XN000022-1994-08-12 — Page 17

FRIDAY, AUGUST 12, 1994

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THE EXCEPTION TO THIS WAS SOME HIGHER CONCENTRATIONS ON JULY 10 (AT MONG KOK, TOTAL SUSPENDED PARTICULATE LEVELS WERE 95 PER CENT OF THE 24-HOUR STANDARD).

THESE HIGHER LEVELS AROSE BECAUSE ON JULY 9 AND 10 THERE WAS LITTLE RAINFALL AND WIND, AND SUNSHINE LEVELS WERE HIGH.

THESE ARE

HONG KONG,

CONDITIONS THAT OFTEN LEAD TO POOR AIR QUALITY IN

THE GASES AND PARTICLES DESCRIBED ORIGINATE FROM VARIOUS SOURCES. SO2 IS MOSTLY PRODUCED WHEN FUELS THAT CONTAIN SULPHUR ARE BURNED. NOZ IS FORMED DURING COMBUSTION BY THE COMBINATION OF NITROGEN AND OXYGEN.

HOWEVER THE MAJORITY OF IT IS FORMED IN THE ATMOSPHERE BY THE OXIDATION OF NITRIC OXIDE (NO), ALSO A PRODUCT OF COMBUSTION.

VEHICLE EXHAUSTS ARE IMPORTANT SOURCES OF NO AND NO2 IN TERMS OF IMPACT ON LOCAL AIR QUALITY.

THESE EXHAUSTS ARE ALSO A MAJOR SOURCE OF AIRBORNE MATTER, ESPECIALLY THE SMALLER RESPIRABLE PARTICLES.

OTHER SOURCES OF PARTICLES INCLUDE INDUSTRY, BOILERS, CONSTRUCTION ACTIVITIES, THE SEA AND THE SOIL.

IT

PARTICULATE

FURNACES AND

IS WORTH NOTING THAT WHILE THE WEATHER AND CLIMATE ALWAYS AFFECT CONCENTRATIONS OF POLLUTANTS IN THE AIR, THE ONLY SURE WAY OF REDUCING THE LEVELS IS TO REDUCE EMISSIONS FROM THE MAN-MADE SOURCES.

NOTE TO EDITORS:

FOR

AIR QUALITY

AND FURTHER INFORMATION ON THIS AIR QUALITY REPORT

PRINCIPAL ISSUES, PLEASE CONTACT ACTING PROTECTION OFFICER MR S W PANG ON TEL 594 6401.

OTHER

ENVIRONMENTAL

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