First, recall that the SNIFF emissions inventory discussed above clearly indicates that industry is not the leading source of particulate emissions in Ciudad Juárez. Rather, the leading sources are vehicles, unpaved roads, and soil erosion (Table 1). Moreover, even leaving aside vehicles and soils, the single most important industrial subsector in terms of air pollution is brick kilns, not maquiladoras (Table 2). In fact, brick kilns emit more particulate matter than all other industrial plants combined. Given that vehicles and brick kilns emit far more combustion-related fine particulates than maquiladoras, we can be fairly certain that.
