Occurrence of Glyphosate in Water Bodies Derived from Intensive Agriculture in a Tropical Region of Southern Mexico

Adiyaman city, which is located in the north of the Ataturk Dam Lake, has no wastewater purification facilities which results in municipal, agricultural, and industrial wastewater discharges directly entering the reservoir. To assess the pollution in the dam lake, we used several oxidative stress biomarkers in blood tissue of Cyprinus carpio. Fish samples were taken from Sitilce, polluted area by untreated wastewaters, and Samsat, relatively clean area, in the reservoir in August 2012. The activity of catalase and level of malondialdehyde increased while activity of superoxide dismutase and glutathione level decreased in fish from Sitilce site when compared to Samsat site. The findings of the present investigation suggest that the presence of certain prooxidative compounds that can lead to oxidative stress in the fish at the Sitilce site and oxidative stress biomarkers may be important in order to evaluate the effects of untreated wastewaters on living organisms in the dam lake.     

Risk Assessment and Toxic Effects of Metal Pollution in Two Cultured and Wild Fish Species from Highly Degraded Aquatic Habitats

Lake Qaroun is an inland lake at the lowest part of El-Fayoum depression, Egypt. It receives agricultural and domestic non-treated drainage waters, which are also used for aquaculture in Qaroun area. The results of the present study aimed to provide comparable data between wild (collected from Lake Qaroun) and cultured (collected from Qaroun fish farms and the reference site) Nile tilapia Oreochromis niloticus and mullet Mugil cephalus, as indicators of natural and anthropogenic impacts on aquatic ecosystem as well as to evaluate the human hazard index associated with fish consumption. Metal concentrations in fish tissues showed a species-specific bioaccumulation pattern. Statistically significant differences were observed in the mean metal concentrations with lower bioavailability in M. cephalus compared with O. niloticus in internal vital organs (liver, kidney, and muscle) but much higher in external organs (gill and skin). Histopathological alterations and evident damages were observed in gill, liver, and kidney of both species collected from Lake Qaroun and Qaroun fish farms compared with those from the reference site. The results showed significant increase of plasma aspartate aminotransferase and alanine aminotransferase activity as well as creatinine and uric acid concentration in both fish species from polluted locations. The human health hazard index showed that the cumulative risk greatly increases with increasing fish consumption rate, thus yielding an alarming concern for consumer health.     

Histopathological,hematological, condition-factor,and organ weight changes associated with selenium accumulation in fish from Belews Lake,North Carolina

Green sunfish (Lepomis cyanellus) were collected from two study sites in Belews Lake, North Carolina, for assessment of correlations between several biological parameters and bioaccumulation of selenium. The fish had elevated concentrations of selenium in the hepatopancreas (liver) and exhibited histopathological and other manifestations of selenium poisoning. Condition-factors of Belews Lake fish were significantly correlated with selenium concentrations in hepatopancreas and skeletal muscle, indicative of capillary permeability changes and resultant edema, supported by the occurrence of significantly increased hepatopancreas-weight-to-body weight ratios in the fish having the higher tissue selenium levels. Gill lamellae were noticeably swollen and vacuolated. Hematocrits of the selenium-contaminated fish were significantly lower than those of the reference fish. The hepatopancreas exhibited lymphocyte infiltration, vacuolation of parenchymal hepatocytes around the central veins, and increased numbers of Kupffer cells. The mesonephros exhibited focal intra-capillary proliferative glomerulonephritis. Hearts showed swollen, inflammatory cell-filled pericardial spaces, diagnosed as possible uremia-induced pericarditis. Ovaries in fish with the higher liver selenium levels exhibited numerous necrotic and ruptured egg follicles. These conditions were observed in the Belews Lake Site 2 fish, but did not occur in reference green sunfish, nor did they occur consistently in fish from the less-contaminated Belews Lake Site 1.     

Individual and Combined Effects of Heavy Metals on Serum Biochemistry of Nile Tilapia Oreochromis niloticus

Changes in serum biochemistry in response to single- and combined-metal exposure were studied in a freshwater fish Oreochromis niloticus. Fish were exposed to 5.0 mg/L Zn, 1.0 mg/L Cd, and 5.0 mg/L Zn+1.0 mg/L Cd mixtures for 7 and 14 days to determine levels of biochemical parameters and metals in blood serum. The individual and combined effects of metals caused an increase in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and in levels of albumin, transferrin, ceruloplasmin, cortisol, glucose, and total protein, whereas they caused a decrease in cholesterol levels. At both exposure periods, increased ALT activity of fish exposed to Cd was higher compared with the Zn and Zn+Cd groups, respectively. The decreased cholesterol level was higher in the Cd alone, and for Cd in combination with Zn, than in Zn alone at 14 days. Zn or Cd levels increased in the blood serum of fish exposed to metals individually or in combination. When fish were exposed to the mixtures of Zn+Cd, concentrations of these metals in their serum were lower than in fish exposed to individual metals. One metal blocks or even antagonizes the gill epithelium absorption of the other and thereby limits the distribution of the metal in blood. The results indicate that biochemical parameters in fish blood can be used as an indicator of heavy-metal toxicity.     

Assessment of Metals in Fish from Lake Macquarie, New South Wales, Australia

The concentrations of the metals cadmium, copper, mercury, lead, silver, selenium and zinc were measured in the muscle and gonad tissues of five species of fish, yellowfin bream (Acanthopagrus australis), silverbiddy (Gerres subfasciatus) and trumpeter whiting (Sillago maculata), southern log finned goby (Favonigobious lateralis), and the halfbridled goby (Arenigobius frenatus) from the contaminated Lake Macquarie NSW and three relatively uncontaminated reference estuaries, Wallis Lake, Port Stephens, and St. Georges Basin NSW. Fish from Lake Macquarie were found to have elevated concentrations of selenium, lead, cadmium, and zinc in one or both of these tissues in these species. Increased concentrations relative to background concentrations were most often observed at Cockle Bay, the site with the highest concentrations of these metals in sediments. The degree to which fish accumulated metals appeared to be related to life history characteristics of the species, with sediment-dwelling fish showing the greatest propensity to accumulate metals.     

High Hair and Urinary Mercury Levels of Fish Eaters in the Nonpolluted Environment of Papua New Guinea

Hair and mercury concentrations of 134 fish-eating subjects in the Lake Murray area and 13 non-fish-eating subjects in the upper-Strickland area, Papua New Guinea, were studied. Hair mercury levels among the subjects in the Lake Murray area (mean = 21.9 μg/g, range = 3.7–71.9 μg/g) and urinary mercury levels (mean = 7.6 μg/g creatinine, range = 1.4–25.6 μg/g creatinine) were markedly higher than levels found in subjects from the upper-Strickland area (mean hair mercury = 0.75 μg/g, mean urinary mercury = 0.48 μg/g creatinine). Mercury intake of the fish eaters, estimated from mercury concentrations found in fish and from the observed amounts of fish consumed, was approximately 73 μg/d. Hair and urinary mercury concentrations were correlated significantly (r = .59), indicating that urinary mercury excretion was elevated because fish consumption was very high.     

Mercury concentrations in fish from Lake Mead,USA, related to fish size,condition, trophic level,location, and consumption risk

Total mercury (Hg) concentrations were determined in the skeletal muscle of 339 fish collected during the fall of 1998 and spring of 1999 from Lake Mead, USA, the nation's largest human-made reservoir. Five species of fish representing a range of trophic levels and the lake's principal game fishes were studied. Hg generally increased with trophic level and fish size. Median Hg concentrations (ng/g wet mass) were 277 in striped bass, 168 in channel catfish, 160 in largemouth bass, 75 in bluegill, and 8 in blue tilapia. Overall, fish from Las Vegas Bay and Boulder Basin had the lowest Hg concentrations, possibly a result of biodilution in this biologically productive area. In general, fish-mercury advisories might include a warning about consuming fillet from emaciated fish, based on the finding that Hg concentrations in 59 striped bass (captured during a scarce-food season) correlated inversely (r = −0.89, p < 0.001) with a fish nutritional-status factor. This is consistent with starvation-concentration, whereby Hg in fish muscle is lost at a slower rate than the muscle mass. The median concentration found for 139 striped bass corresponds to a recommended risk-based consumption limit of three 8-oz. (227-g) meals per month for a 70-kg adult. Finally, this paper serves as a useful archive for future research and long-term studies of Hg in Lake Mead fish. Received: 13 September 2001/Accepted: 10 March 2002     

Oxidative Stress and Genotoxicity Biomarker Responses in Grey Mullet (<Emphasis Type="Italic">Mugil cephalus</Emphasis>) From a Polluted Environment in Saronikos Gulf,Greece

This study aimed to assess oxidative stress and genotoxicity biomarkers in grey mullet Mugil cephalus from a site receiving discharges from industrial and harbor activities and a reference site in Saronikos Gulf, Greece. Cellular antioxidant defenses, i.e., antioxidant enzyme activities (catalase, selenium [Se]-dependent glutathione peroxidase, glutathione-S-transferase) and oxidative damage, i.e., lipid peroxidation (measured as thiobarbituric acid reactive substances) were used as biomarkers of oxidative stress. The micronucleus test was used for evaluation of chromosome damage, and the frequency of cells with double nuclei was used as an indication of damage to cell divisions. Antioxidant enzyme activities were lower in fish from the polluted site compared with fish from the reference site, suggesting deficiency of the antioxidant system to compensate for oxidative stress. This is further supported by the higher lipid peroxidation levels in fish from the polluted site, which represent oxidative damage. Micronuclei and double-nuclei frequencies were higher in fish from the polluted site compared with fish from the reference site, indicating genotoxic effects. Correlations between biomarkers suggest that observed effects were due to contaminants exhibiting oxidative stress potential that can also induce genotoxicity. Results suggest that the selected biomarkers in M. cephalus are useful for the assessment of pollution impacts in coastal environments influenced by multiple pollution sources.     

Influence of Dioxin and Metal-Contaminated Sediment on Phase I and II Biotransformation Enzymes in Silver Crucian Carp

Several biochemical responses were measured in silver crucian carp (Carassius auratus gibelio) after exposure to sediments obtained from contaminated Ya-Er Lake, No. 1 pond, and an unpolluted reference site, Honglian Lake. After 1 week of exposure, a significant induction of the phase I biotransformation enzyme (ethoxylresorufin-o-deethylase, EROD) was found (83-fold of control), whereas the phase II biotransformation enzyme (glutathione S-transferase, GST) exhibited a slight, but significant induction (1.4-fold of control) after 4 weeks of exposure. The level of cellular glutathione in the liver was also slightly elevated after 4 weeks of exposure. The delayed response of GST to the contaminants indicates that the phase I and phase II biotransformation enzymes are regulated differently in fish. The results suggest that EROD is a sensitive bioindicator to assess the toxicity of dioxin-contamined sediment in the laboratory.     

Comparison of Organochlorine Pesticides,PCBs, and Heavy Metal Contamination and of Detoxifying Response in Tissues of <Emphasis Type="Italic">Ameiurus melas</Emphasis> from Corbara,Alviano, and Trasimeno Lakes,Italy

Accumulation of cadmium (Cd), mercury (Hg), lead (Pb), chromium (Cr), hexachlorobenzene, γ-HCH, DDTs, and PCBs has been investigated in the muscle of Ameiurus melas sampled during the same period from Lake Corbara, Alviano, and Trasimeno. Glutathione content and the enzymatic activities of glutathione reductase, glutathione peroxidase, catalase, glutathione S-transferase, and glyoxalase I were examined in gills, liver, and kidneys of each specimen. Catfish from Alviano, compared to those of Corbara and Trasimeno, showed the highest contamination of DDTs and PCBs and the lowest levels of biochemical parameters. Most likely, OCPs and PCBs content might be responsible for the compromised antioxidant status in these specimens.     

Heavy Metal Accumulation in Lake Sediments, Fish (Oreochromis niloticus and Serranochromis thumbergi), and Crayfish (Cherax quadricarinatus) in Lake Itezhi-tezhi and Lake Kariba, Zambia

We measured the level of heavy metal accumulation in lake sediments, herbivorous (Oreochromis niloticus) and carnivorous (Serranochromis thumbergi) fish, and crayfish (Cherax quadricarinatus) from Lake Itezhi-tezhi (ITT) and Lake Kariba. We used atomic absorption spectrophotometry to quantify the levels of seven heavy metals (Cr, Co, Cu, Zn, Cd, Pb, and Ni). The sediment and the herbivorous fish O. niloticus accumulated a very high concentration of Cu in Lake ITT, most likely due to the discharge of Cu waste from a mining area 450 km upstream. The aquatic species we sampled in Lake Kariba had higher concentrations of Cr, Ni, and Pb relative to those in Lake ITT. This is most likely due to anthropogenic activities, such as the use of leaded petrol and antifouling agents in marine paints. Interestingly, we observed a negative correlation between the coefficient of condition (K) and Ni concentration in the crayfish hepatopancreas. Both O. niloticus and the crayfish had much higher biota-sediment accumulation factors (BSAF) for Cu, Zn, and Cd relative to Cr, Co, Pb, and Ni. The rank of BSAF values for O. niloticus (Cu > Cd > Zn) and C. quadricarinatus (Zn > Cd > Cu) differed from the expected ranks based on the general order of affinity of metals (Cd >> Zn > Cu).     

Chronic Exposure and Decontamination of a Marine Sculpin (<Emphasis Type="Italic">Myoxocephalus scorpius</Emphasis>) to Polychlorinated Biphenyls Using Selected Body Indices,Blood Values,Histopathology, and Parasites as Bioindicators

This study was conducted to assess the health of a subtidal marine sculpin, Myoxocephalus scorpius, naturally exposed in a shipping terminal where polychlorinated biphenyls (PCBs) had been spilled, as well as that of others sculpins after decontamination in the laboratory for 16 weeks. Reference samples were captured at a pristine site upcurrent from the contaminated terminal. Examination of field samples caught by scuba divers showed external and toxicopathic lesions in several tissues; decreased body condition and organ indices; and decreased hemoglobin and lymphocyte levels. No difference in the diversity of parasites was observed between reference and contaminated samples, but abundance was generally greater in fish from the latter site. Although the total number of species of parasites decreased in both groups of depurated sculpins, the abundance of infections on gill and gall bladder was significantly greater in fish from the polluted site. These results suggest that M. scorpius was affected adversely by PCBs and that its responses are ecologically significant as a bioindicator species in degraded habitats. Moreover, remediation might not mitigate the observed anomalies in fish inhabiting the impacted site.     

Liver Cell Estrogen Receptor Binding in Prespawning Female Largemouth Bass, Micropterus salmoides, Environmentally Exposed to Polychlorinated Biphenyls

Estrogen-receptor–like binding was partially characterized in liver tissue of prespawning female largemouth bass, Micropterus salmoides (LMB). Saturation and Scatchard analyses exhibited estrogen binding activity with high affinity (K_d in the 10⁻⁹ M range) and limited capacity (nuclear = 37.4 fmol/g tissue; cytosol = 234 fmol/g tissue). Androgens, progestins, and cortisol competed poorly for binding in competition studies. Thus, LMB liver estrogen binding activity possesses similar properties to estrogen receptors (ER) described in other vertebrates. In a study of prespawning female LMB from Lake Hartwell, SC/GA, a reservoir contaminated by polychlorinated biphenyls (PCBs), individuals environmentally exposed to high levels of PCBs had significantly lower ER binding capacity (Bmax) and higher nonspecific binding (NS) than fish from a relatively uncontaminated reference location. Fish obtained at a site with intermediate levels of PCBs did not exhibit the expected decrease in Bmax. The lower Bmax observed in fish from the location with high PCB contamination is consistent with the reported behavior of liver ER in fish experimentally exposed to PCBs. Increased NS in the ER assays could be related to elevations in albumin associated with the PCB exposure. Received: 15 July 1996/Revised: 17 September 1996     

Chlorinated Hydrocarbons and Biomarkers of Exposure in Wading Birds and Fish of the Lower Rio Grande Valley, Texas

During 1997 we evaluated reproductive success in colonial water birds nesting in the Lower Rio Grande Valley (LRGV), Texas, and correlated success with concentrations of contaminants in eggs. We also measured steroid hormones and gonadosomatic index (GSI) as biomarkers of endocrine effects in common carp (Cyprinus carpio). Nest and fledging success of green herons (Butorides virescens) and great egrets (Ardea alba) were similar to those found in other parts of North America; however, nesting success of black-crowned night-herons (Nycticorax nycticorax) was lower, very likely due to flooding of the nesting area. Except for DDE and toxaphene, all chlorinated pesticides in bird eggs were low and not of concern for negative effects on any of the three species. DDE was highest in green heron eggs and seemed to increase along a geographic gradient from west to east, with eggs from Falcon Reservoir containing low concentrations, and those at Los Indios containing the highest concentrations (approx. 11,000 ng/g WW), near or above the threshold for reproductive impairment. DDE levels in great egrets and black-crowned night-herons were below those that are associated with reproductive impairment. Mean DDE levels in carp at the JAS Farms site were above the threshold level suggested for predator protection. Toxaphene was detected in about 20% of the samples with high levels observed in green heron eggs from Los Indios (mean = 4,402 ng/g WW). These are the highest toxaphene levels reported in bird eggs in the LRGV. Toxaphene levels in fish ranged between 90 and 312 ng/g WW. In general, PCBs in bird eggs and fish tissue were low and at levels not of concern for reproductive effects. The greatest concentrations of testosterone and 11-ketotestosterone were detected in fish from the JAS Farms site, which also had the greatest concentrations of DDE. Increased androgen production and gonad development in fish at this site, relative to Pharr, could be possibly associated with endocrine disrupting effects of p,p'-DDE. DDE, toxaphene, PCBs, and hormones were highest in birds and fish from the eastern edge of the study area. Received: 8 May 2000/Accepted: 22 July 2000     

Selenium, Cadmium, Copper, and Zinc Concentrations in Sediments and Mullet (Mugil cephalus) from the Southern Basin of Lake Macquarie, NSW, Australia

Selenium, cadmium, copper, and zinc concentrations were measured in sediments and the tissues of mullet (Mugil cephalus) collected from the southern basin of Lake Macquarie, NSW, Australia. Trace metals in surficial sediments are enriched in trace metals relative to background concentrations (selenium, 3–19; cadmium, 14–42; copper, 1.5–3.6; zinc, 0.77–2.2 times background). Selenium, cadmium, and copper in Lake Macquarie mullet tissues are elevated compared to those in mullet collected from the Clyde River estuary, a relatively pristine location. Selenium and copper concentrations are also elevated compared to those reported in mullet tissues from other nonpolluted coastal environments. Zinc concentrations in Lake Macquarie mullet muscle tissues are significantly higher than those in muscle tissues of mullet from the Clyde River estuary, but mullet from both locations have similar zinc concentrations in other tissues. These results show that contamination of sediment with trace metals has resulted in elevated trace metals in the benthic feeding fish M. cephalus. Little of the variation of trace metal concentrations between fish was explained by variation in mass. Selenium concentrations in mullet are of concern in muscle tissues as they are above recommended acceptable limits for safe human consumption, while concentrations in tissues are at levels that may effect fish growth, reproduction, and survival. Copper concentrations in mullet tissues are also at levels that may reduce fish growth. Received: 11 September 1999/Accepted: 9 July 2000     

Environmental contaminants and biochemical responses in flatfish from the Hvaler Archipelago in Norway

The levels of several environmental contaminants, including selected polyaromatic hydrocarbons (PAH), organochlorines (DDT/DDE, hexachlorobenzene), 15 polychlorinated biphenyl (PCB) congeners, and polychlorinated dibenzofurans and dibenzo-p-dioxins, PCDF/PCDD), and heavy metals (Cd, Hg, Pb, and As) were analyzed in muscle and liver of three different flatfish species (dab,Limanda limanda; flounder,Platichthys flesus; plaice,Pleuronectes platessa) caught by gill netting at different sites in the Hvaler Archipelago. Indices of biochemical effects in liver S9-fractions were studied by measuring cytochrome P450-dependent monooxygenase and UDP-glucuronyl transferase activities, and by immunoquantitating cytochrome P450 1A1 using an indirect enzyme-linked immunosorbent assay (ELISA). Only low levels of PCDD/PCDF, Cd, and Pb were observed, whereas PCB levels were significantly elevated in fish from the inner sites of the Archipelago compared to a reference site. The contaminant gradient toward the Glomma estuary was correlated with increased cytochrome P450 1A1 activity, measured as 7-ethoxyresorufin O-deethylase (EROD), and with immunoquantitated P450 1A1. In contrast, fish from the site at Idefjorden, although containing elevated contaminant levels, did not show elevated EROD activity, but apparently elevated P450 1A1 protein. These findings may reflect different pollution histories of the sites, and indicate the applicability of biochemical effect indices (i.e., EROD and P450 1A1 immunoquantitation) to monitoring studies. The integrated chemical-biochemical approach employed in this study can obviously be expanded to give fruitful information about cause-effect relationships in other contaminant situations.     

Safety and Efficacy of Fish Oil–Enriched Parenteral Nutrition Regimen on Postoperative Patients Undergoing Major Abdominal Surgery

Background: To evaluate the safety and efficacy of a fish oil–enriched parenteral nutrition regimen in patients undergoing major abdominal surgery, a meta‐analysis of randomized controlled trials was conducted. Methods: An electronic search of PubMed, MEDLINE, EMBASE, Academic Search Premier, and China National Knowledge Infrastructure databases was performed in March 2009. RevMan 5.0 was used for statistical analysis. Results: The combined analysis showed that a fish oil–enriched parenteral nutrition regimen had a positive treatment effect on length of hospital stay (weighed mean difference = ?2.98, P < .001), length of intensive care unit stay, postoperative infection rate (odds ratio = 0.56, P = .04), and serum levels of aspartate aminotransferase, alanine aminotransferase, and α‐tocopherol on postoperative day 6 in these patients. The regimen increased the plasma levels of eicosapentaenoic acid (standardized mean difference = 3.11, P < .001) and docosahexaenoic acid and upregulated the leukotriene B₅ production in leukocytes on postoperative day 6. No significant differences were found between the 2 groups in postoperative mortality; incidence of postoperative cardiac complications; serum levels of bilirubin, triglyceride, or arachidonic acid; or the liberation of leukotriene B₄. No serious adverse events related to fish oil treatment were reported. Conclusions: Based on the meta‐analysis, fish oil–supplemented parenteral nutrition was safe, improved clinical outcomes, and altered the fatty acid pattern as well as leukotriene synthesis. More laboratory parameters should be considered in future meta‐analyses.     

Phase I Enzyme Induction in <Emphasis Type="Italic">Girardinichthys viviparus</Emphasis>, an Endangered Goodeid Fish,Exposed to Water from Native Localities Enriched with Polychlorinated Biphenyls

The present study examines the induction of mixed-function oxidase (MFO) enzymes, including CYP content CYP1A (EROD) activity and alcohol dehydrogenase activity (ADH), in an endemic Mexican fish species, the black-fin goodeid Girardinichthys viviparus, exposed to the water of two localities, Lake Texcoco (LTX) and Lake Zumpango, and to the same matrices enriched in polychlorinated biphenyls (PCBs) to simulate the potential toxic effects of sublethal increases in these xenobiotics. Fishes of both sexes born in the laboratory were exposed for 1, 2, 4, 8, and 16 days. Water from the two types of localities of the black-fin goodeid contains MFO inducers. Of the two, the most contaminated is LTX water, which also contains PCBs. EROD activity was higher in all treatments with female compared with male fish. This suggests greater metabolic compromise in female fish as a response to damage caused by these xenobiotics. In this species, CYP induction displayed two patterns that were not always concurrent with higher CYP1A activity. In the enriched matrix system, biotransformation processes were notably altered. Increased ADH may indicate that this enzyme is involved in the biotransformation of PCBs and their metabolites, particularly in male fish, and provides at least a part of reductive power required by the MFO enzymes; however, specific studies are needed to clarify this point.     

Changes in serum biochemical parameters of freshwater fish Oreochromis niloticus following prolonged metal (Ag, Cd, Cr, Cu, Zn) exposures

Fish serum may reflect status of many biochemical processes in the metabolism. Heavy metals, as environmental stressors, may alter serum biochemical parameters in fishes. Thus, freshwater fish, Oreochromis niloticus, were exposed to low levels (0.05 mg/L) of metals (silver [Ag], cadmium [Cd], copper [Cu], chromium [Cr], zinc [Zn]) to investigate responses of serum biochemical parameters over different exposure periods (0, 5, 10, 20, 30 d). Fish mortality occurred only in Ag exposure, as all fish died between days 12 to 16. Activities of alkaline phosphatase (ALP), alanine transaminase (ALT), and aspartate transaminase (AST) were altered only in Cu- and Cd-exposed fish. Both Cd and Cu exposures decreased the activity of ALP, although they increased the activities of ALT and AST. Glucose concentrations increased in Ag-, Cd-, and Cu-exposed fish, with a sharp increase occurring in Ag-exposed fish before mortality began. Total protein and triglyceride concentrations increased in Ag-exposed fish, although they decreased in Cu-exposed ones. However, all metal exposures increased cholesterol concentration in the serum. Concentration of blood urea nitrogen increased in Ag-, Cd-, and Cu-exposed fish, although it decreased in Cr-exposed ones. Calcium level decreased only in Cu-exposed fish, and Cl(-) level decreased in Ag-exposed fish. Silver and Cu exposures also decreased Na(+) level in the serum. Cadmium and Cu exposures increased serum K(+) levels. The present study, investigating the effects of environmentally realistic metal exposures on serum biochemical parameters, demonstrated that fish serum could sensitively reflect environmental metal stress. Thus, it suggests that serum biochemical parameters could be used as important and sensitive biomarkers in ecotoxicological studies concerning the effects of metal contamination and fish health.     

Investigation of a wood treatment facility: Impact on an aquatic ecosystem in the San Joaquin River, Stockton, California

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and metals were monitored in the river sediments near the McCormick and Baxter (MCB) wood treatment facility, Stockton, CA. Transplanted clams and resident fish species were used to assess bioavailability. The highest PCDD and PCDF contamination in sediments were confined to an area next to the facility and an area in the nearby Stockton harbor (DK location). Pentachlorophenol (PCP) wood treatment at MCB was the most probable source of the contamination. PCBs contaminated a wider area of the Stockton Ship Channel and harbor. Metal concentrations were uniformly low except for the metalloid arsenic in the Old Mormon Slough and lead and zinc near boat docks in the Stockton harbor. Despite high mortality rates, clams (Corbicula fluminea) bioaccumulated PCBs, PCDDs, and PCDFs. In clams, PCBs and 2,3,7,8 TCDD were much closer to equilibrium with the sediments than were higher chlorinated PCDDs and PCDFs. All fish were at background levels for 2,3,7,8 TCDD. All fish had lower lipid adjusted PCDD/F and PCB concentrations in the skinned muscle than in the whole fish. PCBs in fish were above background levels for United States river systems. Although high contamination exists in the river near this superfund site, adverse effects on the aquatic community could not be demonstrated.