Abstract-The acute toxicity of melathion (MAL), atrzine (ATR) and Cadmium (Cd) in zebrafish (Danio rerio) were investigated by acute toxicity (LC 50 ), and the results showed that the 96 h LC 50 followed the order: MAL>Cd>ATR. Furthermore, the accumulation of ecotoxicity in zebrafish body and correlated biochemical responses in brain and muscles were explored and it was found that MAL, ATR and Cd could be rapidly accumulated in fish body shortly after exposure. The activities of superoxide dismutase and catalase in fish body increased after 96h exposure. The acute toxicity caused protein reduction in brain and muscles, and elevation of total lipid dry weight in fish body. Besides, some dose-dependent inhibition of AChE activity was found in brain and muscles of zebrafish exposed to higher concentrations of acute toxins. These can be employed in biomonitoring programs because they showed good correlation with toxins and were sensitive to different concentration patterns.

Acute toxicity of cadmium (Cd) to zebrafish (Danio rerio) was studied. The 24, 48, 72 and 96 h LC50 values (with 95% confidence limits) estimated by probit analysis were 16.73 (20.03-13.98), 12.88 (14.96-11.08), 11.46 (13.21-9.94), 9.68 (11.12-8.43) mg L -1 , respectively. To determine the accumulation and cyto-toxicity of Cd on the brain and skeletal muscle of zebrafish, specimens of zebrafish were exposed to three concentrations of cadmium (0.65 mg Cd L -1 , C1; 0.97 mg Cd L -1 , C2; and 1.94 mg Cd L -1 , C3 (corresponding to 1/15th, 1/10th and 1/5th of 96 h LC50), respectively for 25 days. The concentration of Cd in the fish tissue was detected by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). Tissue alterations of brain and skeletal muscle were observed under light microscope. Cadmium concentrations of the treated fishes showed a significantly exponential increase over time and peaked at Day 25. In term of histomorphology of brain and skeletal muscle, obvious tissue chaos was noticed in the treated fishes compared to the control group. This mess clearly appeared at Day 25 at C3 in the brain where the tissue showed different extents of granule cell loss, degeneration of Purkinje cells, aggregation area of gliosis and many areas of necrosis. Ultra-structural damage of moderate or low levels was observed in the fishes at C1 and C3 after 5 days and C1 after 25 days of treatment. In the skeletal muscle at 25 days of C3 treatment, different degrees of swelling and high necrosis were observed. This indicates that a defense mechanism was started with the accumulation of metal Cd in the tissues over time. Thus, the information provided in this study may be very useful for the deep understanding of the mechanisms of Cd stress in fish.

Abstract-The present study was planned designed to investigate the chronic impacts of herbicide atrazine exposure on stress biomarkers acetylcholinesterase activity (AChE) and oxidative stress responses in brain of zebrafish (Danio rerio), and determine the bioconcentration of atrazine in whole body of fish. Chronic exposure to atrazine unveiled a markedly discourage in the activity of AChE. However, significant increase in the activities of catalase (CAT) and superoxide dismutase (SOD) and both influenced by atraizine, and CAT was over sensitivity to atrazine compared with SOD. The highest bioconcentration factor (BCF) of atrazine in the fish treated was (12.8543×10 4 and 13.5891×10 4 ) after 24h exposure to (0.957 and 1.913 mg L -1 ) and 13.238×10 4 , after 25 d exposure to 0.638 mg L −1 of atrazine respectively. This study showed that the zebrafish have ability to bioaccumulate of the herbicide atrazine rapidly. atrazine accumulation in zebrafish has a private importance due to the implication of atrazine in chronically health problems, as well as the information contained in our study is useful for understand the mechanism of atrazine induced oxidative stress in fish.

No abstract

Air pollution has regarded as one of the most significant environmental problems, due to its direct impact on ecosystems and human health. Economic and industrial development has increased urban atmospheric pollution, especially in developing nations. This research conducted to rate the rainwater quality in different areas of Basrah city. Using biota and rainwater samples carried out on Environmental monitoring of selected metals. From five locations collected samples (Khor Al-Zubair, Al-Zubair district, Basrah City Center, Abil Khaseeb district, and Garma Ali area). Results showed a significant difference in concentrations of trace metals levels between rainwater and date palm (Phoenix dactylifera L.) and Cordia myxa plant leaves and discovered in the following order: Fe > Mn > Cu > Pb. The soluble ions in rainwater followed the following order:− . Vehicles, industry emissions, and waste burning are the main anthropogenic sources of ions and metals. According to WHO standards, concentrations of trace metals have been found in the study areas above the acceptable limits in the sample of both plants. These findings show that special attention should pay to this environmental issue and that these emission levels should cut.