Acute toxicity of copper to sea catfish

Sea catfish (Arius felis) were exposed to aqueous solutions of reagent grade cupric chloride in artificial seawater ($\text{30.0±2.0‰}$, 21–23°C) in four static bioassays. The 24, 48, 72 and 96 h LC₅₀ were calculated and found to be 5.43, 4.17, 3.57 and 2.40 mg l.^?1 copper, respectively. Experimental concentrations of copper producing subtle behavioral changes in this species correspond to less than 0.3% of the 72 h LC₅₀. Based on this comparison with literature values, a new, maximum ‘safe’ concentration for copper in marine waters of 0.01 mg l.^?1 is proposed.     

“Man and Biosphere” — Studies on Sikkim Himalayas. Part 2: Acute Toxity of Mixed Copper-Zinc Solutions on Common Carp,Cyprinus carpio (LINN.)

In batch experiments for 6 to 48 h, individuals of Cyprinus carpio (2 g individual weight) were exposed to mixed solutions of copper and zinc sulphate: pH = 6.3, temperature 15 °C, 6.8 mg/l O₂, 7.1 mg/l Ca²⁺, 0.7 mg/l Mg²⁺. The LC₅₀ for the individual substances on exposures of 24 and 48 h amount to 9.04 and 7.28 mg/l, resp., of Zn and 0.11 and 0.095 mg/l, resp., of Cu. The sum of the biological activity of the two kinds of metal ions is assessed according to MARKING'S index: at low concentrations of the mixed solutions the two metals show an additive effect, at higher concentrations a synergistic effect occurs.     

Acute toxicity of platinum to coho salmon (Oncorhynchus kisutch)

The effects of short-term exposure to tetravalent platinum on survival, opercular movement and post-treatment growth of coho salmon fry (Oncorhynchus kisutch) was investigated. Employing a static water acute toxicity bioassay with platinum as PtCl₄2HCl·6 H₂O, at 8.5±0.2°C, and a water hardness of 55.9±3.5 mg l.^?1 (as CaCo₃), the 24, 48, and 96-h LC₅₀ values were 15.5, 5.2, and 2.5 mg Pt⁴⁺ l.^?1 respectively.Rates of opercular movement for fish exposed to platinum increased with increasing concentrations to a level of 1.0 mg l.^?1. No further significant increases were evident above this level. Hypoactivity of fish exposed to 0.3 mg l.^?1 and higher was evident during the acute toxicity bioassay and much of the post-treatment study. Post-treatment rate of growth for fish exposed to sublethal concentration of platinum for 96 h was less than that of the controls.All organs examined histopathologically were within normal ranges with the exception of the gills and olfactory organ. Lesions in fish exposed to concentration of 0.3 mg l.^?1 and higher were characterized by branchial epithelial hypertrophy and hyperplasia, and necrosis of olfactory epithelial cells.     

“Man and the Biosphere”-Studies on Sikkim Himalayas. Part 1: Acute Toxicity of Copper and Zinc to Common Carp Cyprinus carpio (Linn.) in Soft Water

In the daily exchange of the medium with only 7.1 mg/l Ca²⁺ and 0.7 mg/l Mg²⁺ during the batch experiment the LC_50,96h for Cyprinus carpio is 0.063 mg/l Cu²⁺ and 3.12 mg/l Zn²⁺ at water temperatures of 11 to 14°C. Significant differences in mortality as referred to the LC_50,12h occur for copper only after 72 h of exposure and for zinc after 48 h of exposure. The values of LC_50,96h are clearly lower for both metals in the investigations described than most data given in literature for different fish species.     

A Study on the Effect of Temperature upon the Toxicity of Sodium Pentachlorophenate to the Freshwater Snail Viviparus bengalensis L.

The toxicity of Na-pentachlorophenate to Viviparus bengalensis is investigated by batch tests with daily exchange of medium in the temperature range between 19 °C (February), 27 °C (April), 32 °C (June) and 30 °C (August) at times of exposure between 12 and 96 h. In the range of higher concentrations, pronounced abnormalities in behaviour by secreting mucus and discharging eggs and embryos occur. The LC₅₀ are lowest for all times of exposure at 27 °C, whereas the times of survival with a given concentration are highest at 30 °C. From the LC_{50, 96h, 27°C} = 66 μg/l results a safe concentration of only 47 μg/l Na-pentachlorophenate for Viviparus bengalensis.     

Toxicological effects of biocide Slimicide C-30 on some marine invertebrates

Sublethal and lethal effects of biocide Slimicide C-30 on the developmental stages of mussels Mytilus galloprovincialis and juvenile and adult mysid Leptomysis mediterranea were studied.Biocide at a concentration as low as 0.02 mg l^?1 caused an incipient effect in the embryonic development of mussels where a decreased number of normally developed larvae from eggs was evident. Slimicide C-30 effective concentration (EC 50/96) was 0.07 mg l^?1.In the mysids, the median lethal concentration (96 h LC₅₀) was 0.11 mg l^?1.Previous incubation of Slimicide C-30 at 38°C affected a small delay in mortality time (LT₅₀) but did not cause marked change in the acute toxicity to mysids.     

Toxicity of Interactions of Zinc —Nickel,Copper —Nickel and Zinc —Nickel —Copper to a Freshwater Teleost,Lebistes reticulatus (PETERS)1

The lethal toxicity of mixtures of Zn²⁺ —Ni²⁺, Cu²⁺ —Ni²⁺ and Zn²⁺ —Cu²⁺ —Ni²⁺ to common guppy at 21£C in hard water (total hardness = 260 mg/l as CaCO₃) was studied under static bioassays test conditions with renewal of the test solutions every 24 h. The heavy metals were tested separately and in mixtures. The 48 h median lethal concentrations (LC₅₀) for individual salts were 75 mg/l Zn²⁺, 37 mg/l for Ni²⁺ and 2.5 mg/l for Cu²⁺. Concentrations were expressed in “toxic units” by taking them as proportions of LC₅₀ values. Experiments showed that in the Zn²⁺-Ni²⁺ mixture, when Ni²⁺ was more in proportion, the toxicity was more than additive. The 48 h LC₅₀ value and 95% confidence limits in the Ni²⁺-Cu²⁺ mixture were 0.684 (0.484 … 0.807) toxic units and the mixture produced more than the additive toxicity (synergism.). The LC₅₀ value and its 95% confidence limits in a Zn²⁺?Cu²⁺?Ni²⁺ mixture also suggested that the mixture was again strictly additive. The results indicate that heavy metallic mixtures would pose a greater toxicological danger to fish than the respective individual metals.     

Zytotoxikologische Untersuchung von Schadstoffen und Wasserblüten mit gefrierkonserviertem Bullensperma (Spermatest)

The method is based on the determination of the number of the nonmotile sperms and/or the lethally damaged sperms with the aid of the fluorescent dye primuline. Incubation takes place at a suspension density of 10.000/mm³… 38.000/mm³, at 40°C or 46 °C for 15… 60 min. During the test with sublimate the loss of motility amounts to 55% at 4 mg/l Hg²⁺, the LC₅₀ is 7.3 mg/l Hg²⁺. Phenyl-mercuric acetate causes the total loss of motility with 20 mg/l, the LC₅₀ is above 168 mg/l (equivalent to 100 mg/l Hg²⁺). The LC₅₀ of sodiumpentadecylmonosulphonate and dodecylpyridinchloride are 11.6 and 15.8 mg/l, resp. Filtrates of blooming of cyanophyceae on Baltic, having been digested by repeated freezing and thawing, with 1.5… 6.4 g/l dry matter showed motility losses of 30… 100 % for Nodularia spumigena, whereas no significant effect was produced by a filtrate of Microcystis aeruginosa with 28.2 g/l dry matter as well as water-blooming of Nodularia spumigena from the Small Jasmund Bodden.     

Shear modulus and Q of forsterite and dunite near partial melting from forced-oscillation experiments

An apparatus designed to determine the complex shear modulus of rock samples by forced torsion oscillations at high temperature and in the seismic frequency band 0.003–30 Hz is briefly described. Measurements were performed on natural dunite from Åheim (Norway) up to 1400°C and on polycrystalline forsterite up to 1500°C at 1 atm pressure. The two materials were chosen to study, by comparison, the effect of melt on the elasticity and anelasticity of mantle rocks.Between 1000 and 1200°C the absolute values of the shear modulus G are almost equal for both materials. Above 1200°C G for natural dunite decreases progressively with temperature and at 1400°C and 1 Hz reaches $\text{～}\text{1}\text{3}$ of its value at 1100°C. In contrast, G of pure forsterite depends little on temperature. For petrological reasons, supported by simultaneous measurements of the electric resistivity, there is strong evidence that the decrease of G in dunite above 1200°C is due to melt from the lower melting components of the dunite. Based on different models estimates of the melt fraction are made.At high temperature, in both materials Q^?1 is characterized by a monotonic decrease with frequency according to ω^?α, with α ≈ 0.25. An apparent activation energy of 38±5 kcal mol^?1 for forsterite and 48±8 kcal mol^?1 for dunite was found with no significant change in the regime of partial melting. From this it is concluded that Q^?1, even at partial melting, is dominated by solid state high temperature background absorption. There is no indication from these experiments for a constant-Q-band at low seismic frequencies or an increase of Q proportional to frequency as suggested by some seismologists. The present results are in good qualitative agreement with those for Young's modulus obtained previously by strain retardation experiments.     

Magnetic properties of synthetic titanomagnetites

Magnetic properties and crystal structure parameters of synthetic solid solutions Fe₃O₄Fe₃TiO₄, Fe₂O₄MgFe₂O₄ and Fe₃O₄Mg₂TiO₄ have been studied. Basic regularities in the behaviour of saturation magnetisation (I_s), Curie temperature (T_C) and cubic lattice parameter a during the substitution of Ti and Mg ions for Fe ions have been found. As the concentration of Ti ions increases, I_s reduces from 70 Gs·cm³ g^?1 to 0, T_C changes from 580 to 130°C and a from 8.391 to 8.520 Å. Growth of the Mg concentration leads to changes in I_s to 19.8 Gs·cm³, g^?1, T_C, to 440°C and a, to 8.360 Å. The full Fe ions substitution gives $\text{“a”=8.440}\text{A}\text{?}$.Chemical compositions of the samples, in which the valency variation of Fe ions at oxidation leads to an increase in susceptibility and T_C, have been determined.     

Differentiation of the sensitivity to copper and cadmium in different life stages of a copepod

Copper is more toxic to all life stages of the copepod Tisbe than cadmium. The most sensitive life stage of Tisbe to both copper and cadmium is the one-day-old nauplius. The resistance of larval stages of Tisbe increases with age (one-day-old nauplii 48h $\text{lc}{}_{50}\text{=0.3142}$ mg Cu l^?1. and 0.5384 mg Cd l^?1, 0.3415 mg Cu l^?1. and 0.645 mg Cd l^?1. for five-days-old nauplii and 0.5289 mg Cu l^?1. and 0.9061 mg Cd l^?1. for ten-days-old nauplii. The two reproductive stages of Tisbe tested (females with ovigerous bands and females bearing the first ovigerous sac) demonstrated an increased sensitivity to metals and proved more sensitive than the ten-days-old copepodids (only females with ovigerous bands had a similar sensitivity to copper with the ten-days-old copepodids).     

Toxicity and long term effects of a sublethal concentration of cadmium on the growth of the fingerlings of Ophiocephalus punctatus (BL.)

The LC₅₀ for exposure of 48 and 96 h is 34.64 and 18.5 mg/l Cd²⁺, respectively. During the exposure to 3.5 mg/l Cd²⁺ from the 13th day significant differences of length and mass occur with respect to the control. Over a total of 31 days of experiment the reduction of growth rates is 11% for the longitudinal growth and 16% for the increase in weight.     

Influence of Temperature on the Toxicity of Phenol and its Chloro- and Nitro-derivatives to the Fish Notopterus notopterus (PALLAS)

There is determined the LC₅₀ for 24 … 96 h of phenol, 2,4-dinitrophenol and pentachlorophenol as sodium salt by static assay at water temperatures of 16, 23 and 36°C. In addition, the combinations of the three substances were tested in the same way. With decreasing temperature, the toxicity of the individual substances decreased by 6.5 … 22%, that of the mixtures by 10 … 87%; with rising temperature, the toxicity increased by 38 … 747% and 75 … 744%, respectively. The safety limits at 23°C lie between 0.3 μg/l for a synergistically acting mixture and 0.9 mg/l for an antagonistically acting one; for the individual substances this range is 3.5 μg/l to 0.5 mg/l.     

Effect of Zinc,Copper and Mercury on Channa marulius (HAMILTON)

Static bioassay acute toxicity tests of Zinc, Copper and Mercury were conducted to determine the median lethal concentrations (LC₅₀s) of a freshwater teleost Channa marulius (HAM .) The 96 h LC₅₀ and 95% confidence limits for Zn²⁺ were 25.61 (24.13 … 27.12) mg/l; 0.90 (0.80 … 1.038) mg/l; for Cu²⁺ and 0.314 (0.257 … 0.371) mg/l for Hg²⁺. However, these values decreased at 240 h of exposure and were: 21.09 (18.29 … 24.60) mg Zn²⁺/l; 0.66 (0.568 … 0.841) mg Cu²⁺/l; and 0.131 (0.103 … 0.158) mg Hg²⁺/l. The relative potency ratio of Zn/Hg, Zn/Cu and Cu/Hg suggests that fish were most sensitive to Hg, followed by Cu and Zn ions. The acute toxicities of mixtures of Zn²⁺?Cu²⁺; Zn²⁺?Hg²⁺, Cu²⁺?Hg²⁺ and Zn²⁺?Cu²⁺?Hg²⁺ up to 48 h of exposure were also investigated. The additive index and ranges for Zn²⁺?Cu²⁺ were ?0.241 (-0.577 … 0.054); 0.056 (-0.269 … 0.475) for Zn-Hg; 0.285 (-0.043 … 0.718) for Cu-Hg; and -0.542 (-1.215 … 0.005) for Zn-Cu-Hg. All the mixtures tested showed a greater than additive toxicity because index ranges overlapped zero.     

Short Term Effects of Aldrin and Swascofix CD-38 on the Feeding and Respiratory Behaviours of Clarias batrachus and Cirrhina mrigala

Fish were kept in non-toxic water or at 0.5, 0.25 and 0.125 of the LC_50,96h of the ten-side or insecticide for 24 h and fed with toxified and non-toxified feed. Toxified feed in normal water resulted in a maximum feed intake, while normal feed in toxified water resulted in a minimum one. In each case, the feed intake was lower compared with the control, and the feed intake was inversely proportional to the toxicant concentration. In a simple respirometer the oxygen consumption in mg · kg^?1 · h^?1 was tested for 1, 2, 4, 6, 8, 10, 12, 24, 36, 48, 60, 72, 84 and 96 h of exposure to 1.5, 1.0 and 0.5 of the LC_50,96h of both substances. It was a flow device which was closed only for measurement for one hour. 1.5 LC₅₀ Aldrin causes a continuous reduction of respiration until death. The same effect occurred with Cl. batrachus for 1.5 LC₅₀ of the tenside, whereas with C. mrigala death was caused by a pronounced increase of respiration. In all other cases, after a phase of sensitization for 4 … 8 h respiration increased considerably to more than 300% of the control, which was followed after 12 … 24 h by acclimatization to normal respiration values.     

Acute Toxicity of Phenol,Pentachlorophenol and Sodium Pentachlorophenate to a Freshwater Ostracod Cypris subglobosa (Sowerby)

The toxicity of phenol, pentachlorophenol and Na-pentachlorophenate to Cypris subglobosa is determined in the batch experiment for 96. h. In the sequence mentioned, the LC_50,96h of the three substances are 71.8, 6.56 and 4.41 mg/l, respectively. In the range of 6 … 95 h the mean survival time shows a negative regression to the toxicant concentration, which, however, is not significant statistically for Na-pentachlorophenate. In agreement with this, the LC₅₀ for 12, 24, 48, 72 and 96 h of exposure shows a significant decrease. Due to the comparatively high LC_50,96h for pentachlorophenol and Na-pentachlorophenate for C. subglobosa about in comparison with fish, the species is little suited to the toxicological investigation of wastewater.     

High-temperature anelasticity and elasticity of mantle peridotite

An apparatus has been devised which allows precise creep and relaxation measurements to be made on minerals and rocks at temperatures up to 1600°C and at very low deviatoric stresses (1 < σ < 300 bar). This paper is concerned with measurements on mantle peridotite (lherzolite) from Balmuccia (Zone of Ivrea, Italy).The reaction of the sample to a step-like increase in stress is called its “creep function”. It is shown that the creep function contains all the necessary information to derive the spectra of the quality factor Q(ω) and of Young's modulus E(ω), within the seismic range of frequencies, provided the material behaves as a linear system. This has been proven up to a strain of 5 × 10^?5.The Q^?1-spectra at 1200 and 1300°C, obtained by Fourier inversion from the creep function, show no pronounced peak in the frequency band 0.01 < tf < 1 Hz and exhibit a general tendency to decrease slightly with frequency. The creep function: ?(t) = ?_u · [1 + 3.7 · q · {(1 + 50t)^0.27 ? }], where q is related to Q, satisfactorily describes the data at high temperatures and leads to $\text{Q}{}^{\mathrm{?1}}\text{(ω, T) = 3 × 10}{}^3\text{· ω}{}^{\mathrm{<mtext>?0.27\; ·\; </mtext><mtext>exp</mtext>}}\text{(}\text{?30}\text{RT}\text{)}$E(ω) is related to Q(ω) by the material dispersion equation. Above 1100°C the unrelaxed Young's modulus decreases rapidly with temperature according to an activation energy of about 20 kcal/mole. A lowering of short period S-wave velocity by 40% and P-wave velocity by 10% occurs below the solidus. Therefore, no partial melting is required in the asthenosphere.Steady-state creep at low axial stresses (20 < σ < 100 bar), obtained from the same rock, follows the relation $\text{?}\text{?}\text{= 3 × 10}{}^7\text{· δ}{}^{1.4}\text{·}\text{exp}\text{(}\text{?125}\text{RT}\text{)}$ indicative of grain boundary diffusion or superplasticity. At higher stresses a power law $\text{?}\text{?}\text{= 45 · δ}{}^4\text{·}\text{exp}\text{(}\text{?125}\text{RT}\text{)}$ typical of dislocation creep, is found.The frequency dependence of Q and the ratio of the activation energies of Q and are indicative of so called “high-temperature background absorption”, as the dominant mechanism, and of a diffusion-controlled dislocation mobility common to both absorption and creep. From a, b, and c, relations between the effective viscosity η_f and Q of the form: $\text{log}\text{η}{}_{\mathrm{e??}}\text{=}\text{1}\text{α}\text{·}\text{log}\text{Q ? (n ? 1) ·}\text{log}\text{ω +}\text{log}\text{D}$ are derived, where α ～ 0.25, n is the power of σ, and D is a constant.     

Seismic array evidence for a two-layer core transition zone

Measurements of traveltimes and traveltime gradients for PKP phases recorded at the Warramunga seismic array from distances between 113° and 176° provide evidence for a two-layer transition zone in the earth's core. The basic data consist of paper recordings played out at 40 mm/sec from analog magnetic tape with amplitude gain control and narrow bandpass filters. Measured values of $\text{d}\text{T}\text{dΔ}$ are perturbed by structure beneath the array and it is necessary to correct for this effect by an empirical approach. On the basis of the $\text{d}\text{T}\text{dΔ}$ values and traveltimes, two precursor branches to PKP_DF for Δ < 143° are identified consistently. These continue as branches intermediate to PKP_DF and PKP_AB for Δ > 145°. The corrected $\text{d}\text{T}\text{dΔ}$ values of all phases are smoothed and used to derive a velocity model for the core. The preferred model includes two velocity discontinuities of less than 0.1 km/sec each in the core transition zone to generate the two additional PKP branches. Together with the velocity jump at the outer-inner core boundary, these discontinuities define two layers each a few hundred kilometers thick. It is argued that recent proposals concerning inhomogeneities at the base of the mantle or within the transition zone as the source of PKP precursors do not agree with our observations nor those of other researchers. Inhomogeneities are not excluded but are considered a secondary effect for PKP phases, the primary effect being due to two discontinuous velocity increases in the transition zone.     

Immune responses to combined effect of hypoxia and high temperature in the green-lipped mussel Perna viridis

Flow cytometry was used to examine immune responses in haemocytes of the green-lipped mussel Perna viridis under six combinations of oxygen level (1.5 mg O₂ l⁻¹, 6.0 mg O₂ l⁻¹) and temperature (20 °C, 25 °C and 30 °C) at 24 h, 48 h, 96 h and 168 h. The mussels were then transferred to normoxic condition (6.0 mg O₂ l⁻¹) at 20 °C for further 24 h to study their recovery from the combined hypoxic and temperature stress. Esterase (Est), reactive oxygen species (ROS), lysosome content (Lyso) and phagocytosis (Pha) were reduced at high temperatures, whereas hypoxia resulted in higher haemocyte mortality (HM) and reduced phagocytosis. For HM and Pha, changes were observed after being exposed to the stresses for 96 h, whereas only a 24 h period was required for ROS and Lyso, and a 48 h one for Est. Recovery from the stresses was observed for HM and Pha but not other immune responses.     

Studies on the Toxieity of Pulp and Paper Factory Wastes to the Fish Notopterus Notopterus (PALLAS)

Studies are performed on the toxicity for 24, 48, 72 and 96 hours in the static test with dilutions of 10 … 32 vol.% of wastewaters from the pulp and paper production as well as of the mixed wastewater. The pulp waste shows the highest toxic effect, the LC₅₀ of the three types of wastewater being between 15 and 27% in dependence on the test conditions. A general increase of the toxic effect is caused by a rise in temperature from 26 °C to 36 °C and an increase of the pH value from 7.5 to 8.2. The increase of the oxygen concentration from 5.2 to 7.2 mg/1 results in a reduction of the toxicity of the pulp and mixed wastes, the size of fishes having a significant effect only for the pulp waste. Concentrations of wastes of 6 … 9% may be regarded to be harmless for long periods of time.