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[Effects, detection and prevention of water pollution].
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Physical changes of the environment and health effects with special reference to water pollution and sanitation in Malaysia.
Development of a human community are not without changes in its environment. Such changes result in either beneficial or adverse effects on human health. In Malaysia, in the wake of the New Economic Policy aimed at the redressing of the poor population and income distribution, development of the nation has brought about various changes in the environment. Some of these changes have elevated basic public health problems, while others, particularly new agricultural practices and industrialisation programmes with urbanisation trends, have brought a new set of problems due to water pollution and sanitation. Various measures are being taken to protect and to improve the environment so that progress can be realised with minimum adverse effects. This also calls for assistance from international sources, in terms of expertise, training and funds.
Aeromonas primary wound infection of a diver in polluted waters.
Two separate species of Aeromonas, A. sobria (not listed as a species in Bergey's Manual of Determinative Bacteriology, 8th ed.) and A. hydrophila, were primary pathogens isolated from the leg wound of a diver conducting operations in polluted waters. This is the first recorded instance of a primary infection of soft tissue in a human caused by two species of Aeromonas, one of which was resistant to tetracycline. Because of the very rapid development of this wound infection, cytotoxicity of these organisms was examined in several biological systems. A. sobria was hemolytic for sheep erythrocytes, cytotoxic for Y-1 adrenal cells, and enterotoxic in rabbit ligated intestinal loops, whereas A. hydrophila was hemolytic and cytotoxic. Pertinent clinical, bacteriological, and environmental features of the case are presented.
[Modified method for determining water pollution by using a Serratia marcescens culture].
The method for determining the degree of water pollution with the aid of a bacterial tracer has been improved by using: (1) a technique for maintaining the culture of Serratia marcescens; (2) a medium whose composition provided for a high level of prodigiosin in the bacterial culture; and (3) an express method for assaying the degree of pigmentation during growth of Ser. marcescens on solid media.
[New approach to control of water pollution using hydrobiological methods].
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Mechanism of radiation purification of polluted water and wastewater.
The paper summarizes the results of the studies on radiation purification of polluted water and wastewater conducted in the author's laboratory in cooperation with other institutions. The removal of heavy metals (cadmium, lead, chromium and mercury) from water and wastewater, the purification of wastewater from surfactant and petroleum products, molasses distillery slops, municipal wastewater in the aerosol flow, river water from colored natural organic pollutants, wastewater of dyeing complex and paper mill, the decomposition of some dyes, hydrogen peroxide, chlorine-containing organic compounds, formic acid, etc. were investigated in detail. As a rule, electron-beam treatment in combination with ordinary methods (biological, coagulation, adsorption, flotation, etc.) was used. The main attention is paid to the mechanism of purification of the studied systems. The role of redox reactions of primary products of water radiolysis and secondary short-lived species formed from pollutants, formation of precipitates capturing the pollutants etc. is discussed.
Inter-zonal tradable discharge permit system to control water pollution in Tianjin, China.
In recent years, Chinese environmental authorities have expressed interest in the use of Tradable Discharge Permits (TDP) as a regulatory instrument to control pollutant emissions. Environmental professionals still have not had enough experience, however, in designing and managing TDP systems, especially for non-uniformly dispersed pollutants. As an empirical study, this paper proposes an interzonal TDP system and analyzes its effectiveness in cost savings and environmental protection for reducing water pollutant COD (chemical oxygen demand) in Tianjin, China. Zonal permit system (ZPS) and emission permit system (EPS) are discussed for comparison. The inter-zonal TDP system is demonstrated to improve cost efficiency by allowing permit trades between zones, as long as water quality constraints are satisfied. The transactions are assumed to proceed in a multilateral sequential way and are simulated with a circularly running linear programming (LP) model. The simulation of permit transactions among 20 firms shows that to reach the same COD removal target, ZPS, interzonal TDP system, and EPS lowered the total reduction cost by 12.8%, 14.6%, and 15.8%, respectively. EPS, however, brought about "hot spots" problem. Finally, the transaction costs and the sensitivity of the three TDP systems to changes in both COD reduction rate and the initial permit allocation are discussed, and policy implications are addressed.
[Drinking water pollutants--their monitoring and elimination exemplified by lead and halogenated hydrocarbons].
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The 2-phenylbenzotriazole-type water pollutant PBTA-2 has cytochalasin B-mimetic activity.
The 2-phenylbenzotriazole (PBTA)-type water pollutant, 2-[2-(acetylamino)-4-[N-(2-cyanoethyl)ethylamino]-5-methoxyphenyl]-5- amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-2), has been recently identified in samples from the Nishitakase River in Kyoto, Japan, and shows potent mutagenic activities in Salmonella typhimurium in the presence of a microsomal metabolizing system (S9 mix). In the present study, we conducted the in vitro micronucleus (MN) test on PBTA-2 in the absence and presence of S9 mix in two Chinese hamster cell lines, CHL and V79-MZ. In the MN test, PBTA-2 was weakly positive in CHL cells and strongly positive in V79-MZ cells. Because the positive results were accompanied by a statistically significant increase in the number of polynuclear (PN) and/or mitotic (M) cells, we examined treated cells in metaphase to see if numerical chromosome aberrations were being induced. We found that PBTA-2 induces polyploidy in both CHL and V79-MZ cells. A detailed analysis of MN preparations showed that in CHL cells, PBTA-2 predominantly induces equal-sized binucleated cells. Rhodamine phalloidin staining revealed that PBTA-2 causes actin filament abnormalities in both cell lines similar to those caused by cytochalasin B. Cytochalasin B induced PN cells predominantly and dose dependently, and almost all the cells were equal-sized and binucleate. The results suggest that PBTA-2 has cytochalasin B-mimetic activity, although agents affecting actin filaments, such as cytochalasins, phallotoxins and chloropeptide, have been derived only from molds so far. This study also suggests that our MN test protocol may be used to identify chemicals that have cytochalasin B-mimetic activity as well as those that induce numerical aberrations.
Sheep dip chemicals and water pollution.
The Tweed River Purification Board's objective of reducing the numbers and significance of water pollution incidents by a proactive approach based on persuasion and education is described. This has consisted of prioritising potential pollutant sources which have then been investigated in detail followed by discussion and agreement with dischargers as to remedial measures. The paper describes in detail the Board's investigation of pollution from the organophosphate (OP) sheep dips, Diazinon and Propetamphos, and their effects on surface waters throughout its area. Examination of historical incidents and a preliminary survey of sheep farms in the Ettrick Water catchment in 1989 confirmed the potential for serious pollution. Comparison of OP concentrations in the Ettrick with strategic sites throughout the catchment confirmed the widespread nature of the problem and led to visits to every sheep farmer in the Board's area in 1990 and 1991, when 795 dippers were investigated. The study involved risk assessments of the location of dippers and the spent dip disposal practice which confirmed that poor siting, inadequate disposal and particularly poor management of the dipping operation were responsible for the pollution problems observed. Practical advice on the management of dipping and disposal of spent dip was given individually to farmers. The success of the project in reducing pollution is reflected in a significant and sustained reduction in OP concentrations in environmental samples. The future of ectoparasitic treatments for sheep, the potential for antidotes to spent sheep dip and legal obligations relating to its safe disposal is also considered.
Protamine precipitation of two reovirus particle types from polluted waters.
Two forms of virus particle are released from reovirus-infected cell cultures, infectious reovirus and potentially infectious reovirus (PIV). PIV particle forms have a complete outer coat and are not infectious until the outer coat is altered or removed. The PIV concentration in polluted waters, however, has not been determined. Protamine sulfate precipitation, using 0.25% fetal bovine serum and 0.005% protamine sulfate for the first precipitation of the sample and 0.0025% for the second, was employed to concentrate infectious reovirus and PIV from water and sewage. Infectious reovirus and PIV particles were concentrated over 500-fold from river water inoculated with virus, and virus recoveries of between 80 and 100% were achieved. Virus precipitates stored at -20 degrees C as a protamine-virus concentrate showed a 5% loss of PIV after 14 days. Virus preparations were assayed, before and after treatment, with 200 micrograms of chymotrypsin per ml, using a fluorescent-antibody procedure. Protamine sulfate precipitation and fluorescent-antibody detection are effective ways to recover and assay reoviruses present in raw sewage.
Water management practices in rural and urban homes: a case study from Bangladesh on ingestion of polluted water.
Although Bangladesh has achieved remarkable success in extending the availability of hand pumped and piped water, unsafe water is still ingested. This brief study attempted to assess water management practices in rural and urban homes in Bangladesh so as to establish the routes by which unsafe water is ingested, to examine methods of collection and storage, and determine why unsafe water sources are used when unsafe supplies are available. Forty-eight rural and forty-five urban slum households were studied. Observations, interviews and water quality investigations were conducted. The results show that the respondents were aware that hand pump/tap water is safe and took care to use these safe sources for drinking purposes. However, they continued to use surface water for non-drinking activities such as bathing, washing and rinsing their mouths. Reasons were given that it was a traditional practice to bathe in surface water and was more enjoyable. One of the reasons given for not using hand pumped water to wash clothing and food was that such groundwater caused staining. Bacteriological results from such ingested water showed the quality, especially in rural areas, to be poor. Results also showed the internal surfaces of the base of storage containers to be heavily contaminated with bacteria. This showed that water that was safe when it was first drawn would became contaminated during storage. This study had a limited scope; much further research is needed to find what determines and how water becomes contaminated in containers. These factors include how to reduce contamination of water, in particular the relationship between growth of bacteria in stored water and the material from which the container is made and how to improve the overall quality of water. On the management side, studies could be conducted as to how to improve people's understanding of the use of water for domestic purposes and its safe management.
[Studies on dynamics of water pollution in ports basins (author's transl)].
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Controlling water pollution.
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[Bacteria Salmonella in sewage and polluted water].
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A review of the literature of 1965 on wastewater and water pollution control.
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