Air Quality Monitoring Network Management in Hong Kong Peter Louie and Chris Cheung Environmental Protection Department, Hong Kong SAR Government Better Air Quality 2002

1. Network Management 2. Air Quality Monitoring Network 3. Data Processing and Dissemination 4. Quality Assurance System CONTENTS

 Ambient air pollution  Occurs occasionally under calm weather condition  “Smog” caused by emissions from both HK and the South China region Air Pollution Issues

General Picture of HK’s Air Quality  Levels of major pollutants Low levelLead Low levelSulphur dioxide Low levelCarbon monoxide On a rising trendOzone High level at roadside [exceeded long-term (1 year) AQO] Nitrogen dioxide High level at roadside [exceeded long-term (1 year) AQO] Respirable suspended particulates

NETWORK MANAGEMENT Contractor Operated Stations EPD 5 x 9 x EPD Operated Stations Contract Management QA/QC Works

HI-VOL SAMPLERS WET/DRY DEPOSITION SAMPLER PARTICULATE MONITOR OPEN PATH ANALYZER METEOROLOGICAL MONITORS POINT ANALYZER AIR QUALITY MONITORING NETWORK Roadside Station General Station 塔門 Tap Mun 東涌 Tung Chung 東區 Eastern 銅鑼灣 Causeway Bay 中西區 Central / Western 旺角 Mong Kok 荃灣 Tsuen Wan 觀塘 Kwun Tong 大埔 Tai Po 元朗 Yuen Long 葵涌 Kwai Chung 沙田 Sha Tin 深水  Sham Shui Po 中區 Central ■ ■ ■ ■ General Station With TAP samplers

Air Monitoring Station (Central & Western)

Ambient Air Quality Monitoring Station (Tsuen Wan)

Air Monitoring Station (Tsuen Wan)

TAPs Monitoring Station (Tsuen Wan)

Roadside Station (Mong Kok)

DATA PROCESSING AND DISSEMINATION AIR QUALITY DATA MANAGEMENT SYSTEM 2000 AIR QUALITY IN HONG KONG AIR QUALITY REPORT INTERNET WEBSITE GRAVIMETRIC ANALYSIS ELEMENTAL ANALYSIS DATEL LINE API REPORTING SYSTEM API HOTLINE ： GENERAL API ROADSINE API INTERNET WEBSITE HI-VOL SAMPLERS WET/DRY DEPOSITION SAMPLER PARTICULATE MONITOR OPEN PATH ANALYZER METEOROLOGICAL MONITORS POINT ANALYZER REMOTE DATA LOGGING SYSTEM CENTRAL DATA MANAGEMENT SYSTEM Station A API 84...

空氣污染指數 Air Pollution Index API

空氣污染指數的目的 PURPOSES OF AIR POLLUTION INDEX 提供快捷而簡單的空氣污染資料 Provide timely and simple information on air pollution 1.1. 在空氣污染事件未發生前, 給予市民忠告 Advise people before the onset of air pollution incidents 2.2.

AIR POLLUTION INDEX BANDS Severe VeryHigh High Medium Low More than two times the short-term AQO value Between 1 to 2 times the short-term AQO value Between half and 1 time the short- term AQO value Between half and 1 time the long-term or 50% of short-term AQO value Less than 50% of long-term or 25% of short-term AQO value *Short-term - 1 hr or 24 hrs average Long-term - 1 year average

QUALITY ASSURANCE QUALITY CONTROL QUALITY ASSESSMENT Applies in …………….. Site Selection Precision of Equipment Equipment Calibration Equipment Maintenance Applies in …………….. Site Selection Precision of Equipment Equipment Calibration Equipment Maintenance Includes…………………. Routine Precision Checks Performance Audits System Audits Includes…………………. Routine Precision Checks Performance Audits System Audits

Types of Quality Control : QC and QA Quality Control –control the quality by field and data processing staff (responsible for daily operation of sampling network) Quality Assurance –control the quality by QA staff (not involved in daily sampling work)

Quality Control (QC) Precision checks - gases : biweekly one point check - particulates : collocated sampling for Hi- vol samplers - Control limits : 20% for gases 10% for particulates

Quality Assurance (QA) Accuracy - Performance Audit by QA staff Traceability System Audit Inter-laboratory Comparison

System Audit Documentation & labeling Data processing Vertical audit Training - check the competence & annual reassessment records - observe operation at site Safety Site environment

Conclusions EPD’s Air Quality Monitoring Network is managed by using a combination of quality assurance system and out-sourcing arrangement Better understanding of air pollution issues Cost-effective policies and solutions can be developed

END 完 Thank You 謝謝