XN000022-1993-07-12 — Page 21

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MONDAY, JULY 12, 1993

THE EPD ANALYSIS FOR THAT DAY REVEALED THAT DISPERSION OWING TO LOW WIND SPEED, COUPLING WITH DURING THE DAY, PROVIDED FAVOURABLE CONDITIONS FOR NITRIC OXIDE IN THE AIR TO NITROGEN DIOXIDE.

A POOR POLLUTANT ABUNDANT SUNSHINE

THE OXIDATION OF

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. VEHICLE EXHAUST 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 11 STATIONS, INCLUDING THE THREE MENTIONED ABOVE. SHORT-TERM MEASUREMENT CAMPAIGNS ARE ALSO UNDERTAKEN AS AND WHERE THE NEED ARISES.

NOTE TO EDITORS:

FURTHER ENQUIRY CAN BE DIRECTED то PRINCIPAL ENVIRONMENTAL PROTECTION OFFICER, MR W S TSUI, ON TEL. 594 6401.

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WATER STORAGE FIGURE

STORAGE IN HONG KONG'S RESERVOIRS AT 9 AM TODAY (MONDAY) STOOD AT 72.2 PER CENT OF CAPACITY OR 423.067 MILLION CUBIC METRES.

465.465 MILLION

THIS TIME LAST YEAR THE RESERVOIRS CONTAINED CUBIC METRES OF WATER, REPRESENTING 79.4 PER CENT OF CAPACITY.

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