Climate change impact on the photodegradation of polycyclic aromatic hydrocarbons in soils

Identifier:  TDX:2556

Handle: https://hdl.handle.net/20.500.11797/TDX2556

Authors:  Marquès Bueno, Montserrat

Abstract:
The Intergovernmental Panel on Climate Change (IPCC) assessments have evidenced that the Earth’s climate is changing faster, because of an increasing emission of greenhouse gases. Although a global impact is expected, high latitude and Mediterranean regions are especially vulnerable areas. The increase of temperature and UV-B radiation will alter the fate and behavior of a wide range of pollutants, such as polycyclic aromatic hydrocarbons (PAHs). Therefore, these pollutants are potentially vulnerable to the climate change. This PhD thesis was aimed at evaluating the impact of temperature and light intensity on the fate of PAHs in Mediterranean soils. Concentration changes of the 16 US EPA priority PAHs in soils, its ecotoxicological impact, and the identification of photodegradation by-products, were experimentally conducted at lab scale by comparing current environmental conditions and the IPCC RCP8.5 climate change scenario, for the Mediterranean region. Physicochemical properties of each individual PAH, temperature, light intensity and soil texture were identified as key factors regulating the PAH dynamics. The experiment was also conducted under solar radiation, which significantly enhanced the PAH photodegradation in comparison to values at lab scale. An increase of PAH photodegradation by-products, such as oxy- and nitro-PAHs, was also detected in soils subject to high temperature and light intensity. Because these new substances might be more toxic than parental compounds, the impact of climate change may be dramatic for the ecosystems and the human health.