PB
Lead is an accumulative neurotoxin associated with cognitive defects in children and infants.
The inclusion of lead as an air pollutant is primarily a consequence of its usage as a pigment in paints, and the use of tetraethyl lead as an antiknocking agent in gasoline.
With widespread controls on lead usage and the introduction of unleaded petrol, ambient lead levels have fallen dramatically (>95%) in developed nations, although releases still occur primarily associated with metal production and certain formulations of aviation fuel.
Levels of lead (and other heavy metal pollutants) are usually determined by use of air filtration to collect a sample (on aerosol), followed by elemental analytical determination using techniques such as X-ray fluorescence, instrumental neutron, or inductivity coupled plasma mass spectrometry (ICP-MS).