Which 'Sea City' Has Worse Air Quality Than Seoul?

Fine Dust Concentration Ranks India, China, Turkiye, UAE, and Korea
By City, Busan 5th, Seoul 8th... Delhi, India is 1st

A study comparing the annual average fine particulate matter (PM 2.5) levels by country has been released, drawing attention. Among several countries, South Korea ranked 5th in the 'poor' fine dust category, and contrary to expectations that China would be first, India took the top spot.

A view of Seoul, the capital of South Korea, filled with fine dust.
[Photo by Getty Images Bank]

On the 18th, British home appliance company Dyson released the results of the 'World Air Quality Connected Data.' This data was collected from 2.5 million of its air purifiers in households across 44 cities in 39 countries worldwide during the year 2022. Dyson gathered over 500 billion data points through a smartphone app that operates the air purifiers, and stated that the sample size for South Korea was 72,645. The WHO's recommended PM 2.5 level is 5μg per cubic meter.

The countries with the highest annual average PM 2.5 concentrations were ▲India (55.18 μg/m³) ▲China (30.78 μg/m³) ▲T?rkiye (20.77 μg/m³) ▲UAE (20.37 μg/m³) ▲South Korea (18.17 μg/m³), in that order.

The cities with the highest annual average PM 2.5 levels were ▲Delhi, India (69.29 μg/m³) ▲Beijing, China (33.38 μg/m³) ▲Shanghai, China (27.72 μg/m³) ▲Shenzhen, China (24.56 μg/m³) ▲Busan, South Korea (20.08 μg/m³) ▲Istanbul, T?rkiye (19.95 μg/m³) ▲Dubai, UAE (19.39 μg/m³) ▲Seoul, South Korea (18.47 μg/m³) ▲Mexico City, Mexico (18.24 μg/m³) ▲Vienna, Austria (17.01 μg/m³), respectively.

It was found that indoor PM 2.5 levels increase during colder seasons in both the Northern and Southern Hemispheres. In South Korea, indoor air pollution was most severe in January, with January's PM 2.5 concentration being more than 2.6 times higher than the lowest level recorded in August.

Dyson stated, "As the weather gets colder, people spend more time indoors and operate heating systems that combust fuel with windows closed. When combustion continues in a closed space, pollutants cannot escape outside and accumulate, worsening indoor air quality. Therefore, managing indoor air quality during winter is essential."

■ Protecting Your Body from the Invisible Enemy, Fine Dust

1. What is Fine Dust?
- Fine dust generally refers to particles with a diameter of 10㎛ or less. Particles with a diameter of 2.5㎛ or less are classified as fine particulate matter (PM 2.5). Fine dust mainly originates from the combustion of fuels such as coal and petroleum or from vehicle exhaust emissions.

2. Effects of Fine Dust on Our Body
- Fine dust enters the respiratory tract when breathing and penetrates deep into the alveoli, potentially causing various respiratory diseases.
- Patients with chronic obstructive pulmonary disease, bronchitis, asthma, bronchiectasis, and other lung diseases may experience worsened symptoms due to fine dust.
- Prolonged exposure to fine dust can weaken the immune system, making one more susceptible to colds and pneumonia.
- Besides respiratory diseases, the incidence of cardiovascular diseases, skin disorders, and eye diseases is also known to increase.

3. Avoid Outdoor Activities on Days with Fine Dust
- People with respiratory or cardiovascular diseases, children, the elderly, and those with weakened immune systems should avoid outdoor activities as much as possible.
- If going outside is unavoidable, using a dust mask can help filter out fine dust.
- It is important to wash hands thoroughly after returning home from outdoor activities.

4. Can Air Purifiers Help Solve Fine Dust Problems?
- Reports indicate that using air purifiers equipped with High-efficiency Particulate Air (HEPA) filters can reduce indoor fine dust concentrations.
- However, since different air purifiers use different filters and results are inconsistent, it is difficult to say that all are effective.
- Indoor pollutants include gaseous pollutants such as nitrogen dioxide (NO2) and formaldehyde, as well as various airborne microorganisms. Therefore, reducing fine dust alone does not fully improve indoor air pollution.