Toxic atmospheric pollutants from crematoria ovens: characterization, emission factors, and modeling.

Human remains and corpses' cremation is an increasing practice worldwide alternative to burials, which have increased their cost and reduced spaces in cemeteries. Alike to other combustion processes, cremation produces pollutant emissions that contribute to worsen air quality in modern cities. A 6-month sampling campaign was performed in order to characterize emissions from corpse cremation in three different crematorium ovens and develop emission factors which were used to determine the population exposure to those pollutants during cremation activities applying a dispersion model. The main difference among crematoria was the inclusion or non-inclusion of controlled air supply devices. Using isokinetic samplings in the chimneys crematoria, emissions were measured and characterized with different chemical analyses. No significant differences were found in arsenic and metal concentrations among different crematories, although carbon monoxide, particles, elemental carbon, organic carbon, and polycyclic aromatic hydrocarbon concentrations in facilities without controlled air supply were up to seven times higher than those with controlled air supply. Nevertheless, these pollutants exceeded standards in all crematoria. Except for elemental and organic carbon concentration that correlated with corpse weight, other recorded cadaver characteristics bear no relation with pollutant emissions. Emission factors among different ovens did not present significant differences; then, they were used for dispersion modeling of particles and mercury emissions over Mexico City when 35 crematoria operate simultaneously through an hour showing that PM2.5 and Hg increase 0.01-1 μg m-3 and 0.01-0.1 ng m-3, respectively, in that scenario.