|
(W/MC274) Enpoint modelling for toxics in LCA: Application to the impacts on human health of gasoline, diesel and natural gas vehicules. Jolliet, Olivier1, Tauxe, Annick1, Crettaz, Pierre1, 1 ABSTRACT- A new approach has been developed to calculate Disability Adjusted Life Years (DALY's) for carcinogens and non-carcinogens, based on epidemiological data when available or on ED10h (best estimate of the effect dose inducing a 10% added risk for humans). The ED10h is calculated directly from bioassays available in IRIS and extrapolation to low dose exposure is discussed in details. ED10h are also correlated to the more widely available tumour dose TD50 (carcinogens) and NOAEL (non-carcinogens) to quantify the slope factor of more than 900 chemicals. A weighting is proposed to account for effect severity. For carcinogenic endpoints, the DALYp per affected person amounts on average to 11 years of life lost per affected person and is dominated by mortality. For non-carcinogenic effects, a simplified categorization of the adverse effects into three categories is chosen: 11, 1.1 and 0.11 YLL/person are respectively assigned to high, medium (default) and low severities. To illustrate its potential, the method is combined with calculated exposure efficiencies and applied to the life cycle impacts of gasoline, diesel and natural gas vehicles. For 1 km covered by a reference vehicle (ECE cycle vehicle), diesel cars cause 4 times more damage than gasoline and 10 times more than natural gas cars. Carcinogenic substances have a 1000 times weaker effect than Nitrogen oxides, which dominate the impact due to nitrate particles. For Diesel cars, the effect of particulate matter PM2.5 is also important. The effect of all pollutants for a diesel car amounts to 0.03 DALYs per 100'000 km or 3800 YLL per year in Switzerland and reaches 16% of the damage due to fatal road accidents. Improvement should focus on the calculation of the exposure efficiency of secondary nitrates particles, which shows large differences between models. Key words: Human health, Life Cycle Assessment, DALY, Vehicle impacts |
