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Total mercury and selenium concentrations were determined in 47 swordfish caught in the north-west Atlantic ocean. Only 10 swordfish had total mercury levels equal to or below the World Health Organization (W.H.O.) limit of 0.5 μg of mercury/g of fish. All fish had significant quantities of selenium. All fish that contained mercury up to 2 mg/g had a molar excess of selenium compared to mercury.Two hundred and fifty-one swordfish were analyzed for total mercury and only 12 fish or 4.8% contained more than 2 ng/g total mercury; therefore, it was concluded that in most swordfish there was a molar excess of selenium in relation to mercury.Since selenium has been shown to lower the toxicity of methyl mercury in animal studies by other investigators, it was suggested that the use of swordfish for food should be reviewed.

The reduction of arsenate ion to arsenite ion by a variety of tissues was widely distributed, and not a property of any particular tissue. The nature of the reduction was investigated by using various chemical inducers and inhibitors and is believed to be chemical in nature.

Arsenite ion, as arsenic trichloride was extracted into benzene from strongly acidified tissue homogenates. Following this, arsenite was extracted from the benzene into water, made up in 1N HCl and analyzed polarographically. Arsenate ion, left in the homogenate after arsenite extraction is isolated in exactly the same way following treatment of the homogenate with cuprous ion to reduce arsenate to arsenite ion. Treatment of the acidified homogenate with cuprous ion prior to extraction gives a homogenate which is readily analyzed for total “inorganic” arsenic. The method was efficient to a maximum level of about 20 μg inorganic arsenic since at higher levels lower recoveries were found. Analysis of a variety of marine biological specimens, with levels of total arsenic up to 40.5 ppm, indicated little of this arsenic was present in an inorganic form. Post mortem reduction of arsenate to arsenite was found to occur rapidly in fish tissue.

Field studies on the use of coated polyurethane foam plugs as indwelling water monitors and studies of the ability of such foams to quantitatively extract polychlorinated biphenyls, dieldrin and members of the DDT complex were carried out using waters of an industrial nature and agricultural nature. Recoveries of all spiked materials were generally in excess of 90%. Indwelling foams took from 24-48 hours to reach plateau values and from the levels of plateaus reached it is suggested that only the external surface of the porous plug is active. Use and reuse of plugs as well as extraction in the field is easily accomplished.

Castrated male pigs were injected with approximately .2 mg of CdCl2 five times a week for 12 weeks. Twenty-one organs or sites were sampled to determine the distribution of cadmium in tissues. Concentrations in endocrine glands (wet weight) of 77-90 μg/g in pancreas, 14-21 μg/ in adrenal, 7,7 - 11 μg/g in pituitary, and 1.1 - 6.3 μg/g in thyroid indicate the need for more through examination of the functioning of these organs in the presence of cadmium.

In a sample of 100 live Atlantic cod (Gadus morhua) collected near the entrance of Halifax Harbour, Nova Scotia, in August 1980, 73% had histopathological lesions in their livers similar to those produced by toxicants such as polychlorinated hydrocarbons. These lesions were characterized by fatty degeneration and, in a few samples, desquamation of the epithelia of bile ducts. Only 8% of the fish sampled, all males and at the lower end of the size spectrum, had liver tissue with apparently normal parenchyma. The remaining 19% had early indications of pathologic alterations.

Differences observed in autoradiogram profiles and isotope ratios or corticosteroid metabolites (such as cortisol), in vitro, in interrenal activity between and within hatchery reared salmon (Salmo salar) parr stocks were not observed in corresponding wild stocks. Wild fish from nine Nova Scotian rivers (Annapolis, Black, East, Gold, LaHave, Medway, Musha-mush, Salmon, and Stewiacke Rivers), sampled during May to December all showed similar corticosteroid profiles. Differences were observed in corticosteroid profiles in December between: (1) hatchery stock held in acidic and circumneutral rivers; and (2) hatchery stock held in cages in a limed river, wild stock from this river, and hatchery stock maintained at the hatchery. Copyright 1994, 1999 Academic Press

Fresh interrenal tissue of Atlantic salmon (Salmo salar) parr transformed [³H]pregnenolone and [¹⁴C]progesterone, in vitro, to double-labeled cortisol and corticosterone with yields of less than 3% ³H and 5% ¹⁴C at 0-5°, 8-10°, and 22-24° over various incubation periods. Incubations at 22-24° gave the highest yields. A time-yield study at 22-24° for 0.5 to 3 hr in late March showed that metabolic patterns did not change with time as metabolic yields increased. Double-labeled metabolites, 11-deoxycortisol, 21-deoxycortisol, and 17α-hydroxyprogesterone, were all detected in hatchery-reared Annapolis River stock in April, but not in November. The ³H:¹⁴C ratio of cortisol was significantly lower (P < 0.05) in late April than in early November. Isotopic ratios of corticosterone, but not cortisol, differed significantly (P < 0.05) between immature and precocious parr in November. The isolation of double-labeled corticosterone from all incubations, except immature parr in November, may indicate a metabolic role for the 17-deoxycorticosteroids. No differences in the histology of interrenal tissues were found between Spring (April-May) and Autumn (October-November) parr. Sulfuric acid chromogens on TLC typical of cortisol, corticosterone, and 11-deoxycortisol and other, less polar delta-5-steroids, but not cortisone, in amounts estimated to be 0.1 µg, were detected in head kidney tissues (0.5-4.5 g) and blood plasma (7-18 ml) of parr in July, late November, and early December. Copyright 1994, 1999 Academic Press

The uptake of cadmium from three dietary sources, canned lobster digestive gland, canned porcine/liver, kidney mixture and casein cadmium chloride has been studied in rats fed a level of 20.9 μg Cd/g diet for 90 days. Analysis of the total cadmium levels in kidney, liver, spleen and brain showed uptake from the lobster digestive gland or porcine liver/kidney mixture was only about half of that observed with the casein/cadmium chloride diet. The amount of “free” cadmium present in the lobster hepatopancreas and procine liver/kidney mixture vas 45% and 43% of the total cadmium respectively and it is suggested that these levels of free cadmium are high enough to account for the uptake observed from these two matricies.

A fast and efficient method has been developed for the extraction and concentration of PCB from water. The method uses porous polyurethane foam as the absorption column for the PCB which is eluted with acetone and hexane for G. C. analysis.

A simple, quick, inexpensive and easily reproduced thin-layer chromatographic method for the separation and quantitation of organochlorine pesticides and polychlorinated biphenyls (PCB's) was developed using an aluminum oxide plate, which was developed in a triethylamine: hexane solvent, with steam and U.V. treatment for visualization. The recoveries reported are mostly in the range of 90 to 100%.Polychlorinated biphenyls (PCB's) were first noted by Reisborough1 as materials present in wildlife samples that could give rise to interference in analysis of organochlorine pesticides. Of late analysis of PCB's has become as important as analysis of the pesticides. In both groups of materials many individual components exist and separation of the two groups by some method prior to the generally used gas-liquid chromatographic methodology is essential. Early separation methods were based on liquid-solid chromatography on florisil, silicic acid-celite, alumina, silica-gel and charcoal2,3,4,5,6. Careful activation conditions had to be followed and reports on unsuccessful attempts to duplicate work have appeared.Thin-layer chromatographic (TLC) methods have been used to separate these two groups of materials. The bulk of the T.L.C. methods however are only semiquantitative or confirmatory. We wish to describe a thin-layer separation technique that we have developed which separates PCB's and the common organochlorine pesticides. Elution of spots and analysis of the eluants by gas liquid chromatography indicated the method is quantitative. Further studies using untrained personnel indicated that the method is easily reproduced.

The aluminum chloride catalyzed reaction between β-14C-ethyl iodide and benzene in 1,2,4-trichlorobenzene as solvent was studied under different conditions of temperature and reaction time. Yields of ethylbenzene were estimated by isotopic dilution. Up to 20% rearranged product, α-14C-ethylbenzene, was found. The trend indicated that yield of ethylbenzene was lower and side chain rearrangement greater when the reaction mixture was heated at higher temperature for longer time. The rearrangement apparently occurred after the initial formation of β-14C-ethylbenzene. After a reaction time of 5 min at 154 °C, only 0.1–0.3% unreacted and unrearranged β-14C-ethyl iodide was recovered while the ethylbenzene obtained from the reaction showed about 2% rearrangement. When β-14C-ethylbenzene was heated with aluminum chloride in 1,2,4-trichlorobenzene for 2 or 24 h, rearrangement to α-14C-ethylbenzene was observed. In some experiments, a fragmentation product, toluene, was isolated. Its specific activity suggested that 1 mole of active ethylbenzene gave 2 moles of toluene only one of which was active. The mechanistic implications of these findings are discussed.