Remote sensing of environment and disaster laboratory

Institute of Industrial Science, The University of Tokyo, JapanClassification of air pollution problems in Southeast and South Asia
using time-series data on environment, society, and governancephotoTomoaki Ito, Wataru Takeuchi
Institute of Industrial Science, the University of Tokyo, Japan
Abstract : Air pollution problem is one of the most health-damaging environmental problems that causes millions of premature deaths each year. This study focuses on
public air pollution-related awareness, which is considered a driving force to improve environmental problems. We classified 8 Asian megacities into 3 classes by the trendsof environmental pollution, public pollution-related awareness, and public mitigation policies. It was found that there are common characteristics among the countries ineach classes. In countries with high democracy index value, public pollution-related awareness may have been reflected in public mitigation policy. In contrast, groundswell to improve air quality may have not been reflected in policy making well in countries with low democracy index value. These results imply that the stage of air
pollution problem in country differs by not only environmental pollution and GDP per capita but also public pollution-related awareness and legal system in countries.

1. Introduction▪ Air pollution comprises 11.65% of total death
rate in the world (IHME, 2021).
▪ PM2.5 is the most health-damaging air pollutant
which causes 10.2 millions of premature deaths
every year (Vohra et al., 2021).
▪ Asian megacities experience intensive air
pollution especially caused by PM2.5 (Fig.1,2).

Fig.1 PM2.5 concentration incapital (Blue : WHO guideline)▪ Past study on Environmental Kuznets Curve revealed
relationship between GDP per capita and environmental
degradation (Fig.3).
▪ It is assumed that improvement of air quality can be
attributed to reduction effects by legal system andpublic desire to obtain superior goods such as better
environment (Morrissey, 2000).

Fig.2 Poor air quality in Dhaka, Bangladesh (Dec 10th, 2023)

Fig.3 Conceptual diagram of Environmental
Kuznets Curve (Mitić et al., 2019)

2. Methodology▪ Research objective
1. Grasp of stages of air pollution problems in Asian countries
considering not only environment but also society and governance.
2. Development of a method to partially complement the lack of
cross-country dataset on society.

▪ Originality
1. Cross-country analysis using homogenous time series data on
environment, society, and governance.
2. Acquisition of insight of common features among environment,
society, and governance in each stage on air pollution problems.

Fig.5 Overall flowchart of this study
Table 2. Democracy index value of study area in 2020

Table 1. Adoption of European emission standards in study area
1995

2000

2005

2010

2015

2020

2025

▼▼▼▼▼▼▼

RegionSoutheast Asia

Thailand
Malaysia
Philippines
VietnamIndonesiaIndia a)
India b)South Asia

Bangladesh c)
Bangladesh d)

Pakistan

Fig.4 Study area, Southeast and South Asian megacities populated byover 5 million people in 2010

3. Results
Table 3. Comparison of R, indicator of PM2.5
concentration among various megacities
RegionSoutheastAsia

SouthAsia
WesternEurope

North
AmericaNationIndonesia
Philippines
Thailand
Vietnam
Malaysia
India
Pakistan
BangladeshFranceUnited
Kingdom
Germany
United States
CanadaMegacity
Jakarta
ManilaBangkok
Ho Chi MinhKuala Lumpur
Delhi
Karachi
Dhaka
ParisLondon

R_mean
R_sd
44.0
16.2
22.68.446.4
17.6
47.9
14.0
35.0
16.7
40.2
20.4
9.6*
10.3
48.1
19.0
6.7
10.2
7.7
8.9

HessenDusseldorf
New YorkToronto

5.7

4.4

4.7
4.4

4.8
5.5

* Underestimation of R in desert area such as Karachia) Nationwide b) NCR, 13 cities

Euro1Countries with relatively
good air quality

Euro2c) Gasolined) Diesel

Euro3Euro4Euro5Euro6

Democracy index
6.30
6.56
6.04
2.94
7.19
6.61
4.31
5.99

Class 1 : Countries with relatively good air quality

Class 2 : Countries with progressive tightening regulations

Class 3 : Countries without progressive tightening regulations▪ Features
1. Relatively good air quality
2. decreasing trend of public air pollution-related awareness3. Recent stagnation of introduction of stricter regulations
4. High democracy index value▪ Features
1. Poor air quality
2. Recent uptrend of public air pollution-related awareness3. Introduction of stricter regulations▪ Features
1. Poor air quality
2. Recent uptrend of public air pollution-related awareness3. Stagnation of introduction of stricter regulations
4. Relatively low democracy index value

Fig.7 The result of STL decomposition to R, indicator of PM2.5
concentration in Kuala Lumpur

Fig.9 The result of STL decomposition to R, indicator of PM2.5
concentration in Jakarta

Fig.11 The result of STL decomposition to R, indicator of PM2.5
concentration in Dhaka

Study area in Southeastand South Asia

Lower public air pollution-related awarenessR_mean ≧ 40

R_mean < 40Nation
Indonesia
Philippines
Thailand
Vietnam
Malaysia
India
Pakistan
Bangladesh

Recent uptrend of public air pollution-related awareness

Recent uptrend of public air pollution-related awarenessCountries with poor air
quality

Philippines, Malaysia

Countries with progressive
tightening regulations

Indonesia, Thailand,
Vietnam, India

Countries without progressive
tightening regulations

Pakistan, Bangladesh

Fig.6 The result of classification into 3 classes
for each study areas

4.Discussion

Fig.8 The result of STL decomposition to relative search volumeof “air pollution”, indicator of public awareness in Kuala Lumpur

Fig.10 The result of STL decomposition to relative search volumeof “polusi udara”, indicator of public awareness in Jakarta

Fig.12 The result of STL decomposition to relative searchvolume of “air pollution”, indicator of public awareness in Dhaka

Table 4. Adoption of European emission standards in Malaysia

Table 5. Adoption of European emission standards in Indonesia

Table 6. Adoption of European emission standards in Bangladesh

1995

2000

2005

2010

2015

2020

2025

1995

2000

2005

2010

2015

2020

2025

1995

2000

2005

2010

2015

2020

2025

▼

▼

▼

▼

▼▼

▼

▼

▼▼▼

▼

▼

▼

▼

▼

▼

▼

▼

▼

▼

Malaysia

Indonesia
Euro1Euro2Euro3

Euro4Euro5Euro6Euro1Euro2▪ Improvement of air quality can lead lower public air pollution-related awareness (Fig.8). It may
have been reflected in stagnation of installation of stricter regulations (Table 4) in class 1 withhigh democracy index value.
▪ Either society or governance gets high motivation to improve air quality and may stimulate theother in class 2. In the case of Indonesia with relatively high democracy index value, society has
got high motivation to improve air quality since 2019 (Fig.10) and it may have been reflected intightening of regulations in two stages in 2022 (Table 5).
▪ Recent uptrend of public awareness was found in class 3 (Fig.12). However, it may not have beenreflected in policy making because of relatively low democracy index value (Table 6).
▪ Countries with relatively high democracy index value in class 2 may experience decreasing trendof public awareness corresponding to improvement of air quality as class 1.
▪ The stage of air pollution problem in India is different from that of Pakistan and Bangladesh byFig.13 GDP per capita in South Asian countries considering political system although they are almost the same GDP per capita and pollution level.

Euro3Euro4Euro5Euro6Bangladesh c)
Bangladesh d)c) Gasoline d) Diesel

Euro1Euro2Euro3Euro4Euro5Euro65. Future work
▪ Additional empirical analysis in Middle Eastern or SouthAmerican countries with medium-income level.
▪ Validation of R, indicator of PM2.5 concentration using
ground observation data on PM2.5 concentration.
▪ Introduction of more comprehensive method to evaluate
air quality including not only PM2.5 but also other airpollutants.
▪ Consideration for effect of bias caused by increase of
Google user rate (Fig.14). This problem will be resolved bytermination of rapid spread of smartphones.

Fig.14 Rate of Google users in study area, calculated by productof internet penetration and market share of Google

For further details, contact: Name, Bw-605, 6-1, Komaba 4-chome, Meguro, Tokyo 153-8505 JAPAN (URL: http://wtlab.iis.u-tokyo.ac.jp/ E-mail:finalfantasy413@g.ecc.u-tokyo.ac.jp)