RESUMEN
Soil/sediment samples of four different land types were collected from aquaculture land, farmland, industrial land and river bottom sediment in the estuary area of Dagu River. The contents of Cr, Cu, Zn, As, Cd and Pb in 0-30 cm inner surface samples were detected, and the distribution characteristics of heavy metal content in surface soil/sediment of different land use types in the estuary area were analyzed. Local accumulation index method, potential risk index evaluation method and principal component analysis method were used to analyze the pollution status and sources of heavy metals. The results showed that the heavy metal accumulation levels in soil and sediment samples in the study area were As > Cd > Cu > Pb > Zn > Cr, and the heavy metal content exceeded the soil background value in Shandong Province, but the potential risks were all in a low risk state. The main sources of Cr, Zn and As are transportation sources and natural sources, while the main sources of Cd and Pb are agricultural.
Asunto(s)
Monitoreo del Ambiente , Metales Pesados , Ríos , Estuarios , Cadmio/análisis , Plomo/análisis , Medición de Riesgo , Metales Pesados/análisis , Suelo , ChinaRESUMEN
Although the occurrence and distribution of various chemicals on microplastics (MPs) has been widely studied, little was known about the concentrations of poly- and perfluoroalkyl substances (PFASs) on MPs. In this study, MPs from eight rivers draining into Pearl River Estuary (PRE) region were collected and analyzed. Higher concentrations of PFASs on MPs (105-9.07 × 103 ng g-1) were found in the drain outlets receiving wastewater from most urbanized cities with large population densities. On the other hand, lower concentrations of PFASs on MPs (10.3-227.8 ng g-1) were found in the drain outlets receiving wastewater mostly from agricultural and forested areas. Specially, 8:2 disubstituted polyfluoroalkyl phosphates (8:2 diPAP) was detected with the highest frequency, in 92.5% of the samples. Furthermore, a positive Spearman correlation was found between 6:2 disubstituted polyfluoroalkyl phosphates (6:2 diPAP) and perfluorotetradecanoic acid (PFTeDA) (rs = 0.621, p = 0.012), indicating they might share similar sources. PFASs on MPs were found to vary significantly with different seasons. Higher concentrations of PFASs on MPs were found in dry seasons, while lower concentrations were observed in wet seasons. The results of this study should be important for the understanding of PFAS occurrence and distribution on MPs and the partitioning mechanism of PFASs on MPs in estuary systems.