XN000022-1994-01-13 — Page 27

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THURSDAY, JANUARY 13, 1994

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.

AIR POLLUTION LEVELS REMAINED RELATIVELY CONSTANT THROUGHOUT THE MONTH AS A RESULT OF LITTLE CHANGE IN WEATHER CONDITIONS.

HOWEVER,

THERE WERE SOME MINOR VARIATIONS IN AIR QUALITY OVER THE CHRISTMAS HOLIDAYS. ON BOXING DAY, ELEVATED GASEOUS POLLUTANT LEVELS WERE RECORDED.

AS

THE DISPERSION OF AIR POLLUTANTS WAS INHIBITED UNDER A LOW LEVEL INVERSION AND LIGHT WIND SITUATION, AND NO2 LEVELS AT MONG KOK INCREASED SUFFICIENTLY TO BREACH THE 150 UG/CUBIC METER 24-HOUR AIR QUALITY OBJECTIVE.

AGAIN THIS MONTH, LEVELS OF POLLUTANTS WERE GENERALLY HIGHER AT THE STREET-LEVEL SITE OF MONG KOK THAN AT THE OTHER TWO SITES WHICH ARE LOCATED ON ROOF TOPS.

THE FOUR POLLUTANTS DISCUSSED HAVE DIFFERENT ORIGINS. S02 MOSTLY ORIGINATES FROM THE COMBUSTION OF SULPHUR CONTAINING FOSSIL FUELS.

NO2 IS FORMED EITHER DIRECTLY DURING COMBUSTION OR, BY THE ATMOSPHERIC OXIDATION OF NITRIC OXIDE (NO) WHICH IS ALSO PRODUCED DURING COMBUSTION.

VEHICLE EXHAUST IS A MAJOR SOURCE OF NO AND NO2. IT IS ALSO A MAJOR SOURCE OF AIRBORNE PARTICLES; OTHER SOURCES INCLUDE INDUSTRY, FURNACES AND BOILERS, CONSTRUCTION ACTIVITIES, THE SEA AND SOIL DUST.

THE

EPD CURRENTLY MONITORS AIR QUALITY CONTINUOUSLY AT EIGHT STATIONS, INCLUDING THE THREE MENTIONED ABOVE, SHORT-TERM MEASUREMENT CAMPAIGNS ARE ALSO UNDERTAKEN AS AND WHERE THE NEED ARISES.

NOTE TO EDITORS:

FURTHER ENQUIRIES CAN BE DIRECTED TO

PROTECTION OFFICER.

PRINCIPAL ENVIRONMENTAL

MK RAYMOND LEUNG ON TELEPHONE 594 6401.

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