Biomedical subjects

W L Lappenbusch

Publications and source records attributed to W L Lappenbusch.

16 recordsLinked to original sources

PubMed1986

Drinking-water contribution to natural background radiation.

The average concentrations of naturally occurring radionuclides in drinking water are estimated from recent measurements and are used to estimate the annual effective dose equivalent associated with drinking water due to the different radionuclides. The annual effective dose equivalents are determined from the annual intake of these radionuclides using dosimetric information based on ICRP Publication 30 dosimetric models and cohort analysis considering risk coefficients developed by the U.S. Environmental Protection Agency using data from the report of the Biological Effects of Ionizing Radiation Committee (BEIR III) of the National Academy of Sciences. The resulting contribution from drinking water sources to the annual effective dose equivalent is in the range of 0.002 to 0.05 mSv/y (0.2-5 mrem/yr) for those using community drinking water supplies (approximately 216 million people in the United States). The contribution to the annual effective dose equivalent from 222Rn dissolved in water is in the range of 0.8-30 mu Sv/y (0.08-3 mrem/yr) based on the inhalation pathway following the release of 222Rn from drinking water.

Background Radiation↗

PubMed1985

Regulatory development of the interim and revised regulations for radioactivity in drinking water--past and present issues and problems.

Developing the Revised Regulations for Radioactivity in Drinking Water under the Safe Drinking Water Act requires information from all related areas and disciplines. As one step in the regulatory process, the background and history of that process as it applies to radioactivity in drinking water is described. The issues involved in developing the revised regulations are as follows: monitoring and sources of exposure, dose evaluation, health effects, engineering, economics and general policy development.

Animals↗

PubMed1984

Compliance data for the occurrence of radium and gross alpha-particle activity in drinking water supplies in the United States.

Most of the results of the first systematic nationwide monitoring of public water supplies for 226Ra have been received. Approximately 50,000 public water supplies have been sampled of a total of 59,812. It is estimated that once the drinking water from all supplies has been analyzed, approx. 500 samples will exceed the Maximum Contaminant Level (MCL) of 5 pCi/l. Almost all the violations occur for ground water supplies. Monitoring in some states is incomplete but the geographical distribution of these water supplies that exceed the MCL is clear. This study is compared to other information concerning the concentration of 226Ra in drinking water supplies and the implications of this information are discussed.

Alpha Particles↗

PubMed1983

Health effects guidance for uranium in drinking water.

The interim regulations for radioactivity in drinking water were promulgated in 1976 (Federal Register, Friday, 9 July, 1976, p. 28402). These regulations specifically excluded uranium because of uncertainties concerning its toxicology, treatment technology and occurrence. At this time, EPA's Office of Drinking Water is considering proposing a health effects guidance level of 10 pCi/l. (0.37 Bq/l.) for uranium in drinking water. This paper describes the approach that EPAs Office of Drinking Water is considering in developing the guidance level. This value has not yet been officially determined to be EPA's formal guidance, but is presented as a working hypothesis for review and comments. Included here is a discussion of occurrence, pharmacokinetics and health effects. The calculation of doses uses the ICRP 30 model and the risk determination uses EPA's newly developed life table approach. The risk level from ingesting drinking water with a uranium content of 10 pCi/l. is estimated to be about 3 X 10(-5) excess cancers/lifetime.

Alpha Particles↗

PubMed1983

Occurrence of uranium in drinking water in the U.S.

Uranium is found in ground and surface waters due to its natural occurrence. In some cases, its presence is due to human activities such as mining and milling uranium. Thus, it is also found in drinking water. The range of concentrations existing in drinking water supplies in the U.S. is tabulated and examined. The range of isotopic abundances are also listed. Projections from the available data lead to estimates that of the 59,812 community drinking water supplies in the U.S., 25-650 would exceed a uranium concentration of 20 pCi/l., 100-2000 would exceed 10 pCi/l. and 2500-5000 would exceed 5 pCi/l.

United States↗

PubMed1983