Hillel I. Shuval

A sensitive micromethod for the determination of methemoglobin in blood.

Abstract A modification of the Evelyn and Malloy method for the determination of methemoglobin in blood is presented. A higher precision of the assay is achieved, and sample stability is increased up to 24 h, thus making the procedure suitable for field surveys aimed at detecting slightly raised methemoglobin levels.

A micromethod for the determination of nitrite in blood

Abstract The diazotization-coupling reaction for the determination of nitrite is modified and adapted for micro-analysis of blood and plasma. The limit of detection by the proposed method is 0.01 μg of nitrite-nitrogen and only 0.1 ml of blood is needed for analysis. The results showed high reproducibility; the standard deviation at nitrite concentrations of 1–6 μg ml′-1 varied from 0.025 to 0.110. Some applications of the method showing the recovery of nitrite from blood and its components are discussed.

Approaches to Resolving the Water Conflicts Between Israel and her Neighbors—a Regional Water-for-Peace Plan

ABSTRACT The disputes over surface and ground water resources between Israel, Jordan, and the Palestinians are particularly acute since all three are well below the Water Stress Level of 500 cubic meters/person/ year as defined by Falkenmark. Based on currently accepted principles of international water law neither the upstream source country nor the downstream historic user country has absolute sovereign rights to control the use of international bodies of surface or ground water An accommodation, based on the principles of equitable apportionment and community of interest, considering the legitimate needs of each partner to the dispute, should be arrived at through direct negotiations. Since the total amount of water resources available is insufficient, it is a zero sum game and any attempt to find a solution by reallocation of the limited resources between the disputants is likely to lead to a deadlock. The approach proposed is to increase the size of the pie by developing a regional Water-for-Peace Pl...

Coliforms, fecal coliforms, and fecal streptococci as indicators of water pollution

The presence and survival of coliforms, fecal coliforms, and fecal streptococci were studied in sewage treatment plants, heavily polluted rivers, a lake, and other drinking water sources. In all cases the fecal streptococci were generally more resistant to the natural water environment and to purification processes than the other indicator organisms and, at points distant from the original source of pollution were often the only indicators of the fecal nature of the pollution. In two of the systems studied the survival of the fecal streptococci paralleled the survival of enteric viruses better than the coliforms. The fecal streptococci may thus in certain cases provide a better estimate of the probable virus content in lightly contaminated water than the other two indicators.

Infant methemoglobinemia and other health effects of nitrates in drinking water

SUMMARY Nitrates in water supplies in concentrations over 45 mg/1 (as NO3) have led to numerous cases of infant methomoglobinemia, particularly in infants up to six months of age, whose main liquid intake is powdered milk formula made up with tap water containing high concentrations of nitrates. Other possible negative health effects associated with the ingestion of nitrates in water for extended periods have been detected in animal studies including changes in heart blood vessels, and behavioral effects. The possible association of nitrates in water with the formation of the potent carcinogens nitrosamines, is still to be determined. However, sufficient evidence is presently available to support the strict adherence to current nitrate drinking water stanard of 45 ppm.

The phase-separation method for the concentration and detection of viruses in water☆

Abstract This paper reports on the further development and refinement of the Phase-Separation Method for concentrating and detecting enteroviruses in water. In this method a water sample of several litres to be tested for viruses is mixed with a combination of organic polymers, which after detention in a separatory funnel produce two phases. The small bottom phase concentrates the viruses of the sample and can be easily drained off. The procedure is repeated to achieve a concentration factor of 500. Virus recovery efficiency is high and as few as 1–2 virus infectious units per litre of sample can be effectively detected. Field surveys of sewage and water samples illustrate the application of this low cost and efficient method which should provide a valuable tool for epidemiological investigations, studies of the virus removal efficiency of various treatment processes, as well as in the routine monitoring of potable water supplies for virus contamination.

Regrowth of coliforms and fecal coliforms in chlorinated wastewater effluent

Abstract Observations made both in the field in chlorinated effluent, and in laboratory experiments show that coliforms and fecal coliforms are capable of regrowth in chlorinated wastewater. Under field conditions regrowth of coliforms in chlorinated effluent held in a storage reservoir for about 3 days appeared inversely correlated to: (1) The residual chlorine in the storage reservoir and (2) The number of coliforms surviving chlorination. In the laboratory experiments regrowth occurred after initial doses as high as 11 ppm total chlorine even when there was no chemical inactivation of the chlorine. Fecal coliforms did not generally show regrowth to the same extent as coliforms. Regrowth occurred even when coliforms were not detectible in 10-ml of samples after chlorination. Since coliforms and fecal coliforms are capable of regrowth in chlorinated sewage effluent and admixtures of it, the sanitary significance of the number of coliforms after storage or in receiving bodies of water is difficult to interpret. Thus standards might be based on the number of coliforms, or fecal coliforms detected in effluents immediately after chlorination. However, this would not be justified if in addition to coliforms, pathogenic bacteria can regrow in chlorinated effluents.

Are the Conflicts Between Israel and Her Neighbors Over the Waters of the Jordan River Basin an Obstacle to Peace? Israel-Syria as a Case Study

Are the conflicts over water resources between Syria, Lebanon and Israel who share the transboundary waters of the Jordan River Basin a major obstacle to the peace process? The Syrians and Lebanese have in the past claimed as their own all of the sources of the Jordan River which arise in their territory. International water law provides a strong legal basis to assure the water rights and continued use of water by a downstream riparian, such as Syrias use of the Euphrates which arises in Turkey and similarly, Israels use of the Jordan River, based on prior use in an international river basin. This paper will evaluate the water security implications for Israel of a possible peace agreement with Syria and Lebanon which would involve Israel forgoing the continued use of those amounts of water from the Jordan River that were approved by the Israel Government under the so-called Johnston Plan of 1956 — 35 million m3/yr. for Lebanon from the Hasbani Springs and 42 mm3/yr. from the Banias Springs and Jordan River for Syria. The maximum replacement cost for that amount of water by desalination of seawater may be about

Survival of Enteroviruses and Bacterial Indicator Organisms in the Sea

0.70/m3 or, some

Comparison of adsorption-elution methods for concentration and detection of viruses in water

56,000,000 per year. This is not a great amount of money as part of the price for peace. The paper also shows that Israel does not have to hold on to the entire area of the Golan Heights to assure its water security and that a 1–3 km water security zone along the Syrian side of the international border under joint and international inspection can be an effective water security measure to assure inspection, monitoring and control of all the sources of the Jordan River and Lake Kinneret vital to Israels water security. The scare stories published by some groups in Israel, that Syria could, after a peace agreement is signed, covertly divert essentially all of Israels water resources derived from the sources of the Jordan River or 30% of the countrys water supply are highly unrealistic. Such major works could not go undetected and Syria and the world recognize that such an act would be viewed as a causus belli and as an act of war by Israel. In an era of peace, development of the shared water resources of the Jordan and continuous water systems in a program of regional cooperation can bring benefits to all of the partners on the Jordan River Basin.