Air quality in Tinh Dong Nai

How good is the air quality in Tinh Dong Nai?

Tinh Dong Nai is a Vietnamese state approximately 30 kilometres east of Ho Chi Minh City which is often looked upon as the southern capital city. It has an excellent road connection with Ho Chi Minh City from Vietnam Highway 1. In 2018 the estimated population was 1.25 million people.

At the beginning of 2021, the air quality in Tinh Dong Nai was noted to be “Unhealthy for sensitive groups” with a relatively high US AQI number of 111. During the months of November and December, Ho Chi Minh City had also experienced this level of air pollution but for the remaining 10 months, the level was classed as “Moderate”. These figures are based on suggested levels by the World Health Organisation (WHO).

What can be done to improve the air quality in Tinh Dong Nai?

Dong Nai has been monitoring the AQI (air quality index) since 2003 to keep track of the changes in air quality in many areas. The whole province currently has 126 monitoring stations, which are mainly found in high-risk areas (52 monitoring locations around industrial zones (IPs), 10 locations around industrial clusters, 25 locations in residential areas, 13 locations at some major intersections and 9 locations in solid waste treatment areas. The frequency of operation is every 2 months with many parameters such as temperature, humidity, wind direction, wind speed, particulate matter of both PM2.5 and PM10, carbon monoxide (CO), sulphur dioxide (SO₂), nitrogen dioxide (NO₂), ammonia (NH₃), hydrogen sulphide (H₂S) and noise levels recorded.

The results of monitoring the air situation for 3 consecutive years and 9 months of 2019 show that the AQI index in the area is relatively stable, the parameters in most of the monitoring locations meet Vietnamese standards. However, there are still some areas with local air pollution occurring at some time during the monitoring, which is mainly dust in the mining areas and traffic concentration areas. However, monitoring positions in some industrial clusters detected dust concentrations in excess of an acceptable level.

Additionally, results from 2 monitoring stations continuously recorded and noted that the AQI levels are within the allowed standard threshold. Inevitably, pollution still occurs locally at some intersections with a high density of vehicles at rush hour. From this result, it can be said that Tinh Dong Nai has not faced the risk of air pollution on a large scale.

On 23^rd September 2020, the local authorities had to intervene and suspend operations by one particular factory. The La Nga Sugar Joint Stock Company which is located in La Nga Commune, Dinh Quan district, Dong Nai province.

Because of the monitoring program on the implementation of the regulations on environmental protection, the local authorities discovered that Cane Joint Stock Company in La Nga commune had allowed exhaust gas exceeding the prescribed standards and discharged wastewater without permission into the environment. The production was suspended for 9 months and the company was required to take preventative measures in order to prevent a similar occurrence in the future. They were fined 4 billion VND and were informed that if they are now able to work within the parameters laid down by the local authorities, they will be allowed to restart their operations.

The activities of a carpentry workshop which was causing noise and dust and greatly affecting the daily life of the households in the area were reported to the local authorities who came to an agreement with the workshop who agreed to relocate to an area away from the residential part of the city.

Is the air quality the same in all of Tinh Dong Nai?

In May 2019, whilst monitoring 19 industrial clusters, dust parameters were detected in locations around some industrial clusters from 1.06-1.57 times higher than the acceptable levels. These are the areas where many companies produce construction materials and there is a high volume of trucks carrying soil and rock which are frequently moving from one site to another.

Recently, the Department has implemented many solutions as well as requiring the waste source owners to invest in environmental protection works such as mist spraying, a cleaner means of transport and investment in new technology. Waste gas from their chimneys can be treated before being released into the atmosphere. They are also encouraged to use clean-burning materials for production. As far as mines in the area, the Department has installed cameras to transmit data to the unit for monitoring and supervision. And advice when the air quality is unacceptable.

In Nhon Trach industrial park (Nhon Trach district), the synthetic dust parameter exceeded the standard by 2.56 times. Observation at the Long Thanh Industrial Park showed that the synthetic dust index exceeded the standards by1.15 times. Xuan Loc industrial park exceeded by 1.23 times; Ho Nai industrial park exceeded by 1.16 times; Tam Phuoc industrial park exceeded by 1.19 times; Amata industrial park exceeded by 1.35 times; Bien Hoa 1 industrial park exceeded by 1.37 times, and Bien Hoa 2 industrial park exceeded by1.34 times higher than regulated standards.

In addition, monitoring in the Dong Mu Rua temporary landfill area in Nhon Trach district showed that the environmental index of synthetic dust in this area exceeded the standard by 9.19 times the permitted level. Also at the Hiep Phuoc intersection, the environmental parameters for synthetic dust parameter exceed by 1.42 times the permitted standard.

It was stated that this could have an adverse impact on the health of people in the affected area. The local authorities can now instigate remedial plans in order to restore a healthy environment to the affected area.

Does the transportation system contribute to poor air quality in Tinh Dong Nai?

In January 2020 the local authorities of Dong Nai province issued an official document on strengthening air pollution control and the handling of hot spots for dust pollution and emissions in the area. In particular, they requested that the results of the air quality monitoring are published online so that residents have free and easy access to the figures and can plan their actions, accordingly. In Ba Ria Vung Tau the local authorities have installed large LED screens at two main intersections which display the air quality in real-time. Perhaps this is something to be considered for the future. With advances in modern technology, it is possible to access this information through a downloadable app on a smartphone.

Where does most of the air pollution in Tinh Dong Nai come from?

As with most cities, the major cause of air pollution in cities comes from vehicle exhaust. Other sources are from the large industrial zones situated on the edges of the city and also from poor quality air that is blown in from other regions, sometimes even from other countries.

Because of its proximity to Ho Chi Minh City, many people commute between the two cities on a daily basis. Many of the vehicles are old and not maintained to high standards. There are 1000’s of motorbikes on these roads as they make up the most popular form of transport because of the availability, convenience and low running costs. Gasoline can be adulterated with the addition of cheap hydrocarbons which are certainly not good for the environment.

Many of the large, heavy-duty trucks are powered by diesel which is a particularly high source of soot or black carbon (BC). This is categorised as PM2.5 particles which are dangerous to the human body because of their microscopic size. They can easily bypass the body’s natural defence mechanism and penetrate deep into the lungs. Here they lodge themselves at the base of the bronchial tubes, in the alveoli. It is here where oxygen and nitrogen dioxide are exchanged so these small particles easily find their way into the bloodstream. Once in the blood, they eventually find their way to the heart where most of the damage can be done.

Most of the gas generated from the process of burning firewood, coal and charcoal has not been treated before discharge into the environment. Almost 99 per cent of combustion products are substances such as nitric oxides (NO_x), steam (H₂O), carbon dioxide (CO₂) and PM2.5 and PM10 particles. During the burning process, a large amount of soot, ash and some toxic gases are produced. There is a company who provides flexible technology solutions in each waste gas treatment unit, technology measures are implemented based on the waste source quality assessment standards. Depending on waste sources such as fuel burning whose concentrations and characteristics of the source are different, the company provides services in many forms from turnkey projects to supplying individual pieces of equipment. They can typically supply air pollution control equipment, the construction of waste gas treatment works and offer consultations as to how best to take control of the situation.

What are the health effects of breathing poor quality air in Tinh Dong Nai?

The Department of Natural Resources and Environment regularly publishes the AQI index in each specific region. In areas with unacceptable levels, the Department recommends that people from sensitive groups, such as children under the age of 14 years, pregnant women, and senior citizens go out only when necessary and even then spend as little time as possible in the dirty air. When going outside, it is advisable to wear a good quality mask and shield where possible when exposed to a polluted environment. At the same time, the Department also informs industries and localities when AQI is bad, so they can take measures to control, regulate traffic and strengthen control of emissions.