Grab sampling either using the active charcoal method in combination with an ionization chamber or using a working level monitor was performed for the measurement of radon concentration in Taiwan''s two largest cities Taipei and Kaohsiung. Long-term monitoring of radon concentration in dwellings and business buildings was also carried out with cellulose nitrate films as the alpha detectors. The average indoor radon concentration in these two cities is 17±6 Bq m^-3. The outdoor radon concentration is about one-half of that on average. As assessed according to the model of UNSCEAR 1988, the induced effective dose equivalent is 0.67 mSv y^-1. Radon concentration in coal mines showed an average of 88.5±9.5 Bq m^-3.

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Coal, fly ash and bottom ash samples were taken from a 300-MWe coal-fired power plant with a daily coal consumption of 2400 tons. A high volume sampler coupled with several mesh testing sieves was used tc separate fly ash samples into different size fractions. Determination of the concentrations of ⁴⁰K, ²³⁸U, ²²⁶Ra ²¹⁰Pb, ²¹⁰Po, ²²⁸Th and ²²⁸Ra was carried out either by gamma or alpha spectrometry. For elements volatilized during combustion, their radionuclide concentrations decrease with increasing particle size. The enrichment factors for all radionuclides mentioned above were studied. Their values range from 31.0 for ²¹⁰Po to 2.2 for ²²⁸Ra. Of all radionuclides studied, ²¹⁰Po and ²¹⁰Pb are the most volatile elements; therefore, an increase in the natural radiation level should first be indicated by an increase in these two nuclides.

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Neutron-induced activities ⁶⁰Co and ¹⁵²Eu have been measured for samples collected from the Atomic-Bomb Dome locating at 161 m from the hypocenter of the Hiroshima Bomb. Specific activities ⁶⁰Co/ Co and ¹⁵²Eu/Eu at the time of the detonation have been determined as 10.0±1.0 Bq mg^-1 (steel sample S4) and 80±9 Bq mg^-1 (granite sample G1), respectively. Detailed measurements of ⁶⁰Co and ¹⁵²Eu activities for samples collected from various locations of the Dome show almost no directional dependence whether the sample faced to the epicenter or not, nor vertical height dependence between 17 m height and the ground level. In addition, ¹⁵²Eu was not detected in the sample collected from the basement. It has been shown that the present ⁶⁰Co activity value, the nearest steel one to the hypocenter, as well as other short distance data are systematically lower than the calculated values based on the neutron fluence of the DS86.

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Previous work on small intestinal radiation injury has reported changes in epithelial and non-epithelial tissues, but with few quantitative comparisons of different responses by individual cell types.
The approach used here quantifies the responses of mouse duodenum to X-irradiation with 6 Gy, 10 Gy and 20 Gy, sampled three days after treatment, and 10 Gy sampled 6 hours, 1 day and 3 days after treatment. Tissue area measurements and counts per circumference for 13 different structural elements are subjected to statistical tests. New data reported here for X-irradiation include the fact that cryptal cells do not respond uniformly, indicating that the crypt/microcolony cannot always be used as a standard unit in assessing radiation injury. Non-epithelial structures, such as submucosal arterioles, are also affected.
The data display also includes control-referenced ratios, from which are calculated Tissue Indices and a final Morphological Index, which estimates total structural damage¹⁾. The Indices are useful in drawing attention to unexpected changes in extent or range of data sets. In addition, the Epithelial Index appears to be a sensitive indicator of radiation damage, even at low doses and early time points. The data display includes a graph of the total Indices and summary tables of data, and encourages close study of the constituent data points.

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