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Data collected on air quality monitoring programs are unusable in the raw form that are collected. It is therefore desirable to summarize the data in ways that make them relatively easy to interpret and use them for regulatory
purposes. In this survey, pollution standard index (PSI) was calculated for five major pollutants (CO, 03, NOx,
S02, PMIO) in Tehran and Isfahan in 1378. The data were classified on the basis of standard air quality chart to levels of: good, moderate, unhealthful for sensitive groups, unhealthful, very unhealthful and hazardous. After
collecting data, analysis was done using Excel, Word and SAS and the results were presented in tables and
charts.
Results indicated that Khordad, Shahrivar, Aban and Bahman in Tehran and Khordad in Isfahan were the most contaminated months. As indicated, in Tehran for 90 percent of days iri 1378 the index was greater than the standard level; for 50 percent, the air quality was very unhealthful and for 4 percent, hazardous. In Isfahan, for 9
percent of days, the index was greater than the standard level; and for 4 percent, the air quality was very
unhealthful. When PSI is more than standard, for 96 percent of days in Tehran and 70 percent in Isfahan, the
responsible pollutant was considered to be Carbon Monoxide the main source of which in cities are cars and
vehicles. Thus, management efforts for air pollution reduction should be focused on transportation control.