Hong Kong Air Quality Objectives
Concentration in micrograms per cu bic metre (i)
Pollutant
1 Hour (ii)
8 Hours (iii)
Averaging Time
24 Hours
(iii)
}
Health effects of pollutant at elevated ambient levels
3 Months (iv)
1 Year (iv)
Sulphur Dioxide
800
Total Suspended
CONFIDS
Partial lates
Respirable (v)
Suspended
Particu lates
Nitrogen Dioxide
300
Carbon Monoxide
30,000
10,000
Photoche mi cal Oxidants (as
240
ozone) (vi)
Lead
350
80
Respiratory illness; reduced lung function; morbidity and mortality rates increase at higher levels.
260
80
Respirable fraction has effects on health.
180
55
150
80
Respiratory illness; reduced lung function; cancer risk for certain particles; morbidity and mortality rates increase at higher levels.
Respiratory irritation; increased susceptibility to respiratory infection; lung development impairment.
CONFIDENTIAL
Impairment of co-ordination; deleterious to pregnant women and those with heart and circulatory conditions.
Eye irritation; cough; reduced athletic performance; possible chromosome damage.
1.5
Measured at 298° K (25°C) and 101.325 kPa (one atmosphere).
Affects cell and body processes; likely neuropsychological effects, particularly in children; likely effects on rates of incidence of heart attacks, strokes and hypertension.
Not to be exceeded more than once per year. Arithmetic means.
(i)
(ii)
Not to be exceeded more than three ti mes per year.
(iii)
(iv)
(v)
(vi)
Respirable suspended particulates means suspended particles in air with a nominal aerodynamic diameter of 10 micrometres and smaller.
Photoche mi cal oxidants are determined by measurement of oz one only.
47 -
Table 1
(para. 4.5)