Aftim Acra

Disinfection of oral rehydration solutions by sunlight.

The use of a salt/sugar oral solution for rehydration in cases of diarrhea is being encouraged by the World Health Organization for developing areas. 1 problem so far with this treatment has been a question as to their safety when prepared with contaminated water or stored in contaminated vessels. An experiment was tried in which the recommended solution was mixed with contaminated water. Some of the containers were exposed to direct sunlight, some kept in the dark, and some stored in normal room conditions. Although the heat in the containers stored in sunlight did not rise significantly, the solutions were found to be purified. It is speculated that the germicidal action resulted from solar radiation near the ultraviolet range. The solution, itself, did not change composition. The microorganisms were not able to regrow within 24 hours after solar irradiation. 50 additional experiments confirmed the findings. It is concluded that this technique of solar irradiation of contaminated solutions will be effective. All types of containers were effective.

An improved lead-tetraacetate: Schiff procedure.

Sections from tissues fixed in a 10% solution of formalin in 90% alcohol were treated with lead tetraacetate (PbAc4) in different solvents: glacial acetic acid, dilute acetic acid, methanol, ethanol, toluene and benzene. The excess reagent was removed with a 2% solution of ethylene diamine tetraacetate (EDTA) at pH 8. The sections were then stained with Schiffs reagent for 20 minutes. The chemical stability of PbAc4 in different solvents, the effect of its concentration and the time of exposure on the intensity of the Schiff reaction, were studied. A 0.023 N solution of PbAc4 in benzene with a reaction time of 5 minutes is recommended. The stability of PbAc4 in benzene permitted such solutions to be used for 3–4 days. Satisfactory results were obtained with mammalian tissues, algae, bacteria, fungi and protozoa. Some of the preparations obtained by using the technics described are illustrated in an accompanying plate of photomicrographs.

Mercury levels in some species of fish from the coast of Lebanon

The muscle tissue of 266 fish caught along the coast of Lebanon from Beirut to Tyre (85 km) were analysed for total mercury content. The mean levels for the 13 species ranged from 0·028 mg/kg of wet tissue for Siganus rivulatus to 0·0.54 mg/kg for Mullus barbatus. Whereas no significant differences (P < 0·05) in mercury levels were noted between species, in most cases a direct relationship was found between the weight or length of fish of the same species and total mercury content. Similarly, there were no significant differences (P < 0·05) between herbivore and carnivore species, nor between resident and migrant ones. All of the values obtained in the present study fall below the widely accepted limit of 0·5mg/kg of edible tissue.

Lead-glazed pottery: a potential health hazard in the Middle East.

Lead-glazed pottery produced by obsolete methods in Lebanon and other countries in the Middle East is potentially hazardous when used in contact with acidic foods. This conclusion was deduced from the testing of 423 glazed utensils for the amount of lead leached by 4% acetic acid. Control measures, surveillance, and regulations are therefore warranted.

Concurrent Demonstration of Desoxyribose Nucleic Acid and 1,2-Glycols

Sections from rat tissue were fixed in 10% formalin in 90% alcohol and placed in a 1.0% suspension of sodium bismuthate (NaBiO3) in 40% phosphoric acid for 40 minutes at room temperature. Bismuth phosphate crystals were removed with 2N HCl. The sections were next placed in the Schiff reagent for 20 minutes. By this method the DNA was hydrolyzed by the phosphoric acid and the 1,2-glycols were oxidized by the NaBiO3. In both cases aldehyde groups were released and subsequently stained by the Schiff reagent. A photomicrograph is included demonstrating the nuclei, goblet cells, striated border and basement membrane stained by this combined method.

Indicators of coastal groundwater quality changes induced by seawater infiltration

The diminishing public water supply in Greater Beirut induced by various factors since the 1960s reaching its climax during the civil war (1975–1992), led to the drilling of a multitude of private wells in the Cenomanian coastal aquifer. The increasingly high extraction of the groundwater led to progressive changes in the quality of the ground‐water due to seawater infiltration. This problem stimulated some studies directed at detecting and assessing the status and magnitude of the seawater infiltration, but most of them failed to apply any reliable diagnostic indicators designed to detect and to trace any changes in the quality of the groundwater. In contrast, the present study demonstrates the application of certain diagnostic indicators (DI) devised specifically for the detection, progress and trends of seawater infiltration into an aquifer.

Concurrent Demonstration of Desoxyribose nucleic Acid and 1,2-Glycols. 2. Periodate Oxidation

Formalin-fixed sections of rat intestine were treated in a solution of 0.5% periodic acid in 50% aqueous phosphoric acid for the concurrent demonstration of 1,2-glycols and DNA. The effects of varying the concentration of reagents, time of exposure and temperature on the results showed that, at 28°C, good reactions were obtained in 10–15 min when the concentration of the phosphoric was between 40 and 60% and that of the periodic acid between 0.05 and 0.50%.

Supplementary water from private wells in greater Beirut: a 1982 survey in retrospect

Drilling of private wells in Greater Beirut has increased sharply in the past few decades, thus inducing a marked rise in seawater infiltration, as the amount of extracted groundwater gradually exceeded the amount of natural recharge water. This phenomenon provoked a number of studies on groundwater in Greater Beirut, including the present one, which involved a survey of 75 private wells based on a questionnaire to obtain information pertaining to these wells. Samples of water from 42 of the wells were collected and examined to determine the quality of the groundwater in the study area, particularly regarding the magnitude of seawater infiltration at the time of the investigation. The results obtained and their interpretation are reported and discussed, including the deteriorating quality of the groundwater and associated problems which call for a continuous monitoring program.