Distribution, sources and risk assessment of polycyclic aromatic hydrocarbons in surface sediments from the Yellow Sea coast, China.

To study the distribution, sources, ecological/health risks, and the impact of regional economic variations on polycyclic aromatic hydrocarbons (PAHs) contaminations along the coast of the Yellow Sea in China, sediments from a broad coastal coverage were collected and analyzed. The total contents of 16 priority PAHs varied between 1.4 and 1675.9 ng/g except in the site of H18 (3191.4 ng/g) adjacent to Qingdao City, with an average value of 295.7 ng/g. PAH pollution along the coast presented a distinctive geographical feature, which was closely linked to local human activities, such as Rongcheng with industrial zones and aquacultural areas, and Yancheng Wetland with developed aquaculture. The source analysis results indicated that PAHs were mainly from pyrolytic sources, with smaller contributions from petroleum spills and combustion. Risk assessment suggested that PAH pollution along the Yellow Sea coast showed negligible biological risks and health risks in most areas.

Sedimentary record of polycyclic aromatic hydrocarbons in mud deposits along the southeastern coast of Liaodong Peninsula and its relation to the anthropogenic and natural activities in the Northeast China.

The concentrations of polycyclic aromatic hydrocarbons (PAHs) in two 210Pb-dated sediment cores collected from mud deposits along the southeastern coast of the Liaodong Peninsula were investigated to reconstruct the sedimentary records of PAHs and their relationship with anthropogenic and natural activities. The concentrations of 16 PAHs (∑PAHs) were low and remained stable before the year 1820, reflecting an autarkic agricultural civilization. From 1820 to 1900, with the gradual lifting of prohibition, people migrated into Northeast China, resulting in the release of large amounts of ∑PAHs into the environment. At the beginning of the 1900s, the ∑PAH levels in the two cores displayed increasing trends with significant fluctuations, linked to a period of social turbulence with continuous wars in Northeast China. After 1949, vertical ∑PAH trends in the cores predominantly reflected trends in economic development. Based on the different PAH composition trends (2-3-ring and 4-6-ring PAHs), we consider that historical energy usage in Northeast China can be divided into three stages: biomass fuel use dominated before 1920, biomass and fossil fuels co-existed from 1920 to 1980, and fossil fuels dominated after 1980. In addition, this study also demonstrates that the PAH concentrations (2-3-ring PAHs) in these two sediment cores can be used, to a certain extent, to identify anthropogenic fire events.

Assessment of heavy metal contamination in surface sediments from the nearshore zone, southern Jiangsu Province, China.

We determined the heavy metal concentrations and evaluated the pollution status of 213 surface sediment samples collected from the nearshore zone of southern Jiangsu Province, China. The distributions of lead (Pb) and zinc (Zn) were similar, and their concentrations were highest in tidal creeks dominated by fine-grained sediments, such as the Dawanhong and Wangcanghong creeks and the outer part of Lanshayang Creek. The spatial distributions of chromium (Cr) and cadmium (Cd) were similar, with high concentrations south of Yangkou Port and Haozhi Port. Copper (Cu) concentrations were high off the coast of Rudong. The sediments were not polluted by Cu, but were weakly polluted by Cd, Cr, Pb, and Zn. The results of principal component analysis indicated that Pb and Zn were mainly from natural sources, Cd and Cr were from anthropogenic sources, and Cu was from a mixture of natural and anthropogenic sources.

Distribution, sources, and ecological risk assessment of quinotone antibiotics in the surface sediments from Jiaozhou Bay wetland, China.

The distribution, sources, and risk assessment of eight quinotone antibiotics (QNs) in the surface sediments from the wetland in Jiaozhou Bay were investigated. The results showed that QNs were detected in all samples, and the total concentrations of QNs in the sediments ranged from 0.276 to 5.229ng/g. The highest concentration occurred at the entrance to the Yang River wetland. Principal component analysis suggested that the QNs mainly originated from sewage discharges from hospitals, human and aquaculture industries. Risk assessment, based on risk quotients, indicated the current ofloxacin level might be a medium risk level, while other QNs were all low risk. Nevertheless, there should still be concerns due to high consumption of QNs by human beings, animals, and aquatic organisms in the wetland. This investigation provides baseline data that the government can use as a reference guide to control QNs residues in Jiaozhou Bay wetland.

Distribution, sources, and ecological risk assessment of polycyclic aromatic hydrocarbons in surface sediments from the Nantong Coast, China.

The distribution, sources, and ecological risk assessment of 16 polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the Nantong coast in China were investigated. The results indicated that the total concentrations of the 16 PAHs in the surface sediments from the study area ranged from 1.4 to 87.1ngg-1 dw (mean value 19.9ngg-1 dw), which were generally low compared to the adjacent offshore area and other coastal zones around the world. The selected PAH ratios and the principal components analysis for each site showed that petroleum combustion and petrogenic pollution (mainly caused by petroleum spills) were the dominant PAHs sources in the surface sediments of the coast. The ecological risk assessment indicated that most of the individual PAHs had few negative effects in this area.

Distribution, sources and ecological risk assessment of PAHs in surface sediments from the Luan River Estuary, China.

The distribution, sources and risk assessment of 16 polycyclic aromatic hydrocarbons (PAHs) of surface sediments in the Luan River Estuary, China, have been investigated in the research. The results indicated that the total concentrations of 16 PAHs in surface sediments of the Luan River Estuary ranged from 5.1 to 545.1 ng g(-1)dw with a mean value of 120.8 ng g(-1)dw, which is relatively low in comparison with other estuaries around the world. The PAHs in the study area were mainly originated from pyrogenic sources. Besides, PAHs may be contaminated by petrogenic PAHs as indicated by the selected ratios of PAHs, the 2-tailed Pearson correlation analysis and principal components analysis at different sites. The result of the ecological risk assessment shows little negative effect for most individual PAHs in surface sediments of the Luan River Estuary, China.

An assessment of human influences on sources of polycyclic aromatic hydrocarbons in the estuarine and coastal sediments of China.

Sediments collected from the coastal area of China, embracing west coast of Bohai Sea, south coast of Shandong Peninsula, and the Changjiang estuary (listed in order of decreasing north latitude), were analyzed for polycyclic aromatic hydrocarbons (PAHs). ∑PAH (Sixteen US EPA priority PAHs) were 2.7-350.9ng/g. Petroleum residue was the major contributor of PAHs in the coastal sediments of China due to oil leakage from ships and offshore oil fields. The contribution of vehicular emissions in coast of North China was significantly lower than that in the Changjiang Estuary, and the reverse was true for coal combustion. PAH concentrations in the sediment core of the Changjiang estuary steadily increased upward and the variation was primarily due to economic development and severe floods. The impact on PAHs by vehicular emissions (37.2%) and petrogenic sources (45.8%) overwhelmed combustion sources (17.0%).