Pollution of ground water by mercury and its residues in chicken tissues

The aim of this study was to investigate the relationship between mercury concentration in well water and its residues in chicken tissues in particular areas of Abees, Alexandria Governorate. The concentration of mercury in ground water, beside in liver, kidney, muscle tissues and blood samples of 12 chickens from four poultry production farms was estimated using atomic absorption spectrophotometer. The highest mercury concentration levels were observed in the kidney followed by the liver in detectable levels samples. The level of mercury in ground water was undetectable of 81 micro g/L. There is no doubt that the relationship of mercury accumulation levels in kidney and those in liver tissues were proportionally correlated. The rate of mercury accumulation is independent of the intake level and the toxic level could be reached eventually, even at a very low intake level. It is evident therefore that even very small concentration of mercury in environment may cause health risks affect exposures

Effect of environmental pollution by some pesticides on the mortality rate and behaviour of the Nile bolti, tilapia nilotica

Adult Tilapia nilotica were exposed to water containing different concentrations of three types of insecticides pollutants including methomyl, cypermethrin and malathion. These pollutants are currently used and contaminate the Egyptian waterways. Survival and behaviour were the responses used for measuring the toxic effects. The data indicate that the mortality rate increased with the increase of toxic dose and exposure time and therefore, the survival percentage decreased with the increase of insecticide concentration. The order of toxicity of the three used pesticides is arranged in a descending manner as methomyl, cypermethrin and malathion repectively. From the TLm measurements, the 24 h. LC[50] in Tilapia nilotica was 0.16, 0.58 and 0.80 mg.l[-1] for methomy1, cypermethrin and malathion respectively. The behaviour pattern of the toxicant fishes was found to be in the form of hyperexcitation followed by a state of unbalance and a reduction in activity till death occurred