A mathematical combination of the concentrations of air pollutants (weighted in some
fashion to reflect the estimated health impact of the specific pollutant) which gives
an approximate numerical measure of the quality of the air at a given time. These
indices have little scientific basis but have been used to inform the public (in a
qualitative fashion) of the degree of pollution present at a given time. It is recommended
that the actual measured pollutant concentrations be used by all information services
when possible with simultaneous reference given to the corresponding concentrations
which are considered by health authorities to be hazardous to human health.
PAC, 1990, 62, 2167
(Glossary of atmospheric chemistry terms (Recommendations 1990))
on page 2172
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A.Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. https://doi.org/10.1351/goldbook