Acrylamide is a chemical used mainly in industrial applications and the treatment of drinking and wastewater, making it easy to enter aquatic ecosystems. There are few studies known about the toxicity of acrylamide to aquatic organisms which have shown evidence of a number of histopathological effects. To assess the effects of acrylamide to freshwater fish, Zebrafish (Danio rerio) embryos were exposed to serial concentrations of acrylamide (0, 100, 300, and 500 mg/L) to investigate the acute toxicity effects on teleost embryogenesis. Embryos less than 24 hrs old were exposed under static non-renewal conditions for ten days or until hatching. The toxic endpoints evaluated include: egg/embryo viability, hatchability, and morphological/developmental anomalies during organogenesis. The acute toxicity test resulted in a 48 h-LC50 of 585 mg/L for egg viability. Exposure of embryos significantly reduced hatchability and larval survival, in a concentration dependent manner. Dimethyl sulfoxide (DMSO) was used as a solvent carrier to permeate the uptake of acrylamide through the chorion membrane. No significant damages or complications were observed in embryos exposed to DMSO. At 500 mg/L, the highest test concentration, the survival of embryos was greatly reduced within 24 hrs of exposure. The lower test, 100 mg/L, produced a significant number of developmental anomalies to the Zebrafish that included dorsal tail flexure, severe pericardial edema, facial and cranial defects and decreased heartrate (40 bpm). Premature hatching of embryos and developmental arrest was observed in all concentrations. The severity of these anomalies was concentration-dependent and resulted in low survival rate and high frequency of malformations. These results indicate that acrylamide is teratogenic and provide support for sub-lethal toxicity testing using Zebrafish embryos.

We evaluated the acute toxicity of Tetrachloroethylene (C(2)Cl(4)), and investigated its sub-chronic effects on the embryonic development of Japanese medaka (Oryzias latipes). One-day-old eggs/embryos of this fish species were exposed, under static renewal conditions, to serial concentrations (0, 20, 40, 60, and 80 mg/L) of C(2)Cl(4) for 96 h (acute) and 10 days (sub-chronic) time periods. The toxic endpoints evaluated included: egg/embryo viability, hatchability, and morphological/developmental abnormalities. The acute toxicity test resulted in a 96 h-LC(50) of 27.0 (19.5-32.9) mg/L for egg viability. Exposure of eggs to sub-chronic concentrations (0, 1.5, 3, 6, 12, and 25 mg/L) of C(2)Cl(4) significantly reduced hatchability and larval survival, in a concentration dependent manner. At the highest tested concentration (25 mg/L) of the sub-lethal exposure, larval survival was greatly reduced to within three days post-hatch. The lowest tested concentration (1.5 mg/L) produced a significant number of developmental effects to the Japanese medaka, including abnormal development of the circulatory system, yolk-sac edema, pericardial edema, scoliosis, hemorrhaging, blood pooling, and defects in heart morphology. The severity of these abnormalities was concentration-dependent. It can be concluded from these results that tetrachloroethylene is teratogenic to the Japanese medaka.

Simazine and propazine are selective triazine herbicides currently in use to control broad-leaved weeds and annual grasses around the world. Bisphenol A (BPA) is an industrial chemical used in the production of polycarbonate plastics often found in consumer goods, such as plastic containers, baby bottles etc. These synthetic compounds are known to increase the risk of cancer, cause adverse reproductive effect in reptiles, mammals, birds, humans, and lead to other health problems. They have become some of the principal agents of contamination in water bodies around the world through herbicide runoff, industrial waste and leaching. Some triazines such as atrazine are banned in most European countries for over ten years due to their adverse reproductive effect in mammals, birds and humans; however propazine and simazine are still in use around the world. The removal of these compounds from contaminated water is an exigent challenge. In this study, we investigated their affinity for the surface of nanoparticles (NPS) and standard metallic oxides in an effort to exploit the unique potential applications of NPS for water purification systems. We studied the adsorption of the two triazines and BPA on the surface of NPS of iron (III) oxide, NPS of carbon, bulk iron (III) oxide and aluminum oxide at pH 6 and pH 8 using UV-Visible spectroscopy. Result indicates that these compounds have different affinity towards the surface of metallic oxides and carbon at various pHs. In general, there is relatively high adsorption of some of these compounds on the surface of NPS compared to bulk particles. NPS of carbon have shown the highest affinity for all the three compounds. The lower pH was found to be favorable for all of the compounds except for BPA. BPA have shown high adsorption at pH 8 than at pH 6.