One of the most frequent complaints from communities surrounding the bauxite mining and alumina processing plants is dust. The dust in the air can be measured and compared with the air quality standards that define the acceptable limits to protect health. The instruments measure particulate matter (PM), which is the term, used for a mixture of solid particles and liquid droplets in the air. The ambient air quality standards for particulate matter are:
- Total suspended particulates (TSP) which is a measurement of the amount of particles in the air with diameter less than or equal to 100 microns and
- PM10 which measures particles with diameter less than or equal to 10 microns (i.e. respirable portion).
Both of these standards have short-term and long-term values referred to as 24-hour maximum and the annual average.