Speciated non-methane organic compounds emissions from food cooking in Mexico

Non-methane organic compound (NMOC) emissions from different sorts of food preparation sites, were quantified for the first time in Mexico, in order t o develop emission profiles for further application in the chemical mass ba lance receptor model (CMB). Restaurants using charcoal grills and LP gas st oves, "tortillerias", food frying places and rotisseries were sampled using SUMMA((R)) stainless-steel canisters to analyse NMOC by high-resolution ga s chromatography. The results obtained show that profiles determined from f ood cooking processes have similarities to those found in LP gas combustion , which is the most common fuel in Mexico used for this purpose, although t here were differences in the relative composition of propane and butane in both cases. This suggests that, the rates of combustion of propane and buta ne are different. It has also been detected that propene, a reactive olefin is produced during the combustion process. The obtained profiles of restau rants, rotisseries and fried food show an important contribution of two car bon compounds (ethane, ethylene and acetylene) that can be attributed to th e complex process of grease and meat cooking. The presence of these compoun ds cannot be attributed to vehicular sources since the concentrations are h igher than in ambient air. These were also determined from aromatic compoun ds such as benzene, toluene and xylene in the combustion of vegetal charcoa l. The measured concentrations indicate that NMOC emissions from cooking ma y become an important indoor source of NMOC under crowded conditions in clo sed places. (C) 2001 Published by Elsevier Science Ltd.