Anthropogenic accumulation based on chemometrics of the radionuclide K-40 in tropical soils in the northeast Brazil.

The continuous use of fertilizers can increase the radionuclides levels in soils, and their accumulation and concentration are related to their characteristics and the various processes of use and soil occupation. Analyzing data from radiometric and pedological measurements often demands the use of more robust tools for better integration of results. This work presents the results of a study to evaluate the accumulation of 40K, in an area of the Zona da Mata region in Pernambuco, Northeastern Brazil, due to the contribution of natural or artificial sources. 40K activity concentration was measured by high resolution gamma spectrometry in 108 soil samples, as well the organic matter content and particle size distribution. Results showed the 40K activity ranged from 103 to 1843 Bq.Kg-1, with the arable soils showing levels above the world average value (420 Bq.Kg-1). A higher prevalence of 40K was observed on arable soils, regardless of soil type, organic matter content, depth or texture. Agricultural activities increased of 40K levels in different degrees, depending on the type of crop used, with an accumulation factor of up to 4 times greater compared to soils not impacted by agricultural activities. The radiochemometric diagnosis maded it possible to draw up a strategic management plan to improve the management practices of family farming in order to maximize production efficiency, and promote the conservation of natural resources and environmental preservation.

Metal contaminants in rice from Cuba analyzed by ICP-MS, ICP-AES and CVAAS.

Mercury, lead, cadmium and arsenic are considered hazardous pollutants in the environment, which can result in a risk for human health. This study aimed to determine the contents of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn by ICP-MS, CVAAS and ICP-AES in paddy and brown rice, grown in different soils of Cuba. The interest to include Cr, Ni, Cu and Zn was because these elements are found in very high levels in agricultural soils. To assess the safety of the dietary intake of these metals, the estimated weekly intake was calculated. The contents of Cd and As were below the maximum limits. A higher value was obtained for Pb when compared to Codex Alimentarius limits. The weekly intake of Cr and Ni was higher than the maximum weekly intake recommended by FAO/WHO.

ENVIRONMENTAL IONIZING RADIATION DOSE OUTDOOR IN AN INHABITED AREA WITH A HIGH CONCENTRATION OF URANO-PHOSPHATE IN NORTHEAST OF BRAZIL.

A marine phosphorus region with high concentrations of phosphate, coastwise of Pernambuco, Northeast of Brazil, is densely inhabited. Rock phosphate deposits naturally contain uranium ore that produces ionizing radiation from it and its natural descendants, furthermore, its thorium and potassium concentrations are comparable to those usually found in soils. Radiological monitoring of this environment is important to verify the occurrence of harmful effective doses for the adjacent population. This study aimed at the in situ radiometric monitoring in four cities of the north of the Metropolitan Region of Recife-Pernambuco, estimating the effective environmental dose to which the local population is subject. In total, 91 points were monitored with a discriminator-type detector. The outdoor environmental effective dose rates ranged from 1.99 ± 0.09 to 7.59 ± 0.36 mSv y-1, with an average of 2.60 ± 0.69 mSv y-1.