Atmospheric deposition of hydrophobic organic chemicals in the northwestern Mediterranean Sea: comparison with the Rhone river input

• Published in: Marine chemistry 1994-04, Vol.46 (1), p.153-164
• Main Authors: Lipiatou, Elisabeth, Albaigés, Joan
• Format: Article
• Language: English
• Subjects: Marine
• ISSN: 0304-4203; 1872-7581
• DOI: 10.1016/0304-4203(94)90052-3

Atmospheric deposition is an important contributor of natural and anthropogenic chemicals to the Mediterranean Sea. In this study, size-differentiated aerosols were collected on Mallorca in the western Mediterranean Sea and analyzed for polycyclic aromatic hydrocarbons (PAH) and n-alkanes. Total PAH and n-alkane concentrations were comparable to previous studies in the area. The mass median effective diameters ( mmed) for both PAHs and n-alkanes occur in the fine-particle fraction (0.7–1.5 μm, PAHs; 1.1–2.4 μm, n-alkanes). Total PAH dry particle fluxes, calculated by the six-step method were 15–35 μg/m 2/yr; total n-alkane dry particle fluxes were 0.8–1.3 mg/m 2/yr. Particle fluxes were dominated by the coarse particle sizes (> 3 μm) for both PAHs and n-alkanes. Calculated wet plus dry deposition was ∼ 28–61 μg/m 2/yr for PAHs and ∼ 1.1–1.7 mg/m 2/yr for n-alkanes. Different transport pathways occur in the atmosphere and the water column for the low and high molecular weight PAHs. In comparison with the Rhone River input, atmospheric deposition of PAH represents 15–30% of the total input in the Gulf of Lions, distant from the river mouth. Considering the northwestern Mediterranean Sea, atmospheric deposition is the dominant source, contributing 7.8–17 T/yr of PAHs.