Friday and Saturday, December 6-7, 1996
Common Room, University House,
and J G Crawford Building, National Centre for Development Studies,
Australian National University
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Seminar on Environment and Development in Vietnam
Friday and Saturday, December 6-7, 1996 Common Room, University House,
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Some Aspects of Air Quality in Ho Chi Minh City, Vietnam
Hiep Nguyen Duc
c/o Environment Protection Authority NSW
PO Box 29, Lidcombe NSW 2141
Tel: +61 (2) 795-5205; +61 (2) 795-5454
Fax: +61 (2) 709-2836
Email: hduc@airmoon.epa.nsw.gov.au
Abstract
This paper reviews the state of air quality in Ho Chi Minh City as conducted by several organisations in recent years. A comparision of the air quality in HCM City with some other cities in the region is also made. It is shown that the air quality of both indoor and outdoor (ambient) has been deteriorated in recent years. This is mainly due to the increase in the usage of vehicles and an increasing number of industries in and around the city.
Compared with other cities, such as Beijing, Tokyo, Bangkok and Manila, the level of SO2 pollution is below those of these cities while the levels of CO and NO2 are approaching the levels of these cities. In the case of particle pollution, the peak particle level at some heavy traffic sites in HCM city is very high and exceeds those of Bangkok and Manila. The lead pollution is less than that of Bangkok . However, the lead level will be rapidly increasing unless concrete action is implemented.
Experiences of other cities in the area of environment management can be applied to prevent serious degradation of air quality in the city. Suggestion for some measures that can be incorporated quickly into an integrated air quality and transport management plan is also presented.
Introduction
Ho Chi Minh (HCM) City is a major city in Vietnam with a population of 4.7 millions (1994). It has an area of about 2,056 km 2 and an average density of 2,282 inhabitants/ km 2. The tropical climate has a yearly average temperature of 27 &176;C and relative humidity of 77.8% (1).
As in other bustling and growing cities in the region, the main contribution of air pollution is from motor vehicles. Besides motor vehicles, industrial sources in the city and surrounding areas of Dong Nai province are also contributing to the air pollution problem especially in the residential areas around these sources.
As projected, the population of the city will easily exceed 5 millions in the year 2000. This means the city is in the category of supercities . Eventhough, it is still not in the league of megacities such as those of Bangkok, Jakarta, Beijing or Manila, the high economic growth in recent years has accompanied a rapid degradation of environment quality.
Due to an increase level of air pollution in the city, a number of organisations in the city have recently conducted some initial studies of air quality and the effects of air pollution on the population. Permanent monitoring stations are not yet established but data are collected occasionally for a number of days at a number of sites in the city. These sites are mainly near heavy traffic roads. The collected data are not yet comprehensive to give an overall picture but is indicative enough to give some information on the state of air quality in HCM City.
Air Pollution due to motor vehicles
Recent data measured from a number of monitoring stations operated by the Center for Environmental Technology and Management (CEFINEA) of Ho Chi Minh University of Technology has been available and published (1)(3)(5). These data show that many air pollutants such as CO, NO2, particles have concentrations exceeded the standard levels. The noise level is also persistent high.
During one particular day on the 25/04/1996, data measured from the intersection of Dinh Tien Hoang and Dien Bien Phu streets shows that the maximum hourly concentration of particles is 3.6 mg/m3 , 12 times the current Vietnamese standard (3).
The concentration of CO measured on 25/04/1996 is 62.65mg/m3 , 1.5 above the standard. Similary, the NO2 concentration measured on 23/04/1996 exceeds the standard 1.5 times. The average noise level is between 76 to 86 dBA with a peak of 98dBA while the standard for residential area is 60dBA (3).
The air pollution in the city is overwhelmingly due to motor vehicles. Currently the city has more than 1.1 million of which motor cycles is more than 1 million. Each month, there are more than 1,000 are added to the city traffic. The vehicles currently use mainly leaded petrol.
Approximately 200,000 tons of petrol fuel and 190,000 tons of diesel are consumed each year. The emission into the airshed is about 2,200 tons of SO2, and 25 tons of lead.
The economic growth in the past ten years reflects in the increasing large number of vehicles. During peak traffic period, on Cach Mang Thang Tam Street, the vehicle density count is 10,000 per hour compared to 5,800 per hour in 1990 and only 2,800 per hour in 1985 (1). The growth of traffic however is not offset by the upgrade and the construction of new roads. In 1994, the traffic density in some of the congested streets are presented in Table 1 (1)
Name of Street Traffic Density
(quantity/hour)
Ba Thang Hai 13,000
Tran Hung Dao 12,500
Hung Vuong 10,015
Ly Thuong Kiet 11,306
In 1980, the hourly average particle level from traffic streets is about 3 to 3.1 mg/m3 during wet rainy season and about 3.2 to 3.4 mg/m3 during dry season. However, in 1990, at the same locations, the hourly average level increases to 5 - 5.1 mg/m3 during wet season and 7.8 - 8 mg/m3 during dry season. The corresponding increase for SO2 is from 0.8 mg/m3 to 0.97 mg/m3 (3).
A recent study by CENIFEA (1) on the daily variation of some air pollutant concentration due to air traffic emission shows the following results :
(1) For CO, the daily average concentration at significant traffic crossings is between 2 to 10 mg/m3 with the maximum hourly value up to 23.3 mg/m3.
(2) The NO2 daily average concentration is between 0.05 to 0.25 mg/m3. The peak hourly value can reach 0.726 mg/m3 at Dinh Tien Hoang-Dien Bien Phu street and 0.6 mg/m3 at Hang Xanh roundabout.
(3) Dust particle concentration ranges from 0.8 to 15 mg/m3 at various times of the day with the maximum concentration of 37 mg/m3 at the crossing of Dinh Tien Hoang and Dien Bien Phu streets on the 15 March 1995.
(4) Lead concentration at a number of sites varies between ~0 to 0.41 mg/m3 at various time of the day. The ratio of lead contained samples and total analysed samples is low.
(5) The air pollutant concentration varies depending on the month due to seasonal effects. At the Minh Phung - Hau Giang crossing, the monthly average concentration for CO is 0.06 to 4 mg/m3, for NO2 0.05 to 0.3 mg/m3 and TSP 0.4 to 1 mg/m3. In the dry season, the average concentration is 2-3 times higher that that in the rainy season.
Air pollution due to industrial sources
Industries also contributes significantly to the pollution especially for areas near the sources. Many of these sources are small factories and the indoor pollutant levels inside these sources are very high. There are 700 large industrial sources and about 24,000 small scale factories in and around the city. The large industrial sources are mainly concentrated in Nha Be and Thu Duc areas. The small factories, mainly family business, are scattered in all districts with the largest concentration is in the District 5, 6, 11 and Tan Binh (1).
Almost all of these sources are located in residential areas. Many of the types of equipments and technology are old and has been in operation for more than 10 years. Some of them are more than 25 years old and are not fitted with any pollution control devices (1). A survey, conducted recently, shows many foreign joint-ventured factories operated with outdated imported equipments causing considerable environmental pollution (14).
Investigation by the Center for Environmental Technology and Management (CENIFEA) (1) shows that the total dust concentration (Total Suspended Particulates, TSP) are very high in the indoor environment of almost all industry types especially in the construction material and metallurgy industries.
The total emission of pollutants to the airshed due to fuel comsumption of all industries each year is 30,000 tons of SO2, 5,750 tons of NO2 and 1,650 tons of particulates. In addition, a total of metallurgy industries produces between 2,840 to 4,260 tons of particulates and between 994 to 1,420 tons of CO per year (1).
In 1995, of 43 company factories on the black list, 30 % of these are in Thu Duc, an industrial growth area near HCM City. Two major companies, Posvina and PS (toothpaste production), are emitting large quantity of acid gases each day to the surrounding residential areas (5). Residents complained about the pollution effect of these sources and was reflected in the media such as against the factory operated by Miliket noodle company. In HCM City suburb of Tan Binh, the steel work factory operated by Southern Steel Corporation ( Cong ty Thep mien Nam) is also a target of complain (4).
The ambient air pollutant concentration of some pollutants around some industrial sources are shown in Table 2 (1). A number of them , such as the Tan Binh steel work and the Miliket noodle company, exceeds the ambient standards for dust, SO2 and CO.
Table 2 - Air pollutant concentration outside some industries in HCM City (in mg/m3)
No Industry and sampling site Dust SO2 CO NO2 Others
1 Chana textile - Outside 0.18 0.142 0.08
factory, distance 25 m
2 Phuong Dong detergent- 0.4 0.42 0.3
Outside factory, distance
of 15m
3 Quan khu 7 Cement Outside 0.8 0.26
factory, distance of 40m 0.4 0.22 0.055 1.78
Outside factory, distance 0.022 0.66
of 120m
4 Tanbinh metallurgy 0.76 0.4
Outside, distance of 40m 0.51 0.36 0.154
Administrative area 1.3
5 Nhabe metallurgy - 0.3 0.277
Administration area
6 Milipa instant noodle 0.7 0.35 0.1 3 HC: 15
-Outside
Standard 0.5 0.5 0.085 3
Health effects of air pollution
It is known that primary pollutants such as particles (PM10 and PM2.5), Nitrogen oxides, Sulphur dioxide, Carbon monoxide and secondary pollutant such as Ozone has an adverse effects on people health. Particles has been shown to cause an increase in mortality rate. People with ashma and respiratory diseases are highly susceptible to particles, nitrogen oxides, sulphur dioxide and ozone. In addition, lead particles had serious effects on children development. Children with high lead levels are deficient in weight, tend to have low count of red blood cells. Their IQs are also lower than those with lower lead levels.
The health effect of air pollution on the traffic police officers was recently conducted by the Labour Protection Unit of HCM City (Phan Vien Bao Ho Lao Dong Tp HCM) (5). Due to long exposure of high levels of air and noise pollution, traffic police personels suffer a tuberculosis rate of 2.9 % while the average rate is 0.075 %. The rate (presumably using yearly data) of nose, throat and ear infection is 76% while 32% of them has reduced hearing abilities.
There is currently no known studies conducted by the health authorities on the effects of air pollution due to gaseous pollutants or particles on ashma or death rate as well as the level of lead in blood due to vehicle emission.
In Bangkok, Thailand, the traffic police reckons 40% of their number have chronic lung ailments. It is not un-usual to see they have scarves or white clothes wrapped around their mouths and noses (6). A Public Health Ministry study (10) of 214 people who regularly use buses at a station found that 26% suffered ill-effects from carbon monoxide (CO). These people were exposed to a CO level of 67 ppm (part per million) against the standard of 10 ppm.
This is not included the effects due to gaseous gases such as the highly toxic and mutagenic polycyclic aromatic hydrocarbons (PAH). A comprehensive study (10) of lead level in the blood of children has shown that , before the introduction of unleaded petrol in 1991, the average lead level was 17 micrograms/decilitre and reduced to 9.23 micrograms/decilitre in 1996. The acceptable level, as specified by the US Center of Disease Control, is 10 micrograms/decilitre.
A similar study, the Urban Air Project, conducted by the Philippines Department of Environment and Natural Resources (DENR) in 1994 showed that of a sample group of 170,000 people in the cities exposed to lead pollution and traffic : 762 (or 0.45 %) had varying degrees of coronary diseases and 91,207 (or more than 50%) suffered from hypertension. This study also showed that at least 39% of the lead pollution came from cars and 58% came from public utilities vehicles (17).
Comparision with other regional cities
Compare with other cities in the regions which also experienced rapid economic growth in recent decades, the air pollution problem in HCM City is not as bad but rapidly becoming a serious problem unless some measures are taken.
As the population is rapidly increasing and the continuing growth of vehicle usage, the air pollution at some section of the city, especially near heavy traffic or highly congested road, reaches the level of those of high polluted cities. In megacities, defined as cities having a population over 10 millions by the year 2000, such as Beijing, Bangkok, Jakarta and Manila the situation is much worse.
In each country, the air quality standard is usually defined by the national environment organisation in that country. These standards are usually different from country to country. It is therefore more useful to compare the air quality based on the World Health Organisation (WHO) recommended goals. The different standards of some selected countries and the WHO goals are shown in Appendix 1.
It is difficult to compare the air quality of various cities using the average values measured at some specific locations as these locations may not be representative of the whole airshed region. The method of measurement can be very different in each country. Normally, a reference standard such as used by the US EPA is adopted but, more often than not, the instrumentation and quality assurance protocol is different. Furthermore, the population exposure to air pollutants are hard to measure. Nevertheless, it is informative to compare the air quality of some cities using values of the worst pollution events that happen at some locations in the concerned cities.
Particles
Total suspended particulate (TSP) pollution is reported (11) as serious in major cities in Asia, including Bangkok, Manila, Jakarta, Beijing, Seoul, Bombay and Calcutta.
The particulate level in Bangkok and Jakarta were so bad that the World Bank called for "immediate action" to tackle the problem (7)(16) in these two cities. One in six people in Bangkok now suffers from allergies as a result of the high level of particles in the air (7). The levels of particles at some traffic sites are very high. Measured hourly values have been reported as high as 2.18mg/m3 at one site (7). The annual average level, between 1980 to 1987, near the commercial centre of Jakarta is around 0.4-0.5mg/m3 (16) which is 8 times above the WHO annual goal.
In Manila, the daily average concentration of particles is 3 times the WHO and the Philippine standard level of 0.15 mg/m3 (15). The TSP level in Beijing is very high during winter season. This is due to the use of coal as the main source of heating and power generation. Ando et al (2) has reported that the 1991 monthly average value in Beijing is about 0.217 mg/m3 and the maximum hourly particle level around the residential area approaches a level of 0.8 mg/m3. Even during summer, as in 1985, the monthly particle level was approaching 0.2mg/m3.
There is no data yet on the measured particle levels in the residential areas of HCM City. However, data from some heavy traffic sites showed that the average peak hourly value of TSP is of the order of 6mg/m3 (3) which is very high compared to the peak value of about 0.4mg/m3 measured at the main traffic roads in Tokyo (2).
The monthly average of TSP reaches 1mg/m3 during the dry season at one street crossing (1). From the monthly average value above, the daily average can be inferred to a value of the same order. This is about 6 times the WHO standard. The maximum hourly value of 15 mg/m3 was recorded at another street. This is much higher than the maximum level reported in Bangkok from traffic sites.
It is clear that particle air pollution due to vehicles is a serious problem in HCM City. It is significantly higher than the particle pollution due to traffic in some other cities such as Bangkok and Manila.
In contrast, for indoor environment in HCM City, the domestic fuel usage for cooking has been recently switched from oil and wood to cheaper natural gas. This contributes to a reduced particle and carbon monoxide exposure.
Fine particles (PM10 and PM2.5)
Fine particles are respirable components in the TSP. They are major sources of public health concerns. At the present, fine particles are not measured in many cities. We can infer some estimates of fine particle levels using data available in cities which has similar emission characteristics.
In a recent preliminary study conducted jointly by the Korean Ministry of Environment and the US EPA (8), it has been reported that ultrafine particulate matter (PM2.5) daily average measured at two sites in Seoul were about 74 and 180 micrograms/m3 respectively. Roughly 50% of PM-10 samples are made up of PM2.5. That means the level of TSP including fine particles PM10 and PM2.5 can reach up to 1mg/m3. The WHO standard for fine particles PM10 is 0.07mg/m3.
A detailed study of the fine particle level in Jakarta by the Indonesian Environment Impact Mangement Agency with Ausaid help (16) has shown that the monthly average level of PM10 in centre of Jakarta is between 0.04 mg/m3 in the wet season to 0.08 mg/m3 in the dry season. The maximum daily average measured can reach a value of 0.14 mg/m3. For fine particle PM2.5, the monthly average level is between 0.02mg/m3(set season) to 0.04 mg/m3 (dry season).
If this data is extrapolated to other cities, it is clear that all major cities in the region including HCM City has fine particle levels exceeding many times the WHO goal for PM10.
Lead
The daily measured lead concentration measured at various sites in HCM City has been reported to contain lead concentration from trace value ~0 up to 0.41mg/m3 (1). The daily average at some sites could therefore be very high compared to the WHO annual goal. It is likely that the yearly averages for a number of sites exceed the WHO annual goal.
This level, however, is not as bad as in Bangkok. In Yaowarat area, the lead level was recorded at 0.96 mg/m3 in 1996 (10) even long after the introduction of the unleaded petrol in 1991. Before 1991, the lead level was as high as 2.34mg/m3. Other cities also recorded high level of lead concentration, such as Manila where the annual lead level exceeds the WHO goal (15) and Lahore in Pakistan where the annual average lead concentration at traffic sites is 0.004mg/m3, 3 times the recommended WHO goal (12).
It is expected that the lead pollution in HCM City is getting worse unless the government authority introduce the use of unleaded petrol.
Sulphur dioxides
Currently, as reported by WHO, Beijing and Seoul has serious SO2 pollution. The WHO guidelines are often exceeded by more than a factor of two (11). In Beijing, coal-fired power stations and the use of coal for domestic heating contribute significantly to SO2 pollution in winter. In one study (2) conducted in Dec. 1991, the measured monthly average ambient SO2 concentration in residential area was 0.233 mg/m3 which was about 5 times of that measured around main roads in Tokyo. The extensive use of coal for energy in China has produce serious sulphur dioxide and carbon dioxide pollution in many major cities of China. It also causes acid rain problem even in neigbouring countries of Korea, Japan, Taiwan and Philippine (13).
Ho Chi Minh City does not have SO2 problem as the main SO2 sources are only some large factories located in the Thu Duc area. The main power source is from hydroelectricity and most domestic usage is from natural gas or electricity. However, the concentration level near some traffic sites and industries are very high. For example, outside Tanbinh factory, the measured maximum hourly concentration is 0.76mg/m3 at 40m (1), two times higher than the WHO guideline standard.
Nitrogen oxides
From the data measured by CENIFEA (1), the level of nitrogen oxides at some traffic sites in HCM City is very high.
The monthly average, for December 1991, of NO2 measured at various main roads in Tokyo is ~0.111 mg/m3. In Bejing, for the same period , the ambient monthly average concentration recorded in the resential area is about 0.07mg/m3 (2).
From the range of daily averages measured at a number of sites in HCM city, a monthly average of about 0.15 mg/m3 can be inferred. This value is about the same order as that measured in Tokyo. This suggested that the main causes of this high level are due to some highly congested roads and the poor emission control of the vehicle exhaust system.
Carbon monoxide
The main source of CO pollution is from motor vehicles, especially older vehicles without catalytic converter. The more the number of motor vehicles, the more the CO pollution is. In Bangkok, the daily average measured concentration of ambient CO at a number of roadside stations is between 8.9 to 20.35 mg/m3. In one public health study (10) conducted recently at a bus station, people was shown to be exposed to the hourly average concentration of 80mg/m3 of CO.
In HCM City, the hourly value, recorded at a number of traffic sites by CENIFEA (1), ranges from 0 to 23.3 mg/m3. However, on 25/4/1996, the maximum hourly value of CO was measured at 62.65 mg/m3 which is 1.5 times above the standard. It can be said the the CO pollution in HCM is now approaching the level of Bangkok.
Ozone
Ozone is a secondary pollutant formed, in the presence of strong sunlight, from the reaction of oxigen with nitrogen oxides and hydrocarbon emitted mainly from motor vehicles. Smog, the combination of ozone and nitrogen oxides, is the most frequent gaseous type of air pollution in summer. In many cities in Asia, it is usual to have both particle pollution and smog happen at the same time.
Ozone pollution is frequently recorded as very high in HongKong (18) and Taipei. Although ozone is not usually measured in Manila, Bangkok or Jakarta, ozone pollution is expected to be very high in these cities. The emission of motor vehicles without catalytic converters and the presence of strong sunlight for most hours of the day make the smog formation and the ozone concentration very likely to exceed the WHO standard . It is expected therefore that the smog level in HCM City is of the same as that of other cities as the meterological condition and the emission characteristics are of similar nature.
Current measures and responses
The government has recognised the pollution problems causing rapid deterioration of the environment in recent years. After the Environment Law was adopted in 1994, on 26-04-1995, the Government issued a procedure to prosecute all cases of environment violation. In July 1995, the People Committee of HCM City has ordered the Office of Science, Technology and Environment (So Cong nghe va Moi truong) to conduct an inventory and inspection of all industrial air pollution sources in the city. Sources which has serious environment effects in relation to air, water and noise to the surrounding residents were asked to improve or risked of having the sites closed.
The Ministry of Science Technology and Environment (MOSTE) currently has a plan to set up some permanent environment monitoring stations (EMS) in many cities, especially in Hanoi, HaiPhong and Danang, with help from other countries such as Canada. In HCM City, the HCM University of Techology, has assisted in this effort by providing some technical help and evaluation.
In the area of environment management, recently the UN Development Program (UNDP) also provides a 1.12 million US dollars in a project called Capacity 21 Trust Fund to help the government to introduce environment issues in the development policies. This follows similar programs conducted before in China and India. To address the growing problem in Bien Hoa industrial area of the nearby province of Dong Nai with roughly half of the factories having outdated emission control, the UNDP also has set aside almost $1 billion US for cleanup and waste reduction. Another related UNDP project is to convert some industrial processes (especially in cosmetics) to a new processes for the protection of the ozone layer.
In 1995, the Chamber of Commerce and Industries of Vietnam, with sponsors from World Widllife Fund(WWF) and UN Development Program (UNDP), has organised a conference "Commercial development and Environment", many environment specialists has reported an alarming situation of environment pollution in many cities of Vietnam especially in HCM City. Besides air pollution, water and ground water pollution as well as waste pollution is now a serious problem that has to be tackled.
In Ho Chi Minh City, the government also actively implements the policy of moving houses near the creeks and canals, encouraging people to move to new places to protect the water and air quality as well as the hyegene of city living. A number of `Green day' and `Green week' has been initiated with the participation of youth organisations to raise the awareness of environment in the population (5).
On the issue of air pollution, a plan to set up a number of permanent air quality monitoring stations in HCM City and others in the Southern provinces has been actively pursued. More importantly, the HCM People Committee, in March 1996, announced the order to enforce the emission compliance of on-road vehicles (3). Since then, the traffic police department has conducted regular enforcement throughout the city. In the "Clean and Green" week, 12-19/5/96, 410 vehicles were booked for emission offence.
Suggestion for Air Quality management plan in HCM City
The experiences in dealing with the environment problems in other Asian cities that have happened in recent years can benefit the plan to manage the air quality in HCM City. These cities has similar development pattern in line with the strong economic growth. In view of the growing problem in HCM City, the following practical measures could be considered and incorporated in the management plan.
(1) Introduction of unleaded petrol - Spectacular gain in the reduction of lead levels has been achieved in many cities which adopted a gradual phase-out of leaded vehicles. In Bangkok, Thailand, after unleaded petrol was introduced in July 1991, the 1996 study of newborn babies showed that the lead level in the blood is one third of that before the introduction of unleaded petrol (10).
Of all pollution control measures, the abatement of lead is probably the most important gain in terms of the benefits for the health of people living in the cities, especially for children.
As SO2 is not a great concern in HCM City but consideration should be given for the encouragement of the use and the gradual introduction of low sulfur diesel fuel. This will reduce the SO2 emission from buses and utility vehicles which is the main source of high SO2 level near traffic sites. The introduction of low sulfur diesel fuel has been acted upon in Thailand in 1991. As Bangkok is relying on large power plants for electricity, power generating plant also began to use clean coal technology in 1992.
(2) Set up standards for emission control of vehicles for registration and enforce the emission compliance of on-road vehicles. The introduction of catalytic converter for motor vehicle should also be considered.
One example of this measure is that of the Thai MOSTE and the Pollution Control Department (PCD) who together set up emission standards for cars in 1992 and for motorcycles in 1993. In 1995, all buses, 3-wheeled cars (tuk-tuk) and boats were tested for emission compliance before registration.
According to the Environment Committee of Ho Chi Minh City, up to 85% of on-road vehicles is not complied to the emission regulation. Since the beginning of this year, enforcement of emission compliance of on-road vehicles has been applied by the traffic police. Some of the difficulties in the enforcement are the lack of emission standard and the fine for motorcycles is too low (3). A more effective measure is the check for emission compliance of vehicles to be eligible for registration. The check for emission should be done before any vehicle can be registered.
As nitrogen oxides and carbon monoxide pollution is very high in HCM City, the introduction of catalytic converters in the exhaust system of vehicles will improve the situation. These converters reduce the amount of nitrogen oxides, carbon monoxide and unburnt petrol escaping into the air.
(3) Establish some permanent air quality monitoring stations - Monitoring of air quality is the main means to access the effectiveness of any air quality management plan as well as to provide the state of the air quality in the city. The design of the network and the type of pollutants to be measured is considered an important factor in accessing the state of the air quality for a particular city. Permanent continuous monitoring stations also provide data for finding the long term trend of air pollutant level.
Following some lead in considering the importance of air quality monitoring as part of the environment management, a number of countries in the region has recently started establishing a network of air quality stations. The largest air quality monitoring network in Asia is in Taiwan with 66 monitoring stations throughout the large cities of the island with the majority in Taipei. In Bangkok, the Pollution Control Department has started to implement a phase I of establishing 8 permanent monitoring stations in 1993. This will be expanded to have 20 more stations in phase II in the next few years. In Kualua Lumpur, the air monitoring was previously outsourced to private companies but recently the government has funded the University of Malaya to set up a few mobile stations to acquire data. This change was due to the legal problems as the responsibilities of data quality assurance was not clarified.
(4) Develop and provide a daily information / forecasting service of air pollution level (or index) in the city. This will provide timely information to people in the event of high pollution days due to particular meteorological conditions. This will also raise awareness on the environment issue among the people.
(5) Transport planning to reduce the traffic congestion.
A number of initiatives in recent years has been encouraging such road widening, private build, operatate and transfer (BOT) scheme. But this is out of necessary rather than due to a careful or effective planning process. Transport planning also involve traffic divergence in case of congestion, management of traffic flow, effective traffic lighting coordination.. It is noted that the high level of nitrogen oxides and carbon monoxide pollution at many traffic sites is due mainly to congested traffic condition.
(6) Policy to increase the usage of public transport.
At the moment, the provision of public transport, mainly by bus, is low. There is an increasing number of taxiing services by cars and small private buses. The demand for convenient transport in the city is increasing with the an increasing number of tourists to the city. A scheme to expand the bus services in many parts of the city, especially along high traffic routes will ameliorate the traffic and pollution problems.
(7) Conduct studies to understand the characteristic of the airshed in relation to stationary and mobile sources, and the emission inventory for the whole city region.
The airshed studies involve the detailed understanding of the transport mechanism of the air due to meteorology and the emission inventory of both stationary and mobile sources. The airshed model then can be constructed. The model will then be used as a tool to access the different scenarios for different control strategies. This computer model is therefore an invaluable tool to find the best way to formulate an appropriate response to the air pollution problem.
In addition, a few more studies on the effects of air pollution on the people health to ascertain the economic cost of air pollution is also helpful. Relevant studies include the association of the levels of particle, lead, organic compounds (PAH) with people health.
(6) Formulate an effective air quality management plan based on the airshed studies and the economic implication of various control strategies.
Conclusion
The air pollution problem in HCM City is now approaching those of other larger cities in the region. The level of sulphur dioxide and lead is low compared to others but nevertheless it is increasing. The levels of particles, nitrogen oxides, carbon monoxide are of similar or higher than a number of cities such as Bangkok, Beijing, Tokyo or Manila.
To address the growing degradation of air quality in many cities in the Asian region, many government authorities are now actively formulate plan to contain the problem. For example, the Philippines government takes initiatives to meet this challenge. One of the initiative is to call for and organise meeting in 1995 on Sustainable Development within APEC countries to establish collaborative framework in protection the environment. A number of initiatives have been taken recently to contain the air quality problem in HCM City. But unless a more focused and integrated plan is implemented, using experiences from other cities that suffered serious degradation of air quality in the past, the situation of air pollution in the city will be getting worse and harder to contain in the future.
(1) Nguyen Dinh Tuan, Current situation of air pollution in HoChiMinh City - Vietnam
Proceedings of the Asia-Pacific Conference on Sustainable Energy and Environment Technology, pp. 242-248, 19-21 June 1996, Singapore.
(2) M. Ando, K. Katagiri, K. Tamura, S. Yamamoto, M. Matsumoto, Y. Li, S. Cao, C. Liang
Indoor and outdoor air pollution in Tokyo and Beijing supercities.
Atmospheric Environment, Vol.30, No.5, pp.695-702, 1996
(3) Xuan Trung , Kiem Soat O Nhiem giao thong: Khong de.
Tuoi Tre Thu Bay, 21/09/1996
(4) N. Dung, O Nhiem Moi Truong, ba con keu nhung khong ai nghe thay ..? ,
Phap Luat, So 19 (236), 23-5-1995
(5) Dang Dinh Nguyen, O Nhiem Moi Truong Do Thi : Thuc trang va giai phap,
Saigon Giai Phong thu bay, so 276, 25-05-1995
(6) Joe Parker, Keep cool and avoid the traffic,
in the Australian, 8/10/1996.
(7) S. Towprayoon, M. Kozlov, T. Kaeowjaroon, Application of mapping for assessment of air pollution in big city.
Proceedings of the Asia-Pacific Conference on Sustainable Energy and Environmental Technology, pp. 249-255, 19-21 June 1996, Singapore.
(8) US EPA Report 905-R-95-011, Mesures to address visibility reduction from airborne contaminants in Seoul, Republic of Korea
Contact Dr. Lee, e-mail lee.siduk@epamail.epa.gov
(9) A. Elleg, Urban household air pollution monitoring in Hanoi, Vietnam
Renewable Energy for Development, Feb. 1995, Vol.8, No. 1
(10) The Bangkok Post, Unleaded petrol cuts level of lead poisoning
Bangkok Post, Mar. 18 1996.
(11) WHO & UNEP, Urban air pollution in megacities of the World
Blackwell, Oxford, 1992
(12) D. Smith et al, Concentrations of particulate airborne polycyclic aromatic hydrocarbons and metals collected in Lahore, Pakistan.
Atmospheric Environment, Vol.30, No. 23, 1996, pp.4031-4040.
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Appendix 1
Country air quality standards
Pollutant Country Annual avg. Daily avg. Daily max. Hourly avg.
Total Suspended
Particulates China 0.3 1.0
(mg/m3) India 0.2
Indonesia 0.26
Thailand 0.1 0.33
Phillipines 0.15 0.25
Vietnam 0.3
Japan 0.1 0.2
USA 0.075 0.26
Australia 0.09
(NSW)
WHO 0.06-0.09 0.15-0.23
Particulate
matters USA 0.05 0.15
<10um Australia 0.05 0.15
(mg/m3) (NSW)
EU 0.07
WHO 0.07
SO2
(mg/m3) China 0.06 0.15 0.5
India 0.08
Indonesia 0.26
Philippines 0.37 0.85
Thailand 0.1 0.3
Vietnam 0.5
Japan 0.11 0.26
USA 0.08 0.365
Australia 0.06 0.7
(NSW)
WHO 0.03 0.09 0.35
Nitrogen
oxides China 0.12 0.1-0.15 0.15
(mg/m3) India 0.08 0.0925
Indonesia 0.093
Philippines 0.19
Thailand 0.32
Vietnam 3.0
Japan 0.04-0.06
USA 0.1
Australia 0.1 0.32
(NSW)
WHO 0.16 0.19-0.32
Ozone
(mg/m3) USA 0.235
Australia 0.2
(NSW)
WHO 0.065 0.15-0.2
Pollutant Country Annual avg. 3-month avg. Daily avg.
Lead
(mg/m3) Indonesia 6.0
Thailand 0.01(7)
Vietnam 0.01
EU 0.002
USA 0.0015
Australia 0.0015
(NSW)
WHO 0.0005-0.001
Pollutant Country Annual avg. 8-hour avg. Hourly avg.
CO
(mg/m3) India 2
Indonesia 22.6
Vietnam 40.0
Australia 10.0 30.0
(NSW)
USA 10.0 40.0
WHO 10.0 30.0
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