Pollutant Standards Index (PSI)(空氣污染指標)line分享列印本頁
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A. Definition

The index is based on measurements of the concentrations of five pollutants: PM 10 (particulate matter of 10 micrometers or less), sulfur dioxide, carbon monoxide, nitrogen dioxide, and ozone. Air quality standards have been developed for each of these. For each pollutant, a value of 100 is assigned to the maximum permitted concentration of that pollutant. After determining a value for each of the five pollutants, the highest of the five numbers is reported as the pollutant standards index (PSI) for the day.

Conversion of the concentration of pollutants to index:
PSI PM 10 : average in 24 hours?? SO 2 : average in 24 hours CO : the maximum of average of 8 hours in a day 24 O 3 : maximum in 24 hours?? NO 2 : maximum in 24 hours
?μ g/m 3 ppb ppm ppb ppb
50 50 30 45 60 -
100 150 140 9 120 -
200 350 300 15 200 600
300 420 600 30 400 1200
400 500 800 40 500 1600
500 600 1000 50 600 2000

General health effects:
PSI 0~50 51~100 101~199 200~299 >=300
Descriptor ?Good Moderate Unhealthy Very Unhealthy Hazardous
Color descriptor
General health effects None Few or none for the general population. Mild aggravation of symptoms among susceptible people, with irritation symptoms in the healthy population. Significant aggravation of symptoms and decreased exercise tolerance in persons with heart or lung disease; widespread symptoms in the healthy population. Early onset of certain diseases in addition to significant aggravation of symptoms and decreased exercise tolerance in healthy persons. At PSI levels above 400, premature death of ill and elderly persons may result. Healthy people experience adverse symptoms that affect normal activity.
Source:
Environmental Protection Administration, R.O.C.(Taiwan)
Updated:
2018-07-04
Hit:
345
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