Ultrafine and nanoparticles emissions from hospital waste incineration: characterization and chemical speciation.

Focus on atmospheric particulate matter has recently steadily shifted towards finer size fractions, namely those particles with dimensions included from 2.5 µm down to the minimum practical detection limit of few nm. These fractions share the higher burden of health related effects arising from particle pollution, with ultrafine (UFP) and nanoparticle (NP) aerosols (size less than 0.1 and 0.05 µm respectively) actually receiving a constantly rising attention. Reference data available are mainly addressed to their presence in ambient air, whilst much less investigations have dealt with characterization of emission sources of potential interest and still fewer with their chemical speciation, in terms of the content of some trace toxic compounds involved in health effects. Present paper reports on an extended field scale investigation of UFP and nanoparticle size fractions emitted from a hospital waste incineration facility. Measurements were conducted at stack emissions with an electric low-pressure impactor counting system for the evaluation of total particle number concentrations and size distributions in the range 7 nm - 10 µm. Sampled fractions were also evaluated for their content of trace metals of toxic concern (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sb, Sn, Tl, V, Zn), analysed in terms of total concentrations and size distributions within fine, ultrafine and nanoparticle fractions. Measurement results obtained are reported and discussed in terms of absolute values and size dependent chemical profiles, and further examined in comparative terms with similar data available for other sources.