Higher accumulation of toxic heavy metals in rice grown in agricultural soil may lead to health disorder. The present study was carried out to assess the levels of different heavy metals like potassium, calcium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper and zinc in agricultural soil. The soil samples were collected by soil auger from the arable fields of Nolam near Dhaka Export Processing Zone Area (DEPZA), Savar, Dhaka of Bangladesh. The samples were irradiated using 3MV Van de Graaff Accelerator at the Atomic Energy Centre, Dhaka and Proton Induced X-ray Emission (PIXE) technique was employed for the analysis. The results indicated a substantial build-up of heavy metals in surface soil andsub-surface soil. Average metal concentrations were calculated and compared with reference values. The persistence of heavy metals in surface soil was higher than the sub-surface soil and it exceeded the standard safe limit. Uptake and translocation factor of heavy metal from surface soil to sub-surface soil were quite distinguished for almost all elements examined. In terms of health risk, the observed highest concentrations of these elements in soil could have an effect on human health which may pose public health hazards and for this pretreatment process of waste water is necessary for reducing the amount of heavy metals before using it to the agricultural soil. Wastewater from industries or other sources carries an appreciable amount of toxic heavy metals therefore their discharge into the environment must be minimized and carefully controlled.

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Packed and unpacked spices may contain high level of lead that poses health threats. It may be due to soil contamination or artificial mixing of heavy elements to make the spices look brighter to attract customers. Some spices sample like turmeric and red chilli powder of local market in Bangladesh were collected to determine the toxicity present in them. The sample were dried and pressed to make pellet and irradiated by proton beam of 2.4 MeV and in the current range of 10-15 nA using 3 MV Van de Graaff Acclerator, Atomic Energy Centre, Dhaka and the IBA technique PIXE has been used for all of the experiments. Accuracy and precision of the technique were assured by analyzing certified reference material in the same experimental conditions. The elements that were found to be present in these samples are P, S, Cl, K, Ca, Mn, Fe, Zn. Among the investigated sample, one turmeric powder sample contains excess Pd which may affect human health. Proper care should be taken on processing the spices.

Image noise analysis of a large ring PET scanner "macro PET" performed using two different phantoms, namely a Jaszczak SPECT phantom and a uniform cylindrical phantom. In the present work, simple 2D filtered back projection was used to reconstruct all the images, and in almost all the cases a Hamming filter of cutoff frequency 0.4 and a 256 by 256 matrix with zoom factors from 1 to 4 were used in order to investigate the imaging capabilities of the new scanner and the influence of filter and cut-off frequency on the filtered back projected images. Results indicate that 11.1 mm cold rod in the Jaszczak phantom images can consistently be seen. The Coefficient of variation (CV) results for Hann and Hamming filters are very similar and increase approximately in linear fashion with higher cutoff frequency. The value of CV for the Parsen filter is lower than the value for Hann and Hamming filters. It concludes that all filters with low cut off-frequency (<0.6) would suppress image noise but decrease contrast.