Persistent organic pollutants in a multimedia environment, andassociated human health risks: case studies in the region ofCampania, Italy, and south-central China

Abstract

Persistent organic pollutants (POPs) are notoriously toxic chemicals that pose significant threats to human health and ecosystem security. As a result of their volatility and persistence, POPs can be subject to long-range atmospheric transport (LRAT) and, as a result, may be redistributed globally. The harm of POPs to the eco-system is regarded as a global environmental problem, threatening people and animals, which has caused heavy losses economically, ecologically and socially. The environmental problems caused by POPs have finally lead the international community to address the global presence of POPs and reduce their emissions to the environment. Many treaties and laws have been enacted to eliminate or restrict the production and use of some POPs, of which the Stockholm Convention of 2004 on POPs is one of the most famous. Soils are important POPs reservoirs due to their tremendous retention capabilities for these compounds. The huge quantities of POPs accumulated in soils have been an important reemission sources to the atmosphere even after the phasing out of these compounds decades ago. Atmospheric processes are largely responsible for the transport and deposition of polycyclic aromatic hydrocarbons (PAHs), and these compounds may adhere to both atmospheric aerosols and dustfall. Organochlorine pesticides (OCPs) can be easily adsorbed on to suspended particulate matter (SPM) as sediments. SPM can then precipitate in sediments and eventually lower the OCP concentrations in water. Under favorable conditions, sediments can be resuspended, release previously adsorbed OCPs back into the water phase, and initiate another cycle of environmental contamination. So far, the Stockholm Convention has not been ratified by Italy, however, several other regulatory schemes, such as a European Directive in 2000, the UNECE POPs Protocol, and the Rotterdam Convention, are actively followed. The region of Campania falls within the subtropical zone and enjoys a Mediterranean climate. High temperatures in tropical/subtropical regions can facilitate the volatilization and escape of POPs from soils, sediments, and water. The lack of sufficient data on POPs residues, limits the understanding of their health effects, environmental dynamics, and the ultimate fate of these chemicals. China is one of the largest agricultural industries in the world, and was once the largest global producer and consumer of OCPs, especially in the arable southeast region. This Ph.D. thesis presents the results of a series of investigations using a systematic sampling method and geostatistics to illustrate spatial and temporal variations in the concentrations of POPs in different environments, and associated human health risks in Campania, Italy, and south-central China.