Smaller particulates related to combustion are much more dangerous because they are inhaled deeply into the lungs (Cifuentes et al. 2000, Laden et al. 2000). But note that even if particulate matter from soil is excluded, industry is still a relatively minor source of PM emissions, accounting for just 14% of remaining emissions. Even within the industry subsector, maquiladoras are not the leading source of two of the SNIFF air pollutants—PM and SO2. That distinction belongs to small-scale brick kilns (Table 2).2 (Note that, although the SNIFF does not include information on whether the emissions sources in.
