Mercury,cadmium, zinc,copper and selenium in harbour porpoise (Phocoena phocoena) from West Greenland

Muscle, liver, kidney and skin samples taken from 78 harbour porpoises (Phocoena phocoena) were analysed for mercury, cadmium, zinc, copper and selenium. The highest concentrations of mercury were found in the liver (geometric mean 4.17 g/g wet weight), whilst the highest concentrations of cadmium were in the kidney (g.m. 13.2 g/g ww). The levels of cadmium were more than ten times higher than in harbour porpoises from the North Sea and the British NW coast, whilst the mercury levels were about the same. The importance of the cadmium content in the prey is discussed, but this attempt did not revealed the differences. Very high levels of zinc (g.m. 359 g/g ww) and selenium (g.m. 28.6 g/g ww) were found in skin samples, respectively seven and ten times more than in liver. A significant correlation was found between age and the level of mercury and cadmium in all organs. The concentration of mercury and selenium in liver and skin samples and of cadmium and zinc in kidney samples were highly correlated.     

A SURVEY OF SIZES AND WEIGHTS OF BEMISIA TABACI (HOMOPTERA:ALEYRODIDAE)B BIOTYPE LIFE STAGES FROM FIELD GROWN COTTON AND CANTALOUPES

Abstract Size and weight measurements were made for all the life stages of Bemisia tabaci (Gennadius) B biotype from field grown cotton ( Gossypium hirsutum L.) and cantaloupe ( Cucumis melo L., var. cantalupensis ) in Phoenix, AZ and Fargo, ND, USA in 2000 and 2001. Nymphal volumes were derived from the measurements. The average nymphal volume increase for settled 1 st to the late 4th instar was exponential. The greatest increase in body volume occurred during development from the 3rd to early 4th instar. Nymphs on cotton leaves were wider, but not longer compared with those on cantaloupe. Ventral and dorsal depth ratios of nymphal bodies from 1 st to late 4th instars from cantaloupe leaves were significantly greater compared with those from cotton leaves. During nymphal development from 1st to 4th instar, the average (from the two host species) ventral body half volume increased by nearly 51 times compared with an increase of 28 times for the dorsal body half volume. Adult female and male average lengths, from heads to wing tips, were 1 126 μm and 953 μm, respectively. Average adult female and male weights were 39 and 17 μg, respectively. Average widths, lengths, and weights of eggs from cotton and cantaloupe were, 99 μm, 197 μm, and 0.8 μg, respectively. Average widths, lengths, and weights for exuviae of non-parasitized nymphs from both cotton and cantaloupe were 492 μm, 673 μm, and 1.20 μg, respectively; and widths, lengths, and weights of parasitized nymph exuviae were 452 μm, 665 μm, and 3.62 μg, respectively. Both exuviae from non-parasitized and parasitized nymphs from cotton leaves were wider, longer, and heavier than those from cantaloupe leaves.     

EXPERIMENTS ON THE MODE OF ACTION OF DIELDRIN SEED-DRESSINGS AGAINST SEEDLING ATTACK BY THE LARVAL FRIT FLY, OSCINELLA FRIT L

Experiments with dieldrin seed-dressings were done to see whether the conditions favouring their action against wheat bulb fly larvae apply also to frit fly.
Experiments with oats and wheat in boxes and a small field trial with oats showed that fewer newly hatched larvae were killed when dieldrin-treated seed was sown deeply than when sown 1/4 - 1/2 in. deep; shallow sowing probably puts the insecticide where the larvae are likely to meet it before they attack the plant. Kill was never complete even with dieldrin applied at almost forty times more than the highest rate normally used. This is partly because some larvae hatch from eggs on the plant and these, unlike those from soil eggs, can enter the shoot without touching the seed dressing.
Even in the most favourable circumstances (large doses of dieldrin applied to the shallow-sown seed and the plant at the one-leaf stage at the time of attack) there was little evidence that frit fly larvae are killed inside the shoot by systemic action of dieldrin translocated from the seed. This is not because the pales which normally surround the oat seed impair the uptake of insecticide, or because of any other factor specific to oats. Frit fly larvae also survived in wheat from seed dressed with doses of dieldrin that can kill almost all wheat bulb fly larvae by systemic action. Possible reasons for this difference are discussed.     

Persistence and distribution of insecticidal seed-dressings for control of the wheat bulb fly, Leptohylemyia coarctata

Samples of plants and soil from two experimental sites, one clay loam and one peaty loam, were analysed chemically to try to explain differing results with γ-BHC and dieldrin seed-dressings applied to control wheat bulb fly on different soil types, and to suggest reasons for patchy plant stands and occasional failure to control the pest. Seed dressed with dieldrin yielded more than untreated seed on both sites, whereas seed treated with γ-BHC yielded as much as seed treated with dieldrin on the clay site, but it yielded less than untreated seed on peat. The chemical analyses showed that the poor performance of γ-BHC on the peat site could not be explained by its failure to persist, because the soil still contained considerable quantities of γ-BHC at the time of insect attack. Possible reasons may be sorption of the poison by organic matter making it less available, and deeper sowing, permitting larvae to reach the plants without prolonged contact with the insecticide. Bayer 38156 (O-ethyl S-p-tolyl ethyl phosphonodithioate) and trichloro-nate (O-ethyl O-2,4,5-trichlorophenyl ethyl phosphonothionate) persisted in soil long enough and were sufficiently toxic to wheat bulb fly to suggest that organophosphorus compounds might provide alternatives to chlorinated hydrocarbon insecticides for control of the fly. Analyses made on seeds dressed at the laboratory for the experiment showed that the amounts of insecticide on seeds were smaller than expected and that the amounts on individual seeds differed greatly. Of ten samples of seeds dressed commercially with y-BHC, three carried very little insecticide, and the variations in the other seven samples were greater than with experimentally applied dressings.     

Cadmium and mercury levels in saudi women and its possible relationship with hypertension

The association between elevated blood pressure and blood cadmium and mercury levels was examined (2001–2002) in 185 Saudi women previously selected for a case-control study of lead and hypertension risk. Blood pressure was measured twice according to the World Health Organization recommendations. Cadmium and mercury were determined with graphite furnace and hydride system-atomic absorption spectrometry, respectively. Mean blood cadmium concentrations were 0.874±0.995 μg/L in hypertensive and 0.785±0.665 μg/L in controls. While blood mercury concentrations for hypertensives and controls were 3.506±3.617 μg/L and 3.687±3.186 μg/L, respectively. Participants were classified according to the median of blood cadmium and mercury levels. After adjustment for potentially confounding variables, the final logistic regression analyses revealed that women with blood cadmium ≥0.627 μg/L were 3.934 times were more likely to be hypertensive than those with blood cadmium levels <0.627 μg/L, although this was marginally significant (p=0.098). This was likely the result of the small number of subjects, resulting in the weak power to detect a strong significant difference between hypertensives and control cases. On the other hand, the final regression model showed no association between hypertension and mercury. However, this finding should not be conclusive because of the inappropriate choice of the biomarker indicator. Nevertheless, our study supports the hypothesis that exposure to cadmium might increase the risk of hypertension.     

Different bioavailability in humans of wheat and fish selenium as measured by blood platelet response to increased dietary Se

The bioavailabilities of selenium (Se) from Se-rich fish species and Se-rich wheat were compared in a study involving 32 healthy volunteers. Initial serum Se values were 109±16 μg/L (mean±SD). For 6 wk, one group (n=11) included Se-rich bread in their diet, bringing daily average intake of Se up to 135±25 μg/d. Another group (n=11) consumed Se-rich fish daily (average Se intake: 115±31 μg/d), whereas the control group (n=10) ate their normal diet, providing 77±25 μg Se/d. Serum Se increased by 17% (P<0.01), and platelet Se increased by 30% (P<0.01) in the wheat group. Although platelet Se decreased by 11% in the fish group, no changes in serum and platelet Se in the fish or control group reached statistical significance. Glutathione peroxidase (EC 1.11.1.9; GSH-Px) activity in serum and platelets did not change during the study, nor did platelet mercury (Hg) content. Since the dietary intake of Hg, arsenium (As), and fatty acids could not satisfactorily explain the lack of response in the fish group, the results are indicative of low bioavailability of fish Se in humans. At present, wheat Se seems to be the most important factor contributing to the body stores of Se in this study population. Dr. Norheim died on January 9, 1991.     

Mercury and chlorinated hydrocarbons in the food chain of Lake Päijänne, Finland

The sediments and various organisms in Lake Päijänne were examined for contaminants. The average mercury content of water plants was 9, of plankton 14, of sediment 114, of zoobenthic predators 83, of fish 332–1510 and of birds 240–13685 μg kg⁻¹ (wet weight). The average PCB content of plants was 3, of plankton 21, of the zoobenthos 44, of fish 36-117 and of birds 219–13490 μg kg⁻¹. The average ΔDDT content of plants was 0.5, of plankton 6, of the zoobenthos 14, of fish 7–42 and of birds 144-8262 μg kg⁻¹. Regional differences in mercury content were most pronounced in sediment and fish. PCB concentration was highest near a town. ΔDDT was quite evenly distributed. Water plant species did not differ from each other, nor did the plankton fractions. The zoobenthic predators contained more chlorinated hydrocarbons than did the herbivores. There were clear differences between most species of fish and the chlorinated hydrocarbon content was highest in vendace. In adult birds levels of all residues were significantly higher than in juveniles.
In most cases PCB content was positively correlated with ΔDDT and in birds PCB, ΔDDT and mercury levels were correlated. DDT residues occurred mostly as DDE, but in vendace the proportion of DDT was high. At most trophic levels, ΔDDT/PCB was 0.15-0.40 but in birds it reached 1–2.     

Localization of choline acetyltransferase in laminae of the rat olfactory tubercle

Abstract: We report the distribution of choline acetyltransferase (ChAT) activity in the laminae of the rat olfactory tubercle. Within its posterior medial portion, the tubercle contains three parallel histological laminae that can be separated by cutting tangential sections from frozen tissue. ChAT was measured in homogenates of consecutive sections (16 μm) cut parallel to these laminae. The distribution of ChAT activity, as a function of tubercle depth, showed a broad peak centered at 500 μm from the ventral surface of the brain. Enzyme activity measured at this depth (85 pmol acetylcholine formed/μg protein/h) was 2 1/2 times greater than that measured in the outermost, plexiform, layer. Stereotaxic injections of kainic acid (1 μg in 1 μ1) made directly into the tubercle were used to eliminate intrinsic neurons. Three days after injection, histological examination revealed the almost total absence of neuronal cell bodies and the proliferation of glial cells. The greatest decreases in ChAT activity (50%) were seen at depths of 300–600 μm whereas no loss of activity occurred in the plexiform layer.     

Species of Anguilla as indicators of mercury in the coastal rivers and lakes of Victoria, Australia

Mercury concentrations in the axial muscle tissue of most (243) of the 254 Anguilla australis and most (20) of the 27 A. reinhardtii collected from 30 sites in coastal rivers and lakes in Victoria, Australia, during 1975–78 were well below the Australian statutory health limit (0.5 μg g⁻¹ wet weight). For A. australis the mean mercury concentration was 0.17 μg g⁻¹ (±0.16 s.d. , range 0.01–1.60 μg g⁻¹); for A. reinhardtii the values were 0.37 ± 0.23 μg g⁻¹ (range 0.12–1.10 μg g⁻¹). Statistical analyses showed that variation in mercury concentration due to total length accounted for only 13% of the total variation in A. australis and 2% in A. reinhardtii whereas locality accounted for 54 and 68%, respectively. Both species are thus considered suitable as indicators of mercury pollution.     

Ascorbic acid status in high-mountain charr,Salvelinus alpinus,in relation to the reproductive cycle

Synopsis Concentrations of total and dehydroascorbic acids and of glutathione were determined in tissues of male and female Arctic charr at different stages of the reproductive cycle. In fish inhabiting an Alpine lake (2344 m above sea level) the ascorbic acid concentrations were significantly higher in the ovary (344 g g^–1 in August) than in the testis (62.6 g g^–1). The ascorbate concentration was significantly higher in liver and kidney of males than in females in the period prior to spawning. This suggests that there was an intensive investment of body ascorbate reserves in the ovary and the results indicated that females deposited approximately 10 times the amount of vitamin C in ovaries than males deposited in testes. However, the endogenous stores cannot account for all ascorbate deposited in ovaries and the remainder must come from food consumed in summer. Since the resident charr of the high-mountain lake had the ascorbate concentration in ovary by one order of magnitude higher than in cultured salmonids it is plausible to speculate that the change in ascorbic acid metabolism reflects the adaptation to the harsh environmental conditions.     

The use of large volume,transparent, enclosed sea-surface water columns in the study of stress on plankton ecosystems

A brief account is given of the Controlled Ecosystem Pollution Experiment (CEPEX) program, with results from a recent experiment disigned to ascertain effects of mercury on planktonic ecosystems. The experimental modules are 1300 m³ transparent, flexible, polyethylene cylinders 9.5 m in diameter and 23.5 m deep, floating for periods up to three months at the sea surface of Saanich Inlet, British Columbia. Groups of three cylinders are filled simultaneously by being raised to the surface from 35 m, a procedure shown to produce biological replicability. An experiment is described in which mercury at 1 and 5 g l^–1 was added to two modules, with a third serving as a control. In both polluted modules temporary reductions in heterotrophic activity of micro-organisms and carbon assimilation of phytoplankton were observed, followed by a return to control levels. Only at the higher mercury concentration were any effects observed in the zooplankton, which included reduced feeding inCalanus, mortality and molting failure ofPseudocalanus and decreased growth in young fish.     

Updated Mortality Analyses of Pernis Epidemiological Data on Human Exposures to Aldrin and Dieldrin

An extensive clinical and epidemiological study of workers engaged in the manufacturing and formulation of aldrin and dieldrin, the Pernis study, provides occupational hygiene and biological monitoring data on individual exposures over the years of employment and provides the opportunity to investigate dose response relationships for these chemicals. The human epide miological mortality data on these workers, who were exposed to fairly substan tial lifetime average daily doses of aldrin and dieldrin, suggest that low dose exposures do not significantly increase human mortality and may even de crease the human mortality hazard rate. While hormesis from low dose expo sure to aldrin and dieldrin is not statistically significant, it is observed in the raw data and in the best fitting dose response models. The decrease in risk suggests increased survival time at low doses of aldrin and dieldrin. Using an upper bound on cancer potency based on mouse liver tumors, the U.S. Environmental Protection Agency (EPA) estimated that lifetime average daily doses (LADDs) of 0.0000625 and 0.00625?µg/kg body weight/day would correspond to increased cancer risks of 0.000001 and 0.0001, respectively. However, the best estimate from the Pernis epidemiological data is that LADDs of 0.0000625 and 0.00625?µg/kg body weight/day correspond to no increase in cancer risk and a decrease in the probability of mortality from all causes by the age of 70 years. At low doses of aldrin and dieldrin, the estimated decrease in mortality in a reference period of 70 years is more than 1000 times larger than the U.S. EPA's upper bound on the increase in the lifetime probability of cancer.     

Eimeria saudiensis N. Sp. (Apicomplexa: Eimeriidae) from the Arabian Oryx (Oryx leucoryx) in Saudi Arabia

Oocysts of Eimeria saudiensis n. sp. (Apicomplexa: Eimeriidae) are described from the feces of the Arabian oryx, Oryx leucoryx , from the Riyadh Zoo, Saudi Arabia. The oocysts were ellipsoidal or slightly ovoid, 31.2 times 24.5 (24.3–36.5 times 20.0–27.6) μm with a bilayered wall about 1.7 μm thick. The micropyle was covered by a dome-shaped cap. The oocyst residuum was absent, but tiny polar granules were present. The sporocysts were elongate ovoid, 14.3 times 7.2 (11.5–18.5 times 6.0–9.0) μm, had a Stieda body, but lacked a substiedal body. The sporocyst residuum was present, composed of numerous small granules. The sporozoites were elongate club-shaped, and contained two prominent refractile bodies.     

Isospora Normanlevinei N. Sp. and Isospora Coluzzii N. Sp. (Apicomplexa: Eimeriidae) In Emberiza Cirlus (Cirl Bunting) (Passeriformes-Emberizidae)

ABSTRACT. The morphological characteristics of two new species of Isospora observed in Emberiza cirlus (Cirl Bunting) from Italy are reported. the oocysts of Isospora normanlevinei n. sp. are spherical or sub-spherical, with a smooth double-layered wall, and measure 24.2 times 23.7 (21.0-26.5 times 21.5-25.5) μm; each oocyst contains 2 to 10 polar granules. No micropyle or residuum was observed. the piriform sporocysts measure 19.4 times 11.2 (17.0-21.0 times 10.0-12.5) μm and contain a dispersed residuum. the Stieda body is flat; the substiedal body, with scattered clear and dark granules, may be either symmetrical or asymmetrical. the oocysts of I. coluzzii n. sp. are asymmetrical and rounded shape and measure 28.6 times 24.2 (25.0-31.5 times 21.5-26.0) μm. the oocyst has a double-layered wall and 2 to 3 polar granules. Neither micropyle nor residuum is present. the sub-ellipsoidal sporocyst, measuring 18.2 times 10.0(16.5-20.0 times 9.0-11.0) μm, has a dispersed sporocyst residuum. the Stieda complex is symmetrical.     

Eimeria sinaitae n. sp. (Apicomplexa: Eimeriidae) from the Rock Agama (Agama sinaita) in Saudi Arabia

Eimeria sinaitae n. sp. is described from the gall bladder of Agama sinaita from Wasie, Saudi Arabia. Sporulated oocysts are elongate-ellipsoid 34.4 times 22.0 (29.0–40.0 times 17.4–24.5) μm. Oocyst wall is smooth, greenish yellow, 1.2 (1.0–1.4) μm thick, and two-layered. Micropyle, polar granule, and oocyst residuum are absent. Sporocysts are ellipsoid 11.4 times 7.6 (9.8–15.0 times 6.7–9.0) μm. Sporocyst residuum is present. The sporocysts lack a Stieda body. Sporozoites are crescent-shaped, blunt at one end and tapered at the other. Eimeria species from Agamidae are compared.     

The effect of soil insecticides on the predators and parasites of the cabbage root fly (Erioischia brassicae (Bouché)) and on the subsequent damage caused by the pest

Field experiments on the effect of residues of aldrin and dieldrin in the soil on the beetle predators of the cabbage root fly, showed that populations of adult carabid and staphylinid predators were altered by aldrin/dieldrin residues at concentrations of 0.06 p.p.m. and above. The lower insecticidal concentrations were aged residues which had become intimately mixed with the soil. Although the residues reduced the numbers of trapped Aleochara spp., concentrations below 0.5 p.p.m. increased the numbers of Bembidion lampros, probably because their movement was stimulated by the insecticide. Harpalus spp. and Feronia spp. were unaffected by residues below the concentration toxic to cabbage root-fly eggs and larvae. The reductions of the predators implied by the trapping records increased the survival of the cabbage root-fly eggs and larvae, thus leading to augmented damage to cauliflowers, cabbage and Brussels sprouts, which resulted in reductions in yield of up to 70%. Larval and pupal parasitism by Aleochara spp. and Idiomorpha rapae were also reduced by the insecticide residues, although concentrations of 0.2 p.p.m. and above were required to decrease parasitism by I. rapae.     

Chlorinated hydrocarbons in North Sea whiting (Merlangius merlangus L.), and effects on reproduction. I. Tissue burden and hatching success

Artificially inseminated eggs of feral North Sea whiting (Merlangius merlangus) were incubated in the laboratory in order to determine reproductive success. After incubation, two measures for reproductive success, total hatch and viable hatch, were determined and correlated with chlorinated hydrocarbon residues in the respective ovaries. From their specific toxicities and the sum of all determined chlorinated hydrocarbon contaminants, a contamination factor (CF) was calculated. Significant negative correlations were found between total hatch and DDT, including its metabolites (ΣDDT), dieldrin and the CF. ΣDDT and the CF were also negatively correlated with viable hatch. A threshold value of ovary contamination above which impairment of reproductive success was likely to occur was set at > 200 μg kg⁻¹ wet wt. for ΣPCB, > 20 μg kg⁻¹ wet wt. for ΣDDT and > 10 μg kg⁻¹ wet wt. for dieldrin.     

Effects of insect growth regulators on the hairy rose beetle, Tropinota squalida (Col., Scarabeidae)

Abstract:  Saponin extract from alfalfa roots, azadirachtin from the neem seed oil, synthetic ecdysteroid agonist RH-2485, and the juvenoid hydroprene disturb the development and reproduction of Tropinota squalida . Feeding beetles on diets containing 750 p.p.m. saponins, 7.5 p.p.m. RH-2485, and 1.13 p.p.m. azadirachtin reduces their progeny from 51 second instar larvae per female to 24, 15, and 15 larvae, respectively. When the larvae of untreated adults are fed for 1 week on dung with 75 p.p.m. saponins, 50 p.p.m. RH-2485, and 0.45 p.p.m. azadirachtin, the rate of adult emergence drops from 80% (controls) to 20, 0 and 13%, respectively. No adults emerge when the treatment is continued through the second and third larval instars. Two topical treatments of larvae with 0.2  μ g hydroprene decrease the rate of adult emergence from 90 to 11%, and treatments with 2  μ g prevent adult development in all insects. The observed effects warrant testing of azadirachtin, RH-2485, and hydroprene in the field. Several types of their application for the control of T. squalida are suggested.     

Urinary mercury levels in females: Influence of skin-lightening creams and dental amalgam fillings

The influence of application of skin-lightening creams and dental amalgam fillings on the urinary mercury (Hg) level was evaluated in 225 females (ages 17 to 58 years) living in Riyadh, capital of Saudi Arabia. The arithmetic mean of the urinary Hg level was 6.96 ± 20.43 g l, in the range 0 to 204.8 g l. The mean urinary Hg level adjusted by creatinine (Cr) was 11.22 ± 37.23 g g Cr, in the range 0 to 459.37 g g. No significant difference in urinary Hg was noted between the females regarding the use of skin-lightening creams. On the other hand, results showed that urinary Hg concentration was influenced by the use and number of dental amalgam fillings. No women were identified with symptoms or signs that could be attributed to Hg intoxication. Urine analyses for creatinine, urea, uric acid, phosphorus, magnesium, glucose and calcium showed significant correlation with urinary Hg. This suggests that chronic exposure to Hg may be associated with a deterioration of renal function.     

Coccidia of Brazilian Mammals: Eimeria Marajoensis N. Sp. (Apicomplexa: Eimeriidae) From the Anteater, Tamandua Tetradactyla (Xenarthra: Myrmecophagidae)

ABSTRACT Feces from a juvenile specimen of the anteater Tamandua tetradactyla from Ponta de Pedras, Marajó, Pará, northern Brazil, contained three different coccidial oocysts: Eimeria tamanduae Lainson, 1968; E. corticulata Lainson & Shaw, 1990; and a third species previously unrecorded and described here as Eimeria marajoensis n. sp. Oocysts of the latter parasite are spherical to subspherical, 13.9 ± 1.5 times 13.4 ± 1.4 (11.1-16.5 times 11.1-16.5) μm, shape index (length/width) 1.0 (1.0-1.2). the oocyst wall is a single, Colorless layer about 0.6-1.0 μm thick with no striations or micropyle. There is no oocyst residuum, but a single, round, oval or irregularly shaped polar granule of about 0.75-2.5 μm is consistently present. the sporocysts are broadly ellipsoidal, 7.1 ± 0.7 ± 5.3 ± 0.6 (6.0-8.8 times 4.0-5.7) μm, shape index 1.3 (1.2-1.5), with a delicate wall bearing a minute stieda body. No sub-stieda body was visible. the sporocyst residuum consists of some 10-20 rounded granules, lying between the two slightly curved sporozoites which measure approximately 6.5 times 2.0 μm. Sporocyst refractile bodies were not discernablc.