Processes contributing to acid release/consumption during weathering of a lignite mine spoil (2.3% w/w S as sulfides) from As Pontes (N.W. Spain) were studied under three moisture conditions (at field capacity or under alternate wetting-drying or forced percolation), which were simulated in laboratory experiments. Oxidation of sulfides to sulfates was favoured under all three moisture conditions, releasing most acid in spoil kept at field capacity. Hydroxysulfates formed in spoil kept at field capacity or under alternate wetting-drying conditions, thereby contributing to acid release. Acid consumption by dissolution of clay minerals, especially micas, was favoured under all three moisture conditions, but was particularly intense in spoil at field capacity. Dissolution of aluminium oxides was also favoured under all the moisture conditions studied.

The discharge of acidic mine drainage waters onto a hillslope in Dalarna, central Sweden, has lead to the contamination of the podzol soils with Cu, Fe, Ni, Pb, Zn and sulfate. Samples from contaminated and reference soils have been collected for chemical and mineralogical analyses. Jarosite is identified by x-ray diffraction analysis as a precipitate in the upper horizons (A, E, B) of the contaminated soils, where the soil acidity (pHKCₗ ∼ 2.6) promotes jarosite stability. The sequential chemical extraction of soil samples indicates that, in the reference A horizon, Cu, Pb, Ni and Zn are bound primarily to cation exchange sites and organic matter. In the A horizon of the contaminated soils closest to the rock dump, metal partitioning is dominated by the Fe oxide fractions, despite the high organic matter content; Pb is almost completely bound to crystalline Fe oxides, possibly adsorbed to Fe oxides or occuring in a jarosite solid solution. In the reference B and C horizons, Cu, Ni and Zn are primarily adsorbed/coprecipitated in the Fe oxide fractions, while Pb remains with a large fraction bound to organic matter. In the Fe-rich B horizon of the contaminated soils, the partitioning of the metals in cation exchange sites and to organic matter has greatly increased relative to the reference soils, resulting from the mobilization of organo-metal complexes down the profile.

The effects of the organophosphate insecticide diazinon on selected population parameters of the freshwater cladoceran Moina macrocopa were studied. Survivorship and average longevity were affected by exposure to 1.00 μg L⁻¹ or higher concentrations. Exposure to diazinon had no effect on the time of first reproduction, but animals did not reproduce in 10.00 μg L⁻¹ and the number of offspring produced by a female during her entire life span was reduced in 1.00 μg L-1. The intrinsic rate of population growth and the generation time were not significantly affected by exposure to diazinon.

The influence of alkaline dust pollution (pH of water solution of dust 12.3–12.7) from a cement plant (Kunda town, Estonia) on chlorophylls and carotenoids of the needles of 60–80 year old Norway spruce was studied on sample plots established at different distances from the emission source. The highest sensitivity to dust impact was measured in the content of Chl a, Chl b, carotenoids and elements regulating or participating in the biosynthesis of pigments (Mg, Fe, N, Mn).

Sediments from 8 river mouths of the Catalonian coast (Spain) were examined for keratinolytic fungi. Out of 1250 river and marine samples examined, 499 (39.9%) were positive for these fungi. Aphanoascus fulvescens (anamorph + teleomorph), Chrysosporium keratinophilum, Ch. tropicum, Ch. an. of Arthroderma curreyi, Ch. pannicola, Ch. europae and Ch. indicum were the predominant species in the sediments. River samples were rich in keratinolytic fungi, whereas in marine beach sediments they occurred sporadically. The results of a preliminary experiment demonstrated that, marine water exerted a dramatical impact on river keratinolytic fungi causing their total or near-total elimination. The qualitative and quantitative compositions of river keratinolytic mycoflora depended on the degree of water contamination with sewage and on natural factors (mainly temperature). The keratinolytic mycoflora of two rivers was possibly altered dramatically by water contaminants, including poisons of industrial origin, and marine salinity. The problem of public health risk resulting from the distribution of keratinolytic fungi within the highly-frequented recreational waters is discussed.

Virus detection in drinking water is very important to protect human health. The different methodologies for analysing human pathogenic virus are very time consuming and expensive, so until now only a few specialised laboratories carried out this analysis. Detection of bacteriophages may be possible by examining the aquatic virus, with advantages of easy and cheap. The bacteriophages ofBacteroides fragilis have been proven as specifically present in human faeces and have relationships with water contaminated by enterovirus. Our study, for the first time in France, discovered theB. fragilis phages present in sample of sewage, Seine river and raw water for water supply. Our results also presented thatB. fragilis phages may be a better indicator for water bacteriology compared with classical bacteriological indicators in water treatment. On the other hand, our results demonstrated that MPN method (Most Probable Number) has more advantages than that of PFU (Plaque Forming Units).

Combined effects of organic or inorganic pollutants on soil microbial activities were investigated in field plots grown with four types of covering plants. It was derived from this study that combined effects were dependent not only on the type and dose of pollutants, addition of soda lime, plant type and season variation, but also on test parameters. When jointly added, higher doses of Cd, Cu, Pb, Zn and As caused significant inhibition. Addition of soda lime could even enhance inhibition. Joint effects of phenanthrene, MET (active ingredient: paclobutrazol) and 1,2,4-trichlorobenzene were not significant, and may be covered by other biotic or abiotic factors. Compared with other two parameters (respiration and microbial biomass), dehydrogenase activity appeared to be more sensitive for evaluating the toxicity of anthropogenic pollutants in soil. Soil samples collected in summer often had higher microbial activities than those in fall. The microbial activity in soil decreased with covering vegetation in the order alfalfa > pine > poplar and maize, albeit some exceptions were observed.

Huge areas of the Russian forests suffer from insufficient forest management. A scenario has been developed for an improved management program that would be implemented over the next 40 years. Possible options have been aggregated into three interlinked groups: increase in forest productivity through improvement of the forest conditions and the structure of the Forest Fund, decrease of carbon release by mitigation of disturbance regimes, and improvement of landscape management. One prerequisite in developing this scenario was that the cost of sequestering one ton of carbon should not exceed US$3 (1992 dollar value). In this article a simple model is described to illustrate the following possibilities for increased carbon fixation by improved forest management: large-scale reforestation and afforestation, replacement of stands with low productivity and replacement of so called soft deciduous species and “climax” stands, and implementation of rational silviculture (thinning). The results indicate a potential for an increase in carbon fixation in Russian forest ecosystems of 24.4 Pg over 100 years, after the first year that the actions discussed are implemented. The net sink of carbon was determined to be 16.5 Pg in the “low” estimate and 42.5 Pg in the “high” estimate. There are, however, many uncertainties in the data and there are difficulties in adequately modeling the possibilities for implementation under current conditions in Russia. In spite of these uncertainties, we conclude that there is great potential for economically justified increased carbon fixation through improved forest management in Russia.

A study was carried out recently to determine the pollution level of waters in the Karachi harbour and adjoining backwaters. Nine locations were selected, four in the backwaters, two on the seaside, and three in the main navigable channel. Four of these locations were deliberately selected to coincide with those of a previous study conducted in 1982 by Pakistan Council of Scientific and Industrial Research (PCSIR) so that the values for the concentration of different pollutants could be compared. Analysis was conducted for pH, bicarbonates, Total Solids, Volatile matter in Total Solids, Chlorides, Sulphates, Calcium, Magnesium, Sodium and Potassium.The results indicate that the composition of sea water as far as the concentration of above constituents is concerned has not changed much since the time of the PCSIR study, viz 1982, except that the organic matter concentration has increased. The reasons for this increase in organic loading and its possible impact are discussed in this paper.

A total of 51 lakes in southern Quebec, Canada, were sampled between 1985 and 1993 to study changes in water chemistry following reductions in SO₂ emissions (main precursor of acid precipitation). Time series analysis of precipitation chemistry revealed significant reductions in concentrations and deposition of SO₄ ²⁻ from 1981 to 1992 in southern Quebec as well as reductions in concentrations and deposition of base cations (Ca²⁺, Mg²⁺), NO₃ ⁻ and H⁺ in the western section of the study area. Reductions in atmospheric inputs inputs of SO₄ ²⁻ have resulted in decreased lakewater SO₄ ²⁻ concentrations in the majority of the lakes in our study, although only a small fraction (9 of 37 lakes used in the temporal analysis) have improved significantly in terms of acidity status (pH, acid neutralizing capacity — ANC). The main response of the lakes to decreased SO₄ ²⁻ is a decrease in base cations (Ca²⁺+Mg²⁺), which was observed in 17 of 37 lakes. Seventeen lakes also showed significant increases in dissolved organic carbon (DOC) over the period of study. The resulting increases in organic acidity as well as the decrease in base cations could both play a role in delaying the recovery of our lakes.