Ambient air arsenic levels along the Texas-Mexico border

The Texas-Mexico border region is one of the most rapidly developing areas in the state. Unprecedented economic and demographic growth is placing stress on a system already overburdened with air, water, waste, and public health problems. This paper reports the results of an initial survey of the past and present ambient air levels of arsenic along the Texas side of the border. Ambient air arsenic levels have increased over time, exhibit seasonal variations, and are higher in specific areas when compared to the rest of the state. Five of the 20 areas in Texas having the highest 24-hour levels of arsenic are found along the border. In areas where emissions have been significantly reduced at the source, arsenic levels remained high in the environment for over two years. This provides a potential continuum for human exposure. The results of this study emphasize the need for bi-national development and implementation of air quality control programs along the Texas-Mexico border.