pm 2.5
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Introduc)on in PM2.5 measurements in Urban China
(中国城市空气颗粒物PM2.5监测简介)
Roeland Jansen
PhD Student, Fudan University
Green Drinks China, Shanghai, August 9, 2012
My presenta)on
• Introduc)on in PM2.5 • Why people talk about it?
– (为什么人们开始讨论？)
• How to characterize PM2.5? – (PM2.5的特征是什么？)
• Where PM2.5 comes from and where it goes? – (PM2.5的来源和转化？)
• Why some days are nice and most days are not so nice? – (为什么空气质量时好时坏？)
• What can we do with our measurements? – (我们如何进行监测？)
Why people talk about PM2.5 and what are they talking about?
(为什么人们开始讨论研究PM2.5 关于它的关键问题是什么？)
Effect on humans (对人类的影响) • Most harmful for:
• Elderly, • Children (0-‐7 years) and • People with Asthma • People with heart disease
• Most harmful are the “human body unknown species” such as trace elements (=heavy metals) and elemental carbon which are inside PM2.5
• Don’t do any physical ac)vi)es with high PM, don’t go running. Instead go aXer a rain period or period with strong wind.
Effect on the Environment (对环境的影响)
• Dry deposi)on: gravity, wind, buildings, trees • Wet deposi)on: rain, snow, etc.
Global warming effect.
What does PM look like? (PM的结构?)
Aerodynamic diameter “dp”
PM10 dp ≤ 10 μm (about 1/6 of a human hair) PM2.5 dp ≤ 2.5 μm (about 1/24 of a human hair) Expressed in μg/m3
d = 1 cm I = 1 cm3 Inside are up to 10000 par)cles
This means that every breath you take contains about 5000000 par)cles
What does PM look like?
Reprinted from Fu et al., 2012
Names and standards(命名和标准)
• PM = par)culate maber • PM = Aerosols = Par)cles = solid/liquid dispersed in the atmosphere
• Standard comes from Ministry of Environmental Protec)on (MEP) and is
• Annual Average = 35 μg/m3 (2010 BJ: 75 and SH: 50)1
• Compare Annual Average set by USA MEP is 15 μg/m3
1 Ministry of Environmental Protec)on and Shanghai Environmental Monitoring Center
Where does PM2.5 come from? The “Natural” sources (来源)
Sea: NaCl
Desert: SiO2 (=sand)
Vulcano: Sulfate Calcium Aluminium
Where does PM2.5 come from? The human or “Anthropogenic” sources (=harmful)
NOx SO2 VOC OH NH3
Local sources and transport from point sources
Xiamen
Beijing
Nice day! (晴空万里)
Not so nice day!（天气阴霾）
That’s why some days are nice and most are not so nice!
Reprinted from Jacob
Where does PM2.5 go? (沉降过程) • Dry deposi)on: gravity, wind, buildings, trees • Wet deposi)on: rain, snow, etc. • Chemical conversion by oxida)on • Transport in the Environment
Transport in the Environment
Reprinted from NASA (Science vol. 300: 1103-‐1104, 1996) Picture taken at 278 km height
在环境中的迁移
Situa)on in China
0
5
10
15
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25
30
China US EU
Energy use (1.000 TWh) 1990
Data from OECD, IEA
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5
10
15
20
25
30
China US EU
Energy use (1.000 TWh) 1990-‐2008
1990 2008 1990 2008 1990 2008
Data from OECD, IEA
146
20 7 0
20
40
60
80
100
120
140
160
0
5
10
15
20
25
30
China US EU
Energy use (1.000 TWh) 1990-‐2008
1990 2008 1990 2008 1990 2008
Data from OECD, IEA
17 22 5 0
10
20
30
40
50
60
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80
90
100
0
200
400
600
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1400
China US EU
PopulaGon Growth from 1990-‐2008 (million) and in %
1990 2008 1990 2008 1990 2008
Data from OECD/World Bank
111
-‐2 1
-‐10
10
30
50
70
90
110
130
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
China US EU
Energy use (kWh) per capita 1990-‐2008 in %
1990 2008
Effect with Increasing wealth
1990 2008 1990 2008
Data from OECD, IEA and World Bank
Economics and rela)on with the Environment
• Increase in Energy needs is supplied by Coal factories(煤矿厂供应了不断增加的能量需求):
• Burning Coal is a major contribu)on to Air Pollu)on • 70% of the Energy in China is from Coal
• Every 7 to 10 days a new Coal factory opens • 30% of the world (2003)
• Increase in traffic
• Increase in Agriculture • All have a big impact on the environment
Why China is/was so bad? (为什么中国污染这么严重？)
• Lack of Environmental awareness for decades;
– (数十年来缺少环保意识) • Low efficiency of Coal factories;
– (煤矿工厂能效利用率低下) • High-‐pollu)ng vehicles; – (车辆尾气污染严重)
• Economic growth more important than the Environment? – (经济发展利益高于环境利益)
• But things are changing… – (然而情况正在改变…….)
Sample and analyze PM2.5
(PM2.5的采样和分析)
Filter measurements (过滤器监测)
Collected aerosol mass M on filter (eg 24 hrs)
Air Pump Flow control
PM2.5 Inlet MassConc= Mass before-‐ Mass aXer (Mass 24hr-‐Mass t0) / airflow
Eg: 3020 ug – 1100 ug / 1 m3/hr = 80 ug/m3
What’s inside a PM2.5? (PM2.5的组成)
Filter
Collected aerosol mass M on filter (eg 24 hrs)
Air Pump Flow control
PM2.5 Inlet
Filter
Collected aerosol mass M on filter (eg 24 hrs)
Air Pump Flow control
PM2.5 Inlet
General composi)on
Very Harmful!!
Measurements in Shanghai (PM2.5在上海的监测情况)
• 24 sta)ons to monitor PM2.5 – (有24所监测站)
• Scien)sts es)mate that ~50% of PM2.5 comes from vehicle exhaust. – (据科学家估计有约50%的PM2.5来自于汽车尾气)
• Each sta)on costs about 80.000 – 380.000 RMB – (每所监测站的平均费用在80.000 – 380.000 元)
• Hourly data (available for public) – (实时数据（对公众开放）)
Towards a solu)on?
What does the government do (政府有何措施？):
• Eliminate 150.000 high-‐pollu)ng cars by 2014; – (到2014年淘汰150000辆重污染型汽车)
• Improve fuel oil, gasoline and diesel quality; – (提升燃油，汽油，柴油的质量)
• Lower the amount of sulfur in gasoline; – (减少汽油中的含硫量)
• Control of dust in construc)on sites; – (有效控制建筑工地的扬尘)
• Coal-‐fired boilers replaced with cleaner energy hea)ng; – (用清洁能源代替燃烧煤矿资源)
Fudan: 4th Teaching building
Our current research: Visibility
Reprinted from Malm, 1999.
Hangzhou site in ZheJiang Uni
App
• hbp://air.fresh-‐ideas.cc/en/
Thank you!
And special thanks to Annie (刘佳)
SCIENCE:
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