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In this paper, we measured more than 4200 beard samples collected from a single person every day over a 12-year period and analyzed them based on a standard-free method. It was found that the sulfur concentration remained almost constant from a long-term perspective but showed small periodic elevations. Silicone, phosphorus and rubidium showed significant periodic changes with a cycle of several years. While manganese, strontium and molybdenum seemed to show long-term changes, there were no significant differences due to their large standard deviations. Concerning seasonal changes, silicone and phosphorus showed decreasing trends in summer, albeit without significant differences. The bromine concentration showed clear seasonal variations, rising in winter and falling in summer, suggesting the possible influence of seasonal changes in the elemental components in the airborne particles that pass over to Japan from the Asian Continent. These findings confirmed that beard analyses are useful not only for evaluating changes in trace element concentrations in the human body but also for clarifying the main pathways of the intake of these elements.

Trace elements in four kinds of soybean and three kinds of salt have been measured by means of in-air PIXE. In soybeans, which were made in Japan, America, Canada and China, six kinds of trace elements were detected, such as Mn, Fe, Ni, Cu, Zn and Br. The concentration of these elements varied depending on the place they were made. American soybean showed characteristic feature compared with other soybeans. As to the bromine concentration, American soybean contains ten times as much as Japanese one. In salts Br and Sr were detected.

Concentrations of chemical elements in different organs of healthy, of tumor (rhabdomyosarcoma R1H) bearing and of cis-diamminodichloroplatinum (cisDDP) treated rats were analyzed with a 2 MeV proton microprobe. Characteristic concentrations were found in spleen, liver, kidney, muscle and tumor. Bromine concentrations were elevated after three weeks of tumor growth. As a result of cisDDP application, they dropped considerably. These alterations were found not only in tumor tissue but also in organs not directly involved in tumor growth (e.g. liver and spleen). Platinum as a marker for the drug could be detected in all tissues except muscle. The highest concentrations were found in the kidney. With the scanning microprobe, elemental maps in several tissues were investigated. These could be correlated to histological details (e.g. in spleen and tumor).

Trace elements in five kinds of flour which were made in Japan. America and Canada, have been measured by means of in-air PIXE. Twelve kinds of trace elements were detected, such as Cl, K, Ca, Sc, Cr, Mn, Fe, Co, Ni, Cu, Zn and Br. The concentration of these elements varied depending on the place where they were made. In order to check the target preparation procedure, two types of sample preparation have been used, such as wet ashing by nitric acid in a microwave oven and making a paste by an internal standard solution. Comparisons of the results of both samples ensures that bromine was not lost during micro-wave oven heating. Analytic fitting of PIXE spectra by a personal computer and a commercial apllication software was successfully used.

We have measured the elemental concentrations of soy sauce and its actual raw materials which are used in a certain soy sauce factory. In the present measurement, we measured de-fatted soybean, wheat and salt as raw materials and soy sauce and soy sauce waste as final products. Five kinds of elements, such as Mn, Fe, Cu. Zn and Br, were detected. We obtained elemental concentrations of them except for Mn in each materials. The measured elemental concentration in soy sauce agreed well each other with the calculated one within the experimental errors using the measured concentration in the raw mateials and their weight in actual producing process. Contrary to our expectation, it was found that wheat contributes to soy sauce bromine concentration dominantly in the present case.

Nuclepore filters have been widely used for collecting atmospheric aerosols and such samples are quite convenient for PIXE since they can be analyzed without any treatment. However, some special methods, (which is somewhat different from existing standard methods for general samples), must be applied in order to perform quantitative analysis. We have developed a method of quantitative analysis for all elements making use of bromine, which is almost uniformly contained in general Nuclepore filters, as an internal standard. Then, for quantitative analysis of light elements, the standard-free method, which makes use of total yield of continuous x-rays, has been applied and it is found that this method can be successfully applied to practical aerosol samples. Moreover, the method was applied to bio-samples prepared by cutting frozen samples with a microtome, and the result is almost satisfactory. It is found that the present method can be successfully applied to any sample which can be made uniform.

Some small fragments of rag paper - made more than a thousand and a few hundred years ago, and excavated at Turfan, west of China by the Otani-expedition dispatched there during the late Meiji and the Taisho eras - were measured by PIXE. Bromine was highly Detected in all these ancient fragments and modern paper samples that had been placed together with these Turfan manuscripts. In other paper samples, bromine could not be detected (H⁺, 4MeV, 50μC and H⁺, 2MeV, 100μC) and their average concentration was about 1.1ppm (S.D.=1.11ppm, N=15, 0.3~3.4ppm). The bromine contamination of ancient sutras is mainly caused by larvicide of methyl bromide, and the observation suggests that the ancient manuscripts might be spoiled gradually by agricultural chemicals for protecting them from vermin.