The 10 most serious air pollution country in the world

There are two hundred million people living in the world.
10 of the world's most polluted places are in 8 countries:
Argentina, Bangladesh, Garner, Indonesia, Nigeria, Russia, Zambia and Ukraine.
Particle counter is the best helper to check air quality.
It can check both the 0.3μm and 2.5μm fine particulate matters.  also the PM2.5 and PM10.
Some team also use the laser particle counter to demo the air purifier Working performance.