatt al-Arab River, and transportation via the natural processes, such as drainage, appeared to be the sole source. Based upon the observation that the original compound (p,p'-DDT) has not been detected in this river, it has also been concluded that there was no recent contribution of DDT here. Relatively higher residue levels of sumDDT, endrin and dieldrin were encountered in the muscles of the Indian shad captured from the Shatt al-Arab River (average concentrations were 163, 80 and 28 microg kg(-1) wet weight respectively). However, these elevated values were attributed to this fish being migratory and it being exposed to these pesticides elsewhere.     

Brominated flame retardants in Alburnus alburnus from Cinca River Basin (Spain)

Thirty-two bleak fish (Alburnus alburnus) from three places along the Spanish River Cinca, a tributary of Ebro River, were collected for polybrominated diphenyl ether (PBDE) and hexabromocyclododecane (HBCD) determinations. Sampling sites corresponded to up- and downstream from Monzon, a heavily industrialized town draining to the river. Four different PBDE congeners (BDE-47, -153, -154 and -183) and HBCD were found at levels ranging from not detected (nd) to 573 ng/g wet weight for total PBDEs and from nd to 1643 ng/g wet weight for HBCD. The lowest values were found upstream of the industrialized area. Concentrations in fish were compared with previous data in sediment samples collected at the same sampling sites, and large fish to sediment ratios for these brominated compounds indicate that they are highly bioavailable. Moreover, PBDE and HBCD concentrations are correlated with fish length and weight indicating the bioaccumulation of these contaminants.     

Mercury assessment and evaluation of its impact on fish in the Cecina river basin (Tuscany, Italy)

This paper reports the results of mercury contamination monitoring in the Cecina river basin (Tuscany, Italy). Mercury was measured in the waters, sediments and fish species of the river and its most important tributaries. In fish specimens the organic form was also determined. The results showed high mercury levels in most of the samples analysed. Particularly high concentrations were found in the sediments of the S. Marta canal flowing into the Cecina, where a chlor-alkali plant discharges its wastes, and high levels were still detectable 31 km downstream from the confluence. Near the S. Marta confluence many fish specimens were very contaminated and a study on Leuciscus cephalus cabeda growth suggested that at this site mercury accumulation occurs in these organisms since they are very young.     

Distribution of alkylphenols in the Pearl River Delta and adjacent northern South China Sea, China

The occurrence of alkylphenols (APs) was investigated in surface water and sediments from the Pearl River Delta and adjacent northern South China Sea. Most of the water samples contained detectable amounts of APs, ranging up to 0.628 microg l(-1) for nonylphenol (NP) and 0.068 microg l(-1) for octylphenol (OP). APs were found in all of the sediment samples with concentrations ranging from 59 to 7808 microg kg(-1) for NP and from 1 to 93 microg kg(-1) for OP. The Zhujiang River showed the highest concentrations of APs in both water and sediments. Significant decrease of APs concentrations going from the Zhujiang River to the Shiziyang River was observed. The Xijiang River contained concentrations of APs slightly higher in water but relatively lower in sediments than the Lingding Bay, which might be attributed to their different hydrodynamic and sedimentary characteristics. There was a decreasing trend of APs in water from the rivers to the estuary and further to the sea on the whole. In the Lingding Bay and its outer waters, concentrations of APs in sediments increased to a maximum and then decrease seaward, which was consistent with the distribution trend of the sediment organic carbon contents. Linear regression analyses showed the concentrations of APs were markedly correlated with the sediment organic carbon contents, indicating that the sediment organic carbon is an important factor controlling the levels of APs in sediments.     

Organochlorine and mercury contamination in fish tissues from the River Nestos, Greece

Polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) isomers, dichlorodiphenyltrichloroethane (DDT) and its metabolites, other organochlorine pesticides such as hexachlorobenzene (HCB), chlordane compounds (CHLs, including trans-chlordane and cis- and trans-nonachlor) and the heavy metal mercury were quantified in muscle and liver of the European chub (Leuciscus cephalus, Linnaeus, 1758) and in the muscle of the barbel (Barbus cyclolepis, Heckel, 1837) at two sampling sites of the River Nestos, Greece. PCBs in muscle and DDTs in the liver tissues were the predominant organochlorinated contaminants. Among the PCBs, congeners 47 (up to 9.60 ng g(-1) wet wt.), 180 (up to 1.15 ng g(-1) wet wt.) and 190 (up to 1.50 ng g(-1) wet wt.) were the most frequent and abundant. The contamination degree by the sum of PCBs on the fish tissue samples from the River Nestos is lower or similar to PCB levels found in other ecosystems. Among the organochlorine pesticides, essentially only p,p'-DDD, p,p'-DDE and alpha-, beta- and gamma-HCH were found, with the former appearing at mean levels up to 30.71 ng g(-1) wet wt. From a public health standpoint, residue organochlorine pesticide levels from our work are considerably lower than the recommended tolerance limits. Finally, mean values of Hg in chub were significant lower (up to 31.04 ng g(-1) wet wt.) compared to those detected on barbel (up to 169.27 ng g(-1) wet wt.). The concentrations of Hg in fresh water fish from the River Nestos did not exceed WHO and US EPA health guidelines, and were suitable for human consumption.     

Polychlorinated dibenzo-p-dioxins and dibenzofurans in commercial diphenyl ether herbicides,and in freshwater fish collected from the application area

This paper describes the analyses of polychlorinated dibenzodioxins, dibenzofurans, and related compounds in diphenyl ether herbicides, CNP, NIP, and X-52. The levels of tetra-, penta-CDDs, and tetra-CDFs were about 150, 30, and 15 ppm, respectively in CNP formulations. NIP and X-52 contained lower chlorine alalogs. Isomer distribution of PCDDs in CNP agreed with an estimate from the reaction of chlorophenols. Freshwater fish samples heavily contaminated with CNP in the application season also contained 0.2 ppb of 1,3,6,8-tetra-CDD.     

Health risk assessment of heavy metals in Cyprinus carpio (Cyprinidae) from the upper Mekong River

The purposes of this research are to quantify the concentration of heavy metals (Zn, Cu, As, Pb, Cd, and Hg) in the water and fish tissues of common carp (Cyprinus carpio) in the upper Mekong River and to thereby elucidate the potential dietary health risks from fish consumption of local residents. Surface water and fish tissues (gill, muscle, liver, and intestine) from four representative sample areas (influence by a cascade of four dams) along the river were analyzed for heavy metal concentrations. Results revealed that the levels of heavy metals in fish were tissue-dependent. The highest Cu and As levels were found in the liver; the highest Zn and Pb levels occurred in the intestine, and the highest Hg level was found in the muscle. The total target hazard quotient (THQ) value for residents is > 1 for long-term fish consumption, and local residents are, therefore, exposed to a significant health risk. Results from the current study provide an overall understanding of the spatial and tissue distribution of heavy metals in water and fish body along the upper Mekong River under the influence of cascade dams and highlight the potential health risk of As for the local residents of long-term fish consumption.

     

Pesticides residues in the Prochilodus costatus (Valenciennes, 1850) fish caught in the São Francisco River,Brazil

The objective of this study was to determine the levels of pesticides in the fish Prochilodus costatus caught in São Francisco River, one of most important rivers in Brazil. Thirty-six fish were captured in three different areas, and samples of the dorsal muscle and pooled viscera were collected for toxicological analysis. We evaluated the presence of 150 different classes of insecticides, fungicides, herbicides and acaricides by multiresidue analysis technique using liquid chromatography-tandem mass spectrometry (LC-MS/MS), with the limit of detection of 5 ppb. In this study, organophosphorus and carbamate pesticides were detected at the highest levels in the caught fish. Among the 41 organophosphorus pesticides surveyed, nine types were detected (chlorpyrifos, diazinon, dichlorvos, disulfoton, ethion, etrimfos, phosalone, phosmet and pyrazophos) in the muscle, viscera pool, or both in 22 (61.1%) fish. Sampled tissues of 20 (55.6%) fish exhibited at least one of the eight evaluated carbamate pesticides and their metabolites: aldicarb, aldicarb sulfoxide, carbaryl, carbofuran, carbosulfan, furathiocarb, methomyl and propoxur. Fungicides (carbendazim, benalaxyl, kresoxim-methyl, trifloxystrobin, pyraclostrobin and its metabolite BF 500 pyraclostrobin), herbicides (pyridate and fluasifop p-butyl), acaricide (propargite) and pyrethroid (flumethrin) were also detected. In conclusion, P. costatus fish caught in the São Francisco River contained residues of 17 different pesticides, in both muscles and the viscera pool, indicating heavy environmental contamination by pesticides in the study area.     

Bioavailability of PAHs in the Biobio river (Chile): MFO activity and biliary fluorescence in juvenile Oncorhynchus mykiss.

Cytochrome P450-dependent monooxygenase (MFO) activity and levels of bile PAH metabolites were measured in fish (Oncorhynchus mykiss) exposed to Biobio river (Chile) water. Experiments were performed simultaneously in both the field and laboratory to investigate whether the river water contained notable bioavailable PAH fractions. The field experiment was conducted using fish caged for 41 days at La Mochita (Biobio river mouth) whereas the laboratory experiment involved a 21-day exposure treatment with water collected in the same area. Induction of hepatic MFO, assayed by benzo(a)pyrene monooxygenase activity (BaPMO), and levels of PAH metabolites in the bile were measured in groups of eight (field experiment) and four specimens (laboratory experiment) sampled after 5, 10, 21 and 41 days of exposure. BaPMO was induced by a factor of 23 and 25 in fish caged for 21 and 41 days, respectively. Likewise, a significant BaPMO induction was found in the fish group experimentally exposed to river water for 21 days. Biliary fluorescence measurements, recorded by fixed wavelength fluorescence (FF) and synchronous fluorescence spectroscopy (SFS), revealed significantly high levels of PAH metabolites in bile samples of fish caged for 21 and 41 days. A positive relationship was found between BaPMO activity and biliary PAH metabolites. This study provides evidences that (i) Biobio river water contains a significant bioavailable PAH fraction in terms of marked effects on fish and (ii) the biological indicators MFO activity and bile PAH metabolites represent an excellent screening methodology to assess PAH exposure.