Radium 226 and

Radium 226 and Radium 228 (combined) none 5 pCi/L Increased risk of cancer Erosion of natural deposits... 

When thorium emits alpha particles, it disintegrates into other daughter radionuclides (radioactive materials), such as radium-226 and radon-222 (from thorium-230 in the uranium-238 decay series) or radium-228 and thoron (radon-220 from thorium-232 in the thorium decay series). It eventually decays to stable lead-208 or -206, which is not radioactive. More information about the decay of thorium can be found in Chapter 3. The toxicological characteristics of radon, radium, and lead are the subject of separate ATSDR Toxicological profiles. 

Hu SJ, Kandaiya S. 1985. Radium-226 and h concentration in Amang. Health Phys 49 1003-1007. 

Case Radium-226 and Radium-228. The concept of risk projections from experimental dose-response curves has been highly developed in the case of estimating risks to the population from low doses of radiation. Such methods were later extended to estimate risks from other carcinogens in drinking water and other media. Radioactivity can contribute risks from teratogenic, genetic, and somatic (carcinogenic) effects. 

How would you write balanced nuclear equations for the alpha particle decay of radium-226 and the beta particle decay of iodine-131 ... 

The Environmental Protection Agency (EPA) regulates the amount of radium in drinking water so that it will not contain more than 5 pCi of combined radium-226 and radium-228 per liter of water. The amount of radioactivity from all sources that is allowed in drinking water and the amount that workers may be exposed to in nuclear plants is regulated. 

There is no information on the lethal effects of radium due to acute oral exposure. Many deaths, especially from bone cancer, have occurred in humans following long-term oral exposure to radium-226 and radium-228. As described by Rowland et al. (1978), female radium dial painters in the 1920s who "tipped" their paint brushes with their lips or tongues ingested radium in the process. The dial paint usually contained long-lived radium-226 and shorter-lived radium-228. A toxicity ratio has been developed for these isotopes it has been estimated that radium-228 is about 2.5 times as effective,... 

Based on data on these dial painters from the 1985 listing of radium cases studied at the Argonne National Laboratory (Gustafson and Stehney 1985) Rundo et al. (1986) have estimated that the lowest total intake level of radium associated with a malignancy was 60 pCi (2,222 kBq) or 1.03 p Ci/kg (38 kBq/kg) based on an estimated 58 kg body weight for a woman. These estimates are based on current radium body content modified by the Norris retention function (to account for the decrease in body radium content with time since exposure) and an estimate of radium-228 from measurements of radium-226 and the known or presumed ratios of these isotopes in the materials to which these persons were exposed (Rundo et al. 1986). 

Ocular effects have not been reported in humans or animals exposed to radium via inhalation, oral, or dermal routes. However, ocular effects have been observed in both humans and animals injected with radium. Cataracts were reported in 6% of the German patients who had been injected with radium-224 as children (Chmelevsky et al. 1988a Stefani et al. 1985). In contrast, the incidence of cataracts in female dial painters was not correlated with total radium intake or age at first exposure, nor was there a difference in appearance times between high and low total radium intakes (Adams et al. 1983). However, the dial painters were exposed orally, the isotope was mainly radium-226, and very few of these dial painters were exposed when younger than 15 years of age. Any of these factors may account for the difference between the results observed in these two studies. 

Radium is a naturally-occurring metal and is almost ubiquitous at low concentrations in air, water, soil, rocks, and food. The median concentrations of radium-226 and radium-228 in drinking water are generally low, but there are geographic areas where higher concentrations of radium are known to occur. The utilization of coal and uranium has resulted in re-distributing radium in the environment, but the overall effects appear to be small. Estimated levels of average human exposure to radium of nonoccupational populations are presented in Table 5-1. 

Combined radium-226 and -228 Gross alpha particle activity (excluding radon and uranium)... 

Pearson, J.E. Jones, G.E. (1966) Soil concentrations of emanating radium-226 and the emanation of radon-222 from soils and plants. Tellus, 18, 655-61. 

Radionuclides (alpha particle emitters, beta particle emitters, radium-226, and uranium)... 

The activity of a radioactive sample is quoted in Becquerels (named after the discoverer of natural radioactivity) and it varies from one element to another. One atomic disintegration per second is called one Becquerel (Bq). A further unit often used is the Curie (Ci), which is the activity produced by 1 g of radium 226 and is equal to 3.7 x 1010 disintegrations per second. 

A. Gross alpha particle activity, Radium-226 and Radium-288... 

Radium-224 and its decay products Radium-226 and its decay products Radium-228 and its decay products Radon-222 and its decay products Schistosoma hematobium (infection with)... 

There were only a few measurements of radium-226 and uranium in the ground level air. Preliminary data on the vertical distribution of radium-226 and uranium in the troposphere and stratosphere measured during periods of 3-11 years have been reported by Jaworowski and Kownacka (1976), Kownacka (1980) and Kownacka et al. (1985), and measurements of uranium in six samples of high-altitude aerosols have been reported by Krey et al. (1979). 

Four naturally occurring isotopes of radium are known. They are radium-223, radium-224, radium-226, and radium-228. Isotopes are two or more forms of an element. Isotopes differ from each other according to their mass number. The number written to the right of the element s name is the mass number. The mass number represents the number of protons plus neutrons in the nucleus of an atom of the element. The number of protons determines the element, but the number of neutrons in the atom of any one element can vary. Each variation is an isotope. 

Tanner, A.B., 1964b. Physical and chemical controls on distribution of radium-226 and radon-222 in groundwater near Great Salt Lake, Utah. In J.A.S. Adams and W.M. Lowder (eds.). The Natural Radiation Environment. Univ. Chicago Press, pp. 253-276. 

The US Environmental Protection Agency (EPA) drinking water limit for radium-226 and radium-228 combined is 5 pCil. EPA s limit for maximum soil concentration for radium-226 in uranium and... 

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