30 Eye Opening Photos of Environmental Pollution

Criteria gases include carbon monoxide (CO), sulphur dioxide (SO2), nitrogen dioxide (NO2) and ozone (O3); criteria particles are denoted by their size range, with PM10 and PM2.5 denoting the mass concentration of particles smaller than 10 micrometres (millionths of a metre) or 2.5 micrometres, respectively. Hazardous air pollutants are toxic chemicals, for example, benzene and arsenic.