Particulate Matter (PM) Standards in Asia

Transcription

1 Particulate Matter (PM) Standards in Asia Particulate Matter (PM) is a complex mixture of extremely small solids and liquid droplets. It is made up of a number of components, including acids (such as nitrates and sulfates), organic chemicals, metals, and soil or dust particles (US EPA, 2010). Their properties are often categorized according to aerodynamic particle diameter in micrometers (See Figure 1). All current air quality standards for particles within and outside Asia refer to the weight of particles measured in units of μg/m 3. TSP and black smoke were used as indicators of airborne particles in the past but TSP has lost relevance because these can be filtered by nose and mouth. PM 10 and PM 2.5 is preferred for more targeted response to the problems related with PM exposure as they are more dangerous to public health. PM Standards in Asia Figure 1. The size of various particles in comparison to the width of a human hair. Of the 19 countries and one city surveyed in 2009 and 2010, CAI-Asia found that four countries (Afghanistan, Cambodia, Lao PDR and Myanmar) still has to establish air quality standards. Table 1. Categories of PM according to size Type TSP Size Particles with aerodynamic diameter between micrometers While most Asian countries have adopted the PM 10 standard in differing degrees, more is needed in the development of a PM 2.5 standard. Several Asian countries have more lenient PM 10 and PM 2.5 standards when compared with European Union Air Quality Standards (EU AQS), World Health Organization (WHO) Air Quality Guidelines, and United States Environmental Protection Agency (USEPA) National Ambient Air Quality Standards (NAAQS). PM 10 PM 2.5 Ultrafines World Health Organization (WHO) Ambient Air Quality Guidelines Particles with aerodynamic diameters less than 10 micrometers which may reach the upper part of the airways and lung. Particles with aerodynamic diameters 2.5 micrometers and smaller regarded as more dangerous because they penetrate more deeply into the lungs and may reach the alveolar region Particles with aerodynamic diameters 0.1 micrometers and smaller Source: SEI, 2008a. Previous versions of WHO Ambient Air Quality Guidelines (e.g. in 2000) did not provide guidelines for particles, as it is considered unlikely that a threshold level within which particles have no harmful effects can be found. In the revised 2005 Guidelines however, WHO made use of the link between exposure and effects to establish limit values. WHO also introduced interim targets (IT), levels of which indicate specified mortality responses based on published risk coefficients from multi-centre studies and meta-analyses (Table 2).

2 Table 2. WHO Air Quality Guideline (AQG) and Interim Targets: Basis of Selected Level for 24-hr Mean Annual Mean Levels Standard (µg/m 3 ) Standard (µg/m 3 ) Category PM 10 PM hr PM 10 PM 2.5 Annual Levels associated with about 5% increase of short-term Levels associated with about 15% higher longterm mortality risk relative to the AQG level. IT mortality risk relative to AQG value. IT IT WHO AQG Levels associated with about 2.5% increase of short-term mortality over the AQG value. Levels associated with about 1.2% increase in short-term mortality over the AQG value. Based on relationship between 24-hour and annual PM levels Table 2. Summary of PM (TSP, PM 10, PM 2.5 ) Standards in Select Asian Countries (µg/m 3 ) 2 In addition to other health benefits, these levels lower the risk of premature mortality by approximately 6% [2 11%] relative to the IT-1 level. In addition to other health benefits, these levels reduce the mortality risk further by approximately 6% [2-11%] relative to the IT-2 level. Lowest levels at which total, cardiopulmonary and lung cancer mortality have been shown to increase with more than 95% confidence in response to long-term exposure to PM 2.5 Countries TSP 24-hr TSP Annual PM hr PM 10 Annual PM hr PM 2.5 Annual Afghanistan Bangladesh Bhutan (Industrial) Bhutan (Mixed) Bhutan (Sensitive) Cambodia China: Grade I China: Grade II China: Grade III Hong Kong SAR Hong Kong SAR India India Indonesia Lao PDR Malaysia Mongolia Myanmar Nepal Pakistan Pakistan Philippines Republic of Korea Singapore Sri Lanka Thailand Viet Nam

3 Countries 3 Notes for Figure 1. 1 = Proposed air quality objectives for Hong Kong SAR. 2 = NAAQS for Industrial, Residential, Rural and Other Areas 3 = NAAQS for Ecologically Sensitive Areas (notified by Central Government) 4 = Draft: Effective from 1st Jan 09 5 = Draft: Effective from 1st Jan 2012 PM 10 All current PM 10 standards in Asia including USEPA's PM 10 limits for 24-hour and annual averaging periods are more lenient than WHO guidelines. Figure hr PM 10 Standards in Asian countries vs. WHO AQG, US EPA and EU NAAQS. China: Grade I Bhutan (Sensitive) Sri Lanka Hong Kong SAR* India*** India** Republic of Korea Bhutan (Mixed) Thailand Nepal Singapore Pakistan ***** Bangladesh Mongolia Viet Nam Philippines Malaysia Indonesia China: Grade II Hong Kong SAR Bhutan (Industrial) Pakistan**** China: Grade III Myanmar Lao PDR Cambodia Afghanistan EU 50 µg/m 3 WHO IT-3 75 µg/m 3 US EPA 150 µg/m 3 WHO AQG 50 µg/m 3 WHO IT µg/m 3 WHO IT µg/m Hr PM 10 Standard (µg/m 3 ) Notes for Figure 2.

4 Countries 4 Figure 3. Annual PM 10 Standards in Asian countries vs. WHO AQG and EU NAAQS. China: Grade I Bhutan (Sensitive) Sri Lanka Hong Kong SAR* Republic of Korea Thailand Bangladesh Mongolia Viet Nam Malaysia Hong Kong SAR India*** India** Bhutan (Mixed) Philippines China: Grade II Pakistan ***** Bhutan (Industrial) China: Grade III Pakistan**** Nepal Singapore Indonesia Myanmar Lao PDR Cambodia Afghanistan WHO AQG 20 µg/m 3 WHO IT-3 30 µg/m 3 WHO IT-2 50 µg/m 3 EU 40 µg/m 3 WHO IT-1 70 µg/m Annual PM 10 Standard (µg/m 3 ) Notes for Figure 3.

5 Countries 5 PM 2.5 Asian countries are slowly moving towards developing PM 2.5 but there is still a long way to go. Of the 20 countries included in the review, only seven have PM 2.5 standards (note: Hong Kong and Pakistan are still in the process of formally approving proposed standards). Figure Hr PM 10 Standards in Asian countries vs. WHO AQG, US EPA and EU NAAQS. Singapore Pakistan ***** Pakistan**** Sri Lanka Mongolia India*** India** Bangladesh Hong Kong SAR* Viet Nam Thailand Republic of Korea Philippines Nepal Myanmar Malaysia Lao PDR Indonesia Hong Kong SAR China: Grade III China: Grade II China: Grade I Cambodia Bhutan (Sensitive) Bhutan (Mixed) Bhutan (Industrial) Afghanistan WHO AQG 25 µg/m 3 US EPA 35 µg/m 3 WHO IT-2 50 µg/m 3 WHO IT µg/m 3 WHO IT-1 70 µg/m hr PM 10 Standard (µg/m 3 ) Notes for Figure 4.

6 Countries 6 Figure 5. Annual PM 2.5 Standards in Asian countries vs. WHO AQG, US EPA and EU NAAQS. Singapore Pakistan ***** Bangladesh Pakistan**** Sri Lanka Mongolia Hong Kong SAR* India*** India** Viet Nam Thailand Republic of Korea Philippines Nepal Myanmar Malaysia Lao PDR Indonesia Hong Kong SAR China: Grade III China: Grade II China: Grade I Cambodia Bhutan (Sensitive) Bhutan (Mixed) Bhutan (Industrial) Afghanistan WHO AQG WHO IT-2 WHO IT-1 10 µg/m 3 25 µg/m 3 35 µg/m 3 WHO IT-3 15 µg/m 3 US EPA 15 µg/m 3 EU 25 µg/m Annual PM 10 Standard (µg/m 3 ) Notes for Figure 5.

7 7 TSP The use of PM 10 and PM 2.5 is preferred for a more targeted response to the problems related with PM exposure. These smaller particles are more dangerous since they have direct entry into the human body. TSP lost relevance since most of the particles it covers can be trapped outside by the nose and mouth. TSP has been phased out by the EU, WHO and US EPA. Many in Asia are slowly making the transition to adoption of PM 10 standards and are slowly phasing out the use of TSP. Figure Hr TSP Standards in Asian Countries Notes for Figure 6.

8 8 Figure 7. Annual TSP Standards in Asian Countries Notes for Figure 7. References Clean Air Initiative for Asian Cities (CAI-Asia) Center, Air Quality in Asia: Status and Trends 2010 US EPA Particulate Matter. Schwela, Dieter, Haq, Gary, Huizenga, Cornie, Han, Wha-Jin, Fabian Herbert, Ajero, May, Urban Air Pollution in Asian Cities. United Kingdom SEI, Foundation Course on Air Quality Management. WHO, WHO Air Quality Guidelines Global Update 2005 Particulate matter, ozone, nitrogen dioxide and sulphur dioxide. World Health Organization, Regional Office for Europe, Copenhagen Clean Air Initiative for Asian Cities Center. All rights reserved. CAI-Asia, Factsheet No. 2 Particulate Matter (PM) Standards in Asia. Pasig City, Philippines. CAI-Asia Center Robinsons-Equitable Tower, ADB Avenue, Pasig City 1605 Metro Manila, Philippines Tel /Fax , center@cai-asia.org