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The fractionation of 10 metals (As, Co, Cr, Cu, Mn, Ni, Pb, Se, V, and Zn) within labile fractions in shallow marine sediments collected from the coasts of Sabah and Sarawak, Malaysia, was evaluated. Spatial distribution revealed that coastal sediments from Sabah were approximately 10% higher in metal content than sediments from Sarawak. Risk assessment code, enrichment factor, and pollution accumulation index calculations were used to investigate the environmental hazards of elements. For the risk assessment code, the modified Tessier sequential extraction procedure was applied. The risk assessment code values showed that metal V recorded the lowest environment risk (~ 10%) while As, Co, Cr, Cu, Mn, and Zn exhibited medium risk (Risk assessment code range of 11%–30%). The element Ni displayed no risk (0.67%) to the environment, whereas Se and Pb recorded the highest risk with values of 47% and 52%, respectively. For the enrichment factor calculation, the continental crust data presented by Taylor (Taylor, Geochim Cosmochim Acta 28:1273–1285, 1964) were used as background, with metal Al used as a reference element. Results illustrated that most of the metals show enrichment (enrichment factor > 1). However, Se was considered extremely severe to the environment (enrichment factor > 50). While the pollution accumulation index calculation demonstrated that all metals under study can be considered as non-contaminant elements except for Ni, V, and Co. These findings indicated that marine sediments in Sabah are more polluted with metal contaminants than the sediments in Sarawak, despite both states having numerous active oil- and gas-related production facilities.

Various commercially imported ceramic materials used in the building of Sudanese dwellings were examined in order to determine their natural radioactivity and radiological hazard parameters. In this context, twenty-five different consignments were sampled and analyzed using (3 × 3 ) sodium iodide gamma spectrometry system NaI(Tl). The identified average activity concentrations of 238 U, 232 Th, and 40 K were 183 ± 70, 51 ± 44, and 238 ± 77 Bq/kg dry-weights, respectively. A positive correlation between 238 U and 232 Th in the investigated samples was identified from the observed significant correlation (R 2 = 0.8). Interestingly, a low Th/U ratio (~0.3) was recorded, which could be related to the systematic loss of thorium during the fabrication process. The measured activity concentrations for these radionuclides were comparable with the reported data obtained from similar materials used in other countries showing similarity in ceramic materials used in buildings. Five different radiation indices, such as the average radium equivalent (Ra eq ), the absorbed dose rate (D), the annual effective dose equivalent (AEDE), the external hazard index (H ex ), and the radioactivity level index (l γ ), which indicate hazardous radiation, were estimated from these measurements. The obtained results revealed average values of 274 ± 106 Bq/kg, 125 ± 48 nGy/h, 1.23 ± 0.48 mSv/y, 0.74 ± 0.29, and 0.94 ± 0.37, for Ra eq , D, AEDE, H ex , and l γ , respectively. The mean values of Ra eq and H ex were in good agreement with the international limits, while the means of D and l γ were higher than the universal values. Calculated AEDE in about 60% of the samples exceeded the universal limit of 1 mSv/y for the public exposure (maximum value of 2.16 mSv/y). The investigated parameters were in the same range for the majority of imported samples; however, they were slightly higher than the locally produced ceramic, highlighting the importance of monitoring imported materials for their radioactivity contents.