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Abstract Strong global demand leads to significant production of fluoropolymers (FP) in China which potentially release large quantities of perfluorooctanoic acid/perfluorooctanoate (collectively called PFOA/PFO) to the environment. Modelling the fate and transport of PFOA/PFO provides an important input for human health risk assessment. Considering the effects of urbanization and existing forms of PFOA/PFO, this study used the modified multispecies Berkeley-Trent-Urban-Rural model to simulate the transfer behavior of PFOA/PFO in the Bohai Rim, China. Spatial distributions of PFOA/PFO emissions during the year 2012 for the study area were illustrated. About two thirds of the total amount of PFOA/PFO was estimated to be released into fresh water, and the total releases to rural areas were 160-fold higher than those to urban areas due to the location of fluorochemical industrial parks. The simulations predicted that hydrosphere was the fate of PFOA/PFO, followed by soil and vegetation, which was consistent with field data. The highest PFOA/PFO concentration was modeled in the Xiaoqing River basin with a value of 32.57 μg/L. The PFOA/PFO concentrations in urban soils were generally higher than those in rural soils except for grids 1, 3 and 46. In addition, it was estimated that the total flux of PFOA/PFO entering into the Bohai Sea was 24.57 ton/year, 100-fold higher than that of perfluorooctane sulfonates (PFOS). Graphical abstract Unlabelled Image Highlights • More than 67% of the total PFOA/PFO emission was released into fresh water. • Total releases of PFOA/PFO to rural areas were 160-fold higher than urban areas. • PFOA/PFO concentrations in urban soils were generally higher than rural soils. • Except for hydrosphere and soil, vegetation was also an important sink of PFOA/PFO. • The total flux of PFOA/PFO into the Bohai Sea was estimated to be 24.57 ton/year. [ABSTRACT FROM AUTHOR]

Climate change and emissions rates of contaminants are expected to affect distribution and fate of Persistent Organic Pollutants (POPs) in the environment, however, studies on these combined factors are rare. In this study, Perfluorooctane Sulfonate (PFOS) is used as an example to assess how those two factors synthetically affect fate and disposition of POPs in the Bohai Rim of China by using the Berkeley-Trent-Urban-Rural (BETR-Urban-Rural) model. We set up three climate change scenarios and four emission scenarios to conduct the simulations. The results show that climate change could have significant effects on the transport and fate of PFOS mainly including advection, inter-compartmental transfer under the “worst case” emission scenario. For most grids, a remarkable decrease in concentrations of PFOS are predicted for fresh water and urban soil in the future, with precipitation and temperature being predominant factors, whilst for coastal water and rural soil, an increasing trend is predicted. Additionally, predicted sum of sources to the Bohai Sea increases greater than removals from the Bohai Sea in the future, adding evidence that concentrations of PFOS in coastal water will increase more in the future. Under scenarios of reduced emissions and climate change, concentrations of PFOS in each compartment decreased more rapidly over time. We suggest that assessment of future climate change impacts on fate of PFOS could take emission reductions into consideration. [ABSTRACT FROM AUTHOR]

The redundancy or deficiency of selenium in soils can cause adverse effects on crops and even threaten human health. It was necessary to assess selenium resources with a rigorous scientific appraisal. Previous studies of selenium resource assessment were usually carried out using a single index evaluation. A multi-index evaluation method (analytic hierarchy process) was used in this study to establish a comprehensive assessment system based on consideration of selenium content, soil nutrients and soil environmental quality. The criteria for the comprehensive assessment system were classified by summing critical values in the standards with weights and a Geographical Information System was used to reflect the regional distribution of the assessment results. Boshan, a representative region for developing selenium-rich agriculture, was taken as a case area and classified into Zone I-V, which suggested priority areas for developing selenium-rich agriculture. Most parts of the North and Midlands of Boshan were relatively suitable for development of selenium-rich agriculture. Soils in south fractions were contaminated by Cd, PAHs, HCHs and DDTs, in which it was forbidden to farm. This study was expected to provide the basis for developing selenium-rich agriculture and an example for comprehensive evaluation of relevant resources in a region. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl acids (PFAAs) are ubiquitous in the global environment, even in remote regions. With increasing production and application of PFAAs in China, their distribution patterns have been widely reported, however with less attention to inland northwestern regions. Long-range transport and direct releases from local activities have been regarded as the main reasons for PFAAs distribution in such a remote area. To identify and quantify the contributions of different sources to PFAAs occurrences, an investigation was conducted in the Tianchi lake, nature reserve. A total of 20 water samples, 8 soil, 4 sediment and 10 fresh snow samples were collected and analyzed in 2015. The mean PFAAs concentrations were 3.38 ng L−1 in surface water, 1.06 ng g−1 dw in soil, 0.53 ng g−1 dw in sediment, and 3.31 ng L−1 in fresh snow, respectively. High levels of PFAAs were observed in surface water (15.41 ng L−1) from Western Tianchi pond and surface snow (14.24 ng L−1) from the site near a ski resort around Tianchi Lake indicating potential pollution by local human activities. The correlation between individual concentrations among water, soil and snow indicated the snow deposition as an important source. Although with limited sample size, principal component analysis associated with multiple linear regression (PCA-MLR) and positive matrix factorization (PMF) analyses have identified two major sources, which are characterized as tourism activities with dominance of perfluorooctanoic acid (PFOA) and long-range transport with abundant perfluorobutanoic acid (PFBA). Their contributions to total levels were 41% and 52%, respectively. These two sources contributed differently to the PFAAs presences in Tianchi and Western Tianchi Lakes. Source analysis indicates that the western Tianchi lake with a relatively small catchment was affected mainly by local activities. Unlabelled Image • PFBA was the most abundant PFAAs in Tianchi lake. • Higher levels of PFAAs were observed from sites near scenic spots and ski resort. • The profile of PFAAs in snow was highly correlated with that in water and soil. • Two sources were identified with dominances of PFOA and PFBA, respectively. [ABSTRACT FROM AUTHOR]