Efficient search procedures for extreme pollutant values

Extreme pollutant values are of great interest in water quality monitoring because of their frequent toxicological significance. The principal barrier to the detection of these values, however, is the cost of extensive and comprehensive monitoring. This paper demonstrates an efficient method to determine the maximum sample measurement from a finite set of sequential samples without explicitly testing them all. It is assumed that the process of sample measurement is distinct from collection and has higher costs. It is further assumed that the measurements have high positive autocorrelation.A methodology is presented based on a common industrial testing procedure referred to as composite sampling—the physical pooling or compositing of a set of sequential samples before measurement. A method known as primary first order compositing (PFOC) was found to be superior to the traditional technique of random sampling, particularly if small composite sizes are utilized.The authors are, respectively, operations research analyst, Vancouver, B. C.; Associate Professor and Chairman, Policy Analysis Division, Faculty of Commerce and Business Administration, University of British Columbia; and Associate Professor, Management Science Division, Faculty of Commerce, U.B.C.     

Factor analysis of trace-element data from tree-bark samples in The Netherlands

Monte Carlo-assisted factor analysis has been applied to a data set of 20 trace-element concentrations in tree-bark samples obtained from 123 locations in The Netherlands, with the aim to investigate the suitability of bark as a biomonitor for air pollution. A Monte Carlo approach was used to give more insight to the uncertainties and significance levels of the factor analysis results. Notwith-standing a rather strong influence of soil material on the concentration levels, factor analysis enabled the identification of five significant pollution source types, all of which corresponded with source types found in an earlier biomonitoring study in The Netherlands using epiphytic lichens. A more detailed comparison with the lichen results showed a remarkable difference in lead concentrations between bark and lichen. It was concluded that bark can be successfully employed as a biomonitor for air pollution. The power of factor analysis to adequately determine the soil contribution may render extensive sample washing procedures superfluous.     

Multimedia environmental monitoring: 50 years at Hanford

Environmental monitoring has been an ongoing activity on the U.S. Department of Energy's Hanford Site in southeastern Washington for almost 50 years. Objectives are to detect and assess potential impacts of Site operations on air, surface and ground waters, foodstuffs, fish, wildlife, soil and vegetation. Data from monitoring effects are used to calculate the overall radiological dose to humans working onsite or residing in nearby communities. In 1989, measured Hanford Site perimeter concentrations of airborne radionuclides were below applicable guidelines. Concentrations of radionuclides and nonradiological water quality in the Columbia River were in compliance with applicable standards. Foodstuffs irrigated with river water taken downstream of the Site showed radionuclide levels that were similar to those found in foodstuffs from control areas. Low levels of ¹³⁷Cs and ⁹⁰Sr in most onsite wildlife samples and concentrations of radionuclides in soils and vegetation from on- and offsite locations were typical of those attributable to worldwide fallout. The calculated dose potentially received by a maximally exposed individual (i.e., based on hypothetical, worst-case assumptions for all routes of exposure) in 1989 (0.05 mrem/yr) was similar to those calculated for 1985 through 1988.In addition to monitoring radioactivity in fish and wildlife, population numbers of key species are determined. Chinook salmon (Oncorhynchus tshawytscha) spawning in the Columbia River at Hanford has increased in recent years with a concomitant increase in winter roosting activity of bald eagles (Haliaeetus leucocephalus). An elk (Cervus elaphus) herd, established by immigration in 1972, is also increasing. The Hanford Site currently serves as a refuge for Canada goose (Branta canadensis), great blue heron (Ardea herodias), and various plants and other animals, e.g., mule deer (Odocoileus hemionus), and coyotes (Canis latrans).     

Trend evaluation of water quality parameters in the Niagara and St. Lawrence Rivers

Physical and chemical (nutrients and major ions) indicators of water quality monitored by Environment Canada between 1977 and 1987 in the Niagara River at Niagara-on-the-Lake and in the St. Lawrence River at Wolfe Island are analyzed for seasonal and annual variations. Parametric methods such as moving averages and linear regression and nonparametric methods (Spearman's rank coefficient) are used to test for the existence of trends in these data. The results indicate that specific conductivity, sodium and chloride have decreased significantly over the period of study. During the same period there is no significant trend for either discharge and nutrients.     

Soil properties and crop productivity as influenced by flyash incorporation in soil

Field experiments were carried out during 1996–97at Gulawathi, Muthiani and Salarpur Villages, IARI Farm, NewDelhi and NCPP Campus, Dadri to evaluate changes in soilcharacteristics and growth of wheat (Triticum aestivum L.),mustard (Brassica juncea L.), lentil (Lence esculentaMoench.), rice (Oryza sativa L.) and maize (Zea mays L.) byvarying amounts of flyash addition (up to 50t ha^-1) in soils atsowing/transplanting time of crops. Flyash addition in areasadjoining NCPP Thermal Power Plant, Dadri, Ghaziabad, U.P.ranged from 5–12 t ha^-1 yr^-1 in 1995–96. Shoot and root growthand yield of test crops at different locations after flyashincorporation resulted in beneficial effects of flyashaddition in most cases. The silt dominant texture of flyashimproved loamy sand to sandy loam textures of the surfacesoils at the farmers' fields. The increased growth in yield ofcrops with flyash incorporation was possibly due tomodifications in soil moisture retention and transmissioncharacteristics, bulk density, physico-chemical characterssuch as pH and EC and organic carbon content. The response offlyash addition in the soil on soil health and cropproductivity needs to be evaluated on long-term sustainableaspects.     

Characterization of microbial communities from coastal waters using microarrays

Molecular methods, including DNA probes, were used to identify and enumerate pathogenic Vibrio species in the Chesapeake Bay; our data indicated that Vibrio vulnificus exhibits seasonal fluctuations in number. Our work included a characterization of total microbial communities from the Bay; development of microarrays that identify and quantify the diversity of those communities; and observation of temporal changes in those communities. To identify members of the microbial community, we amplified the 16S rDNA gene from community DNA isolated from a biofilm sample collected from the Chesapeake Bay in February, 2000. The resultant 75 sequences were 95% or more similar to 7 species including two recently described Shewanella species, baltica and frigidimarina, that have not been previously isolated from the Chesapeake. When the genera of bacteria from biofilm after culturing are compared to those detected by subcloning amplified 16S fragments from community DNA, the cultured sample exhibited a strong bias. In oysters collected in February, the most common bacteria were previously unknown. Based on our 16S findings, we are developing microarrays to detect these and other microbial species in these estuarine communities. The microarrays will detect each species using four distinct loci, with the multiple loci serving as an internal control. The accuracy of the microarray will be measured using sentinel species such as Aeromonas species, Escherichia coli, and Vibrio vulnificus. Using microarrays, it should be possible to determine the annual fluctuations of bacterial species (culturable and non-culturable, pathogenic and non-pathogenic). The data may be applied to understanding patterns of environmental change; assessing the health of the Bay; and evaluating the risk of human illness associated with exposure to and ingestion of water and shellfish.     

Interactions between copper and cadmium modify metal organ distribution in mature tilapia, Oreochromis mossambicus

Sexually mature female tilapia were exposed to sublethal concentrations of waterborne Cu and/or Cd over 6 days, and subsequent body concentrations of these metals were determined in several organs. The results show that the distribution of Cu and Cd was metal and organ specific. This is demonstrated, for example, by the observation that in tilapia, Cu exposure did not result in Cu accumulation in the liver, whereas in the intestinal wall, notably high concentrations of Cu and Cd were measured in metal exposed fish. In addition to single metal exposed fish, we also determined Cu and Cd body distribution in Cu?Cd co-exposed fish. The observed interactions in metal accumulation were most pronounced in the organs of fish exposed to low, environmentally realistic, metal concentrations.     

Ecoprofit-Styria-prepare Thirteen pollution prevention case studies in the Styrian industry

The paper focuses upon the organization of a federal state-funded pollution prevention project in the Styrian industry. The project includes 13 companies from the textile, pulp and paper, machine building, wood working and printed circuit board manufacturing industries, covering most of the sectors and sizes in the Styrian industry. It started in January 1994 and will last for one year. It will demonstrate the possibilities of pollution prevention and the need for further research work. This project will make use of the methods and tools that were refined in the Austrian Prepare project. As a first step, a systematic balance of all the inputs and outputs of a company is made, after which the weak points and inefficiencies of material and energy use are identified and the options for improvements, both economical and ecological, are defined. Consequently, modifications in products and production lead to a situation with less waste and emissions. The preliminary lessons from these projects are presented: as a rule, the utilities (consumption of process materials and water, cleaning, energy, preparatory and finishing steps) are treated as black boxes and usually represent a considerable optimization potential. In these areas especially there is usually a lack of information and coordination as well as a need for a systematic and comprehensive approach. Leadership in the company and creative consultants are needed for starting lasting successful pollution prevention projects.     

A biological paleoindicator for early lake acidification: Mallomonadacean (Chrysophyceae) scale abundance in sediments

The Science of Nature -