A ranking index to characterize polynuclear aromatic pollutants in environmental samples

This study investigated the use of a screening procedure to provide a ranking index (RI) for characterizing polynuclear aromatic (PNA) species in atmospheric samples. The ranking procedure employs a cost-effective and rapid screening technique based on synchronous luminescence spectroscopy. The efficacy and usefulness of the ranking procedure are demonstrated by comparing the RI values with data expressed in terms of the benzene-soluble standard, benzo[a]pyrene values, and the total content of fourteen PNA compounds.     

Study of total organic halogen as a means to detect groundwater contamination

Total organic halogen (TOX) was evaluated as a means to detect contamination of groundwater by halogenated organics. Groundwater samples from monitoring wells at 10 Canadian landfill sites were analyzed for carbon adsorbable TOX, total organic carbon and volatile organics. Low concentrations of TOX (range, ND-44; median 8 μg Cl L^?1) were found at nine sites, and elevated TOX levels (?2072 μg Cl L^?1) at the tenth site. This latter site was studied in greater detail, and TOX and GC-MS analyses were carried out for volatile, base neutral, and acid extractable fractions of the water in six monitoring wells at this site. The TOX and GC-MS techniques were found to provide complementary information. GC-MS analysis detected high concentrations of 1,2-dichloroethylene, trichloroethylene, toluene, and ethylbenzene in some of the wells. TOX measurements, however, indicated the presence of halogenated contaminants in the base-neutral and acid extractable fractions, which had not been detected by GC-MS.     

Chattanooga shale exploitation and the aquatic environment: The critical issues

Early identification of the critical environmental issues arising from new energy technologies is needed to ensure adequate consideration of these issues in all phases of research and development. This study examines the potential hazards to aquatic ecosystems from large-scale exploitation (190,000 Mg/day) of the Chattanooga Shale Formation, an immense reserve of oil shale and uranium in Kentucky, Tennessee, and Alabama. Using existing data on regional ecology, hydrology, mining operations, and raw and spent shale chemistry, we identified two major, related environmental issues: (1) the potential for extensive adverse effects on aquatic communities through degradation of water quality and habitat; and (2) the potential conflict between the requirements for shale exploitation, and the habitat and water quality needs of threatened or endangered species. Specific hazards to aquatic ecosystems include erosion, sedimentation, acid mine drainage, raw and spent shale leachates, and surface disposal of immense quantities of solid wastes. Twelve of 19 federally designated, threatened or endangered fish and mollusks in the shale-bearing region were identified as known or recent inhabitants of the counties believed to be most favorable for the exploitation of shale. Of these, five species occur as single populations or are limited to a single river system. The potential for adverse effects on these species is greatest in the counties near the Tennessee-Alabama state line. Future research needs include physical, chemical, and toxicological characterizations of shale leachates and studies of the transport and fate of leachable contaminants. Such research can provide the guidance necessary to minimize impacts on aquatic communities resulting from extraction, retorting, and disposal of shale.     

The dissulution of a manganese ore in dilute aqueous solution

The kinetics and the mode of the dissolution of a manganese ore were studied in the laboratory under various conditions such as pH, redox condition, presence of organic matters, and temperature. The results showed that the iron contained in the ore may play an important role in manganese ore dissolution. The presence of organic substances such as nitrilotriacetate, peat extract, and humic acid tended to enhance the extent of manganese dissolution.     

Determination of lead in roadside dust in Lagos City by atomic absorption spectrophotometry

Roadside dust collected from roads with high, medium, and low vehicular traffic congestion in the city of Lagos have been analysed for lead by atomic absorption spectrophotometry. The analyses have shown that between 2.35 and 7.25 mg Pb/g of dust is present in samples from roads with high traffic congestion.     

A new method for spectrophotometric determination of benzene in air

A new spectrophotometric method for the determination of benzene in air is described. The method is based upon the nitration of benzene to m-dinitrobenzene and subsequent reduction to m-phenylenediamine. m-Phenylenediamine is determined by diazotization-coupling reaction. α-Naphthol is used as a coupling reagent. Beer's law is obeyed in the range of 10–80 μg of m-dinitribenzene per 25 mL sample. The dye shows a wavelength of maximum absorption at 530 nm. The dye is stable for ～ 30 h. Toluene, the major interferent, can be separated. Beer's law, sensitivity, reproducibility, and other reaction conditions such as time, temperature, and acidity were studied. Formation of stable dye is the main advantage of the method over the butanone method for benzene, in which the colored complex is stable for only 5 min. It is possible to determine traces of benzene (0.05–0.30 μg/mL) by extracting the azo dye in 10 mL iso-amyl alcohol; this also increases the stability of the dye up to 42 h.     

Is there a correlation between the number of mutagens and the number of nonmutagens in an environmental sample?

We have adapted a procedure which was developed for studying the correlations in the distribution of genetic factors, such as sex ratios in siblings, to obtain estimates of the correlation between the number of mutagens and the number of nonmutagens in a sample. Positive correlations with correlation coefficients in excess of 0.8 were obtained. The high correlation suggests that it is possible to estimate the number of mutagens in samples with N > 100 compounds as (0.064 ± 0.01) N.     

Inputs and fates of petroleum hydrocarbons in a subtropical marine estuary

Inputs and fates of petroleum from a higly urbanized area to a subtropical marine estuary were investigated by measuring hydrocarbon concentrations in municipal wastewater treatment plants, urban stormwater drains, sediments, and benthic organisms in and around Tampa Bay, FL. The concentrations of petroleum hydrocarbons discharged from secondary and tertiary treatment plants in this area were lower than concentrations previously reported for other treatment plants in temperate regions. Samples collected from urban storm drains under base flow conditions were also low. The generally low levels of petroleum hydrocarbons in the sediments and organisms throughout Tampa Bay suggest that the bay is relatively pristine with respect to petroleum hydrocarbon contamination. Since it is unlikely that the anthropogenic input of hydrocarbons to this estuary is significantly lower than in other urbanized areas, we suggest that elevated annual temperatures in this subtropical system result in increased metabolic rates of microorganisms and more rapid degradation or metabolism of the petroleum hydrocarbons.     

Spectrophotometric determination of nitrite with diphenylamine in potable and polluted water

This paper describes a new method for the determination of nitrite in potable and polluted water, based on the reaction of nitrite with p-nitroaniline to form diazonium salt and its subsequent coupling with diphenylamine in acidic medium. The pink coloured dye formed obeys Beer's law in the range 0.16 to 0.56 μg/ml at λ_max = 540 nm. The molar absorptivity and Sandell's sensitivity being 57.5 × 10³ lmole^?3cm^?1 and 0.0008 μg/cm², respectively. The optimum reaction conditions and other analytical parameters have been studied. Extraction of the dye with chloroform enhances the sensitivity considerably and makes 0.04 μg/ml of nitrite determinable.     

Identification of polychlorinated planar chemicals in fishes from major watersheds near the Great Lakes

Fish from 18 major watersheds near the Great Lakes were collected in 1979, 1980, or 1981, and analyzed by gas chromatography-mass spectrometry for polychlorinated planar organic chemical residues. Isomers of 36 different chemicals were identified by mass spectral data but not quantitated. The list includes isomers of chlorinated dibenzo-p-dioxins and dibenzofurans.     

Changes in physicochemical forms of lead and cadmium added to freshwater

Transformation of physicochemical forms of cadmium and lead added at 1 μ/L to Lake Michigan water have been studied by anodic stripping voltammetry. Unfiltered, 0.45 μ membrane filtered, ultrafiltered, and UV irradiated ultrafiltered samples were used to differentiate metal binding by particulate, colloidal, and dissolved organic matter. The reaction of added metal with colloids and particles is rapid. Their reaction with soluble organic matter is slow, requiring 1 to 2 days for complexation of one-half the added metal.     

Acid deposition and watershed characteristics in relation to lake chemistry in northeastern Minnesota

The relationship between lake sensitivity to atmospheric acidic inputs and the neutralization capacity of watersheds is examined for 267 lakes in northeastern Minnesota. Three water chemistry/sensitivity measures (color, sulfate, and alkalinity) are correlated with variables representative of precipitation and sulfate inputs, hydrology, and the acid neutralization capacity of various watershed components. An ordinal scale for ranking bedrock and surficial deposit neutralization capacity is presented. The watershed variables found to account for the largest percentages of the variability in measured color, sulfate, and alkalinity levels are determined. Color is strongly related to the presence of peat or marsh and hydrologic renewal time, whereas sulfate is primarily related to atmospheric deposition, evaporative concentration, bedrock type, and the presence of coniferous forest. Variation in alkalinity is the most difficult of the water chemistry measures to explain; for headwater lakes, atmospheric sulfate input, water renewal time, the presence of deciduous forest, and the weatherability of underlying bedrock determine much of its variability. The results illustrate important averaging properties of watersheds from small headwater systems to large drainages and the difficulty in obtaining correlations for some water quality measures (e.g., alkalinity) when some variables, such as soils and land cover, are available only as large-area averages.     

Tidal variations in dissolved and particulate phase radionuclide activities in the Esk estuary,England, and their distribution coefficients and particulate activity fractions

Measurements have been made of the radionuclide activities, particularly for plutonium isotopes, of the particulate and dissolved fractions of the tidal waters of the Esk Estuary. A wide range of K_d values indicates the lack of equilibrium conditions in this dynamically changing environment. The particulate activity contributes a major part of the activity of the suspension, with reworked estuarine sediment providing an important component of this. The estuarine circulation system results in the dispersion of particulate radionuclides into the low salinity upper reaches of the estuary, where plutonium isotopes are apparently mobilised, enriching the dissolved fraction activity.     

Geochemical associations of plutonium and γ-emitting radionuclides in caithness soils and marine particulates

Geochemical associations of plutonium and artificial γ-emitting radionuclides have been investigated in soils and marine particulate material from the immediate vicinity of the Dounreay Nuclear Power Development Establishment (DNPDE) Caithness. The artificial radionuclides present in these materials arise from a variety of sources: world-wide nuclear weapons test fallout, direct deposition from atmospheric discharges at DNPD, and the return to land of activity previously discharged to sea (containing contributions from Dounreay and Sellafield). The levels, although sufficient to permit satisfactorily low counting errors, are of negligible radiological significance, the plutonium being more than 1000 times less than the NRPB Generalised Derived Limit (GDL) for well-mixed soil. Sequential leaching using selective extractants was performed to quantify the percentages of each nuclide in the following notional fractions: (a) readily available, (b) exchangeable and bound at specific adsorption sites, (c) chelated as insoluble organic complexes, (d) associated with sesquioxides, and (e) residual. Plutonium was found to be associated mainly with phases (c) and (d), while the γ-emitters present in the marine particulate material showed quite varied distributions. The degree of chemical fixation in the particulates follows the sequence ⁴⁰K¹³⁷Cs¹⁰⁶Ru¹²⁵Sb^239,240Pu¹⁴⁴Ce⁶⁰Co^154,155Eu.     

TCDD distribution in the Spring River,Southwestern Missouri

The waste management practices of a now defunct chemical company created several disposal sites containing 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) contaminated materials. A sampling survey of the Spring River, which drains the disposal sites, was conducted to determine if TCDD contamination of this river had occurred. TCDD was found in fish at concentrations of 0.8 to 55 ng/kg (whole fish) and 1.4 to 18. ng/kg (fillet). In addition, TCDD was present in the fish at least as far as 69 mi (111 km) downstream of the disposal sites. The detection limits were generally not sufficient to determine the sediment TCDD concentration in the river. TCDD was only found in the sediments immediately downstream of the former manufacturing facility, at 12 ng/kg.     

Electron paramagnetic resonance spectrometry of diesel particulate matter

Electron paramagnetic resonance (EPR) spectrometry has been used to study diesel particulate matter. The EPR signals for a graphitized carbon black and particles collected from two different diesel engines have been compared. Variations in the line widths and signal intensities due to various chemical and physical pretreatments of the particles were observed. The EPR signals for the diesel particulates were shown to be sensitive to oxygen, nitric oxide, nitrogen dioxide, and ultraviolet and visible radiation. These results suggest that EPR may be a convenient means for characterizing particles from different sources or for demonstrating particle reactivities. The demonstrated photochemical reactivities of the airborne particles have significant environmental health implications.     

Chemical treatment of chrysotile asbestos in laboratory solutions

This study investigates the problems of degrading or otherwise altering through treatment with simple chemical reagents the fibres of chrysotile, the most common asbestos variety. The experiments conducted were aimed, on the one hand, at destroying the fibrous morphology by chemical breakdown and, on the other, at nucleating and growing crystals (specifically anhydrite, CaSO₄) on fibres thus changing their dimensions. Degeneration runs contained mixtures of asbestos with different solution strengths of HCl, Na₂CO₃, and CO₂-saturated water. Of these, only the HCl runs showed appreciable fibre breakdown. The second sequence proved more successful in that anhydrite crystals were readily grown upon asbestos fibres. The applicability of experimental results to environmental control is considered.     

The effect of complex formation on the adsorption characteristics of heavy metals

In most aqueous environmental systems, inorganic and organic metal complexes represent a significant contribution to the total soluble metal. Metal adsorption is often a highly pH-dependent phenomena. Such behavior can generally be attributed to changes in metal speciation with solution acidity as well as variation in the extent of surface protonation. Thus, because adsorbability may vary drastically between different metal species, (e.g. Cu²⁺ (aq) compared to CuOH⁺) a knowledge of metal species distribution is essential to understanding and interpreting metal adsorption behavior.Organic complexation has been reported to enhance, suppress and have no perceptible effect on trace metal adsorption. Such differences arise because adsorption depends on factors such as the ligand/metal ratio, adsorbability of the free ligand, and various solution parameters (e.g. pH). Most important in determining the effect of complexation on adsorption is the adsorbability of the resulting complexes. Thus, it is difficult to make generalizations about the influence of organic complexation on metal adsorption.Adsorption of metal complexes is frequently reported to be predominantly coulombic in nature; that is, binding of an anionic or cationic complex to an oppositely charged colloidal particle. However, electrostatic forces can often represent an insignificant contribution to the total free energy of adsorption and can be overshadowed by chemical reactions with the surface, hydrogen bonding, and hydrophobic effects.     

Pollution studies on Nigerian rivers: The onset of lead pollution of surface waters in Ibadan

Lead levels in the waters and sediments of the lake of the International Institute of Tropical Agriculture, Agodi Lake, Oba Lake, at three stations on Ogunpa stream, and at three stations on Ona River were measured from October 1977 to June 1978, using the combined APDC-MIBK-flame atomic absorption spectrophotometry technique. The lead levels recorded ranged from 0.2 to 46 μg/L for the aqueous phases; however, the levels in the sediments were much higher, ranging from about 18 to 85 mg/kg (dry weight). Although there is nothing alarming about these levels, the levels of lead in water bodies located in areas with high traffic density were consistently higher than levels for comparable waters in low traffic density areas. Similarly, lead levels were significantly higher in the fresh sediments of water bodies in areas with high traffic density, clearly indicating the onset of lead pollution for those high traffic density areas.     

Seasonal variation of mercury concentrations in organisms of the Cilician Basin

Total mercury concentrations in organisms typical of those found in the Cilician Basin of the northeastern Mediterranean have been measured from 1977 to the present. These concentrations show seasonal variations. Shrimp shows an approximately constant concentration of mercury which might testify to the regulation capacity of shrimp for mercury. Crab, and particular fish, show a seasonal variation which may be correlated with the local application of mercury fungicide, rainfall, and the physiology of the organisms. The rapidity with which mercury applied to the land causes increased concentrations in fish is noteworthy.