19. Nivell d’emissions dels diferents combustibles Nivell d’emissions dels diferents combustibles Contaminant Gasolines Gas-oil Carbó Gas natural Biocombustibles CO 2 Important Important Molt Important Important Poc Important CO Important Poc important Important Poc important Poc important SO x Poc Important Important Molt Important Quasi nul Poc important NO x Important Molt Important Molt Important Poc important Poc important HC Molt Important Poc important Nul Nul Poc important Fums Important Important Molt Important Poc important Important Metalls Poc Important Important Poc important Nul Important