Preliminary study of soot and polycyclic aromatic hydrocarbons in emitted particles from adobe kilns that use scrap tires as fuel

Abstract

Artisanal pottery in Mexico is largely manufactured in handmade adobe kilns using scrap tires as main fuel in rural and periurban areas, making this activity one of the main sources of atmospheric pollutants. An intensive sampling campaign was conducted in a Mexican small town in order to characterize the toxic species emitted by more than 400 adobe kilns working in two scenarios: low and normal activity, as well as to determine their carcinogenic potential. PM₁₀ concentrations ranged 50-80 µg m⁻³ and 77-290 µg m⁻³ during low and normal activity periods, while PM_2.5 concentrations were 33-57 µg m⁻³ and 37-177 µg m⁻³ in the same periods. Organic carbon and elemental carbon presented concentrations around four and seven times greater, respectively, during a normal activity period than during a low activity period in both particle sizes. Quantified polycyclic aromatic hydrocarbons were twice greater during the normal activity period than during the low activity period. Carcinogenic PAHs accounted for 53-59% of total PAHs in all cases and the carcinogenic potential (B[a]Peq) in PM₁₀ during the normal activity was 25 times higher than the European Commission recommendation, proving thereby the high risk that nearby population faces to those emissions.