regional air quality and challenges weeks_seminars pdf/region… · london smog 1952 source:...

Regional Air Quality and

Challenges

Prof. Tao Wang

Department of Civil and Environmental

Engineering

The Hong Kong Polytechnic University

2 May 2013

PolyU Campus Sustainability Weeks

Acknowledgements

• Dr. K.S. Lam at CEE for providing some slides

• The regional air-quality study team at PolyU

• Sponsors:

– Research Grants Council of Hong Kong

– Environment and Conservation Fund, Hong Kong

– Environmental Protection Department, HKSAR

Government

– The Hong Kong Polytechnic University

– Ministry of Science and Technology, China

OUTLINE

1

2

3

4

3

Air pollution control polices

Air pollution level in HK and the PRD

Air pollution basics

Challenge and Research

Air pollution essentials

• The atmosphere contains many gases

– N2, O2, Ar, CO2, water vapor

– 40 trace gases: ozone, helium, hydrogen, nitrogen

oxides

– Aerosols: microscopic liquid or solid particles (dust,

pollen, sea salts, etc.) from land and water

• The Industrial Revolution changed the mixture of

atmospheric gases and particles

• Air pollutants: substances in the atmosphere (gases and

aerosols) that have harmful effects

Three factors determine the

level of air pollution

The amount of pollutants entering the

air

The amount of space into which the

pollution is added

Mechanisms that remove pollutants

from the air

Need to consider emission, meteorology

and chemistry!

Ships

Vehicles Industries

Biogenic sources

NOx SO2 VOCs

Sea salts

Photochemical smog (O3, PAN …)

Haze, acid rain (sulfate, nitrate, SOA)

PM, NOx, VOCs

PM

Regional impact Cross-border impact

Regional

Oxidation Gas-particle conversion

Urban

Emissions

Local vs. regional

pollution

6

Smog: smoke + fog

London smog 1952

Source: British MetOffice Report, 1952

Los Angeles smog (summer)

2013 Beijing winter smog

Air pollutants being

monitored by governments

SO2 (coal burning and ships)

NO2 (NOx=NO+NO2)

CO (vehicle and biomass burning)

O3 (produced in smog)

PM (particulate matter, PM2.5, PM10 (RSP), TSP,

from diverse sources)

Lead (an additive in gasoline)

Have adverse effects on human health and the

environment (e.g. visibility) !

Current air quality objectives

(AQO) in HK

Locations of EPD stations

1. Road side :

Mong Kok

Causeway Bay

Central

2. General urban

3. Sub-urban

Tung Chung

4. Background

Tap Mun

Key air pollutants in Hong

Kong

NO2, RSP, O3

SO2, CO and Lead rarely exceeded the AQO

0

20

40

60

80

100

120

140

NO

2

g/m

3

Stations

Nitrogen Dioxide (NO2)

2011 yearly average

HKAQO

WHO

15

0

10

20

30

40

50

60

70

RS

P (

g/m

3)

Stations

Respirable Suspended Particulate (RSP)

2011 yearly average

HKAQO

WHO

16

0

5

10

15

20

25

30

35

40

45

FS

P (

g/m

3)

Fine Suspended Particulate (FSP)

2011 1-year average

Proposed HKAQO

WHO

0

50

100

150

200

250

300

350

400

Ozo

ne

g/m

3

Station

Ozone (O3)

2011 1-hour average

HKAQO

18

High O3 in sub-urban/rural areas!

0

20

40

60

80

100

120

140

1997 1999 2001 2003 2005 2007 2009 2011

g

/m3

Causeway Bay Station

Trends in ambient air quality in Hong Kong

Roadside

Data comes from HK Environment Protection Dept.

The overall air quality at HK’s roadsides has been improving

NO2

SO2

RSP

19

0

20

40

60

80

100

120

140

1993 1995 1998 2001 2004 2006 2009 2012

g

/m3

Shatin

General


Background levels have been steady


NO2

SO2

RSP

Ozone has been on the rise ! (1994-2010 at Hok Tsui)

Wang et at., ACP, 2009

PolyU background air monitoring station

21

0.52 ppbv/yr

Trend of Reduced Visibility (HKO)

Visibility < 8km, RH < 80%

Source: Hong Kong Observatory

0

200

400

600

800

1000

1200

1400

1600

1800

1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015

Ho

urs

Source: A Clean Air Plan, 2013, Hong Kong Government

Pearl River Delta

Regional Air Quality Monitoring Network

Ambient air pollutants in the region

0

5

10

15

20

25

30

35

40

45

50

μg

/m

3 o

r d

ays

Monitoring Stations

SO2

Annual Average of SO2

Exceedance Days

Class 2 NAAQS(Daily): 150μg/m3

Results from 16 stations in the region

Data comes from A report of PRD Regional Air Quality Monitoring Network Results, 2010

0

10

20

30

40

50

60

70

μg

/m

3 o

r d

ays

Monitoring Stations

NO2

Annual Average of NO2

Exceedance Days




0

20

40

60

80

100

120

μg

/m

3 o

r d

ays

Monitoring Stations

RSP

Annual Average of RSP

Exceedance Days




0

50

100

150

200

250

300

350

400

450

μg

/m

3 o

r h

ou

rs

Monitoring Stations

O3

Maxima Hourly Average of Ozone

Exceedance Hours

Class 2 NAAQS(Hourly): 200μg/m3



Trends in ambient air quality

A regional station South of Guangzhou

But ozone pollution has worsened!

Result from Wanqingsha(万倾沙), 2006-2010

Summary on Air Quality

• Local pollution : roadside

• High NO2, RSP

• Increasing NO2 (due to diesel vehicle)

• Regional smog :

• High ozone, aerosol, poor visibility

• O3 on the rise (complex cause)

Control Policies

• Reducing emissions from:

– Industrial sources (SO2, PM) since 1980s

– Power plants (SO2, PM, NOx) since 1990s

– Vehicles – fuel change, emission-reduction devices, green diesel, tightened standards (mainly in 2000s)

– Volatile organic compounds (VOCs) - architectural paints/coatings, printing inks, consumer products (in 2000s)

Control in Hong Kong

•taxis using

petroleum gas

(08-2000)

•minibuses (08-2002)

•Using EU prophase

or phase I commercial

vehicles.(04-2007)

Vehicle Emissions Control

In 2007 and 2008,

new measures

In 2000, an enhanced

programme

Vehicle Emissions

Control

• dynamometer

smoke test method

to light rail(09-1999)

•to trucks(09-1999)

•particle emission

deduction device

for EU prophase

light vehicles

(09-2000);

•EU prophase

heavy vehicles

(01-2003).

•ultra-low sulfur

diesel (07-2000);

•EU phase V diesel

(12-2007).

•EU standard III

(10-2001);

•EU standard IV

(10-2006);

•penalty for smoky

vehicles (12-2000).

Env. friendly

vehicles

Emission

reduction

devices

Green diesel Tighten

standards Smoke detection

33

• SO2: desulfurization, cleaner energy (广东省环境保护与生态建设“十一五”规划)--

Mar. 2008, other policies started earlier.

• VOCs: emission limits, standard in four

industries (广东省环保厅&广东省质量技术监督) -- Oct. 2010

• NO2: SCR de-NOx, low-NOx burners (广东省“十二五”规划)--Feb. 2011

Control in Guangdong

• Oct. 2008: Policy of Vehicle Emissions Reduction Technology《机动车排放污染防治技术政策》

• Sept. 2009: Comprehensive Management of Petrol Vapour Recovery Program《广东省油气回收综合治理工作方案》

• Sept. 2009: Regulations of Motor Vehicle Environmental Classification Marks《广东机动车环保分类标志管理办法》

• July 2010: Control Regulations of Motor Vehicle Emissions 《广东省机动车排气污染防治条例》

Vehicle Emissions Control in GD

Documents come from Dept. Of Environmental Protection of Guangdong Province

“Double-shifting”(双转移) Policy

• May 2008

• 《 Promotion in Industry and Labor Transfer》（《中共广东省委、广东省人民政府关于推进产业转移和劳动力转移的决定》)

• 《Guidance to the Regional Distribution of Industrial

Transfer 》（《广东省产业转移区域布局指导意见》）issued by Guangdong Economic and Trade Commission- Guangdong Economic and

Trade Industry [2008]385th

Specific Measures of “Double-shifting” Policy

Labor-intensive and resource-based industries are transferred to the mountainous

region of Guangdong; high-quality work force is transferred to the Pearl River Delta.

Labor-intensive and resource-based industries are transferred to the mountainous

region of Guangdong; high-quality work force is transferred to the Pearl River Delta.

Specific Measures of “Double-shifting” Policy

Challenges Roadside pollution remains serious plan to target diesel vehicles

Regional photochemical smog has

worsened more complex (NOx vs VOCs, long-range

transport etc)

Impact of ‘relocating’ pollution to other

places

Regional air quality research at PolyU

Tai O

2000~2001 Hok Tsui

1993~ Now

Mt. Heng

2009

Linan

1999~2000

Taicang

2005

Lanzhou

2006

Mt. Waliguan

2003&2006 Mt. Tai

2003~2009

Beijing

2005&2008

Linan

Taicang

Mt. Heng

Lanzhou

Tai O Hok Tsui

Mt. Waliguan Beijing Mt. Tai

Mt. Tai Moshan

Mt. Tai Mo

2010

Studies in Hong Kong and mainland China

Advanced instrumentation and models

42

Gas

Aerosol

Research Objectives

Understand fundamental atmospheric

processes in regional pollution in the

unique Asian environment

Policy relevant:

• Local vs long-range transport

• Key chemicals forming ozone and haze

• Source of air pollutants

PolyU

Hok Tsui Tung Chung

PolyU scientists lead effort to tackle

smog pollution

2010~2014 (HK$6.55M

from ECF)

Thank You

This is the blue sky in summer

• Funding：MOST (国家科技部)，RMB 25 M

• Period：2005-2010

• Institutions：北京大学，清华大学,中科院大气物理研究所，中科院生态研究中心，中国环境科学研究院，中国气象科学研究院，北京师范大学

National Basic Research Project (973) 国家重点基础研究发展规划项目《中国酸雨沉降机制、输送态势及调控原理》

• Study the cause and impact of

acid rain pollution in China

• Recommend control strategy

Observations

Simulation

Vice environment minister,

Wu Xiaoqing （吴晓青）,

visited the facility in July

2008

Improving the air quality during the Beijing Olympics

http://www.craes.cn/p/2008-07/29/200807291552395.jpg

Consultancy projects from

HKEPD Ozone pollution（2000-2002）

Visibility（2003-2004）

VOC control (2007-2010）

PRD Industrial Pollution (2007-10)

Atmospheric oxidants (2010-2012)

HK photochemical smog (2011-2013)

Results have been used in the formulation of HK’s new Air Quality Objective and air-pollution control regulation

Energy consumption in Guangdong

En

erg

y c

on

su

mp

tio

n

(10

00

0 to

ns o

f S

CE

)

GDP in Guangdong

GD

P (

10

0M

RM

B)

PRD Area: 41,698 km2

Pop.:47.8M (2009)

GDP: ￥3.21Tril

HK Area: 1,104 km2

Pop.: 7.10M (2011)

GDP: HK$ 1.89Tril.

NO2 Data for the map were obtained by SCIAMACHY onboard the European Space Agency’s Envisat

satellite.

HK and PRD – an air pollution hot spot

Asia Europe North America

Low← Pollution →High Image: University of Heidelberg

A world manufacturing center

• Long-range transport?

• Emission change in NOx and VOCs?

• Increased photolysis due to lower

PM?

Why has O3 pollution worsened?

PolyU academics contributing to air-quality improvement

Progress of “Double-shifting” Policy

Data comes from the Economic & Information Commission of Guangdong Province

Transferred Industries

Industrial Output Value

For East, West and Northern

Guangdong (unit: 100 million Yuan)

54

Impact of “Double-shifting” Policy

NO2 and SO2: center PRD dropped; outside increased

Data for march

Center area: Luhu Park, Wanqingsha, Tianh, Liyuan,

Tangjia, Jinjuzui, Huijingcheng, Donghu, Chengzhong,

Haogang, Zimaling Park

Outside area: Jinguowan, Xiapu

0

10

20

30

40

50

60

70

80

2008 2009 2010

center_NO2

outside_NO2

NO2 (unit:μg/m3)

0

10

20

30

40

50

60

70

80

2008 2009 2010

center_SO2

outside_SO2

SO2

55

SO2: China Statistics Yearbook;

NOx: Zhang Q., et al.,2006, 2009 and Lamsal L. N. et al., 2011;

VOCs: Ohara, T., et al., 2009 and Zhang Q., et al., 2009

Emission trends of China

Outlook: SO2 (acid rain,PM)↓, NOx?, VOCs ↑ O3↑

Future Outlook More control on photochemical pollution !

56

0

20

40

60

80

100

120

140

Em

issio

n(1

00

00

to

nn

es)

Year

Guangdong

0

5

10

15

20

Em

issio

n(1

00

00

to

nn

es)

Year

Hong Kong

Annual SO2 Emissions

Data comes from China Statistical Yearbook and HK Environmental Protection Dept. 57

Emissions of major pollutants in HK

Data comes from HK Environment Protection Dept. 58

Research

59

Cutting-edge research

Address fundamental science in a highly oxidative subtropical

environment and all essential elements in smog-pollution

control

Core research areas (1/5)

• New analytical techniques

(e.g., OH and NO3)

• Improved satellite retrievals

• Models with new processes

• Inter-comparison of measurements and models

Cutting-edge new instruments/methods to

study the core of atmospheric chemistry

– previously not available in HK-PRD

• Emission factors/source profiles (anthropogenic and biogenic)

• Model-ready emission inventory

• Validation and uncertainty

• Emission projection

Most complete emission info. – key to

research and control


• Surface and Mount-top supersites

• Ship-based measurements

• Aircraft measurements

• Land/Satellite-based remote sensing


Tung Chung

Mt. Tai Mo

HK-PRD air monitoring

Network •O3, CO, SO2, PM

Surface supersite •Comprehensive species

Mountain supersite • Comprehensive species

Ship • Comprehensive species

Aircraft • Key species

Satellite • Species column

Multi-platform Observation System

The innovative system will provide

unprecedented data for model validations

• Chamber studies

• Source apportionments

• Meteorological simulations

• Photochemical box model

• Fundamental chemistry

• Chemical transport models

• Control options

The multiple models will

provide most reliable

source contributions and

control options


• HK-PRD collaboration

• Public engagement

• Policy recommendation

Strong stakeholder

engagement will ensure

the translation of cutting-

edge science to policy


PolyU

Hok Tsui Tung Chung

On-going ECF funded research on ozone

2010~2014 (HK$6.55M)

67

Growth of Motor Vehicles Guangdong

Ve

hic

le a

mo

un

t(10

th

ou

sa

nd

)

Hong Kong

Data comes from China Statistical Yearbook and HK Transport Dept.

68

0

200

400

600

800

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

Veh

icle

Nu

mb

ers

(T

ho

us

an

ds)

Nitrogen Dioxide (NO2)

2011 1-hour AQO Exceedance

Year CW Eastern

Kwai

Chung

Kwun

Tong

Sham

Shui Po

Tsuen

Wan Sha Tin Tai Po

Tung

Chung

Yuen

Long

Tap

Mun

Causew

ay Bay Central

Mong

Kok

1996 0 0 1 1 0 0 0

1997 0 2 0 0 0 0

1998 0 0 0 0 0 0 0 0 0

1999 0 0 3 1 0 5 0 0 4 2 0 7 3

2000 3 0 0 0 0 0 0 0 0 0 0 1 8

2001 0 0 1 0 0 0 0 0 0 0 0 1 7 0

2002 0 0 0 2 0 0 0 0 0 0 0 0 7 1

2003 4 0 7 3 4 0 0 0 0 0 4 9 5

2004 0 0 0 0 0 0 0 0 0 2 0 0 15 7

2005 2 0 0 0 0 0 0 0 0 0 0 5 10 1

2006 0 0 0 0 0 0 0 3 0 2 0 3 10 6

2007 0 0 0 2 0 0 0 0 0 0 0 6 9 8

2008 0 0 0 0 0 0 0 0 0 0 0 0 10 1

2009 0 0 0 0 0 0 0 0 0 0 0 14 31 12

2010 0 0 0 0 1 0 0 0 0 0 0 48 58 21

2011 0 0 0 0 0 0 0 0 0 0 0 77 57 34 69

Ozone (O3)

2011 1-hour AQO Exceedance

Year CW Eastern

Kwai

Chung

Kwun

Tong

Sham

Shui Po

Tsuen

Wan Sha Tin Tai Po

Tung

Chung

Yuen

Long Tap Mun

1996 5 3

1997 1 0 0 0

1998 0 0 0 0 0 0 0 0

1999 2 0 0 0 0 0 4 0 7 0 8

2000 1 0 0 0 0 0 2 0 8 0 1

2001 1 0 0 0 0 1 2 3 21 0 7

2002 1 0 0 0 1 1 0 1 33 0 3

2003 0 0 0 0 0 1 2 2 26 0 13

2004 12 0 0 0 2 3 10 0 70 9 7

2005 9 0 0 1 2 2 11 0 24 13 26

2006 5 0 0 0 3 1 5 4 15 13 23

2007 5 0 0 0 0 0 11 0 11 13 15

2008 4 0 0 0 1 1 9 0 32 8 14

2009 7 2 1 1 0 0 7 8 20 12 11

2010 5 2 1 0 2 1 3 0 17 7 6

2011 5 1 0 0 1 0 1 0 38 16 15 70

SO2

1. AQO never exceeded in Hong Kong.

2. 1990 limiting S content of industrial fuel.

3. 1997 prohibit new coal-fire power generators.

4. 2008 mandatory ultra low S diesel.

5. 2011 Castle Peak Nox/SO2 scrubber.

6. Control of SO2 in HK is very successful.

71

0

5000

10000

15000

20000

25000

30000

Carbon Monoxide (CO)

2011 1-hour average

HKAQO

72

CO

1. CO is a toxic gas at high concentration.

2. It is emitted by combustion processes.

3. CO is about 1000 g/m3 at roadside.

4. 1-hour AQO of CO is 30000 g/m3 .

5. CO never exceeded AQO in Hong Kong.

73

NO2

1. NO2 is a toxic gas.

2.1-hour AQO of NO2 is 300 g/m3.

3.24-hour AQO of NO2 is 80 g/m3.

4. Roadside NO2

1.> 1-hour AQO;

2.> 24 hr AQO

5.General stations’ NO2 are

1.Mostly < 1-hour AQO but close.

6.TAP Mun never exceeds any AQO.

7. NO2 is basically a local problem.

74

RSP

1. RSP are particulates harmful to health.

2. Annual AQO of RSP is 55 g/m3.

3. Roadside RSP

1.> 1-yr AQO

4.General stations’ RSP are

1.< 1-yr AQO but close.

2.Could exceed AQO a few times each year.

5.TAP Mun RSP is also similar to other general

stations and close to AQO.

6.There is a high level of particulate over the entire

Hong Kong.

7.RSP is a regional problem. 75

Ozone O3

1. Ozone is an indicator of Photochemical smog.

2. 1-hour AQO of O3 is 240 g/m3.

3. Roadside O3

1.Never exceed AQO

4.General stations’ O3 are mostly

1.< 1-hour AQO but.

2.Could exceed AQO a few times each year.

5.Tung Chung, Yuen Long, and TAP Mun RSP are

particularly high in number of exceedance.

6.TC (38 hours per year); TM (15 hours per year).

7.Photochemical smog is episodic and is a

regional problem. 76

0

20

40

60

80

100

120

140

1998 2000 2002 2004 2006 2008 2010 2012

g

/m3

Tap Mun Station

Rural


Background levels have been steady


NO2

SO2

RSP

77

Visibility of HK Airport

78

Visibility

1. Number of poor visibility days has been rising in

the pass 2 decades.

2. HK air quality problems are:

1.Local emissions poor roadside air quality

2.Regional emissions episodic poor visibility

events – smog & photochemical smog.

3. Poor roadside air quality is a local problem.

4. Smog and Photochemical smog are regional

problems.

79

0

10

20

30

40

50

60

70

80

90

0 5 10 15 20 25

ug

/m3

Time of Day

Diurnal Variation of RSP - Year 2011

Roadside RSP at morning hours is less than 55 µg/m3

Local against Regional

80

Causeway Bay

Tap Mun

Local against Regional

0

20

40

60

80

100

120

140

160

180

0 5 10 15 20 25

ug

/m3

Time of Day

Diurnal Variation of NO2 - Year 2011

Causeway Bay

Tap Mun

Roadside NO2 at morning hours is less than 80 µg/m3

81