Multivariate tools to investigate the occurrence of pollutants in a highly anthropised marine area

Environmental monitoring of highly anthropised areas demands for deep survey of different environmental compartments (water, sediment, soil and biota) and determination of numerous bio-geo-chemical parameters, due to the huge impact of natural and anthropogenic organic substances constantly released into these environments. However, the interpretation of the large amount of data is not straightforward task due to their complexity that require a very tricky elaboration especially for the decision making processes. Chemo-metrics tools based on the multivariate statistical data analysis seems to be a powerful tool in addressing such complexity (Mali et al., 2017). In this work they are performed to get insight the occurrence of organic pollutants within a highly populated area such as the Gulf of Naples. The Gulfs of Naples, located along the Eastern Tyrrhenian Sea, is semi-enclosed by the Ischia-Procida Islands to NW, Campi Flegrei and the Campanian Plain in NE, the Sorrento peninsula in SE, and Capri island in W. The Campania region has one of the highest population densities in Italy. The Gulfs of Naples are the receiving environment for persistent toxic substances from the Campania Plain (Albanese et al., 2010; Arienzo et al., 2017). Montuori and Triassi (2012) reported that the discharges of PAHs from the Sarno River to the Gulf of Naples is approximately 8530 g/d. The main goal of this work is to establish the influence of the Campania Plain on the present sedimentation in the Naples bay continental shelf by evaluating organic matter contribution and pollution. For this purpose, superficial sediment samples collected from 158 sites located offshore the Gulf of Naples between Sarno River and Capri Island, were analyzed for total nitrogen and phosphorus, total organic carbon (TOC), grain size, metals, priority polycyclic aromatic hydrocarbons (PAHs), total petroleum hydrocarbon (TPHs), volatile organic compounds (VOCs), polychlorinated biphenyls (PCBs), pesticides and organotin compounds (OTs). The adopted multivariate approach allowed, through a clear spatial representation of score plots, a deep dive into the large dataset generated by the investigation campaign, highlighting the influence of some main factors controlling the contamination pattern, such as organic matter content and depositional environment.