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Gills represent one of the major sites of gas exchange of fish, consequently they are in continuous close contact with the aquatic environment and its pollutants. In the present study the effects on gills of pejerrey fish, Odontesthes bonariensis, under glyphosate-based herbicide subchronic exposure were analyzed. Adult animals were exposed to sublethal concentrations of a glyphosate-based commercial formulation (1 and 10 PMG mg L−1, PMG: glyphosate active ingredient) for 15 days, while control group was maintained in rearing water. Ultrastructural changes in gills were observed by scanning electron microscopy (SEM). The composition of the surface epithelium and specific surface area were determined by energy dispersive spectroscopy (EDS) and N2 (g) adsorption–desorption isotherms, respectively. The herbicide exposure induced severe alterations in gill ultrastructure, as shown in the SEM micrographs. Accordingly, an increase in surface area of the gills of exposed animals was determined. These results support that gills parameters of freshwater fish are sensitive morphological biomarkers for glyphosate exposure. Fil: Menendez Helman, Renata Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina Fil: Miranda, Leandro Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina Fil: Salibián, Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Universidad Nacional de Luján. Instituto de Ecología y Desarrollo Sustentable; Argentina Fil: Dos Santos Afonso, María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina

Oreochromis niloticus was exposed to 10.0 ppb of organophosphate insecticide chlorpyrifos (CPF) and avermectin insecticides abamectin (ABM) and emamectin benzoate (EB) for 48 and 96 h. RBC and Hb decreased in CPF- and ABM-exposed fish after 96-h. Plasma ALT, AST, cortisol, and glucose increased in 96-h CPF-, ABM- and EB-exposed fish, while plasma ions declined in 96-h CPF-exposed ones. Insecticides caused alterations in liver oxidative stress parameters. In fish exposed to CPF, CAT increased after 48-h whereas it decreased after 96-h. Also, CAT declined in 48- and 96-h ABM-exposed fish, whereas it elevated in 48-h EB-exposed ones. Insecticides caused decreases in SOD at 48- and 96-h and in GR after 96-h. GSH elevated in CPF-exposed fish after 48-h, while it decreased in all the tested insecticide exposures after 96-h. Malondialdehyde of fish exposed to insecticides for 96-h increased. Consequently, toxic effects of insecticides on O. niloticus were generally as CPF > ABM > EB.

Considering the constant exposure of fish to copper oxide nanoparticles (CuO-NPs) and copper sulphate (CuSO4) in natural aquatic environments as a result of increased usage of these chemicals in industry, medicine and aquaculture/agriculture over the past few decenniums, the current investigation aimed to reveal their comparative hemotoxic effects on freshwater fish Oreochromis niloticus by measuring hematological and blood oxidative stress biomarkers and Cu levels. Fish were exposed to 0.05 mg/L CuO-NPs and CuSO4 for 4 and 21 days. Both copper forms decreased erythrocyte, hematocrit, and hemoglobin values, and superoxide dismutase and catalase activities while they elevated glucose-6-phosphate dehydrogenase activity, and glutathione, malondialdehyde and Cu levels. Leukocyte levels and glutathione peroxidase activity did not show any significant change. In a conclusion, the current research demonstrates that CuO-NPs and CuSO4 for O. niloticus have similar hemotoxic effects, however, CuO-NPs are slightly more toxic than CuSO4 regarding hematological changes and oxidative stress observed.

In this study, the concentrations of 14 types of organochlorine pesticides (OCPs) and 7 types of polychlorinated biphenyls (PCBs) in four freshwater fish species (Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix and Hypophthalmichthys nobilis) collected from nine lakes in Anhui Province were determined. Among these contaminants, only hexachlorobenzene (HCB), heptachlor, hexachlorocyclohexane (β- and γ-HCH), dichlorodiphenyldichloroethylene (p,p'-DDE) and PCB 101 were detected, and HCB had the highest measured concentrations while the heptachlor showed the lowest concentrations. In the four fish species, C. carpio preferred to accumulate more OCPs and PCBs than C. idellus. Moreover, the health risk assessments demonstrated that consumption of these fish species may pose both non-carcinogenic and carcinogenic risks, especially for children at high exposure level (95th). As the concentrations of contaminants in ventral muscle were higher than that in dorsal muscle, the consumption of ventral muscle should be limited to avoid the potential risk of OCPs and PCBs.

The spatial and temporal variations of microcystins (MCs) in fishes with different trophic levels were studied monthly in Lake Chaohu in 2014. MCs content in muscle was highest in phytoplanktivorous Hypophthalmichthys molitrix (H. molitrix), followed by omnivorous Carassius auratus (C. auratus), and was lowest in herbivorous Parabramis pekinensis (P. pekinensis) and carnivorous Coilia ectenes (C. ectenes). MCs concentration in liver was highest in C. auratus, followed by H. molitrix, and was lowest in P. pekinensis and C. ectene. The main uptake routes of MCs for C. auratus and H. molitrix were via the diet. The mechanism to counteract MCs had not been well developed in C. ectenes. H. molitrix and C. auratus from the western region as they had higher mean concentrations of MCs than fishes from the eastern region. The estimated daily intakes of MCs in 45.4% of muscle samples were higher than the provisional tolerable daily intake set by WHO.

Marking of fish otoliths with oxytetracycline and tetracycline is a widely used method to evaluate the effectiveness of stocking operations. Available protocols for the labeling of fish specify a number of factors influencing mark quality and potential risk for fish during marking. This study investigates the influence of water hardness on mortality of freshwater fish during marking with OTC. In order to pursue this question complexation of OTC with Mg(2+) and Ca(2+) cations was measured spectrophotometrically. Furthermore, zebrafish (Danio rerio) were immersed in OTC solutions (1200 mg/L; 48 h immersion) combined with varying levels of water hardness (5.5, 15.5, 25.5, 32.5°dH). The amount of OTC-Mg-Ca-complexes was positively correlated to water hardness. Moreover, it could be demonstrated that mortality of zebrafish during marking varied as a factor of water hardness. Highest mortalities occurred at the lowest (5.5°dH) and the highest (32.5°dH) tested levels during marking with OTC.

Contamination of freshwater ecosystems such as rivers with hazardous heavy metals is an environmental problem of public health concern. Accumulation of potentially toxic heavy metals in freshwater fish causes a potential health threat to their consumers including humans. The present research aimed to (1) investigate the accumulation of four potentially toxic heavy metals viz. Cr, Ni, Cd and Pb in muscle tissue of the commercially important freshwater fish Schizothorax plagiostomus at different sites of River Swat, River Panjkora and River Barandu in northern Pakistan (2) to compare gross metal accumulation in the fish samples by calculating metal pollution index (MPI) and (3) to assess potential risk to the health of the fish consumers. Samples were analyzed for the heavy metals by flame atomic absorption spectrophotometry (FAAS). Risk analysis showed that Ni risk was higher at River Panjkora and River Barandu, Pb risk was higher at River Swat and River Panjkora while Cd risk was quite low at all the three rivers.

Health status of freshwater fish, Cirrhina mrigala was studied by qualitative and quantitative histopathological analysis, alterations in frequency/prevalence percentages (%) and histological alteration indices (HAI) in response to metal contaminated sediments of the River Ravi aquatic ecosystem. Histo-structures of gill and liver samples of fish were analyzed and comparison between the degree of damage of the alterations in fish organs was performed after exposure to metal contaminated sediments for 7, 14 and 28 days under semi-static water renewal bioassays. Histopathological studies revealed marked histological alterations in the gills and liver of exposed fish as compared to normal tissue structure observed in control fish. The frequency and prevalence percentages observed in 28-day exposed fish were significantly higher as compared to 7- and 14-day exposed fish. The order of frequency and prevalence percentage for gills and liver of exposed fish was as: 28-day > 14-day > 7-day. The highest prevalence percentages recorded were 83 and 80% as focal area of necrosis in gill and liver, respectively, after 28-day exposure. The lowest prevalence percentage observed in 7-day exposed Cirrhina mrigala was dilation of sinusoids (17%).

Total and inorganic arsenic were determined in 108 samples of four freshwater fish species collected from natural water sources and aquaculture systems in the central region of Thailand between March and May 2010. Concentrations of total and inorganic arsenic (dry wt) and percentages of inorganic arsenic in four aquacultural fish species were not significantly different from those found in natural fish. Inorganic arsenic levels found in the four fish species from both sources in this study were much lower than the Thai regulatory standard of 2 μg/g, and hence are considered safe for human consumption.

Atmaca, Enes/0000-0002-8978-3755; Aksoy, Abdurrahman/0000-0001-9486-312X WOS: 000303544900008 PubMed: 22358117 The concentrations of selected Organochlorine (OC) pesticides (alpha-HCH, beta-HCH, gamma-HCH, HCB, aldrin, 2,4'-DDE, 4,4'-DDE, 2,4'-DDT, 4,4'-DDT) and Polychlorinated Biphenyls (PCBs) (28, 70, 74, 81, 99, 101, 105, 118, 128, 138, 153, 156, 170, 180, 183, 187) were measured in two species of cultured freshwater fish (rainbow trout, Oncornhychus mykiss and catfish, Silurus glanis) and two kinds of sea fish (mullet, Mugil cephalus and salmon, Salmo salar) between March 2008 and June 2009 in order to evaluate the status, seasonal changes and potential sources of pollution in the Samsun region of Turkey. Concentrations of total PCBs ranged from 17.6 to 335 ng/g in rainbow trout, 1,063 to 3,234 ng/g in mullet, 21 to 1,887 ng/g in salmon and 108 to 1,172 ng/g lipid in catfish and total OC pesticide concentrations ranged from 303 to 473, 319 to 6,158, 101 to 249 and 34 to 6,069 ng/g lipid in rainbow trout, mullet, salmon and catfish, respectively. It is concluded that the levels of persistent organic pollutants should be monitored regularly and rigorously by the appropriate government agency, with mandatory public reporting. Commission of Scientific Research Projects of Ondokuz Mayis UniversityOndokuz Mayis University [VET-044] This study was supported by the Commission of Scientific Research Projects of Ondokuz Mayis University (Project No: VET-044). The authors thank Gregory T. Sullivan of OYDEM, Ondokuz Mayis University in Samsun, Turkey for editing the English in this manuscript.

Research was performed to investigate the concentration of mercury in muscle and liver of fish species from freshwater (Barbus xanthopterus, Barbus grypus, Liza abu) and saltwater (Cynoglossus arel, Periophthalmus waltoni, Otolithes ruber) in Khouzestan, Iran. In freshwater fish, muscle was polluted in comparison with liver except for Barbus xanthopterus which high levels of mercury were measured in liver. In saltwater fish liver was contaminated than muscle except for Cynoglossus arel which high level of mercury was found in muscle. Significant variations in metal values were evaluated using student’s t test at P < 0.05. Mercury concentrations were well above the permissible limits suggested by WHO and FDA guidelines.

The study evaluated the sublethal effects of the herbicides glyphosate (Roundup) and diuron (Hexaron) and the mixture of them, used extremely in agriculture, through biomarkers in fish. The glutathione S-transferase activity increased (74%) and catalase activity decreased (37%) at the higher exposure concentration of Hexaron in comparison to the control group, suggesting an activation of this metabolism route. Membrane damage was observed at the higher exposure of Roundup and in the mixture group compared to the control group, which can be related to the nuclear alterations observed in these exposed groups. The cholinesterase activity was also inhibited (37%) in mixture group compared to the control group and no gill morphology damage was found. The results suggested a potential synergic effect in some analysed parameters.

The main objectives of study were to monitor the metals concentrations, in freshwater fish species, Carassius gibelio and Esox lucius; and to identify any relationships between species and bioaccumulation of metals. The highest concentration of metals (cadmium, 1.96; copper, 24.2; zinc, 49.6; lead, 5.4; chromium, 4.4) between the fish species and tissues was in the liver of Esox lucius, while the lowest (cadmium,0.21; copper,7.2; zinc,19.4; lead,0.9; chromium,0.6 μg/g) found in the muscle of Carassius gibelio. Results showed that the metal concentrations were in fishes in descending order of zinc > copper > lead > chromium > cadmium, similarly in the tissue liver > kidney > gill ~ intestine > muscle.

Acute (4 day) and short-term (7 day) toxicity studies (at 1/5th and 1/10th of LC(50)) of textile dye wastewaters and their selected ingredients (azo dye methyl red and heavy metals Cd, Cu, Ni and Zn) were made on a freshwater fish Gambusia affinis under laboratory conditions. LC(50) value was found to be the lowest in four cases, and the EC(50) value for reduction in erythrocyte counts in the remaining four tests. Thus, the reduction in erythrocyte counts to the 50% level was similar in sensitivity to fish mortality. The short-term toxicity studies revealed significant disorders in erythrocyte morphology (poikilocytosis) and its counts to be the better indices for toxicity monitoring in the absence of fish mortality.

The levels of organochlorine pesticides residues were determined in five freshwater fish species in Punjab State, India. These species were selected in view of their importance to local human fish consumer. DDTs were the predominant organochlorine contaminants in all species with pp DDT and pp DDE as the main pollutants. Other organochlorines, such as HCH isomers and dieldrin were also found at lower levels in fish species. The alpha-HCH was the dominant isomer of HCH in all fish species followed by gamma-, beta- and delta-HCH. The residues of aldrin, chlordane, heptachlor and endosulphan were not detected in any fish sample. The levels of organochlorines detected in present study were below the tolerance limits recommended at National and International standards.

Toxic heavy metals are increasingly being released into the environment with the advent of agricultural and industrial revolution in India (Khare and Singh 2002; Jayakumar and Paul 2006). A number of geological and anthropogenic activities such as mining, smelting of metals ores, industrial and automobile emission, battery recycling units, painting industries, and application of insecticides and fertilizers contribute to the elevated levels of toxic and hazardous pollutants including toxic metals in the environment (Woodling et al. 2001; Patra et al. 2005; Swarup et al. 2005). Industrial units frequently discharge toxic wastes into different water bodies, which adversely affect the aquatic ecosystem, and heavy metals get accumulated into the tissues of aquatic species including fish intended for human consumption (Jayakumar and Paul 2006). Heavy metals have been detected in low to alarming concentrations in water of many pisciculture water bodies from different parts of India (Das and Kaviraj 2000). Among the toxic heavy metals, lead (Pb) and cadmium (Cd) that are most abundant toxic metals in the environment are emerging global concern due to their potential deleterious hazards on public health. Satyanarayanan et al. (1985) reported that the substantial levels of heavy metals on the East coast of India require special attention because they come with the industrial effluents and city sewages. Besides producing toxic impact on aquatic ecosystem, Cd can also be bio-accumulated and biomagnified via the food web and finally reach to human fish consumers posing public health risks (Viana et al. 2005). Epidemiological and experimental evidences indicate a range of toxic effects of Cd including carcinogenicity, mutagenicity and teratogenic effects in human and animals (Bellinger et al. 2004). Chronic environmental exposures to low levels of Pb are also frequently reported in many developing and industrializing countries, particularly in urban areas (Tong et al. 2000). At low levels, haeme synthesis and other biochemical processes are affected, psychological and neurobehavioural functions are impaired and there is a series of other adverse effects (Goldstein 1992). Although in unleaded petrol phase, Pb concentration declined gradually, still it is environmental concern in India. Pb concentration ranged from 0.04 to 3.91 lg/m in the ambient air (Kaul et al. 2003) and 2.1– 12.3 lg/m in tree leaves in 2004 (Singh et al. 2005) at urban sites of Lucknow, India. Recently, Balagangatharathilagar et al. (2006) reported greater blood Pb levels in dog collected from Bareilly city than in unpolluted rural areas (0.25 vs. 0.1 mg/L). Therefore, concerning potential health risk of Pb and Cd, and their existence in environment as well as aquatic ecosystems in India, a survey was conducted in Western UP (Bareilly city), India to investigate the levels of Pb and Cd in the different tissues of fresh water fish (Clarias batrachus) and chicken.

Dongting Lake is located in the northeastern part of Hunan Province in the People’s Republic of China. The lake covers about 2,740 km 2 , making it the second-largest freshwater lake in China. The lake is an important source of freshwater fish. However, it is also an endemic region of schistosomiasis. Oncomelania hupensis gredler is the only lodging host of schistosome and plays a vital role in schistosomiasis spread. To kill Oncomelania hupensis gredler large amounts of sodium pentachlorophenate (NaPCP), which was found containing polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) impurities, had been sprayed for over 30 years (Bao et al., 1995). PCDD/Fs are chemically stable, persistent hydrophobic organic chemicals and are thought to be biomagnified via the food chain. Those isomers with chlorinated substitutions in the 2, 3, 7, and 8 positions are thought to pose a risk to human health due to their toxicity, carcinogenic potency, and potential effects on animal reproductive and immunological systems. Although the spraying of Na-PCP has been prohibited in the region since 1996, recent studies have indicated that the sediments, soils, and breast milk around Dongting Lake area are contaminated by PCDD/Fs (Zheng et al., 1997; Gao et al., 2005; Zheng et al., 2003). Fish are usually used as bioindicators for the environmental medium and food webs, and can reflect the PCDD/ Fs contaminant status. Moreover, humans are consumers of fish, and exposure assessments now routinely consider fish ingestion as a potential route of human exposure to chemicals in the environment. Consequently, monitoring programs establish limits for the maximum content of these toxicants in a variety of foods. An important regulation is that the European Community (EC) has set a limit of 4 pg/g wet weight of toxic equivalents (WHOPCDD/F-TEQ) for the muscle meat of fish and fishery products (EC, 2001). As do most organic contaminants, PCDD/Fs accumulate in certain organs with the highest proportions found in the fish liver (Wu et al., 2001). This paper describes the levels and bioaccumulation profiles of PCDD/Fs in different fish species livers and gills from Dongting Lake region.

This study evaluated the incidence of nuclear abnormalities (NA) in four fish species from an impacted river in Northeastern Brazil, characterized by accumulation of heavy metals and organic sewage. Two carnivores (Serrasalmus brandtii and Hoplias malabaricus) and two omnivore species (Oreochromis niloticus and Geophagus brasiliensis), used as food sources by local populations, were collected during the dry and the rainy season along Contas River basin. Nuclear abnormalities (bulbs, binuclei, lobes, micronuclei, notches, and vacuoles) were reported in all fish samples, with high occurrence in S. brandtii and H. malabaricus, species commonly found in local fish markets. This result agrees with previous analyses of accumulation of trace metals in both species, suggesting an association of genotoxic effects and biomagnification. Moreover, native specimens collected near urban areas presented higher frequencies of NA while O. niloticus seems to be more tolerant to environmental contamination. Therefore, effective policies are required to reduce the contamination of Contas River, since pollution by xenobiotics are potential threats to both local biodiversity and human population.

In order to determine the effect of a dam on metal concentrations in riverine fish species, we studied fish inhabiting the influent (Cachapoal River) and effluent (Rapel River) of the Rapel Reservoir in central Chile. Heavy metals were quantified in gills, liver and muscle of the catfish Trichomycterus areolatus and the silverside Basilichthys microlepidotus. Also, the bioaccumulation index (BAI) was estimated by considering heavy metal concentrations obtained from water and sediment. Results showed the presence of Al, Cu, Fe, Mn, Pb and Zn in the fish organs. The analysis showed high metal concentrations in catfish inhabiting the influent compared to those collected in the effluent. These results indicate a possible filter effect of the dam for most of the metals identified in the fish organs, because metal concentrations decreased in the effluent. Finally, catfish exhibited a larger BAI for most metals analyzed.

Two sites of collection along river Nile, nearby metal-related factories (site2) and 7 km downstream (site3) were compared to unpolluted reference fish farm (site1). Metals concentration (Cu, Zn, Pb, Fe, Mn and Cd) in water and sediment samples showed highly significant (p 0.01) differences among sites. According to contamination factor and pollution load index values, overall pollution was ordered as site2 site3 site1. Compared with Oreochromis niloticus of site1, activities of superoxide dismutase, catalase and glutathione-S-transferase as well as malondialdehyde formation were significantly (p 0.01) increased in both liver and gills of fish collected from metal contaminated sites. This increment showed a tissue-specific pattern with higher rate of increment in liver than in gills. While reduced glutathione level was sharply decreased in site2 and site3. Micronucleus test was assessed as an environmental genotoxic endpoint in erythrocytes. Assessment of eight nuclear deformations showed gradient frequencies related to the distance from the industrial discharges.

PubMedID: 11911634 [No abstract available]

PubMedID: 9933313 [No abstract available]

Tilapia are widely distributed freshwater fish frequently used for environmental toxicology, comparative biochemistry and physiology studies. Tilapia can persist in a highly polluted habitat and have the potential for the development as a biological monitor of environmental pollution. Metallothioneins (MTs) are a group of small-molecular-weight cytoplasmic proteins induced in many animals including fish, following exposure to metals such as cadmium, copper, zinc, and mercury. An increasing number of reports have indicated that fish MT induction is a sensitive measure of metal contamination in the environment. Fish cytochrome (P450)-dependent monooxygenases are inducible by many environmental pollutants including polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Extensive studies have suggested that fish monooxygenase can serve as a biochemical marker for exposure to PAH- and PCB-types of pollutants. Tilapia P450 is highly responsive to the inductive effects of PAH and PCBs. Tilapia collected from a polluted section of a river showed higher levels of P450 and dependent monooxygenase activities than tilapia collected from an unpolluted section. Previous studies showed that pretreatment with Cd decreased microsomal monooxygenase activities in fish such as plaice, bass, and trout. However, direct information regarding the effects of heavy metals on tilapia P450 are not available. Reports concerning themore » effect of heavy metal on tilapia MT are scarce. The purpose of the present study was to determine the ability of cadmium to modulate P450 and MT in tilapia liver and gill. In addition, we have extended our study to feral tilapia collected from Er-Jen Stream, a polluted river in Taiwan. 16 refs., 1 fig., 2 tabs.« less

Concentrations of mercury in four freshwater fish species from Gandoman and Sooleghan Lagoons and Beheshtabad River were determined by cold vapor atomic absorption spectrometry. Concentrations of mercury in muscle of 90 fish ranged from 21 to 31 μg kg(-1) (mean = 26 μg kg(-1)). Statistical analysis showed no statistical relationship between mean mercury concentration and fish species, although concentration of mercury in different seasons and habitats was statistically different (p0.05). The results indicated that fish from Gandoman and Sooleghan Lagoons and Beheshtabad River have concentrations well below the maximum permissible levels of mercury according to international standards with no health risk for consumers.

The objective of the present study was to investigate the levels of metals (Cd, Cu, Zn, Pb and Cr) in muscle, gill, liver, kidney and intestine of two freshwater fish, Ctenopharyngodon idella and Perca fluviatilis, in Anzali Wetland, Iran. The concentrations were different between the fish species as well as among the tissues of fish. Results showed that the metal concentrations in both fish species were in descending order of Zn > Cu > Pb > Cr > Cd. Results also showed that the Cd, Cu, Zn, and Pb concentrations in the muscle of both fish from Anzali Wetland are below levels of concern for human consumption.

PubMedID: 9595202 [No abstract available]