Total mercury and methyl mercury levels in British estuarine sediments—II

Results from a large-scale study of Mersey Estuary, U.K. sediments are discussed. Correlations are drawn between total mercury, methyl mercury, silt and organic carbon contents of the sediments. These correlations are compared to earlier results, and coefficients range from 0.55 to 0.94.The influence of redox potential and the sulphide content of a sediment on both the ambient level of methyl mercury and the extent of a growth and decay effect in methyl mercury levels in sediments after sampling is discussed. The results show that in an esturary (Clyde, U.K.) where sulphide levels vary from 0 to 8.5 mg g⁻¹ there is a maximum level of methyl mercury found at approximately 5.8 mg g⁻¹ sulphide, suggesting that sulphide concentrations may control methyl mercury levels.     

Interaction and mobility of cobalt-60 between water and sediments in marine environments possible effects by acid rain

In Japan, all nuclear power stations have been constructed facing sea-shores and the operating radioactive wastes have been either stored at the sites or discharged into marine environments, if permissible. The purpose of this investigation was to understand the behavior of a radioactive cobalt (⁶⁰Co), one of the typical radionuclides produced by operating nuclear reactors, in marine environments, namely cobalt interaction between water and sediments. Great emphasis was focused on demonstrating a quantitative difference in behavior of cobalt between marine and freshwater environments.Under natural conditions, cobalt remained in the water phase in marine environments more than 5 times as much as in freshwater environments. In freshwater, most cobalt (over 95%) is absorbed by and permanently retained within bed sediments under the normal environmental conditions. However, in marine environments cobalt gains mobility. Furthermore, this mobility of cobalt once established did not diminish nor disappear when surrounding conditions were changed.In short, cobalt in marine environments is generally mobile. This considerable mobility was greatly influenced by the environmental factors: (e.g. pH, the redox potential, the ionic strength, the type of sediments and the length of reaction time) but, it was primarily determined by the initial environmental conditions. The result of this experiment suggests that the treatment and the storage of radioactive cobalt waste should be done in freshwater environments rather than in a marine environment if we try to reduce the mobility. Because the mobility depends on pH, acid rain is, therefore, to be expected to strongly influence the mobility of ⁶⁰Co in aquatic environments.     

Phosphorus dynamics in hypereutrophic lake sediments

The sediments of two hypereutrophic lakes (Stone Lake, Michigan and Lake Charles East, Indiana) were studied to determine phosphorus sorption and release tendencies as they vary seasonally. Techniques used were chemical extractions of phosphorus forms from core fractions and the incubation of undisturbed cores in the laboratory under ambient conditions of temperature and dissolved oxygen. The uptake of phosphorus during aerobic periods was found to be in accord with previously observed trends in that the amount sorbed was proportional to overlying phosphorus concentration supporting an adsorption type of model. Phosphorus was given off during anoxic periods, however, the specific release rates could not be correlated with the gradient of interstitial phosphorus to overlying phosphorus concentrations as reported by others. Rather, release rates were closely correlated with average interstitial phosphorus concentrations. A diffusion model is presented, applicable to systems similar to those studied, in which soluble interstitial phosphorus varies from a greatly elevated concentration in close proximity to sediment particle surfaces to levels approaching those of overlying phosphorus.     

Comparative studies on trace metal levels in marine biota I. Mercury in marine organisms from western Italian coast,the strait of Gibraltar and the North Sea

The mercury level has been determined in the edible part of 36 marine species (867 specimens) caught from 1975 to 1976 mainly close to the Western Italian coast, the Strait of Gibraltar and in some selected regions of the North Sea. Sample pretreatment was performed after careful preparation by nitric acid pressure decomposition of frozen stored subsamples using up to 2.5 g fresh weight (FW). The analytical method was automated cold vapour atomic absorption spectrophotometry after preconcentration on silver wool. Accuracy and precision of the method was checked by interlaboratory intercomparisons and intralaboratory test measurements of repeatability and also the use of Standard Reference Materials. The total mercury (HgT) values obtained ranged from 20 μg/kg FW to ?2,000 μg/kg Fresh weight for the Mediterranean Sea and for some pelagic species showed significantly elevated mercury values compared with organisms from the Atlantic and North Sea. For benthic organisms, however, probably due to dominating local influences, a similar behaviour has not been observed. Evaluation of body weight/mercury concentration ratios showed significant correlations for several species differing between distinct locations.     

Flameless atomic absorption analyses of mercury in model aquatic systems

Chemical models of freshwater and seawater (34‰ S) have been used to examine the effect of humic material on the analysis of mercury by flameless atomic absorption spectrometry. Solutions containing mercuric chloride (1 μg Hg 1⁻¹) and various concentrations of humic material were allowed to attain equilibrium under carefully controlled conditions. In both media, association between the inorganic and organic entities took place within 90 min at pH ≥ 7 and the organically bound mercury was not detected by an analytical method designed for inorganic mercury. The amount of detectable mercury was related to the quantity of humic material added to the solutions.In experiments involving changes of pH the model solutions showed three characteristics: (1) a flat response in the neutral and alkaline pH range, where the humates are apparently stable; (2) a minima in the pH range 2–4 where the formation of an acid flocculent appears to remove additional mercury from solution: (3) at pH = 1, some release of mercury occurs from the organic precipitate.Photolysis studies using the model freshwater solutions showed that total mercury measurements could be made after 2 h irradiation at pH = 1. Using the same technique methylmercury chloride and diphenylmercury decomposed within 1 h. These results are relevant to routine and analyses of total mercury in natural waters.     

Determination of methyl chrysenes in a coal liquefaction product

Analysis of carcinogenic methyl chrysenes in a complex sample matrix requires a combination of liquid-liquid partition and column chromatography to obtain a chrysene subfraction. Analytically interfering alkyl benzanthracenes are removed by a combination of a selective Diels-Alder reaction and column chromatography. Application to a coal-liquefaction product revealed 98 ppm of chrysene and 106 ppm of 3-methyl, 102 ppm of the 2-methyl, 64 ppm of the 6-methyl, and possibly 19 ppm of the 4- plus 5-methyl chrysenes.     

Some observations regarding pentachlorophenol levels in Haverford Township, Pennsylvania

Due to industrial discharge over many years. Naylor's Run Creek, in Haverford Township Pennsylvania, U.S.A., has accumulated potentially dangerous levels of pentachlorophenol. The analytical procedure for determination of the compound is described, typical analysis results are presented, and possible methods to alleviate the problem are discussed.     

The effect of chemotherapy for mixed fission products on the toxicokinetics of cadmium and mercury in rats

The mixture of calcium alginate, ferrihexacyanoferrate(II) and potassium iodide, which efficiently decreases fission product retention, had no influence on ^115mCd toxicokinetics in rats. This mixture, however, caused increased whole body retention of ²⁰³Hg after oral administration. It is assumed that iodine in the mixture might be responsible for this effect.     

Mercury in feathers of wild birds from the mercury - polluted area along the shore of the Shiranui Sea, Japan

Total mercury content in the feathers of 95 stuffed, wild birds collected all over the shore of the Shiranui Sea (where Minamata disease occurred in many towns and villages in the 1960's) was measured. They were collected over 25 years, from 1955 to 1980. They showed relatively high mercury levels till the late 1970's, although drainage of waste water containing methylmercury from the Chisso Corporation's Minamata Factory was stopped in 1968. In addition, a strong correlation between feeding habits and mercury content was observed; thus the five groups in order of diminishing mercury content were: fish-eating sea birds (mean ± SD = 7.1 ± 3.7 ppm, N = 14), omnivorous water fowl (5.5 ± 5.6 ppm, N = 17), predatory birds (3.6 ± 2.9 ppm, N = 16), omnivorous terrestrial birds (1.5 ± 1.2 ppm, N = 31), and herbivorous water fowl (0.9 ± 0.4 ppm, N = 17). Mercury content of the feathers of omnivorous terrestrial birds in the Shiranui Sea was exceedingly high compared with those in China and Korea. The findings in the present study suggest that stuffed, wild birds may be a good index of past environmental pollution.     

Blood lead levels in Finnish preschool children

The blood lead (PbB), hemoglobin and hematocrit were measured in 286 Finnish children living in the three largest cities of Finland (n = 172), in rural areas (n = 54) and in a lead smelter area (n = 60). PbB was determinated using an atomic absorption spectrophotometric micro method. The precision of the method was good, as was the accuracy tested by an international interlaboratory comparison. The mean PbB in urban, rural and lead smelter areas varied between 6.0–6.7 μg/100 ml⁷ (range 3–17 μg/100 ml) and there were no significant differences between the residential areas. The mean values of hemoglobin and hematocrit were in the normal range. The PbB values in Finnish children studied were low compared with many international studies but at a similar level as in some recent Scandinavian studies.     

Concentration of virus from tap water at ambient salt and pH levels using positively charged filter media

Positively charged filter media were used to recover bacteriophage f2 and poliovirus 1 from tap water at ambient pH level 7.8 without added multivalent cations. Recoveries from 201. vol of water with Carlson-Ford type 4 asbestos filters averaged 65% for the phage and 68% for the poliovirus after elution with alkaline nutrient broth.     

The distribution and origin of mutagens in airborne particulates, detected by the salmonella/microsome assay in relation to levels of lead, vanadium and PAH

At three stations in central Copenhagen, Denmark, samples of particulate matter were collected simultaneously with different contributions from automobile exhaust products. Samples were obtained at street level, 22 m above street level and within a hospital zone; 32 samples were analysed for levels of polycyclic aromatic hydrocarbons (PAH) and elements, as well as for mutagenicity towards S. typhimurium TA1538. Two classes of mutagens were quantified: a non-polar extract rich in PAH and, other promutagens, and a polar extract containing direct acting mutagens (not requiring microsomal activation). Covariances between lead and mutagenicity, and the varying distribution of the polar and non-polar mutagens at the stations, indicate that at all stations the mutagenicity of the non-polar extract is dominated by automobile exhaust products. The polar extract is relatively less influenced by primary traffic emissions; a considerable part of the activity of this extract is attributed to secondary emissions, transformed by atmospheric reactions, and primary emissions from stationary sources.     

Estimation of nitrifying biomass and kinetics in wastewater

A technique is proposed for the in situ measurement of nitrifying bacterial kinetics in mixed culture. A direct addition of known quantities of pure nitrifiers to a mixed liquor sample, along with selective inhibition of Nitrosomonas activity allows the estimation of nitrifier populations and maximum specific substrate removal rates. The method demonstrates that nitrification is zero order for substrate and first order with respect to bacterial concentration. The constant rate responses of batch kinetic tests require only a simple analysis and can be adapted to situations where nitrifier concentrations are small. Application of the technique to a carbon removal-nitrification system subjected to a variety of total Kjeldahl nitrogen loadings indicates that for a fixed carbon loading, nitrifier populations are strongly dependent on the nitrogen concentration of the feed.     

Factors affecting the extraction and analysis of polynuclear aromatic hydrocarbons in water

Factors expected to affect the efficiency of extraction of Polynuclear Aromatic Hydrocarbons (P.A.H.) from environmental water samples have been systematically investigated. Such factors include the initial concentration of P.A.H., the presence of suspended solids and prolonged storage of the sample prior to analysis. Extraction efficiencies between 30 and 85% have been found and these data make possible more accurate measurements of levels of P.A.H. in water. Analyses of environmental water samples have been performed using both Thin layer chromatography (TLC) and Gas-liquid chromatography (GLC). Accuracy of analysis was assessed by addition of P.A.H. to environmental water samples before extraction. Thin layer chromatography was found to be the better procedure for the compounds analysed, and avoided the need for purification of the solvent extract prior to analysis.     

Measurements of alkyllead compounds in the gas and aerosol phase in urban and rural atmospheres

Alkyllead compounds in the gas and aerosol phase were determined simultaneously in urban and rural atmospheres using gas chromatography--atomic absorption spectroscopy and wet chemical (iodine monochloride) methods. The difference in results between the two methods suggests the presence of vapour-phase tri- (and/or di-)alkyllead in both urban and rural air. Concentrations of 0.06-1.6 and 16-205 ng Pb m-3 were found for vapour-phase organolead compounds other than tetraalkyllead in rural and kerbside urban air, respectively. Tetraalkyllead and trialkyllead compounds were identified in atmospheric aerosols at both sites, but these were found to be present at concentrations less than 1.2% of the total gas-phase alkyllead.     

Chronic and reproduction studies in rats exposed to gasifier ash leachates

Ash from the coal gasification process contains a broad spectrum of elements which through leaching (gasifier ash leachates) may enter into the environment. The health effect of such leachates i.e. complex mixtures of inorganic elements is insufficiently known. We investigated the effect of gasifier ash leachates in a chronic-(9-month) and in a three-generation reproduction study. The leachates were prepared weekly by water extraction of ash from a Lurgi coal gasification plant in Yugoslavia, and given to experimental animals instead of drinking water. In the chronic experiment exposed animals showed no changes in mortality rate, haematological findings, concentration of Fe, Zn, Mn in kidneys, liver, testicles and femur, as well as in femur composition and morphometry, gross pathology and organ histology. In the reproduction study the number of pregnancies, weight and number of newborns, and concentration of Fe, Zn, Mn in carcasses of sucklings were the same in control and experimental animals.     

Method of selective dissolution for characterization of particulate forms of Radium and Barium in natural and waste waters

A new method is proposed for characterization of particulate forms of radium and barium in natural and waste waters. Particulate solids suspended in 1–3 l. of water are first concentrated by membrane filtration or by centrifugation to 20–50 ml of a concentrate which is then filtered through a small-size membrane filter. The solids retained by the filter are successively washed with three selective solvents releasing “loosely bound”, “acid soluble” and “barium sulfate” forms of radium and barium. Compositions and volumes of the selective solvents have been chosen using model experiments and partially checked by analysis of natural samples. Radium and barium “in crystalline detritus” remain on the filter and are determined after an acid digestion of the filter. The principal criteria and selectivity of the method are discussed.     

The effects of pH and suspended solids in the removal of organics from waters and wastewaters by the activated carbon adsorption process

The effects of pH, inorganic suspended solids and organic suspended solids on the adsorption of organics by activated carbon were investigated using sewage effluents and selected organic compounds of varying size, structure, molecular weight and properties in model solutions. It was found that suspended solids, and in particular organic suspended solids, could interfere with the adsorption process, both in terms of adsorption capacity and adsorption rate; the effect of the solids diminished as the size of the adsorbate increased. The effect of pH variation became more significant as the acidity or basicity of the adsorbate in solution increased. Adsorption of organics from biologically treated sewage effluents was somewhat more effective in the acid and alkaline pH regions than in the neutral pH region.     

Direct influence of wastewater pollutants on flocculation and sedimentation behaviour in biological wastewater treatment—I model system E. coli B

The influence of different chemicals on flocculation and sedimentation in wastewater was investigated in a model system of washed E. Coli B harvested at the end of the logarithmic phase. It was found that the amount of extracellular polymeric material present in the system affected the coagulation by neutral salts and also the degree of influence of the model pollutants investigated. Considerable effects on sedimentation could be found for several of the pollutants when the cells were in the state of slow coagulation close to the critical coagulation concentration (ccc). These effects were attributed to interactions between the extracellular polymers and pollutants influencing the bridging between cells.     

The effect of pH and hardness metal ions on the competitive interaction between trace metal ions and inorganic and organic complexing agents found in natural waters

The effect of pH and hardness metal ions on the interactions between trace metals and both inorganic and organic complexing agents has been studied under conditions simulating natural aquatic conditions, by employing anodic stripping voltammetric titration techniques. The complexation of Bi(III), Cd(II), Cu(II), Pb(II), and Tl(I) with the hydroxo- and carbonato-ligands found in a carbonate medium has been observed to generally increase with increasing pH. Both labile and nonlabile interactions have been observed. Nonlabile interactions are predominant at low pH and labile interactions generally increase with increasing pH. Neither calcium nor magnesium affects these interactions. The complexation of humic acids with trace metals in a carbonate medium was found to be more intense than metal ion-inorganic complexation. Both labile and nonlabile complexation was found; however, no generalizations can be made concerning the type and extent of complexation because of the individual nature of the interactions of each trace metal. Calcium was found to be more effective than magnesium in inhibiting trace metal-organic complexation. The effect of calcium is to inhibit labile complexation and is most pronounced with the cadmium-humic acid system.