Investigation of polycyclic aromatic hydrocarbons (PAHs) and cyclic terpenoid biomarkers in the sediments of fishing harbors in Taiwan

Unraveling sources of hydrocarbons in subtropical estuaries with distinct degrees of protection in the Southwestern Atlantic Ocean, Brazil

Sedimentary aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) were studied in subtropical estuaries with distinct degrees of legal protection, located in the Southwestern Atlantic Ocean, São Paulo State, Brazil. A multivariate approach was adopted, using the Hierarchical cluster analysis followed by the Principal Matrix Factorization analysis to support the hydrocarbons sources findings using diagnostic ratios. In general, the sites with the highest values of hydrocarbons were in the vicinity of well-urbanized cities, where sewage discharge, harbor and industrial activities take place. Pyrolitic PAHs were the predominant source of PAHs in the sites. The region can be considered not highly contaminated by hydrocarbons; however, specific sites under local anthropogenic impact from sewage and/or urban drainage, presented relatively high hydrocarbons levels. These findings highlight the importance of sources identification as reliable approach to be included in the management plan of protected areas under the inputs of several vectors of contamination.

Comprehensive assessment of metals and organic pollutants in pelagic fishing port sediments

Fishing ports are among the environments that accumulate pollutants along the coast but often lack environmental data and scientific research. This study investigated 8 metals, 16 polycyclic aromatic hydrocarbons (PAHs), 10 phthalate esters (APs), and 2 alkylphenols (APs) in the surface sediments of Qianzhen Fishing Port, the largest pelagic fishing port in Taiwan. Indicator compounds, pollution hotspots, potential ecological risk levels, and pollution sources were evaluated. Results showed that copper, zinc, and bis(2-ethylhexyl) phthalate (DEHP) in surface sediments were pollution indicators posing potential toxicological risks. Metals and PAHs in sediments were mainly from ship-related sources, while PAEs and APs were related to dockland activities. Combining metal and organic pollutants, the sediments had a moderate potential ecological risk, with metals higher than organic pollutants. Cluster analysis and color geographic map of risks indicate sediment pollution hotspots and areas requiring immediate intervention. In the future, sustainable operation and management can be carried out by using metal-free antifouling paint, improving sewage treatment rate, and regular environmental dredging of fishing port.

A systematic evaluation of polycyclic aromatic hydrocarbons in South Atlantic subtropical mangrove wetlands under a coastal zone development scenario

Mangrove forests worldwide are threatened environments considered vulnerable to chronic contamination by hydrophobic contaminants such as polycyclic aromatic hydrocarbons (PAHs). These ecosystems have a key role in the dynamics of biogenic and anthropogenic carbon storage and provide proper conditions for accumulation. One of most important subtropical mangrove swamps in the South Atlantic is located in the Paranaguá Estuarine System (PES), the largest bay of South Brazil surrounded by well-preserved Atlantic rainforests; however, the PES is under imminent risks of damage, e.g., due to incidental oil spills during port operations. In this scenario, PAHs were assessed for the first time in the mangrove sediments of the PES. The concentrations of 16 priority PAHs (EPA) (<DL - 234.3 ng g^-1, 36 samples) were higher than those observed in previous studies for bottom sediments and had a similar order of magnitude as those for other human-impacted mangroves but were lower than those of other heavily impacted mangroves. A moderate level of anthropic contamination was observed, and the main probable sources of PAHs were navigation and domestic effluents. Bulk parameters (TOC/TN ratio and δ¹³C) showed the estuarine land-sea gradient and helped define the preferential sites of PAH deposition due to its correlation with TOC and fine sediments. Marine hydrodynamics and/or dilution processes had a major influence on PAH distribution, resulting in higher concentrations in the inner/sheltered areas of the estuary and lower values in the outer zone of the estuary with higher hydrodynamic energy. The environmental features and anthropogenic forcing of the PES added to the relative absence of a detailed evaluation of the levels of and environmental risks posed by PAHs in other subtropical mangrove ecosystems located in the Southern Hemisphere, reinforcing the importance of the current study.