 |
What does
the API tell us?
The API ranges from 0 to 500 and is divided into 5 bands according to the
potential effects on health. An API number of 100 is particularly important
since it corresponds to the short-term Air Quality Objective values (i.e.
1-hour and 24-hour limits). An API higher than 100 means that one or more
pollutants may pose immediate health effects to some susceptible members
of our community. It should be noted that for an API in the range of 51 to
100, although immediate health effects are not expected for the general
population, long-term effects are possible if this level of air pollution
persists.
The potential
health effects for different ranges of API values are as follows:
| Air
Quality Status |
Air
Pollution Level |
API |
|
Potential Health
Implications |
| Air
quality significantly worse than both short-term and long-term
AQO values. |
Severe |
201
to 500 |
|
People
with existing heart or respiratory illnesses (such as coronary heart disease
and other cardiovascular diseases, asthma and chronic obstructive airways
diseases including chronic bronchitis and emphysema) may experience
significant aggravation of their symptoms.
There may be also widespread symptoms in the general public.
These include eye irritation, shortness of breath, coughing,
phlegm and sore throat. |
| Air
quality worse than both short-term and long-term AQO values. |
Very
High |
101
to 200 |
|
People
with existing heart or respiratory illnesses (such as coronary heart disease
and other cardiovascular diseases, asthma and chronic obstructive airways
diseases including chronic bronchitis and emphysema) may notice mild
aggravation of their health conditions.
The general public may also notice some discomfort. |
| Air
quality within the short-term AQO values but worse than the long-term AQO values. |
High |
51
to 100 |
|
Very few people,
if any, may notice immediate health effects.
Long-term effects may, however, be observed if exposed at such level persistently for months or years. |
| Air
quality within all AQO values. |
Medium |
26
to 50 |
|
None to the general population. |
| Air
quality well within all AQOs. |
Low |
0
to 25 |
|
None to the general population. |
|
|
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