Health risks of environmental exposure to metals and herbicides in the Pardo River,Brazil

Mixture of metals and herbicides in rivers may pose relevant risks for the health of surrounding communities. Humans may be exposed to river pollution through intake of contaminated water and fish, as well as irrigated agricultural products. The aim of this study was to assess the human health risks of environmental exposure to metals and herbicides through water and fish intake in the Pardo River. Metals (Al, As, Be, Cd, Cr, Cu, Pb, Mn, Hg, Ni, Tl, Sn, V, and Zn) were analyzed in river water and in edible fish. Herbicides (ametryn, atrazine, diuron, hexazinone, simazine, and tebuthiuron) were analyzed in river water. Seasonal variances were also studied. Aluminum, Cd, Cu, Mn, Pb, and Zn levels in river water were higher than the USEPA benchmarks. Non-carcinogenic risks due to pollutants mixture exposure were above the limit, and carcinogenic risks of As exposure were >10^?6 in the sampling points during the rainy season. Metal levels in fish were lower than the Brazilian legislation and do not pose a threat to public health. Herbicides were detected in four sampling points, with atrazine concentrations (range 0.16–0.32 μg/L) below the Brazilian standard (2.0 μg/L), but above the European Union standard (0.1 μg/L). Considering the water supply needs of cities located in the Pardo River Basin and the persistence of metals and herbicides, the present study indicated that there was a seasonal influence on non-carcinogenic and carcinogenic risks to human health, especially in the rainy season. Studies for water treatment plants implantation should consider the risks of exposure to persistent substances, in order to protect the population.     

Human health risk from organ-specific accumulation of toxic metals and response of antioxidants in edible fish species from Chenab River,Pakistan

In the current study, the bioaccumulation of essential and nonessential metals and related antioxidant activity were analyzed in three organs (muscle, gills, and liver) of herbivorous (HF) and carnivorous (CF) edible fish of Chenab River. The comparative analysis revealed a more heterogeneous accumulation of metals in the muscles of HF fish than that of CF fish [chromium (Cr, 3.4 μg g^?1), cobalt (Co, 1.7 μg g^?1), copper (Cu, 3 μg g^?1), and iron (Fe, 45 μg g^?1) versus Cr (1.3 μg g^?1), Co (0.1 μg g^?1), Cu (1.1 μg g^?1), and Fe (33 μg g^?1), respectively, P?<?0.001]. These results implied an organ-specific accumulation of metals at different trophic levels. According to logistic regression analysis, the bioaccumulation of metals had marked differences in HF and CF. The antioxidant activity was significantly related to the tissue type and the metals to which the organs are exposed to. The liver of CF fish had a higher activity of antioxidant superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and lipid peroxidase (LPO) than that of HF (P?<?0.05). LPO and guaiacol peroxidase (POD) in both groups were associated with a number of metals, but in HF, cadmium (Cd), Cr, Pb, and Zn were more related with the LPO and SOD activities. Moreover, Cd, Co, Fe, Pb, Ni, Cu, and Zn were above the permissible limits set by various agencies. In numerous cases, our results were even higher than those previously reported in the literature. The results provide an insight into the pollution pattern of Chenab River. These results may be helpful in the future to identify biomarkers of exposure in aquatic organisms.

Total mercury and methylmercury concentrations in native and invasive fish species in Shadegan International Wetland,Iran, and health risk assessment

Human exposure to mercury (Hg) mainly occurs through consumption of aquatics, especially fish. In aquatic systems, the bioaccumulation of Hg across trophic levels could be altered by invasive species through changing community composition. The present study is aimed at measuring total mercury (T-Hg) and methylmercury (MeHg) concentrations in non-native (redbelly tilapia (Tilapia zillii)) and native (Benni (Mesopotamichthys sharpeyi) and common carp (Cyprinus carpio)) fish species throughout Shadegan International Wetland and comparing health risk of their mercury contents to the local population. The concentrations were measured using a direct mercury analyzer (DMA 80). The average values of T-Hg and MeHg for native fishes were 19.8 and 10.49 μg/kg. These concentrations for the invasive fish were 28 and 14.62 μg/kg respectively. Despite having less length and weight than the native fish species, tilapia showed significantly higher T-Hg content, yet the lowest concentration of MeHg was observed in common carp with larger body length and weight. Concerning mercury health risk to consumers, tilapia demonstrated the highest estimated weekly intake (EWI) and percentages of tolerable weekly intake (%TWI) for both T-Hg and MeHg, while the highest hazard quotient (HQ) values were obtained for tilapia and Benni. Taken together, the mercury concentrations in the two native and non-native fishes were acceptable according to the international safety guidelines although the local people shall be warned for consumption of tilapia. Furthermore, the low calculated value of tissue residue criterion (TRC) for the wetland fishes sounds a warning.     

Occurrence of imidacloprid,carbendazim, and other biocides in Italian house dust: Potential relevance for intakes in children and pets

The occurrence of pesticides intended for non-agricultural use was investigated in 206 dust samples drawn from vacuum-cleaner bags from residential flats in Italy. The multi-residue analysis targeted on 95 different active principles was performed with UPLC-MS/MS, with a Limit of Quantification (LOQ) of 0.008 μg/g dry weight. The results indicated the presence of imidacloprid (IMI) and carbendazim (CARB) in 30% and 26% of the samples, with a mean and P95 concentration between 1.6 and 39 and between 0.08 and 4.9 μg/g, respectively. Combined presence of two biocides was noted in 19.4% samples, of three biocides in 9.2% samples, of four biocides in 3.4% samples, and of five and six biocides in 0.5% and 1% samples, respectively. According to the estimated dust intake in infants/toddlers aged 6–24 months (16–100 mg d^?1) and cats (200 mg d^?1), it was possible to obtain risk characterization with respect to the Acceptable Daily Intake (ADI) for IMI of 0.060 mg/kg body weight (bw) proposed by the European Food Safety Authority (EFSA) and the chronic Population Adjusted Dose (cPAD) of 0.019 mg/kg bw d^?1 by US-EPA. Under the worst-case scenario, the presence of IMI in dust indicates potential exceedance of the cPAD in kittens, to be considered as sentinel also accounting for combined exposure. This study highlights the relevance of consumer empowerment about the responsible use of pesticides as biocidal products in indoor environment.     

Heavy metal and Pb isotopic compositions of aquatic organisms in the Pearl River Estuary, South China

The accumulation of trace metals in aquatic organisms may lead to serious health problems through the food chain. The present research project aims to study the accumulation and potential sources of trace metals in aquatic organisms of the Pearl River Estuary (PRE). Four groups of aquatic organisms, including fish, crab, shrimp, and shellfish, were collected in the PRE for trace metal and Pb isotopic analyses. The trace metal concentrations in the aquatic organism samples ranged from 0.01 to 2.10 mg/kg Cd, 0.02 to 4.33 mg/kg Co, 0.08 to 4.27 mg/kg Cr, 0.15 to 77.8 mg/kg Cu, 0.17 to 31.0 mg/kg Ni, 0.04 to 30.7 mg/kg Pb, and 8.78 to 86.3 mg/kg Zn (wet weight). High concentrations of Cd were found in crab, shrimp and shellfish samples, while high concentration of Pb was found in fish. In comparison with the baseline reference values in other parts of the world, fish in the PRE had the highest elevated trace metals. The results of Pb isotopic compositions indicated that the bioaccumulation of Pb in fish come from a wide variety of food sources and/or exposure pathways, particularly the anthropogenic inputs.     

Single and combined effects of aluminum (Al<Subscript>2</Subscript>O<Subscript>3</Subscript>) and zinc (ZnO) oxide nanoparticles in a freshwater fish, <Emphasis Type="Italic">Carassius auratus</Emphasis>

The increasing use of nanoparticles (NPs) worldwide has raised some concerns about their impact on the environment. The aim of the study was to assess the toxicity of metal oxide nanoparticles, singly or combined, in a freshwater fish (Carassius auratus). The fish were exposed for 7, 14, and 21 days to different concentrations of NPs (10 μg Al₂O₃.L^?1, 10 μg ZnO.L^?1, 10 μg Al₂O₃.L^?1 plus 10 μg ZnO.L^?1, 100 μg Al₂O₃.L^?1, 100 μg ZnO.L^?1, and 100 μg Al₂O₃.L^?1 plus 100 μg ZnO.L^?1). At the end of each exposure period, antioxidant enzyme activity (catalase, glutathione-S-transferase, and superoxide dismutase), lipid peroxidation, and histopathology were assessed in the gills and livers of C. auratus. The results show an increase in catalase (CAT) and superoxide dismutase (SOD) activity in the gills and livers of fish, especially after 14 days of exposure to single and combined NPs, followed by a reduction at 21 days. An increase in glutathione S-transferase (GST) was observed in gills after 7 days for all tested NP concentrations (single and combined); while in livers, a significant increase was determined after 14 days of exposure to 100 μg.L^?1 of both single ZnO and Al₂O₃ NPs. Lipid peroxidation (LPO) significantly increased in gills after 7 days of exposure to 100 μg.L^?1 Al₂O₃ NPs (single or combined). In livers, LPO increased significantly after 7 days of exposure to all tested concentrations of both single ZnO and Al₂O₃ (except for 10 μg Al₂O₃.L^?1), and after 14 days of exposure to ZnO (10 and 100 μg.L^?1) and Al₂O₃ (100 μg.L^?1)_. The results from histological observations suggest that exposure to metal oxide NPs affected both livers and gills, presenting alterations such as gill hyperplasia and liver degeneration. However, the most pronounced effects were found in gills. In general, this study shows that the tested NPs, single or combined, are capable of causing sub-lethal effects on C. auratus, but when combined, NPs seem to be slightly more toxic than when added alone.     

Distribution of feminizing compounds in the aquatic environment and bioaccumulation in wild tilapia tissues

This study sampled six times of river water, sediment, and tilapia (Oreochromis niloticus) in the Dan-Shui River, Taipei, Taiwan; 10 feminizing compounds were analyzed using ultra-performance liquid chromatography-tandem mass spectrometry. Bisphenol A (508?±?634 ng/L, geometric mean (GM) 303 ng/L) and nonylphenol (491?±?570 ng/L, GM 328 ng/L) were the most abundant among analytes in the river water. Nonylphenol (770?±?602 ng/g wet weight, GM 617 ng/g wet weight) was also the highest in sediment. Fish may uptake nonylphenol and nonylphenol ethoxylates from river water and sediment because there were significant correlations between the concentrations in these matrixes and those in fish tissues (r _s ranged from 0.21 to 0.49, p?相似文献   

Acute toxicity of copper,lead, cadmium,and zinc to early life stages of white sturgeon (Acipenser transmontanus) in laboratory and Columbia River water

Populations of white sturgeon (Acipenser transmontanus) are in decline in North America. This is attributed, primarily, to poor recruitment, and white sturgeon are listed as threatened or endangered in several parts of British Columbia, Canada, and the United States. In the Columbia River, effects of metals have been hypothesized as possible contributing factors. Previous work has demonstrated that early life stage white sturgeon are particularly sensitive to certain metals, and concerns over the level of protectiveness of water quality standards are justified. Here we report results from acute (96-h) toxicity tests for copper (Cu), cadmium (Cd), zinc (Zn), and lead (Pb) from parallel studies that were conducted in laboratory water and in the field with Columbia River water. Water effect ratios (WERs) and sensitivity parameters (i.e., median lethal accumulations, or LA50s) were calculated to assess relative bioavailability of these metals in Columbia River water compared to laboratory water, and to elucidate possible differences in sensitivity of early life stage white sturgeon to the same concentrations of metals when tested in the different water sources. For Cu and Pb, white sturgeon toxicity tests were initiated at two life stages, 8 and 40 days post-hatch (dph), and median lethal concentrations (LC50s) ranged between 9–25 μg Cu/L and 177–1,556 μg Pb/L. LC50s for 8 dph white sturgeon exposed to Cd in laboratory water and river water were 14.5 and 72 μg/L, respectively. Exposure of 8 dph white sturgeon to Zn in laboratory and river water resulted in LC50s of 150 and 625 μg/L, respectively. Threshold concentrations were consistently less in laboratory water compared with river water, and as a result, WERs were greater than 1 in all cases. In addition, LA50s were consistently greater in river water exposures compared with laboratory exposures in all paired tests. These results, in combination with results from the biotic ligand model, suggest that the observed differences in toxicity between river water exposures and laboratory water exposures were not entirely due to differences in water quality and metal bioavailability but rather in combination with differences in fish sensitivity. It is hypothesized that differences in concentrations of calcium in the different water sources might have resulted in differences in acquired sensitivity of sturgeon to metals. Canadian water quality guidelines, US national criteria for the protection of aquatic life, and water quality criteria for the state of Washington were less than LC50 values for all metals and life stages tested in laboratory and Columbia River water. With the exception, however, that 40 dph white sturgeon exposed to Cu in laboratory water resulted in threshold values that bordered US national criteria and criteria for the state of Washington.     

Bioaccumulation and trophic transfer of mercury in a food web from a large, shallow, hypereutrophic lake (Lake Taihu) in China

Purpose

Due to the fast development of industry and the overuse of agrichemicals in past decades, Lake Taihu, an important source of aquatic products for Eastern China, has simultaneously suffered mercury (Hg) contamination and eutrophication. The objectives of this study are to understand Hg transfer in the food web in this eutrophic, shallow lake and to evaluate the exposure risk of Hg through fish consumption.

Methods

Biota samples including macrophytes, sestons, benthic animals, and fish were collected from Lake Taihu in the fall of 2009. The total mercury (THg), methyl mercury (MeHg), ??¹³C and ??¹⁵N in the samples were measured.

Results and discussion

The signature for ??¹⁵N increased with the trophic levels. Along with a diet composed of fish, the significant relationship between the ??¹³C and ??¹⁵N indicated that a pelagic foraging habitat is the dominant pathway for energy transfer in Lake Taihu. The concentrations of THg and MeHg in the organisms varied dramatically by ??3 orders of magnitude from primary producers (macrophytes and sestons) to piscivorous fish. The highest concentrations of both THg (100 ng g^?1) and MeHg (66 ng g^?1), however, were lower than the guideline of 200 ng g^?1 of MeHg for vulnerable populations that is recommended by the World Health Organization (WHO). The daily intake of THg and MeHg of 92 and 56 ng day^?1 kg^?1 body weight, respectively, was generally lower than the tolerable intake of 230 ng day^?1 kg^?1 body weight for children recommended by the Joint FAO/WHO Expert Committee on Food Additives. Significant relationships between the ??¹⁵N and the logarithm of THg and MeHg showed an obvious biomagnification of Hg along the food web. The logarithmic bioaccumulation factor of MeHg in the fish (up to 5.7) from Lake Taihu, however, was relatively low compared to that of other aquatic ecosystems.

Conclusion

Health risk of exposure to Hg by consumption of fish for local residents is relatively low in the Lake Taihu area. Dilution of Hg levels in the phytoplankton induced by eutrophication is a possible factor inhibiting accumulation of MeHg in fish in eutrophic Lake Taihu.     

Pesticide pressure and fish farming in barrage pond in Northeastern France. Part II: residues of 13 pesticides in water, sediments, edible fish and their relationships

Residues of pesticides in fish farming productions from barrage ponds are seldom studied in spite of increasing health questionings and environmental concerns. The purpose of this study is to establish the pesticide contamination profiles of sediments and edible fish from five ponds in Northeastern France. Multi-residues method and liquid chromatography–tandem mass spectrometry analysis were used to quantify 13 pesticides (azoxystrobin, carbendazim, clomazone, diflufenican, dimethachlor, fluroxypyr, iprodion, isoproturon, mesosulfuron-methyl, metazachlor, napropamid, quizalofop and thifensulfuron-methyl). Ten sediments and 143 muscles samples were analysed, corresponding to two successive fishing campaigns (first fishing date and second fishing date (P2), about 1 year later) on five sites (noted C-0, C-25, C-45, C-75 and C-85 to express the increasing gradient of crop area). Isoproturon was present in all sediments samples (1.8–56.4 μg/kg dry weight). During P2 period, carbendazim was quantified in the fish of site C-0 (0.09?±?0.02, 0.2?±?0.1 and 0.17?±?0.06 μg/kg wet weight (ww) for roach, carp and perch, respectively). Metazachlor was only quantified in perch of the site C-25 (0.13?±?0.02 μg/kg ww). Concentrations of isoproturon were similar for the sites C-45 and C-75 with 0.4?±?0.1 and 0.75?±?0.06 μg/kg ww for carp and perch, respectively. Contamination of fish reflected generally concentrations in surroundings. Isoproturon was the most concentrated and its main source was water for perch while carp was exposed through both water and sediments, highlighting their life strategies in pond.     

Trophic relationships and health risk assessments of trace metals in the aquaculture pond ecosystem of Pearl River Delta,China

Cadmium, lead, zinc, Chromium, copper, nickel and manganese in sediments and in aquatic organisms were collected from the aquaculture pond ecosystem of the Pearl River Delta (PRD), China and analyzed to evaluate bioaccumulation and trophic transfer in food chains, as well as the potential health risk of exposure to the Hong Kong residents via dietary intake of these aquatic products. The results revealed that based on the biota–sediment accumulation factor, omnivorous fish and zooplankton accumulated more trace metals from sediment than carnivorous fish. Concentrations of seven trace metals in aquaculture pond of PRD significantly decreased with increasing trophic levels, showing that these trace metals were trophically diluted in predatory and omnivorous food chains. The hazard index values of all fish species were smaller than 1 for adults and children, indicating there was no health risk from the multiple metals via ingestion of the freshwater fish for the inhabitants.     

A study of polonium-210 distribution aspects in the riverine ecosystem of Kaveri, Tiruchirappalli, India

Distribution of a natural radionuclide (210Po) in water, sediment and biota was quantified along a 95 km reach of the Kaveri River, India. It is observed that the soft tissues of animals concentrated a higher level of 210Po than the hard parts like shell and bone. The ranges of 210Po activity in biological samples were 2.32-10.78 Bq kg(-1) wet (aquatic weeds), 18.94-28.55 Bq kg(-1) wet (plankton), 32.51 to 46.17 Bq kg(-1) wet (snail), 57.42 to 105.78 Bq kg(-1) wet (bivalve), 12.13 to 19.10 Bq kg(-1) wet (prawn) and 1.86 to 4.17 Bq kg(-1) wet (fish). The concentration factors (CFs) for the aquatic organisms ranged from 10(3) to 10(4), indicating a high affinity of 210Po for organic moieties. The bivalve mollusc, Lamellidens marginalis, accumulated higher concentrations of 210Po, suggesting that it could serve as a biomonitor of 210Po radionuclide in riverine systems. Further, the levels of 210Po in water, sediment and biological samples from impoundments were higher than those from stations located in the open river. This may be largely due to aerial inputs of the radionuclide, accumulation of radionucliderich silt and organic matter, and increased biological production in the impounded water body.     

Betulinol and wood sterols in sediments contaminated by pulp and paper mill effluents: dissolution and spatial distribution

The goal was to determine dissolution potency of betulinol and wood sterols (WSs) from pulp and paper mill-contaminated sediments and the current stratification for assessment the load due to potential erosion in the river-like watercourse. Both compounds are wood extractives, which may be toxic to benthos and fish. This research continues a study in which other wood extractives, resin acids and their derivative, retene, were analysed. Sediments were collected from 1, 3.5, 12, 15, and 33 km downstream from the pulp and paper mills, and from 2 upstream reference sites. The dissolution potency into sediment–water elutriates (1?+?4?v/v) was studied by two agitation times and temperatures. The vertical amounts of extractives were determined from the uppermost 20 cm of sediment. The amounts of extractives potentially released were estimated from the sediment layers 0–2 and 2–5 cm by using spatial interpolation. According to the interpolation, the total amount of betulinol and β-sitosterol was calculated as kg/ha in the whole sediment area. Significant concentrations of betulinol (1,666 μg/g, dw) and WSs (2,886 μg/g, dw) were measured from the sediments. According spatial interpolation, the highest calculated amount of betulinol (4,726 kg/ha) and that of the most abundant WS, β-sitosterol (3,571 kg/ha), were in the lake where the effluents were discharged. In the dissolution experiment, the highest concentration of betulinol in sediment (0–10 cm) and elutriate was 412 μg/g (dw) and 165 μg/l, respectively. For WSs, concentrations were 768 μg/g (dw) in sediment and 273 μg/l in elutriate. In a worst-case scenario, betulinol may be desorbed to water in concentrations which are hazardous to aquatic animals. Instead WSs are not a risk in this study area. The amount of desorption varied depending on the concentration of contaminants in sediment, the nature of disturbance, and the sediment organic carbon content.     

Latent effects of early life stage exposure to triclosan on survival in fathead minnows,Pimephales promelas

The objective of this study was to evaluate the effects of early life stage triclosan (5-chloro-2-(2,4, dichlorophenoxy)phenol, TCS) exposure on hatching, development, and survival in the fathead minnow, Pimephales promelas. Embryonic minnows were exposed to TCS (50 and 100 µg L^?1) for 10 days followed by 6 weeks depuration. Mortality and morphological deformities were recorded and quantified during exposure and at the end of depuration. No significant effects on embryonic survival, time to reach the eyed stage, or hatching were found. However, at the conclusion of the depuration period, survival was significantly reduced in TCS exposed fish depending on the concentration. Visual inspection of the exposed fish suggests that mortality is related to spinal deformities, emaciation, and reduced foraging ability. Triclosan exhibits deleterious effects in fish at lower concentrations over longer durations than previously reported. Further, mortality in exposed fish 6 weeks after exposure demonstrates the need for various exposure assays to evaluate effects of TCS.     

Effects of realistic concentrations of TiO<Subscript>2</Subscript> and ZnO nanoparticles in <Emphasis Type="Italic">Prochilodus lineatus</Emphasis> juvenile fish

The impact of nanoparticles on fish health is still a matter of debate, since nanotechnology is quite recent. In this study, freshwater benthonic juvenile fish Prochilodus lineatus were exposed through water to three concentrations of TiO₂ (0.1, 1, and 10 μg l^?1) and ZnO (7, 70, and 700 μg l^?1) nanoparticles, as well as to a mixture of both (TiO₂ 1 μg l^?1?+?ZnO 70 μg l^?1) for 5 and 30 days. Nanoparticle characterization revealed an increase of aggregate size in the function of concentration, but suspensions were generally stable. Fish mortality was high at subchronic exposure to 70 and 700 μg l^?1 of ZnO. Nanoparticle exposure led to decreased acetylcholinesterase activity either in the muscle or in the brain, depending on particle composition (muscle—TiO₂ 10 μg l^?1; brain—ZnO 7 and 700 μg l^?1), and protein oxidative damage increased in the brain (ZnO 70 μg l^?1) and gills (ZnO 70 μg l^?1 and mixture) but not in the liver. Exposed fish had more frequent alterations in the liver (necrosis, vascular congestion, leukocyte infiltration, and basophilic foci) and gills (hyperplasia and epithelial damages, e.g., epithelial disorganization and epithelial loss) than the control fish. Thus, predicted concentrations of TiO₂ and ZnO nanoparticles caused detectable effects on P. lineatus that may have important consequences to fish health. But, these effects are much more subtle than those usually reported in the scientific literature for high concentrations or doses of metal nanoparticles.     

Genotoxic potential of selected cytostatic drugs in human and zebrafish cells

Due to their increasing use, the residues of anti-neoplastic drugs have become emerging pollutants in aquatic environments. Most of them directly or indirectly interfere with the cell’s genome, which classifies them into a group of particularly dangerous compounds. The aim of the present study was to conduct a comparative in vitro toxicological characterisation of three commonly used cytostatics with different mechanisms of action (5-fluorouracil [5-FU], cisplatin [CDDP] and etoposide [ET]) towards zebrafish liver (ZFL) cell line, human hepatoma (HepG2) cells and human peripheral blood lymphocytes (HPBLs). Cytotoxicity was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and acridine orange/ethidium bromide staining. All three drugs induced time- and dose-dependent decreases in cell viability. The sensitivity of ZFL and HepG2 cells towards the cytotoxicity of 5-FU was comparable (half maximal inhibitory concentration (IC₅₀) 5.3 to 10.4 μg/mL). ZFL cells were more sensitive towards ET- (IC₅₀ 0.4 μg/mL) and HepG2 towards CDDP- (IC₅₀ 1.4 μg/mL) induced cytotoxicity. Genotoxicity was determined by comet assay and cytokinesis block micronucleus (CBMN) assay. ZFL cells were the most sensitive, and HPBLs were the least sensitive. In ZFL cells, induction of DNA strand breaks was a more sensitive genotoxicity endpoint than micronuclei (MNi) induction; the lowest effective concentration (LOEC) for DNA strand break induction was 0.001 μg/mL for ET, 0.01 μg/mL for 5-FU and 0.1 μg/mL for CDDP. In HepG2 cells, MNi induction was a more sensitive genotoxicity endpoint. The LOEC values were 0.01 μg/mL for ET, 0.1 μg/mL for 5-FU and 1 μg/mL for CDDP. The higher sensitivity of ZFL cells to cytostatic drugs raises the question of the impact of such compounds in aquatic ecosystem. Since little is known on the effect of such drugs on aquatic organisms, our results demonstrate that ZFL cells provide a relevant and sensitive tool to screen genotoxic potential of environmental pollutant in the frame of hazard assessment.     

Hematological and histopathological changes in silver catfish Rhamdia quelen (Siluriformes) exposed to clomazone herbicide in the Madre River,Santa Catarina State,Southern Brazil

This study evaluated the influence of the clomazone herbicide (2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone) contamination on the hematological parameters and histological changes in gills and liver of silver catfish (Rhamdia quelen) from Madre River, Santa Catarina State, Southern Brazil. Fish were collected between March 2010 and January 2012 at two different sites of the Madre River, one site receiving residual water (contaminated site) from rice culture (n = 49) and another that do not receive residual water (reference site) (n = 48). The herbicide clomazone analysis detected 3.40 ± 1.70 μg/L in the contaminated site and 1.1 ± 0.33 μg/L in the reference site. Fish from contaminated site showed increased (P < 0.05) number of monocytes suggesting the possible defense response as a result of chronic exposure to clomazone. On the other hand, no difference was found in the hematocrit percentage, red blood cell count, total thrombocyte number, white blood cell count, lymphocytes, and neutrophils number. Fish from both sites showed histopathological changes in gills and liver, possibly caused by chronic exposure to contamination. The influence of herbicide sub doses on fish health is also discussed.     

Polychlorinated dibenzo-p-dioxin and dibenzofuran concentrations in common fish species in the Pearl River Delta area, China

Polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs) concentrations in 31 fish samples from 19 commonly consumed freshwater and saltwater species from the Pearl River Delta Area were analyzed. The PCDD/Fs dietary intake from fish for the local population was evaluated to provide a database for setting the national PCDD/F limits in fish for the People's Republic of China. The median concentration from the 31 fish samples was 1.27 pg/g wet weight for the total of PCDD/Fs, and the median WHO-TEQ was 0.26 pg/g wet weight, and ranged from 0.063 to 1.30 pg WHO-TEQ/g wet weight. The dominant contributors to the WHO-TEQ were 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF, which accounted for 38% and 28%, respectively. The dietary intake of PCDD/Fs from fish for local people was estimated to be 0.47 pg WHO-TEQ/kg bw x day. In view of the findings, the dietary of PCDD/Fs from other foods of animal origins in China should be studied in more detail as soon as possible in order that standards can be put forward to protect human health.     

Quantification and characterization of vehicle-based polycyclic aromatic hydrocarbons (PAHs) in street dust from the Tamale metropolis,Ghana

Objective

Concentrations of polycyclic aromatic hydrocarbons (PAHs) in street dust in the Tamale metropolis, Ghana, have been measured in this study.

Results

The concentrations of the various types of PAHs identified in street dust samples from high vehicular traffic density in the metropolis are as follows: naphthalene, 10,000 μg/kg; acenaphthylene, 13,000 μg/kg; acenaphthene, 76,000 μg/kg; fluorene, 18,900 μg/kg; phenanthrene, 40,000 μg/kg; anthracene, 21,000 μg/kg; fluoranthene, 35,200 μg/kg; pyrene, 119,000 μg/kg; benzo[a]anthracene, 17,700 μg/kg; chrysene, 10,600 μg/kg; benzo[k]fluoranthene, 18,700 μg/kg; benzo[a]pyrene, 10,900 μg/kg and benzo[g, h, i]perylene, 21,000 μg/kg. Calculation of the phenanthrene/anthracene ratio indicated that the PAHs identified in this study were from vehicular fallout as the ratio was less than 10.

Conclusion

It is clear from the results of the study that road users in the Tamale metropolis, especially hawkers, are exposed to the harmful effects of PAHs, and this suggests the need for the establishment of mitigation measures by the regulatory agencies.

     

Human and ecotoxicological impacts assessment from the Mexican oil industry in the Coatzacoalcos region,as revealed by the USEtox™ model

Human and ecotoxicological impacts were analyzed in the lower basin of the Coatzacoalcos River (Veracruz, State in Mexico). High pollution levels of contaminants from the oil industry have been reported in natural streams and the Coatzacoalcos River and in their sediments. USEtox? model was employed to evaluate environmental fate, exposure, and effect of nine organic compounds (polycyclic aromatic hydrocarbons and one of which was in the group of polychlorinated biphenyls), a heavy metal (lead), and the effect of the industrial wastewater emitted into the river, on the Coatzacoalcos region. Most of these compounds are highly toxic; they bioaccumulate in human and animal tissue, mainly in the fatty tissues and can damage different organs and systemic targets such as the liver, kidney, hormonal system, nervous system, etc., of both humans and wildlife. The model estimates that 96 % (3,247 kg/day) of organic compounds is transferred from the water into air, whereas only 4 % (151 kg/day) remains in the water. In addition, it predicts that humans are mainly exposed to polychlorinated biphenyls (PCBs) congeners (28 and 153) by eating contaminated fish, due to PCBs accumulating in the fish fat tissue. The number of cases of cancer and noncancer (1 in 862 habitants per additional kilogram) is expected to have an increment due to the higher PCBs exposure of human population. Genetic damages in fishes, earthworms, and toads have been observed and related to higher exposure to organic compounds. The relationship between the field reported data and those one predicted by the USEtox? model have been confirmed empirically by using the nonparametric correlation analysis (Spearman's rho). Based on the USEtox model, the environmental stress in the Coatzacoalcos industrial zone is between 2 and 6 orders of magnitude over geometric mean of acute aquatic EC₅₀s. We think that USEtox model can be used to expand the number of substances that have the current water quality guidelines to improve the water management in Mexico.