Health and Environment Effects of the Motorcycle Emission
in Vietnam Urban Areas
Nguyen Quang Lich1, Wei Chin Chang2
1
2
Faculty of Engineering and Technology - Hue University of Agriculture and Forestry
Department of Mechanical Engineering - Southern Taiwan University of Technology
Abstract:
In Vietnam, the environmental pollution is especially warming in the big city such as Ha Noi, Ho Chi Minh, Hai Phong
and Da Nang. It is not only the bad affect to environment but also its poses a serious threat to human health. One of
main reason of this pollution is exhaust gas from motorcycles. It makes an important contribution to the amount of
pollution emission. Along with economic growth is the increasing of the motorcycle day by day. Due to the convenient
using in the crowed traffic, motorcycles are the most popular transportation mean and become important personal
carriers in Vietnam, more than 18 million amounts are used currently and have 26.16% of them was used more than 10
years. In Hanoi, every one thousand peoples have 497 motorcycles, 446 motorcycles in Da Nang and that number is 506
motorcycles in Ho Chi Minh. The result shows that, in Hanoi and Ho Chi Minh have more than 72% households to had
to catch in particular respiratory disorder and the capita income is reducing about 20% annually by environmental
pollution. In the present paper, firstly the investigation effect of components emission such COx NOx, HC and PM on
,
environment and human health after that we introduced a method which used exhaust gas recirculation (EGR)
combined with liquid petroleum gas (LPG) engine to improve exhaust gas emission from motorcycles. This will not
only reduced CO emission but also decreased the pollution emission such as HC, NO2 and smoke. In addition, the
improvement of economic fuel consumption and better performance will be seen. The results of this study can provide
the Environmental Protection Administration of Vietnam or other Asian country useful method to reduce air pollution.
Keyword: LPG, Human Health, Emission
Nguyen Quang Lich
Email: ngqlich@yahoo.com
Phone: (+84)904263476
Faculty of Engineering and Technology, Hue University of Agriculture and Forestry
102 Phung Hung, Hue City, Vietnam
motorcycles are the most popular and importantly
personal carriers in Vietnam, more than 18 million
1. Introduction
amounts are currently used. There motorcycles are old
Vietnam is a developing country in Asia with an area
and in bad technical condition, causing air pollution
of approximately 330 thousand square kilometers. The
and noise especially near current years, more
population of Vietnam which is about 87 million
motorcycles from China was installed in Vietnam all of
people is growing at an annual about 1.5%. There are
them to meet some technical problems especially
more than 30 % of Vietnam’s population live in urban
produce exhaust gas [5]. Although they have a lot of
areas[1]. Motorcycles are a major pollution’s source in
technical problems but they are favorite transportation
most urban areas. Traffic emissions of carbon
mean because they are suitable for infrastructure
monoxide (CO), hydrocarbon (HC) and nitrogen
condition nowadays in most cities in Vietnam
dioxide (NO2) are precursors in ozone (O3) formation
especially in big cities such Hanoi, Ho Chi Minh and
via photochemical reactions in the presence of sunlight
Da Nang.
[2]. These emissions not only reduce air quality in
urban areas but are also are detrimental to human
health. At very high levels of exposure fluoride can
result in respiratory conditions such as bronchial
hyperreactivity, worsening of asthma symptoms,
impaired respiratory functions, respiratory irritation
and skeletal fluorosis in humans [3].
The air quality in Vietnam is recently decreasing
especially in warming and noise pollution. More than
83% of greenhouse gas (GHG) emissions in Vietnam
urban areas emanated as a result of burning fuel
combustion, 23% of them were produced by
motorcycles which are about 60 million tones annually
Figure.1 Traffic jams in Ho Chi Minh City
[4]. Due to the convenient using in the crowed traffic
Table.1. Information on the three cities in Vietnam [6]
Population
Area (km2)
Hanoi
Ho Chi Minh
3145300
5891100
Da Nang
777100
Region
Motorcycles
Characteristics
921
2095.2
Population density
(person/km2)
3415
2812
1,563,241
2,980,897
1255.5
619
346,587
Capital of Vietnam
Business, Southern of
Vietnam
Industry, Central of
Vietnam
Source: General Statistics Office
Table.2. Average value of emission in three cities Hanoi, Ho Chi Minh and Da Nang [7]
Pollution
CO
HC
NO2
PM
SO2
Ozone
Unit
2005
Hanoi
2006
mg/m3
mg/m3
µg/m3
µg/m3
µg/m3
µg/m3
5.8
2.1
115
321
330
110
6.1
2.3
125
338
371
115
%
difference
+5.1
+9.5
+8.6
+5.3
+11.2
+4.5
2005
6.2
2.2
123
312
335
115
Ho Chi Minh
2006
%
difference
6.6
+6.4
2.4
+9.0
134
+8.9
336
+7.69
361
+7.76
121
+5.2
2005
5.6
2.4
122
335
357
121
Da Nang
2006
%
difference
5.8
+3.5
2.7
+12.5
137
+12.2
351
+4.7
389
+8.9
127
+4.9
Source: VEPA
In some transporting centers of city, dust and CO are
higher than permitted standard. In addition, dioxide
sulfur (SO2) and NO2 is also higher than standard at
rate 3-4 times. Therefore, the emission from
motorcycles makes an important contribution to the
amount of air pollution in Vietnamese urban areas.
Almost the statistic reports from hospitals show that
the number of patients with ear-nose-throat and
breathing diseases makes hospitals in overloading
situation and the rate of death from these is increased...
The danger of pollution in the large cities is very
difficult problem which authorities should be facing
and should bring out the solutions soon.
The studies also show that, the effect of environment
pollution on damage of economic in urban areas about
$ 70 million annually especially have more and more
deaths and diseases. These numbers in Ha Noi, Ho Chi
Minh and Da Nang are succession 1338 deaths and
3869 diseases, 2631 deaths and 4953 diseases, 341
deaths and 748 diseases. Hence, motorcycles emission
control and management is urgent emission in Vietnam
especially in urban areas.
The purpose of this paper is to review the relevant
medical, epidemiological and economic data in
literature related to health effects of outdoor air
pollution, to organize and interpret the findings of
these articles, and to present the results in a format that
emphasizes the impacts of outdoor air pollution on
health and health costs in Vietnam urban areas. In the
addition, it introduces the methods to reduce
motorcycles emission also some commends to manager
and evaluate air pollution in Vietnam that urgent matter
not only in Vietnam but also in the world.
2. Effect of emission on environment and human
health
2.1 Air concentration trend in Vietnam urban areas
Among to developing economics then environment
pollution became big problem in Vietnam especially in
urban areas. Generally, the air pollution trends over
coming day by day. The emission pollution amount
such as CO, HC, SO2, PM and Ozone increasing on
during ten years from 1995 to 2005 [7]. The data of
Vietnam Environment Protection Agency (VEPA)
show that between 2005 and 2006 the air
concentrations of ozone, PM, NO and CO and
increased by approximately 5 to 10% in Vietnam
especially in some cities such Ho Chi Minh and Da
Nang that value is higher than (Table 2). Table 2,
based on data supplied by the VEPA website for three
cities in Vietnam, shows air concentration data for air
components for years 2005 and 2006.
Table.3. Emission limit values
Pollutions
Average
period
PM
24-hr
HC
8-hr
CO
8-hr
SO2
24-hr
NO2
24-hr
O3
8-hr
Source: EU2 Standard
Concentration
µg/m3
600
5500
10,000
120
100
100
The air pollution in Vietnam urban areas has gradually
transformed into something more complex than was
previously found, namely a mix of pollutants stemming
from coal and petroleum. The ambient air quality
situation is not optimistic. Particulate matter, SO2 and
NO2 are now the main pollutants in the cities. The data
from table 2 and according to table 3 show that SO2,
NO2 and Ozone level higher than emission limit level
while PM and CO are approaching this value. In the
addition between 2005 and 2006 almost emission
components in the cities were still increasing especially
SO2 and NO2 in the air are quite severe. Besides, more
studies show that temperature is increasing about 0.10C
annually.
Table.4. Concentrations Substantially Dangerous to
Human Health
Pollutions
Average
Concentration
µg/m3
period
PM
HC
CO
SO2
NO2
O3
Source: WHO
24-hr
8-hr
8-hr
24-hr
24-hr
8-hr
600
12000
57500
2620
938
1200
2.2 Impact of emission on human health
2.2.1
Effect of emission on human health
The impact of motorcycle emission on human health
can be assessed in multiple ways. Questionnaires
distributed to patients and their families provide
information about respiratory symptoms such as
wheezing, shortness of breath, tightness in the chest,
cough and production of sputum. The function of the
lungs can be assessed by various breathing tests. Such
data can be recorded over many years to determine if
there are long-term decrements in lung function.
Events such as the number of asthma attacks, visits for
emergency care and hospitalizations can be tabulated.
Death rates from asthma, chronic obstructive
pulmonary diseases and lung cancer can be related to
short-and long-term exposure to ozone and fine
particulates
The emission of toxic and greenhouse gases (NO2,
CO2, HC, CO…) from motorcycles has long been
recognized as a threat to human health and the
environment, the emission of PM from motorcycles has
been largely ignored until fairly recently. Particulate
emissions from internal combustion engines as well as
from motorcycles have recently come under close
scrutiny because of many negative health effects which
have been attributed to inhalation of fine particles (with
diameters of 2.5 micrometers or less). Recent research
have established strong correlations between ambient
fine particle concentrations and increased morbidity
and mortality rates in urban areas, including increased
rates of heart disease and infant mortality [8].
In particularly, there is a great deal of concern about
the health effects of nanoparticles (which are less than
50 nanometers in diameter). Because of their extremely
small size, nanoparticles are able to penetrate deep into
the lung where they may enter interstitial tissue,
causing severe respiratory inflammation and acute
pulmonary toxicity [3]. Moreover, the lung’s own
removal mechanisms are much less efficient at
removing such small particles are normally retained
within the lung tissue for much longer periods of time
than larger particles. Due of their greatly increased
surface area-to-volume ratio, nanoparticles are able to
support much higher rates of surface free radical
activity than larger particles. While the full scope of
health effects due to particulate emissions is still poorly
understood, it is clear that particles (especially
nanoparticles) do pose some threats to public health
and the environment significant work that is currently
underway throughout the to assess these threat.
Improved instrumentation and techniques for
measurement of particulate matter emissions will be
required to fully assess the problem.
Beside impact of PM then CO emission has effect
strongly on human health also environment. CO is a
colorless, tasteless, odorless, and nonirritating gas that
is a product of incomplete combustion of carboncontaining fuels. It is also produced within living
organisms by the natural degradation of hem-proteins
(e.g., hemoglobin, hemoglobin, cytochromes) or as a
byproduct of xenon-biotic metabolism, especially the
breakdown of inhaled organic solvents containing halomethane (e.g., methylene bromide, iodide, or chloride)
[9] . With external exposure to additional CO, subtle
health effects can begin to occur, and exposure to high
level that can result in death especially harmful to child
and cardiac too strongly. The formation of CO reduces
the amount of hemoglobin available for the
transportation of oxygen around the body. This can
impact on the brain, nervous tissues, heart muscle and
other specialized tissues that require large amounts of
oxygen to function [9]. As a result of oxygen
deprivation, these organs and tissues may suffer
temporary or permanent damage. The most susceptible
to the health effects of ambient air exposure to CO
include those with ischemic heart disease, other forms
of cardiac disease including cyanotic heart disease,
hypoxemic lung disease, cardiovascular disease,
peripheral vascular disease, those with anemia and
hemoglobin abnormalities of children and adult.
Nitrogen dioxide is toxic to various animals as well as
too human. Its toxicity relates to its ability to form
nitric acid with water in the eyes, lung, mucus
membrane and skin. Studies of the health impacts of
NO2 include experimental studies on animals,
controlled laboratory studies on humans and
observational studies. The studies show susceptible
humans, such as asthmatics, exposed to high
concentrations of NO can suffer lung irritation and
2
potentially, lung damage[10].
Finally, the health impacts of exposure to ozone
concentrations have been widely studied using both
epidemiological methods and laboratory studies. The
summaries the health effects associated with exposure
to ozone as [8]:
• Increase in daily mortality, respiratory and
cardiovascular disease
• Increase in hospital admissions and
emergency room visits, respiratory and
cardiovascular disease
• Decrease in lung function
• Increase in symptoms of respiratory illness
such as cough, phlegm and wheeze
• Increase in bronchodilator usage.
2.2.2
Implications for Vietnam Urban areas
The Vietnam Environmental Protection Agency
estimates that the new emission standards for fine
particle emissions (which intend to implement in the
2001- 2005 time period) will prevent approximately
14,000 deaths per year. Some industry groups estimate
that the cost of meeting these new emissions standards
may be as high as $ 3 billion.
Table 5: List death-rate in the Vietnam 2006
Unit: Rate 100,000 peoples
Name of illness
Diseases
Mortality
Lung disease
426.60
74.2
Tonsillitis
291.44
34.2
Bronchitis
250.29
11.4
Gastritis, colitis
237.32
36.3
Grippe
199.38
15.7
Cardiovascular
116.22
26.5
Malaria
106.24
25.4
Accident
103.25
25.3
Asthma
87.92
11.2
Other
234.12
8.2
Total
2052.78
268.4
Source: Ministry of health
Table 5 shows the diseases and death rates in the
Vietnam in 2006. The overall death rate in the
Vietnam is approximately 268.4 per 100,000 of the
population per year. Among them the illness that are
the main cause are air pollution and tobacco such as
lung disease, tonsillitis, bronchitis and cardiovascular
have high rate and trend is increasing in 2006. From
table 5 we can see the death rate since main caused by
air pollution and tobacco and alcohol are
approximately 55% of the Vietnam totals. In general,
the death rate in Vietnam especially in urban areas is
increasing annually. Along with economic growth, the
trend of population in urban areas is raising then
amount motorcycles also increasing that is effect on
public health in particular illness such respiratory and
cardiovascular. Besides, the number of motorcycles
increases so the traffic accident also rising day by day.
The recent years, there are more studies effect of
emission on human health and the result shows as
below:
Respiratory Illness: Respiratory and other illnesses
may be related to the presence of fine particulate
material in the lungs. In a study that compared
findings in three cities in Vietnam, the lungs of women
who died of non-respiratory diseases were studied for
their particle content. The prevailing level of PM in
the air was 4.7 times higher in urban areas than in rural
areas also the lungs examined in urban areas contained
7.4 times more particles than lungs from rural areas.
As children grow, their lungs become larger and the
numerical values for tests of lung function also
increase. Several studies involving three to eight years
of follow-up have shown that deficits in the growth of
lung function, as assessed by lung function tests, are
related to exposure to ozone, fine particulates, NOx
and acid vapor. The prevalence of respiratory illness in
children is related to levels of ozone and fine
particulate pollution. In addition to PM, CO, SO2 and
NO2 are also involved. Deaths from asthma are related
to NO2 and ozone.
Cardiovascular Disease: Fine particulate pollution is
associated with an increase in the incidence of heart
attacks and precipitation of congestive heart failure.
The number of emergency admissions for heart attack
and the risk of death from heart attacks both increase
when PM increases. High levels of exposure to PM
lead to atherosclerosis, which underlies both ischemic
stroke and heart attacks. The probability of having a
heart attack is increased by exposure to traffic. The
risks of dying from CO emission lung cancer and heart
disease after exposure to air pollution are substantially
higher than the risk for all-cause mortality. In Vietnam,
motorcycle emission causes about 3% of mortality
from cardiopulmonary disease, 4.5% of mortality from
cancer of trachea, bronchus and lung, and about 1.1%
of mortality from acute respiratory infections in
children under age of 5 years old. In the three studied
cities, the relative risk of dying is the highest in the
most polluted city in Vietnam. The relation between
daily death rate and the concentration of either ozone
or other emission is linear, i.e. relative risk of dying
varies directly with the level of pollutant. Statisticians
find no evidence for a threshold, i.e. a little air
pollution is bad and more is worse. The magnitude of
the relation depends on duration of exposure.
3. Methodology to reduce motorcycles emission
3.1. Basically of research
In currently, the reserve of petrol gas is decreasing day
by day. The studies bio-fuel for replacement the main
mean of individual transport in Vietnam is
gasoline case. At engine speed of 4000rpm, the
concentration of CO in exhaust gas of LPG driven case
reaches only 25% of this value in gasoline driven case.
Besides, the figure 4 is a result of comparison of NO
emission between LPG engine and gasoline engine.
When speed engine increases NO concentration in
exhaust gas of both LPG and gasoline decreases
rapidly. However, when engine speed higher than
3000rpm then NO emission of LPG engine is still
decreases whereas it increases in gasoline case.
6
3.2. The adjustment technology
CO emission
5
4
%
motorcycles. We have actually more than 18 millions.
Permitting or reducing an amount emission of
motorcycles is very difficult in this our social
economic situation. However, there is the solution to
improve that problem that is using LPG also any biofuel replacements traditional fuel.
LPG has many advantages to compare with gasoline in
pollution issue. LPG is estimated as the super pure fuel
and can satisfy all of standard of expelled gas. Using
LPG will much reduce an amount of HC, CO and NO
in expelled gas. Because the ratio H/C of LPG is higher
than gasoline and fuel mixture of LPG and oxygen is
better than gasoline. Furthermore the rate of
hydrocarbon in expelled gas is reduced because the
volatilizable characters of LPG do not make a layer of
liquid fuel in engine
3
2
In this paper we use LPG as a fuel for motorcycles.
The results of experiment are show that CO and HC are
reducing in comparison with gasoline. In figure 2, 3
and 4 shows that CO HC and NO emission of
motorcycles uses LPG and gasoline.
Gasoline
LPG
1
0
0
1000
2000
3000
4000
5000
rpm
HC emission
1000
Figure 3 Comparison of CO emission between LPG
and gasoline motorcycles
600
35
400
30
200
0
0
1000
NO emission
25
Gasoline
LPG
ppm
ppm
800
2000
3000
4000
5000
rpm
Figure 2 Comparison of HC emission between LPG
and gasoline motorcycles
Pollution analysis in different operation conditions
shows that the CO, HC and NO concentrations of LPG
case are inferior to that of gasoline case. Pollution
reduction rate may reach from 30 to 80%. Reduction
rate is more important when engine load increased.
The figure 2 presents the comparison between HC
concentrations given by gasoline and LPG running
cases. In general, the engine speed increases then HC
emission decreases for both case LPG and gasoline.
However, HC emission level of LPG engines less then
gasoline engine at all engine speed.
The figure 3 presents the result of CO measure in
exhaust gas of LPG motorcycles in comparison with
gasoline case at idle regime. When the engine speed
increases, CO concentration in exhaust gas of LPG
motorcycles decreases rapidly whereas it increases in
20
15
10
Gasoline
5
LPG
0
0
1000
2000
3000
4000
5000
rpm
Figure 4 Comparison of NO emission between LPG
and gasoline motorcycles
4. Conclusion
Motorcycles emission is one of the main sources of
environmental pollution in Vietnam urban areas. The
air pollution is at level higher than standard in the most
city. It poses a serious threat on human health.
Environment pollution that causes traffic emission is
became important in Vietnam especially in urban areas.
According to the survey results of ministry of health
about 72% of household has diseased individual that
the main causes by air pollution. An estimated reduces
20% capita income and more than 20% health and
vitality annually which mean have more 1.7 million
diseases per year.
Using LPG for motorcycles has many advantages in
protecting environment as well as social-economics.
Therefore, it is necessary for us to invest in research
making condition to manufacturing series of
carburetors, LPG tanks and other accessories; this will
reduce cost price and increase practical ability in
changing motorcycles using gasoline into using LPG.
In order to this solution can be widely applied, we
should have LPG distribution networks for motors
bikes in cities. On the other hand, if the government
has preferential taxation policy for LPG fuel using for
transportation means this solution will go into
customers’ lives easily contributing to protect
environment.
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