Air pollution caused by opencast mining and its abatement measures in India.

Opencast mining dominates coal production in India. A survey was conducted to evaluate its local atmospheric impact. Emissions data were utilised to compute dust generation due to different mining activities. Work zone air quality, ambient air quality and seasonal variations are described revealing high pollution potential due to suspended particulate matter (SPM) and consequent impact on human health. Air pollution control measures involve planning and implementing a series of preventive and suppressive measures in addition to dust extraction systems. Different abatement measures are enumerated. Pollution control by trees, the tolerance of trees to different air pollutants and plant species useful for controlling pollution are also discussed. There is a need for wider application of dust control chemicals on haul roads. Sustainable management of pollution can be achieved by the proper implementation of suggested abatement measures.     

Personal exposure levels and microenvironmental concentrations of formaldehyde and acetaldehyde in the Helsinki metropolitan area, Finland

Personal 48-hr exposures to formaldehyde and acetaldehyde of 15 randomly selected participants were measured during the summer/autumn of 1997 using Sep-Pak DNPH-Silica cartridges as a part of the EXPOLIS study in Helsinki, Finland. In addition to personal exposures, simultaneous measurements of microenvironmental concentrations were conducted at each participant's residence (indoor and outdoor) and workplace. Mean personal exposure levels were 21.4 ppb for formaldehyde and 7.9 ppb for acetaldehyde. Personal exposures were systematically lower than indoor residential concentrations for both compounds, and ambient air concentrations were lower than both indoor residential concentrations and personal exposure levels. Mean workplace concentrations of both compounds were lower than mean indoor residential concentrations. Correlation between personal exposures and indoor residential concentrations was statistically significant for both compounds. This indicated that indoor residential concentrations of formaldehyde and acetaldehyde are a better estimate of personal exposures than are concentrations in ambient air. In addition, a time-weighted exposure model did not improve the estimation of personal exposures above that obtained using indoor residential concentrations as a surrogate for personal exposures. Correlation between formaldehyde and acetaldehyde was statistically significant in outdoor microenvironments, suggesting that both compounds have similar sources and sinks in ambient urban air.     

Accumulation of chromium (VI) from aqueous solutions using water lilies (Nymphaea spontanea)

This study describes an investigation using tropical water lilies (Nymphaea spontanea) to remove hexavalent chromium from aqueous solutions and electroplating waste. The results show that water lilies are capable of accumulating substantial amount of Cr(VI), up to 2.119 mg g(-1) from a 10 mg l(-1) solution. The roots of the plant accumulated the highest amount of Cr(VI) followed by leaves and petioles, indicating that roots play an important role in the bioremediation process. The maturity of the plant exerts a great effect on the removal and accumulation of Cr(VI). Plants of 9 weeks old accumulated the most Cr(VI) followed by those of 6 and 3 weeks old. The results also show that removal of Cr(VI) by water lilies is more efficient when the metal is present singly than in the presence of Cu(II) or in waste solution. This may be largely associated with more pronounced phytotoxicity effect on the biochemical changes in the plants and saturation of binding sites. Significant toxicity effect on the plant was evident as shown in the reduction of chlorophyll, protein and sugar contents in plants exposed to Cr(VI) in this investigation.     

Life history of the sandy-beach amphipod Neohaustorius schmitzi (Crustacea: Haustoriidae)

Neohaustorius schmitzi Bousfield, the dominant macroscopic invertebrate on sandy beaches in North Carolina, USA, is strictly intertidal, and distributed from mean low tide to high tide, with an average density of 790/m². Location of greatest densities within the intertidal zone is dependent upon season and sex. An aggregated distribution is shown. N. schmitzi has 2 generations/year: a winter generation which lives about 8 months, and a summer generation which lives about 4 months. The reproductive season extends from February through October, with spring and summer peaks. Each female appears to produce only 1 brood of young. The number of young ranges from 2 to 14, depending upon the length and generation of the female.     

Influence of the mode of matrix porosity determination on matrix diffusion calculations

The theoretical basis for matrix diffusion in fractured rocks and the methodology for the determination of diffusion coefficients in the laboratory are well established. One significant problem, however, remains in that it is difficult to quantify the degree of sample disturbance affecting the geometrical, geophysical and hydraulic properties of the rock matrix. A new technique, with in situ rock impregnation with resin, for examining the diffusion-accessible rock matrix has been developed and successfully adopted to the rock matrix behind a water-conducting fracture in host crystalline rocks at Nagra's Grimsel Test Site in Switzerland and JNC's Kamaishi In Situ Test Site in Japan. In line with the results of a large number of natural analogue and laboratory studies, the existence of an in situ interconnected pore network was substantiated. Matrix porosities determined on the laboratory samples from both the sites are 1.5-3 times higher than in situ values, irrespective of the technique applied. On the Grimsel granodiorite matrix, matrix porosity existing in situ and artefacts of stress release and physical disturbance, induced by sampling and sample preparation, were clearly distinguished, allowing in situ porosity to be quantified. Laboratory work with conventional techniques tends to overestimate the porosity of the rock matrix, hence leading to an overestimation of in situ matrix diffusion. The implications of these differences to a repository performance assessment are assessed with a couple of examples from existing assessments, and recommendations for future approaches to the examination of in situ matrix porosity are made.     

Annual occurrence,abundance and diversity of fish in a South Carolina intertidal creek

An intertidal creek in North Inlet Estuary, South Carolina, USA, was sampled monthly for 1 year to determine the occurrence, abundance and diversity of fish species. Sampling was so conducted as to reduce sampling bias to a minimum and all individuals caught were weighed and measured. A total of 16,611 individuals weighing 202.45 kg and comprising 51 species and 25 families of fish was collected. Three diversity indices were calculated for species number. Analysis of variance revealed that season had a highly significant effect on all indices and the number of species, but had no effect on the number of individuals caught.This work was supported by the Belle W. Baruch Foundation and the South Carolina State Development Board, and is Contribution No. 71 of the Belle W. Baruch Institute for Marine Biology and Coastal Research.     

Modulation of hepatic and intestinal glutathione S-transferases and other antioxidant enzymes by dietary lipids in streptozotocin diabetic rats

Antioxidant enzymes in liver and small intestine were investigated using control and streptozotocin diabetic rats fed diets with 5% olive, sunflower or fish oil for five weeks. In liver, Glutathione Peroxidase and Superoxide Dismutase decreased and in intestine Glutathione-S-transferase (GST) increased by diabetes. In isolated jejunum and ileum, this increase in GST activity was due to an increase in GST-alpha and -mu isoenzymes in jejunum and GST-alpha, mu and -pi in ileum. Since GST plays an important role in protecting tissues from oxidative damage, our results highlight the role of the intestine against free radicals in physiological or pathological situations.     

Foliar response of black cherry (Prunus serotina) clones to ambient ozone exposure in central Pennsylvania

During late summer of 1996 and 1997 we examined ozone-induced foliar injury in a plantation of 111 black cherry trees (ramets) comprising 15 clones originating from wild ortets growing in the Allegheny National Forest, Pennsylvania, and the Monongahela National Forest, West Virginia. The experimental plantation was a clonal seed orchard in Centre County, Pennsylvania, started in 1971 using ortet buds grafted onto seedling rootstocks of mixed origin. Clones differed significantly in severity of foliar injury symptoms (F=31.83, p<0.001). One clone (R-12) had significantly more foliar injury with >50% leaf area affected than other clones during both years. In contrast, clone R-14, which is from the same area in northcentral Pennsylvania as R-12, exhibited significantly less injury (LAA<6%). Although ambient O(3) concentrations were similar in both years, foliar injury was significantly greater (15.7%) in 1996 than in 1997 (9.9%). This is probably explained by lower stomatal conductance in 1997 caused by drier and hotter weather patterns in June and July of that year. Despite very different weather patterns and overall levels of injury in 1996 and 1997, mean clonal injury was significantly correlated between both years of assessment (r=0.92, p<0.001). Within tree crowns, foliage in lower and inner crown positions was significantly more injured than foliage in upper and exterior crown positions. There was no evidence of geographically based population differences in sensitivity to foliar O(3) injury. On the contrary, results demonstrate that wild genotypes of proximal geographic origin may differ greatly in sensitivity.     

Beach topography mapping—a comparsion of techniques

A comparison of current techniques for measuring elevations in the beach and near-shore zones is presented. Techniques considered include traditional methods such as ground survey along transects and airborne stereophotogrammetry, and also newer methods based on remote sensing such as airborne scanning laser altimetry (LiDAR). The approach taken was to identify a representative group of users of beach elevation data, elicit their requirements regarding these data, then assess how well the different methods met these requirements on both technical and financial grounds. Potential users of beach height measurements include those concerned with coastal defence, coastal environmental management economic exploitation of the intertidal zone, and coastal flood forecasting. Three test areas in the UK were identified covering a range of such users and also different beach types. A total of 17 basic user requirements were elicited. For each requirement each method was scored according to the degree to which it could meet the requirement. Total scores were calculated and each method ranked. This was undertaken for all the requirements together, for a subset relating to survey of narrow beaches, and for a subset relating to survey of wide beaches. Approximate costs were also established for the top six methods. Airborne stereophotogrammetry proved to be the best method technically, but was also the most expensive. Ground survey provides very good technical performance on narrower beaches at moderate cost. Airborne LiDAR can achieve good technical performance on both narrow and wide beaches at lower cost than ground survey. The satellite-based waterline method was also inexpensive and gave good results on wide beaches. An overall conclusion is that, while the traditional methods of ground survey and airborne stereophotogrammetry remain the best for engineering-related surveys requiring high levels of accuracy, airborne LiDAR in particular looks set to have a significant impact on beach survey for applications for which a vertical accuracy of 20 cm is acceptable, provided that its technology evolves satisfactorily.     

An elegant application of appropriate technology: the Sheep Creek Hatchery

Alaska's program for rebuilding salmon stock is calledfishery enhancement. Hatchery technology can produce dramatic increases in numbers of fish homing to selected streams. The Sheep Creek Hatchery is unusually efficient— it increases a fish run by a factor of 3000 and produces salmon at 9–11c/kg by minimizing mechanical energy inputs and human labor. The design harnesses the force of gravity and capitalizes on instinctual behavior of the fish. Since migratory fish collect protein from ocean pasturage, the technology increases the share of this resource collected and concentrated for harvest in a specific country or region. While small seaside hatcheries can solve biological problems of depleted fish stocks, economic and political considerations may preclude efficient utilization of the protein produced. Further, the potential for one state or country to concentrate fish near its shores poses new dilemmas for international regulation of harvests.