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PubMed1975

Tumors in fish caught in polluted waters: possible explanations.

The largest excess in tumor incidence due to pollution (616%) was observed in the fish species: Ictalurus nebulosis (the brown bullhead). Extensive analysis of waters on the Fox River in Illinois disclosed a heavy chemical and physical organic and inorganic materials far exceeding State and Federal minimal safety standards. Additional tests showed the presence of numerous human viral agents in the Fox River. Certain chemicals in the water appear to be potential carcinogens for fish. Two types of leukemia were found in 11% of the Esox lucius caught in the Fox River. It is hypothesized that these leukemias might also be of viral etiology. Experiments were conducted on Esox lucius caught in the Fox River. It is hypothesized that these leukemias might also be of viral etiology. Experiments were conducted on Esox lucius (Northern Pike). Interest centered around the possible viral origin of lymphosarcoma of the jaw in that species. Cell-free filtrates of this tumor were inoculated into a test group of fish from pollution-free waters. At the end of seven weeks, lymphosarcoma developed in 89% of the fish inoculated with cell-free homogenates. Control fish receiving inoculation of either Hank's balanced salt solution (HBSS) or normal tissues and kept in separate tanks at all times did not develop lymphosarcomas.

Animals↗
PubMed2004

Removal of water pollutants with activated carbons prepared from H3PO4 activation of lignin from kraft black liquors.

Activated carbons with a high BET surface area and a well-developed porosity have been prepared from pyrolysis of H3PO4-impregnated lignin precipitated from kraft black liquors. Impregnation ratios within the range of 1-3 and activation temperatures of 623-873 K have been used, giving rise to carbons with different porous and surface chemical structure. Increasing the activation temperature and the impregnation ratio leads to a widening of the porous structure with a higher relative contribution of mesoporosity. The potential application of these carbons for the removal of water pollutants has been investigated by measuring their adsorption capacities for phenol, 2,4,5-trichlorophenol and Cr (VI) as representative of toxic contaminants found in industrial wastewaters. The results obtained compare well and even favorably with those reported in the literature for other activated carbons. An impregnation ratio and an activation temperature around 2 g H3PO4/g lignin and 700 K, respectively, are recommended as the best combination of operating conditions to prepare activated carbons for aqueous phase applications although at lower values of these two variables carbons with good adsorption capacities are also obtained.

Adsorption↗
PubMed2005

Controlling water pollution in developing and transition countries--lessons from three successful cases.

The policy prescription for solving environmental problems of developing countries and countries-in-transition (CIT) is slowly getting polarized into two viewpoints. One group of researchers and policy advocates including multilateral organizations upholds extensive use of market based instruments (MBIs) in these countries. The other group argues that institutions need to be built first or the policy makers should select the incremental or tiered approach taking into account the existing capabilities. The group also insists that the financial, institutional and political constraints make environmental regulation in these countries more problematic than in industrialized countries. In the short-run, the immediate needs of the developing countries can be addressed effectively by learning lessons from the difficulties encountered by a few successful cases and accordingly evolving an appropriate policy instrument. In this paper an attempt has been made to highlight three such cases from three different parts of the world--Malaysia (Asia-pacific), Poland (Eastern Europe) and Colombia (Latin America). The paper looks into what policy instruments led to a fall in water pollution levels in these countries and what role did MBIs play in this pollution mitigation? The case studies suggest that it is a combination of instruments--license fee, standards, charge and subsidies--reinforced by active enforcement that led to an overall improvement in environment compliance.

Colombia↗
PubMed2002

Efficacy of a floating sustained release formulation of Bacillus thuringiensis ssp. israelensis in controlling Culex quinquefasciatus larvae in polluted water habitats.

Larvicidal efficacy and residual activity of a floating sustained release formulation of Bacillus thuringiensis ssp. israelensis (Bti) was tested in polluted water habitats against Culex quinquefasciatus, the vector of bancroftian filariasis, breeding in cesspools and cesspits. A total of 25 habitats having 65 m(2) water surface area with C. quinquefasciatus immatures were treated with the formulation at the rate of 15 kg/ha. For comparison, in another area, 18 habitats with a water surface area of 70 m(2) were kept untreated. Evaluation was continued up to 179 days with three rounds of Bti application. The mean number of egg rafts did not differ significantly between treated and untreated habitats during the trial period indicating same level of recruitment. However, abundance of larvae and pupae was significantly lower in Bti treated habitats compared to that in untreated ones. The activity of the formulation, with 2 weeks delay in onset compared to treatment, caused >80% reduction in pupal abundance for a period of 30-34 days. Considering this, it is suggested that monthly application of Bti formulation will considerably reduce the recruitment of pupae of C. quinquefasciatus.

Analysis of Variance↗
PubMed1977

The analysis of organic water pollutants by gas chromatography and gas chromatography-mass spectrometry.

Four methods for the analysis of trace levels or organic compounds in water have been discussed: direct aqueous injection, vapor stripping, solvent extraction, and lipophilic adsorption. Table 6 presents a comparison of these techniques. Direct injection is applicable to compounds having a wide range of polarities and volatilities, but it is not a very sensitive technique. For applications in which low sensitivity is acceptable, direct injection offers a very rapid and potentially accurate means of measuring organics in water. Vapor stripping is a factor of 10(6) more sensitive than direct injection, but this is achieved at the expense of simplicity. This method is applicable to compounds of volatilities less than that of eicosane. A subtle operational problem with most vapor stripping techniques is that the contents of the trap are consumed with one analysis; if anything goes awry, the analysis of that trapped sample cannot be repeated. Solvent extraction has a respectable sensitivity (about 0.5 ppb) and operationally it is very simple. Furthermore, aliquots of the resulting extract can be analyzed many times with different techniques if necessary. Because of the evaporation step, very volatile compounds (greater than that of decane) cannot be measured effectively with solvent extraction. The introduction of a solvent into the water carries with it the potential for contamination. Thus, ultrapure solvents must be used and all glassware should be carefully cleaned [96]. Lipophilic adsorption has the unique property of sampling many hundreds of liters of water. Thus, the method is quite sensitive (potentially in the ppt range) and, in addition, it can provide several milligrams of an isolated component. This latter feature is of considerable advantage if one wants to complement GC-MS analyses with infrared or NMR for difficult structural identifications. As a solvent extraction, the evaporation of the final solvent limits the applicability of adsorption methods to compounds with volatilities greater than that of decane. Finally, the importance of avoiding contamination should be emphasized. Many of the compounds encountered in environmental samples are also common laboratory artifacts, for example plasticizers and antioxidants. When one finds such compounds in a water sample, it is absolutely essential to demonstrate that they are indeed present in the water and are not the result of laboratory contamination. The best such demonstration is procedural blank analyses that are indeed blank.

Chromatography, Gas↗
PubMed1967

Water pollution.

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