Health Impact, Protect Yourself

Your N95 Mask Will Not Protect You from Sulfur Dioxide

01 · Feb · 2021
Photograph by: Selenge Dima

Mонгол хэлээр эндээс уншаарай

By the Breathe Mongolia Team

The time has come to open another can of worms about air pollution, an annual tradition and headache for many in Mongolia. This time, we’ll provide a brief overview of sulfur dioxide (SO2)—a major air pollutant in Mongolia.

What is sulfur dioxide?

Sulfur dioxide (SO2) is a gaseous air pollutant composed of sulfur and oxygen. SO2 is generated by the combustion of sulfur-containing fuels, such as coal, oil, and diesel. It is also emitted by metal processing plant operations. After emission, sulfur dioxide converts to sulfate in the atmosphere and greatly contributes to air pollution in Mongolia. 

How does sulfur dioxide affect our health? 

People with bronchial asthma are more susceptible to the hazardous health effects linked to sulfur dioxide. It narrows the airways, increases the incidence of respiratory diseases, reduces the lungs’ protective mechanism, and provokes chronic cardiovascular disease. Physiological responses include wheezing, shortness of breath, sneezing, and coughing. With the COVID-19 pandemic and the onset of the flu season, cardiovascular, nervous, and respiratory systems are in great danger. 

Is breathing toxic gases and particles for more than half a year without any other choice inevitable? N95 and N99 masks and air purifiers can filter out fine particles, but they cannot filter out toxic gases. Therefore, we can’t protect the health and lives of our loved ones with just these masks alone!

According to the Mongolian Air Quality Standard MNS 4585:2016, the permitted 24-hour average concentration of sulfur dioxide should be 50 μg/m3, and the annual average should be 20 μg/m3. The World Health Organization recommends an average of 20 μg/m3 for 24 hours. Compared to 2019, the sulfur dioxide in Ulaanbaatar’s air in December 2020 was 105 μg/m3, which is 99% or four times higher than the Mongolian air quality standard. It is ten times higher than the World Health Organization’s recommendation.

Name of pollutant Air Quality Standard MNS 4585:2016 Average concentration, μg/m3
Allowable concentration, μg/m3 December 2019 December 2020
PM10 particles 100 138 132
PM2.5 particles 50 113 105
Nitrogen dioxide NO2 50 65 55
Sulfur dioxide, SO2 50 106 211

According to, Ulaanbaatar’s weekly air quality report in January 2021 showed that sulfur dioxide levels exceeded the permissible level (indicated by the red line in the graph) several times a day and were even higher than last year’s levels.

We must not slow down our efforts to fight air pollution! A lot of work must be done to insulate homes and reduce the use of solid and substandard fuels. Moreover, we must improve the quality of construction, and reduce heat loss and energy consumption. Newly appointed decision-makers need to prioritize this severe public health crisis to keep everyone healthy and safe.

According to Mongolia’s Air Quality Reporting Procedure, as soon as the average 24-hour pollution level exceeds the allowable level, medical advice and recommendations should be made available to the general public. It is not enough to put a few colored numbers on! Protect your citizens from the invisible killer—which is no less harmful than the COVID-19 virus—and provide them with information on methods to protect our loved ones daily from air pollution. More information on sulfur dioxide will be available soon.

More Ways to work with us


Ask a question

Can’t find what you’re looking for? Let us know and we will work on finding the answer.

Ask Here >


Share what you know

We are committed to sharing reliable and up-to-date information. If you would like to suggest a helpful resource.

Submit Here >


Volunteer to do research

Our work would not be possible without the support of our global kind-hearted and smart volunteers.

Sign Up Here >