7
-
TUESDAY, OCTOBER 12, 1993
AIR QUALITY REPORT FOR SEPTEMBER
THE ENVIRONMENTAL PROTECTION DEPARTMENT (EPD) TODAY (TUESDAY) RELEASED AIR QUALITY INFORMATION FOR SEPTEMBER.
AN EPD SPOKESMAN SAID THE PURPOSE OF THE ANNOUNCEMENT WAS ΤΟ KEEP THE PUBLIC INFORMED OF THE AIR QUALITY LEVELS IN THE TERRITORY AND TO EXPLAIN THE MEASUREMENTS.
OBTAINED
THE ANNOUNCEMENT NORMALLY CONTAINS MONITORING RESULTS AT ITS MONG KOK, CENTRAL/WESTERN AND KWAI CHUNG MONITORING STATIONS.
THESE LOCATIONS ARE TYPICAL OF THREE OF THE IMPORTANT LAND USE TYPES FOUND IN THE TERRITORY:
LOCATIONS CLOSE TO ROAD TRAFFIC IN BUILT-UP URBAN DISTRICTS,
COMBINED COMMERCIAL AND RESIDENTIAL DISTRICTS, AND
* DISTRICTS CLOSE TO INDUSTRIAL AREAS.
THE REPORTED AIR POLLUTANTS INCLUDE SULPHUR DIOXIDE (SO2), NITROGEN DIOXIDE (NO2), RESPIRABLE SUSPENDED PARTICULATES (RSP) AND TOTAL SUSPENDED PARTICULATES (TSP).
THE GASEOUS POLLUTANTS ARE MONITORED CONTINUOUSLY WHILE PARTICLE SAMPLES ARE COLLECTED FOR 24 HOURS, ONCE EVERY SIX DAYS.
THIS MONTH, THE MEASURED CONCENTRATIONS SHOWED SOME INTERESTING VARIATIONS.
DURING THE FIRST FEW DAYS OF THE MONTH, AIR WAS DRIFTING IN FROM THE NORTH BUT THE WINDSPEEDS WERE LOW. THERE WAS LITTLE RAIN AND PLENTY OF SUNSHINE. THESE CONDITIONS CAUSED POLLUTANT CONCENTRATIONS TO INCREASE AT ALL SITES.
ON SEPTEMBER 1, TSP LEVELS IN MONG KOK WERE ABOUT 80 PER CENT OF THE 260 UG/M3 24-HOUR AIR QUALITY OBJECTIVE,
A.
THE 24-HOUR AQO OF
THE 150
ON SEPTEMBER 3 AND
THE 24-HOUR NO2 LEVELS AT STREET-LEVEL SITE IN MONG KOK HAD EXCEEDED
UG/M3.
THE AIR QUALITY OBJECTIVES ALLOW ONE EXCERDANCE OF THE 24-HOUR LIMIT PER YEAR, THERE HAVE BEEN FOUR THIS YEAR INCLUDING THE TWO REPORTED HERE.
FROM A ROOFTOP MEASUREMENT SITE IN CENTRAL/WESTERN, ALMOST REACHED THE 24-HOUR AQO VALUE ON SEPTEMBER 3.
NO2 LRVELS
THERE WAS ALSO A PEAK IN POLLUTANT CONCENTRATIONS BETWEEN SEPTEMBER 11 AND 15, AGAIN MOSTLY THE RESULT OF LOW WINDSPEEDS ALLOWING LOCALLY EMITTED POLLUTANTS TO ACCUMULATE.
/IN MONG