Environmental and human health impact of different powertrain passenger cars in a life cycle perspective. A focus on health risk and oxidative potential of particulate matter components

Abstract

Different powertrains passenger cars, homologate in compliance with Euro 6 standard, were compared in a life cycle perspective for assessing both environmental and human health impacts. For this latter aspect, some correlation between the emission of heavy metals, elemental carbon, organic carbon, the oxidative potential of particulate matter and the adverse effect on human health were also analyzed and discussed. Battery electric vehicle (BEV) showed the lower greenhouse gases emissions, from 0.1 kgCO_2eq/km to 0.2 kgCO_2eq/km but were charged by the higher emissions of freshwater eutrophication and freshwater ecotoxicity, about 6 × 10^-6 kgP_eq/km and 4 CTUe/km, respectively. Lower resource depletion was detected for cars powered by internal combustion and hybrid powertrains. Amount of particulate matter (PM) emitted resulted lower for petrol-hybrid electric vehicles (Petrol-HEV), of about 5 × 10^-5 kgPM_2.5eq/km. BEV were charged by the higher values of human toxicity cancer, from about 2 × 10^-5 CTU_h/km to about 5 × 10^-5 CTU_h/km whereas Petrol-HEV were credited by the lower impact on human health (DALY/km). The large contribution to PM emission from all the analyzed cars was from tyre and brake wear. Main PM components were elemental (ElC) and organic carbon (OC) compounds. ElC is also a specific marker of PM emitted from traffic. Both ElC and OC were characterized by a strong correlation with the oxidative potential of PM, indicating a threat for human respiratory tract only marginally decreased by the transition from conventional to electric poweretrains vehicles.

Keywords: Battery electric vehicles; Human health; Hybrid electric vehicles; Internal combustion engine; Life cycle assessment; Particulate matter.