Embryo Acute Toxicity Research Articles

Multi-species toxicity evaluation of a chromium-based leather tannery wastewater

This study focused on a comparative evaluation of wastewater from a chromium-based tannery in Izmir (Turkey). Two sampling campaigns included raw wastewater (R), the effluents of coagulation/flocculation process (CF), biological treatment (B) and dried sludge (DS). Samples were analyzed for their metal contents. A set of toxicity endpoints were tested by sea urchin ( Paracentrotus lividius and Sphaerechinus granularis) for the endpoints of acute embryotoxicity, developmental defects, changes in sperm fertilization success and transmissible damage from sperm to the offspring. Furthermore, algal growth ( Selenastrum capricornutum) inhibition and Daphnia magna immobilization tests were performed according to standard procedures. The sea urchin bioassay results showed that raw wastewater toxicity is enhanced by the physico-chemical treatment and is decreased by the biological treatment for both samples. Confirming the data from a previous study, a concentration-related toxicity was exerted by effluent or sludge samples according to the following rank: DS > CF > R > B. On the other hand, offspring quality was not affected by sperm exposure to any wastewater or to sludge samples. However, D. magna was immobilized for both samples by the ranking of R > CF > B while algal growth inhibition was caused in a different order for the samples. Overall results suggest submitting the CF effluent to biological treatment which absorbs the toxic content of the wastewater in leather tanning industry; however, the sludge containing toxic components must be handled very carefully.

Toxicity of leather tanning wastewater effluents in sea urchin early development and in marine microalgae

This study was designed to investigate the composition and the toxicity of leather tanning wastewater and conditioned sludge collected at the leather tanning wastewater treatment plant (CODISO) located in Solofra, Avellino (Southern Italy). Samples were analyzed for their conventional parameters (COD, TSS, chromium and ammonia) and for metal content. Effluent samples included raw wastewater, and samples collected following coagulation/flocculation process and biological treatment. A set of toxicity endpoints were tested using sea urchin and marine microalgal bioassays by evaluating acute embryotoxicity, developmental defects, changes in sperm fertilization success and transmissible damage from sperm to the offspring, and changes in algal growth rate. Dose-related toxicity to sea urchin embryogenesis and sperm fertilization success was exerted by effluent or sludge samples according to the following rank: conditioned sludge > coagulated effluent ⩾ raw influent >> effluent from biological treatment. Offspring quality was not affected by sperm exposure to any wastewater or to sludge samples. Algal growth was inhibited by raw or coagulated effluent to a similar extent and, again, the effluent from the biological treatment resulted in a decreased toxicity. The results suggest that coagulated effluent and conditioned sludge result in higher toxicity than raw influent in sea urchin embryos and sperm, whereas the biological wastewater treatment of coagulated effluent, in both sea urchins and algae, cause a substantial improvement of wastewater quality. Hence a final biological wastewater treatment should be operated to minimize any environmental damage from tannery wastewater.

Effects of pulp and paper mill effluents on reproductive success of largemouth bass

This study evaluated the effects of bleached and unbleached kraft mill effluent on reproductive success of largemouth bass (Micropterus salmoides). Bass were exposed to effluent concentrations (0, 10, 20, 40, or 80%) for 28 and 56 d. Parameters measured included hepatosomatic index (HSI) and gonadosomatic index (GSI) and plasma concentrations of 17beta-estradiol (E2), 11-ketotestosterone (11-KT), and vitellogenin (VTG). At the end of the 56-d period, bass were moved to hatchery ponds to evaluate spawning success. Spawning mats with eggs either were brought indoors for evaluation of fecundities, hatchabilities, and egg and fry size (measured at age 3 d), or were left in ponds and fry number and size recorded (average age of 14 d). Effluent exposure was verified by measuring resin acids (isopimaric, abietic. and dehydroabietic acids) in bile. Compared to controls, exposed bass had greater concentrations of resin acids in bile. In general, exposed females had lower concentrations of E2 and VTG (> or = 20% effluent), whereas males had lower concentrations of 11-KT (> or = 20% effluent) and increased E2 (> or = 20% effluent). The HSI values increased in females (> or = 10% effluent), and GSI values decreased in both sexes (> or = 40% effluent). Fecundity, egg size, and hatchability did not differ across treatments, but an increase in the frequency of fry abnormalities and a decrease in fry weights was observed at effluent exposures of 40% and higher. However, results from the pond study, revealed a significant reduction in fry growth and survival (> or = 10%). This decline may have been caused by an increased frequency of deformities, in conjunction with alterations of growth. These changes could have resulted from alterations in egg quality because of failure of parental reproductive systems, from acute embryo toxicity after translocation of contaminants from the mother to the developing embryo, or from both.

Bauxite manufacturing residues from Gardanne (France) and Portovesme (Italy) exert different patterns of pollution and toxicity to sea urchin embryos

This study was designed to investigate the composition and toxicity of solid residues from bauxite manufacturing plants. Soil and dust samples were collected in the proximity of two bauxite plants (Gardanne, France, and Portovesme, Italy). Samples were analyzed for their content of some selected inorganic contaminants by means of inductively coupled plasma optical emission spectroscopy (ICP-OES) either following acid digestion procedures or by seawater release of soluble components. Toxicity was tested by sea urchin bioassays to evaluate a set of toxicity endpoints including acute embryotoxicity, developmental defects, changes in sperm fertilization success, transmissible damage from sperm to the offspring, and cytogenetic abnormalities. Inorganic analysis showed two distinct sets of inorganic contaminants in Gardanne versus Portovesme, including Al, Cr, Cu, Fe, Mn, Pb, Ti, and Zn; sample composition (seawater-soluble contaminants) and toxicity showed a noteworthy association. The most severe toxicity to embryogenesis and to sperm fertilization success was exerted by some Portovesme samples (0.03-0.5% w/v), with a significant association between toxicity and dose-related seawater release of Zn, Pb, and Mn. Seawater extraction of a toxic dust sample (G20) from the Gardanne factory showed increasing seawater release of Al, Fe, and Mn; the G20 sample, at the level of 0.5%, affected both developing sea urchin embryos and sperm (offspring quality). Soil samples around the Gardanne factory showed the highest frequency of toxic soil sites eastward from the factory. The present data point to solid deposition from bauxite plants as a potential subject of environmental health concern. The results suggest that extraction methods for evaluating the toxicity of complex mixtures should be based on the environmental availability of mixture components. The differences in sample toxicity among the tested sites, however, suggest possible site-to-site variability in geochemical and/or technological parameters.

Factors affecting R6 fungicide toxicity on sea urchin fertilization and early development: roles of exposure routes and mixture components.

A technical fungicide mixture, R6 and its components, cymoxanil (CYM) and cupric oxychloride (Cu-OCl), were tested by sea urchin bioassays (Paracentrotus lividus and Sphaerechinus granularis). A set of toxicity endpoints was evaluated including both lethal and sublethal effects with the following endpoints: (a) acute embryotoxicity, (b) developmental defects, (c) changes in sperm fertilization success, (d) transmissible damage from sperm to the offspring, and (e) cytogenetic abnormalities. Acute effects on developing embryos were observed as early (prehatch) mortality at R6 levels > or =25 microg/ml. The pesticide mixture R6 was tested at realistic concentrations, ranging from 25 ng/ ml to 2.5 microg/ml, and the two components, CYM and Cu-OCl, were tested, either alone or in mixture, at concentrations equal to their levels in the corresponding R6 solutions. R6 was either dissolved in filtered seawater (water only, W-O), or spiked in "pristine" silt-clay sediment or soil samples before bioassays. Developmental toxicity of R6, following W-O dissolution, displayed a significant dose-related increase of larval malformations and differentiation arrest at concentrations of 750 ng/ml to 2.5 microg/ml both in P. lividus and in S. granularis larvae. Developmental toxicity was removed in spiked sediment up to R6 nominal levels (25 microg/ml), 10-fold above the embryotoxic R6 levels in W-O exposure. No significant developmental toxicity was exerted by CYM or Cu-OCl (W-O exposure) up to their concentrations equivalent to 2.5 microg/ml R6. The laboratory-prepared mixture of CYM and Cu-OCl, in the same concentration range, only resulted in minor effects, as larval retardation, suggesting the presence of toxic impurities (or additional components) in the R6 formulation. When sperm from either P. lividus or S. granularis were exposed to R6 before fertilization, a W-O exposure resulted in a dose-related decrease in fertilization of P. lividus sperm (up to 250 microg/ml R6), whereas S. granularis sperm underwent a significant increase of fertilization rate at the highest R6 nominal levels (up to 25 microg/ml). Equivalent CYM or Cu-OCl levels were ineffective on sperm fertilization success in both species. The offspring of S. granularis sperm exposed to 25 microg/ml R6 showed a significant increase in larval malformations, which were not detected in the offspring of R6-exposed P. lividus sperm. Again, CYM or Cu-OCl was unable to exert any transmissible damage from sperm to the offspring in either species. The present study raises the case of possible discrepancies between toxicity of a technical mixture and of its analytical-grade components, also providing evidence for a loss of pesticide toxicity following dispersion in an environmental matrix such as sediment or soil.

Fragrance raw materials monographs

The demand for biofuels increases due to concerns regarding greenhouse gas emissions and depletion of fossil oil reserves. Many substances identified as potential biofuels are solvents or already used as flavors or fragrances. Although humans and the environment may be readily exposed little is known regarding their (eco)toxicological effects. In this study, the three potential biofuels ethyl levulinate (EL), 2-methyltetrahydrofuran (2-MTHF) and 2-methylfuran (2-MF) were investigated for their acute embryo toxicity and teratogenicity using the fish embryo toxicity (FET) test to identify unknown hazard potentials and to allow focusing further research on substances with low toxic potentials. In addition, two fossil fuels (diesel and gasoline) and an established biofuel (rapeseed oil methyl ester) were investigated as references. The FET test is widely accepted and used in (eco)toxicology. It was performed using the zebrafish Danio rerio, a model organism useful for the prediction of human teratogenicity. Testing revealed a higher acute toxicity for EL (LC50: 83 mg/L) compared to 2-MTHF (LC50: 2980 mg/L), 2-MF (LC50: 405 mg/L) and water accommodated fractions of the reference fuels including gasoline (LC50: 244 mg DOC/L). In addition, EL caused a statistically significant effect on head development resulting in elevated head lengths in zebrafish embryos. Results for EL reduce its likelihood of use as a biofuel since other substances with a lower toxic potential are available. The FET test applied at an early stage of development might be a useful tool to avoid further time and money requiring steps regarding research on unfavorable biofuels.