As Bangkok’s air pollution levels reach dangerous new heights, the government is testing a new way to clear the air.

A fleet of drones was deployed on Tuesday to spray water and non-hazardous chemicals into the air in an attempt to reduce pollution, Quartz reports.

Officials tested this method to see if the machines could spray the pollution out of the sky after air quality around the city was deemed hazardous on Monday, containing high levels of particles 2.5 microns and smaller, which are small enough to fill a person’s lungs. These particles, called PM2.5, recently reached 185 micrograms per cubic meter in Bangkok, far surpassing recommended levels. Quality air contains anything under 50 particles per cubic meter, and anything above 150 is deemed dangerous. High levels of PM2.5 can cause health issues including respiratory damage and can worsen cardiovascular disease.

Globally, about 7 million people die each year from air pollution according to WHO.

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Because of Bangkok’s hazardous air quality readings, 10 areas around the city were flagged "code red" and over 30 areas found to be "code orange" by the city’s Metropolitan Administration’s Environmental Office’s Air Quality Division. If the level of air pollutants remains this high for three consecutive days, officials may try to reduce emissions by asking residents to avoid driving in the city.

Many civilians have been wearing masks while traveling throughout the city to avoid inhaling the toxins, however, the efficacy of these masks is disputed. 

Diesel-fueled cars and power plants that burn fossil fuels are common sources of pollution emissions in the area.

Officials conducted a test run of the drones earlier this week in a small park. The results showed that they reduced dust particles in the air by about 10 micrograms per cubic meter. While the drones were successful on a small scale, more testing needs to be done to see if the drones could cover a larger area and clear pollution out of the entire city.

Read More: Clean air and healthy lungs: how to better tackle air pollution

If the positive results continue this week, more drones will be released in other areas around the city including above Vachirabenjatas and Chatuchak parks.

In addition to this, officials are planning on curbing pollution by reducing emissions, by phasing out diesel-fuel cars, inspecting public buses, and enacting daily cleanups of the city’s roads.