A method for the continuous measurement of dissolved oxygen in water has been developed, based on establishing a Henry's law equilibrium between a flowing water sample and the oxygen content of a gas at constant pressure and volume. The results are not influenced by temperature, salt content, pollution, aeration constant, barometric pressure, or the dissolved nitrogen content of water.

No abstract

No abstract

This article is concerned with human health effects of chronic internal exposure for periods approaching a lifetime to very low levels of radioactivity in water that may or may not produce subtle damaging effects. The article examines the apparent differences among recommended standards in the following published documents: the International Commission on Radiological Protection (ICRP) Report No.2; the National Committee on Radiation Protection (NCRP) Handbook 69; two Federal Radiation Council (FRC) guidance manuals; and, the 1962 USPHS Drinking Water Standards. A study of these documents indicates that for individual radioisotopes the recommended limits, although not identical, are not significantly different. All apparent differences between them are more a matter of terminology than of substance. An examination of the several limits proposed for Ra226 will demonstrate this. This radioisotope is selected as an example because it occurs in all of the documents, and because it is a pollutant associated with normal peacetime industrial operations rather than with nuclear weapons testing.

The U.S. Public Health Service (USPHS) has recently completed comprehensive studies of radioactive pollution of the Animas River, an interstate stream, under requirements stated in the Federal Water Pollution Control Act. The studies were conducted as a result of the interstate pollution abatement enforcement action instituted by USPHS at the request of New Mexico. They illustrate several of the basic principles that are important to the rational, successful control of radioactive water pollutants, and provide a practical case study that may be useful as a guide for solving future problems of radioactive liquid waste control. The Animas receives wastes from a uranium ore refinery in Durango, Colorado, and flows south into New Mexico. It is the main source of water for the area and is used for domestic water supply, irrigation of croplands, recreation, and waste disposal. Study results indicated that the total internal radiation exposure of downstream populations was greater than the limits recommended for general population exposure. Studies of the fate of Ra220, the primary pollutant, in the stream environment and in local water plants, led to the development of rational, efficient pollution abatement measures. These measures were installed quickly, and subsequent surveys showed that they resulted in a much higher standard of radiation protection than would have been achieved by enforcement of preset, arbitrary effluent or stream standards.