Qualité de l’air à Ha Tinh

Does Ha Tinh have a high level of air pollution?

Ha Tinh is a city located in north central Vietnam, being the capital of Ha Tinh province, a coastal region of the country. In times past Ha Tinh has come in with some poor readings of air quality, and continues to do so in more recent times, having a high yearly PM2.5 reading that placed it amongst the top 500 most polluted cities in the world, as of 2020.

PM2.5 refers to particulate matter that is 2.5 microns or less in diameter, and is considered as one of the more dangerous forms of pollution emitted from sources such as vehicles, factories and the burning of organic matter. Roughly 30% the size of a human hair, PM2.5 can go down to sizes many microns smaller, giving it the ability to enter into the bloodstream upon inhalation. Such fine particles can lodge deep into the tissues of the lungs, causing damage which can result in scarring or inflammation, as well as passing through the alveoli and into the bloodstream, causing damage to blood vessels and a number of other organ systems.

Regarding the levels of PM2.5 on record in Ha Tinh, it can be seen that in 2020, Ha Tinh had a yearly average reading of 33.4 μg/m³. This placed it in the higher end of the ‘moderate’ ratings bracket, which requires a reading of anywhere between 12.1 to 35.4 μg/m³ to be classified as such. This reading also placed Ha Tinh in 3^rd place out of all cities currently ranked in Vietnam, and 316^th place out of all cities worldwide.

Observing air pollution levels post 2020 (which had slightly skewed results due to the heavy restrictions imposed due to the outbreak of covid-19), Ha Tinh came in with a US AQI reading of 61 in late May of 2021, once again placing it in the ‘moderate’ air pollution bracket for that particular day in which it was taken. US AQI is an aggregate number formed from the calculation of several main pollutants, which will be touched on in the following question.

As per the standards set by the US Environmental Protection Agency (EPA), US AQI readings within the range of 0 to 150 are acceptable, although of note is that the higher end of this can still have health consequences for those who are exposed. For ease of navigating the air quality maps and their relevant graphs, the levels of US AQI are color coded and labelled accordingly, with readings of 0 to 50 being ‘good’ (green color coded), 51 to 100 being ‘moderate’ (yellow) and 101 to 150 being ‘unhealthy for sensitive groups’ (orange). Once the US AQI exceeds this level, the air quality will start to cause numerous health issues to arise, amongst the vulnerable portions of the population and even healthy individuals.

Other readings of US AQI that were recorded over April and May of 2021 were lows of 47 and 48, as well as highs of 101 and 119, putting the air quality into the ‘unhealthy for sensitive groups’ ranking and indicating a time in which the air would have larger volumes of smoke, soot, haze and other forms of harmful particulate matter permeating it.

What are some of the main air pollutants in Ha Tinh?

The main pollutants present in Ha Tinh would be the ones that as mentioned go into making up the US AQI reading, which are found in all cities across the world and anywhere that has some form of industrial activity, or combustion sources taking place. They are nitrogen dioxide (NO₂), sulfur dioxide (SO₂) and ozone (O₃), or smog as it is better known when it gathers in larger amounts.

The various oxides of nitrogen (NOx) that are also released by cars and combustion sources can undergo a chemical reaction and form ozone under the right conditions (high exposure to solar radiation), along with other gases or chemical compounds also contributing to this ozone formation.

Other pollutants include black carbon, which is the main component in soot, and a potent carcinogen when inhaled, making it a very dangerous form of PM2.5 that also has climate changing properties. Along with black carbon, volatile organic compounds (VOCs) are also formed from the incomplete combustion of both fossil fuels and organic matter. Some examples of VOCs are chemicals such as benzene, formaldehyde, styrene and toluene, all of which are extremely harmful to one’s health.

When is Ha Tinh at its most polluted?

Looking at the air quality data gathered over the course of 2020, it can be seen that Ha Tinh had months of higher pollution in the early months of the year, as well as the last two. This indicates a pattern whereby pollution levels start to rise around November, and would continue to stay elevated into the following months of the next year.

January through to April, as well as November and December had the highest readings of PM2.5, coming in with readings of 43.7 μg/m³, 46.1 μg/m³, 51.3 μg/m³, 47.7 μg/m³, 43.5 μg/m³ and 60.5 μg/m³ respectively. This showed that December was the most polluted month of the year with its reading of 60.5 μg/m³, coming in as ‘unhealthy’ (55.5 to 150.4 μg/m³ required) and the only month of the year to achieve this ranking.

When does the pollution level start to get better in Ha Tinh?

The cleanest months of the year in Ha Tinh over 2020 were observed from June through to August, as well as September and October also having adequate levels of air cleanliness, albeit on the slightly higher end. June through to August presented with readings of 10.1 μg/m³, 11.8 μg/m³ and 9.9 μg/m³, making August the cleanest month of the year and the only month to attain the world health organization's (WHO's) target goal for the best quality of air at 10 μg/m³ or less.

What health problems can arise from pollution exposure in Ha Tinh?

During bouts of high pollution, there a number of highly adverse health issues that can arise as a result of exposure. These include ones such as dry coughs and chest pain, along with irritation or inflammation of the respiratory tract and lung tissue. This can also lead to a host of other respiratory ailments that fall under the chronic obstructive pulmonary disease (COPD) bracket, with conditions such as pneumonia and bronchitis presenting themselves, along with asthma and emphysema.

Other conditions include damage to the liver and kidneys, along with cases of ischemic heart disease, strokes, heart attacks and even death amongst certain individuals, thus reinforcing the need to reduce pollution levels or keep possible exposure to an absolute minimum whenever possible.