As concern regarding the toxic effects of bisphenol A (BPA) grows, BPA in many consumer products is gradually being replaced with compounds such as bisphenol S (BPS). Nevertheless, data on the occurrence of BPS in human specimens are limited. In this study, 315 urine samples, collected from the general populations in the United States, China, India, Japan, Korea, Kuwait, Malaysia, and Vietnam, were analyzed for the presence of total BPS (free plus conjugated) concentrations by highperformance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). BPS was detected in 81% of the urine samples analyzed at concentrations ranging from below the limit of quantitation (LOQ; 0.02 ng/mL) to 21 ng/mL (geometric mean: 0.168 ng/mL). The urinary BPS concentration varied among countries, and the highest geometric mean concentration [1.18 ng/mL or 0.933 μg/g creatinine (Cre)] of BPS was found in urine samples from Japan, followed by the United States (0.299 ng/mL, 0.304 μg/g Cre), China (0.226 ng/mL, 0.223 μg/g Cre), Kuwait (0.172 ng/mL, 0.126 μg/g Cre), and Vietnam (0.160 ng/mL, 0.148 μg/g Cre). Median concentrations of BPS in urine samples from the Asian countries were 1 order of magnitude lower than the median concentrations reported earlier for BPA in the same set of samples, with the exception of samples from Japan.

No abstract

No abstract

In this work, twelve heavy metals and arsenic, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, and Zn, in a rice sample collected from some areas of Vietnam have been quantified and implemented by using multiple analytical platforms such as ICP-MS, AAS, and mercury analyser. Seventy rice samples collected from the Red River Delta and mining zone activity were analysed. Concentration of heavy metals and arsenic in rice was analysed after appropriated sample digestion using internal or external calibration curves. The mean concentration (mg kg−1 dried weight) of the analysed elements in rice samples decreased on the order of Mn (19.268) > Fe (13.624) > Zn (8.163) > Cu (3.138) > Ni (0.384) > Cr (0.296) > Co (0.279) > As (0.115) > Cd (0.111) > Pb (0.075) > Hg (0.007) > Se (<LOD). Mercury, a highly toxic element, has been only found in rice samples collected in the mining activity zone (frequency detection 14.5% of total samples). The experimental results indicated that the heavy metals and arsenic found in rice collected from mining activity zone were higher than those in rice harvested from normal cultivated areas like the Red River Delta. The heavy metals and arsenic content in Vietnamese rice samples were also compared with the concentration of heavy metals in other foreign rice samples in some recent publications. The estimated daily intake through rice consumption was calculated and compared with the level proposed by the Food and Agriculture Organization of the United Nations. The results indicated that the provisional daily intake of Cd was higher than the level proposed by FAO, while the intake of other heavy metals was in an acceptable range of CODEX standard.

A research program was established to identify the governing factors for the partition coefficient (K(D)) of heavy metals between suspended particulate and dissolved phases in the Day River system a tropical, highly alluvial aquatic system, in Vietnam. The targeted river system, draining an urbanized-industrialized catchment where discharged wastewater is mostly untreated, could be separated into the least impacted, pristine area, and the most impacted, polluted area. Organic matter degradation was shown to govern the variation of parameters like total organic carbon, biochemical oxygen demand, chemical oxygen demand, nutrients, conductivity, or redox potential. Heavy metals in both dissolved and particulate phases were enriched in severely polluted area because of wastewater inflow that contains concentrated metals and intensification of metal influx from sediment. Results show log K(D) in the order Mn < As < Zn < Hg < Ni < Cu < Cd < Co < Pb < Cr < Fe and As < Zn < Ni < Mn < Cr < Cu < Co < Fe in the polluted zone and the pristine zone, respectively. A decreasing tendency of partition coefficients of 11 heavy metals considered from the pristine to the impacted zones was observed. Three explanations for the difference are: (1) increase of solubility of most heavy metals in low redox potential, (2) competition for the binding sites with major and minor cations, and (3) complexation with dissolved organic matter concentrated in municipal waste impacted water. Apart from domestic waste impact, statistical analysis has contributed to identify the influence of climate condition and hydrological regime to the partition of heavy metals in the area.