Concentration and distribution of toxic elements in rice and husk

Development of radiochemistry in Pakistan – 1960 to 2010

With the inception of Pakistan Atomic Energy Commission (PAEC) in 1956, peaceful uses of atomic energy commenced for the benefit of scientific community as well as masses of Pakistan. Radiochemistry played a vital role right from the beginning. The research and development in this field accelerated soon after the criticality of the first research reactor named as Pakistan Research Reactor (PARR- 1) at the Pakistan Institute of Nuclear Science and Technology (PINSTECH), Islamabad. The first radioisotope produced at PARR-1 for application in nuclear medicine was 131I. Later on, many other radioisotopes were prepared and radiopharmaceuticals were synthesised for their use in industry and hospitals. Besides providing pure radioactive tracers for nuclear medicine, radiochemistry also enhanced the detection limit of impurities at all stages of nuclear fuel cycle for power generation. In 1983, research in the field of nuclear data measurement began. The main aim was to identify suitable conditions for the production of radionuclides for cancer diagnostics, treatment and therapy. With the establishment of a second research reactor (PARR-2) at PINSTECH, research in neutron activation analysis, radioisotope production and separation studies gained more momentum and many research articles were published. Solvent extraction, adsorption and ion-exchange were the main routes of separation in those studies. Separation of heavy metals and treatment of waste generated in a nuclear power plant are other important aspects related to environmental restoration and nuclear waste management, where radiochemistry is required. In future, work in radiochemistry will be continued on similar lines to develop novel radiopharmaceuticals, identify indigenous schemes for nuclear waste management and work out intelligent procedures for material characterization for benefit to mankind, especially the people of Pakistan.

Determination of various nutrients and toxic elements in different Brazilian regional diets by neutron activation analysis

The concentration of 19 elements (As, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Rb, Sb, Sc, Se and Zn) was evaluated in some diets taken from different regions of Brazil by Instrumental and Radiochemical Neutron Activation Analysis. Several populations with different socio-economic living conditions and inhabiting in different regions of Brazil were studied in order to estimate and to detect the variability of the mineral and toxic element content among Brazilian populational groups. The data obtained showed a significant difference between the contents of these elements in the diets from the regions studied. The general conclusions from the data obtained in this study were: 1) regarding the daily amounts of essential elements (Ca, Cl, Co, Fe, Mn, Na, K, Fe, Se and Zn), the Santa Catarina 2 diet showed the closest values when compared to the recommended values of RDA (Recommended Dietary Allowance) and/or WHO (World Health Organization). The Santa Catarina 1(low income groups) showed the lowest when compared to the same values. 2) The intake of toxic elements (As, Br, Cd, Hg, Sb) among the diets does not seem to be a major problem when compared to PTWI (Provisional Tolerable Weekly Intake, WHO), except for Hg intakes in regions near gold mining activities, like Manaus and Mato Grosso, where the values found were near the upper limit set by WHO.