A comparative study on the effects of a pesticide (cypermethrin) and two metals (copper, lead) to serum biochemistry of Nile tilapia, Oreochromis niloticus

The present study was designed to compare the responses in freshwater fish Oreochromis niloticus exposed to a synthetic pyrethroid, cypermethrin (CYP); an essential metal, copper (Cu); and a nonessential metal, lead (Pb). Fish were exposed to 0.05 μg/l CYP, 0.05 mg/l Cu, and 0.05 mg/l Pb for 4 and 21 days, and the alterations in serum enzyme activities, metabolite, and ion levels were determined. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities increased in response to CYP, Cu, and Pb exposures at both exposure periods. While elevations in alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) activities and in cholesterol level were observed in pesticide-exposed fish at 4 and 21 days, they increased in Cu- and Pb-exposed fish at 21 days. Although metal-exposed fish showed increases in cortisol and glucose levels at 4 days followed by a return to control levels at the end of the exposure period, their levels elevated in pesticide-exposed fish at both exposure periods. Total protein levels decreased in Pb- and pesticide-exposed fish at 21 days. Na+ and Cl− levels decreased in pesticide-exposed fish at both exposure periods and in Cu- and Pb-exposed fish at 21 days. The exposures of pesticide and metals caused an elevation in K+ level at the end of the exposure period. The present study showed that observed alterations in all serum biochemical parameters of fish-treated pesticide were higher than those in fish exposed to metals

Determination of Bioaccumulation of Heavy Metals and Selenium in Tissues of Brown Trout Salmo trutta macrostigma Duméril 1858 from Munzur Stream Tunceli Turkey

The objective of the present work was to determine the bioaccumulation of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), mercury (Hg), uranium (U) and selenium (Se) in gill, liver, and muscle tissues of the fresh water fish Salmo trutta macrostigma (Duméril, 1858) in Munzur Stream, Tunceli, Turkey. The highest concentrations of U (1.83 μg kg−1), Pb (119.84 μg kg−1) and Se (1.31 μg kg−1) were recorded in the gills of S. t. macrostigma. Concentrations of As (46.27 μg kg−1), Cd (109.19 μg kg−1), Hg (16.40 μg kg−1), Cu (18.19 μg kg−1) were recorded at highest levels in the liver. The results showed that there were significant differences in concentrations of As, Cd, Cu, Pb, Se, U and Hg in gill, liver and muscle tissue (p < 0.05). Heavy metals were within the edible parts of the investigated fish were in the permissible safety levels for human uses

Summary of Contemporary Research on the Use of Chemical Dispersants for Deep-Sea Oil Spills

Mitigation options for deep-sea oil spills are indeed few. In the open ocean, far from land, booming, burning, and mechanical pickup of oil at the sea surface may be of limited value due to wave and wind conditions. The use of chemicals to disperse oil into smaller droplets is predicated on the assumptions that smaller droplets are more easily dissolved into surrounding waters and that smaller droplets are degraded by bacterial action more rapidly than are larger droplets. During the Deepwater Horizon accident, a novel use of dispersants injected directly into the subsurface source of the blowout was undertaken to treat the oil prior to surfacing. The presence of subsurface “plumes” of small droplets and dissolved oil observed during DWH raised the issue of active measures to sequester oil in the subsurface vs. allowing it to surface. Reducing the concentration of volatile organic compounds surfacing near workers was also a stated objective of subsurface dispersant injection (SSDI) application. Aquatic toxicity testing has evolved significantly from a sole focus on short-term mortality to evaluate a variety of sublethal physiological, genotoxic, and immunogenic impacts affecting animal health and fitness of exposed populations. In this chapter we consider a number of pressing – and heretofore unresolved – issues surrounding the use of dispersants as an oil spill mitigation tool. Further, we advocate continued, targeted research to help resolve ongoing controversies regarding dispersant use