They were installed between November and early January at RMIT University and seven schools from kindergarten to high school levels, a children’s shelter, and the Saigon Innovation Hub scattered across eight districts.

The equipment was bought from Switzerland’s IQAir AirVisual.

Phan Trung Minh Tue, the program coordinator for the installation, said: "Teachers and students at the schools can check the air quality index themselves and make it public to everyone on Air Visual map."

The stations monitor and record the air quality index (AQI), which measures pollution on a scale of 0 to 500, and levels of carbon dioxide and PM2.5, also described as superfine particles.

It cost the consulate $12,100.

Data provided by the recipients is uploaded to the Air Visual map every 10-15 minutes, and the centers have been advised to ensure their wifi is steady to prevent any disruption.

Air monitoring equipment under a U.S.-funded project is installed at An Binh
Primary School in District 2, HCMC. Photo by Phan Trung Minh Tue.

The project targets students as the beneficiaries since they are the most affected by pollution because of their activeness, Tue said.

Tue, a trained environmentalist, said several of the schools were not keen on installing the equipment.

"[They] told me they were wary they would lose face with parents if the air quality is bad. But knowledge leads to changes."

Trinh Ngoc Thu Huong, an eighth grader at the Thanh Da Secondary School in Binh Thanh District, one of the recipients, said her principal started informing students about the air quality last year. 

Huong said: "I always thought the air around our school was clean, but was startled when I saw the index. The index is always above 150 (unhealthy) and only goes under 100 when there are not many people or early in the morning."

HCMC, Vietnam's largest city, was choked by haze regularly last year, with the AQI reaching very unhealthy levels on many days since September.

Authorities had said exhaust from around 10 million vehicles, smoke from 1,000 large factories and dust from construction sites were the three major causes of pollution.

According to the city Department of Natural Resources and Environment, the city plans to set up a comprehensive environmental monitoring system at a cost of VND495 billion ($21.3 million) by 2022.