22
FRIDAY, MARCH 12, 1993
REPORTED THE
AIR POLLUTANTS INCLUDE SULPHUR DIOXIDE (SO2), NITROGEN DIOXIDE (NO2), RESPIRABLE SUSPENDED PARTICULATES TOTAL SUSPENDED PARTICULATES (TSP).
(RSP) AND
CONTINUOUSLY
THE GASEOUS POLLUTANTS ARE MONITORED PARTICLE SAMPLES ARE COLLECTED FOR 24 HOURS, ONCE EVERY SIX DAYS.
IN FRBRUARY, LEVELS OF ALL THE REPORTED POLLUTANTS WERE THE 24-HOUR HONG KONG AIR QUALITY OBJECTIVE (AQO) VALUES.
AT MONG KOK THE LEVEL OF TSP ON FEBRUARY 9 HOWEVER, CLOSE TO THE 24-HOUR LIMIT VALUE OF 260 UG PER CUBIC METER.
AVERAGE
MONTHLY
WHILE
BELOW
WAS VERY
ALL CONCENTRATIONS OF MOST SPECIES AT SITES (APART FROM NO2 AT MONG KOK) WERE WORSE THAN IN THE SAME LAST YEAR, WITH PARTICLE LEVELS BEING SIGNIFICANTLY HIGHER.
PARTICLE
ALL
THREE MONTH
THREE
CONCENTRATIONS FOLLOWED SIMILAR TRENDS AT SITES BUT LEVELS WERE HIGHER AT MONG KOK THAN AT THE OTHER STATIONS.
THIS 18 BECAUSE MONG KOK IS AT STREET LEVEL, AND CLOSE TO VEHICLE EXHAUSTS, AND ALSO BECAUSE THERE ARE A NUMBER OF CONSTRUCTION ACTIVITIES NEARBY.
THEREFORE CONSIDERABLE
THE PEAK OBSERVED AT ALL THREE SITES ON FEBRUARY 9 CANNOT BE EXPLAINED AND REQUIRES FURTHER ANALYSIS.
YET
CONCENTRATIONS
OF
THE GASEOUS SPECIES, S02 AND NO2, WERE SIMILAR AT ALL THREE STATIONS AND FOLLOWED SIMILAR TRENDS.
THIS INDICATES
BY
THAT THE POLLUTANT LEVELS WERE INFLUENCED
BY CONDITIONS AND WERE NOT DOMINATED
LOCAL
GENERAL METEOROLOGICAL SOURCES. FURTHER ANALYSIS OF THESE EVENTS IS ALSO BEING CARRIED OUT.
THE FOUR MOSTLY ORIGINATES FUELS.
POLLUTANTS DISCUSSED HAVE
FROM THE COMBUSTION OF SULPHUR
ORIGINS. DIFFERENT
S02 CONTAINING FOSSIL
NO2
BY OR,
THE DURING COMBUSTION IS FORMED EITHER DIRECTLY
OXIDATION ATMOSPHERIC
18 OF NITRIC OXIDE (NO) WHICH
ALSO PRODUCED DURING COMBUSTION. VEHICLE EXHAUST IS A MAJOR SOURCE OF NO AND NO2.
VEHICLE EXHAUST IS ALSO A MAJOR SOURCE OF AIRBORNE PARTICLES; OTHER SOURCES INCLUDE INDUSTRY,
CONSTRUCTION FURNACES AND BOILERS, ACTIVITIES, THE SEA AND SOIL DUST,
11
THE DEPARTMENT ES MONITORING AIR QUALITY CONTINUOUSLY AT
MEASUREMENT STATIONS, INCLUDING THE THREE MENTIONED ABOVE. SHORT-TERM CAMPAIGNS ARE ALSO UNDERTAKEN AS AND WHERE THE NEED ARISES.
NOTE TO EDITORS:
FURTHER
ENQUIRY
CAN BE DIRECTED
ΤΟ PRINCIPAL
ENVIRONMENTAL
PROTECTION OFFICER, MR R LEUNG ON TEL 594 6401.
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