[Distribution, Sources, and Risk Assessment of Microplastics in Surface Sediments of Yellow River Delta Wetland].

Estuarine habitats are a critical zone of the Earth with strong land-sea interactions, that are strongly influenced by human activities. Microplastics (MPs) pollution in the Yellow River Delta (YRD) wetland, a typical young warm-temperate estuarine wetland, has not been comprehensively studied. The morphology, abundance, particle size, and polymer composition of MPs in the surface sediments of the YRD wetland were determined, and the pollution status and ecological risk in the study area were evaluated using the pollution load index (PLI) and potential pollution risk index (PRI). The results showed that the abundance of MPs in the YRD wetland was 20-520 n·kg-1, with a median value of 150 n·kg-1. The MPs were primarily fibers in shape and black in color, with particle size over 1 mm. The polymer components were primarily rayon, polyethylene, polyester, and polyethylene terephthalate. The PLI and PRI values of the MPs in the area were between 0.04-0.96 and 0.00-171.60, respectively, indicating that the pollution of MPs in the YRD wetland was at a slightly polluted level with low ecological risk.

Alkylphenols in surface sediments of the Yellow Sea and East China Sea inner shelf: occurrence, distribution and fate.

Alkylphenols (APs) have been found as ubiquitous environmental pollutants with reproductive and developmental toxicity. In this study, APs in surface sediments of the Yellow Sea (YS) and East China Sea (ECS) inner shelf were analyzed to assess influences of riverine and atmospheric inputs of pollutants on the marine environment. NP concentrations ranged from 349.5 to 1642.8 ng/g (average 890.1 ng/g) in the YS sediments and from 31.3 to 1423.7 ng/g (average 750.1 ng/g) in the ECS inner shelf sediments. NP distribution pattern was mainly controlled by the sedimentary environment. OP concentration was 0.8-9.3 ng/g (average 4.7 ng/g) in the YS sediments and 0.7-11.1 ng/g (average 5.1 ng/g) in the ECS sediments. Assessment of the influence of distances from land on OP concentrations provided evidence for the predominance of coastal riverine and/or atmospheric inputs rather than long-range transport. And the biological pump may play an important role for sequestration of OP in the nearshore area.

Source apportionment of polycyclic aromatic hydrocarbons in surface sediment of mud areas in the East China Sea using diagnostic ratios and factor analysis.

Polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (AHs) have been quantified for surface sediments collected from the East China Sea (ECS). Our results showed that relatively high levels of PAHs and AHs occurred in both the inner and outer mud areas, while their concentrations at the control site were much lower. AHs for all samples were dominated by the unresolved complex mixture (UCM). Results from diagnostic ratios revealed that sedimentary PAHs were mainly originated from mixed combustion residues of biomass, coal, and petroleum. Combustion residues of petroleum and oil were responsible for the presence of high AHs concentrations. We also conducted factor analysis (FA) to further characterize the PAH and AH sources. Four factors were identified based on the loading of components and attributed to coal and wood combustion (Factor 1), traffic-related sources (Factor 2), petrogenic source (Factor 3) and natural gas combustion (Factor 4).

[Distribution of PAHs in surface seawater of Qingdao coast area and their preliminary apportionment].

The 15 parent PAHs in surface seawater from Qingdao coastal areas have been quantified by solid phase extraction-high performance liquid chromatography with fluorescent detection. The results showed that the concentration of total PAHs ranged from 8.23 ng x L(-1) to 272.02 ng x L(-1), with highest concentration near estuary and lowest at rural location. As for PAHs composition, 2, 3 ring PAHs were dominant, with percentage ranged from 52.2% to 93.8%, while the remaining were 4 to 6 ring PAHs which were ranged from 6.2% to 47.8%. The concentration of total PAHs correlates strongly with dissolved organic carbon (R = 0.944 7) in surface seawater. There was no significant fluctuation in the concentration and composition of PAHs in surface seawater from Qingdao bay area in a one-month period. The two ratios of paired PAH isomeric compounds, fluoranthene to fluoranthene plus pyrene[ Fl/(Fl + Py)] and anthracene to phenanthrene plus anthracene [An/(An + Ph)], for source apportionment suggested that various petroleum related sources, such as oil spill and petroleum combustion, were the major origin at most sampling sites, except in clean areas where PAHs were predominantly derived from coal and wood combustion.