Concentration profile of elemental and organic carbon and personal exposure to other pollutants from brick kilns in Durango, Mexico

Abstract

Emission factors and personal exposure measurements were obtained in the working environment of a brick kiln yard in the municipality of Victoria de Durango, Mexico. Two kinds of kiln were evaluated; one was a fixed traditional kiln (FTK); the other was a local variation of an improved kiln called the ecological Marquez brick kiln (MK2). To distinguish it from the original design, we call it the Marquez kiln Durango (MKD). Ambient emission gases of carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), and non-methane hydrocarbons (NMHC) were continuously followed using Fourier transform infrared spectrophotometry (FTIR). Elemental carbon (EC) and organic carbon (OC) ambient emissions were sampled on quartz filters and analyzed by chemical coulombimetry. Personal exposure to CO was continuously followed using portable monitors, and personal exposure to inhalable particles with diameters of generally 2.5 μm and smaller (PM2.5) was obtained using Teflon filters in portable particle samplers followed by gravimetric analysis. Results show that the FTK emits more PM2.5, EC, and OC per cooking stage than the MKD. In terms of PM2.5 emission factors, relative to the FTK, the MK2 is 61% smaller and the MKD emission factor is 39% smaller. Against our expectations, the MKD showed higher work environment exposure levels. This is due to the untested changes to the original MK2 design and a mismanagement of the operation processes. Personal exposure to CO and PM2.5 of local brick kiln workers was about three times higher than indoor exposure from the use of three-stone wood cookstoves in Mexico. The analysis of emission plumes from FTK and MKD using a coupled emission model dispersion model allowed us to evaluate the impacts, transport, and deposition area of the particle matter in the area surrounding Durango Brickyard (DB).