Global review of national ambient air quality standards for PM10 and SO2 (24 h)
Literature comparing national ambient air
quality standards (AAQSs) globally is scattered and sparse.
Twenty-four hour AAQSs for particulate matter <10 μm in
aerodynamic diameter (PM10) and sulfur dioxide (SO2) in 96
countries were identified through literature review, an
international survey, and querying an international legal
database. Eighty three percent, of the 96 countries with
information on the presence or absence of AAQSs, have 24-
h AAQSs for either PM10 or SO2. Slightly more countries
have 24-h AAQSs for SO2 (76 countries) than PM10 (69
countries). The average 24-h AAQSs for PM10 and SO2 are
95 μg/m3 (95% confidence interval [CI], 82–108 μg/m3, n=
68) and 182 μg/m3 (95% CI, 158–205 μg/m3, n=73). The
population-weighted average AAQS for PM10 is 98 and
155 μg/m3 for SO2. The average AAQS for both PM10 and
SO2 are substantially higher than the recommended World
Health Organization Air Quality Guideline (WHO AQG)
value. Several countries have promulgated AAQSs at the
WHO AQG value for PM10, but none for SO2. Further
examination in selected countries found that air quality
monitoring data, existing AAQSs in other countries, environmental
epidemiology studies, and the WHO AQGs are
considered the most often in establishing or revising AAQSs.
