The cleanest and dirty places in the world are known

The US Virgin Islands, New Caledonia and Puerto Rico are recognized as the places with the cleanest air in the world. It is reported by CNBC. Specialists from the Swiss company IQAir studied the state of air purity in 117 countries, in particular the level of PM 2.5 microparticles in the air, and found that only three surveyed areas  air purification achieve the required standard ·standards.
It should be noted that this Swiss company is engaged in the production of air purifiers. Bangladesh, Chad, Pakistan, Tajikistan and India rank last in the world for air quality.
Note that PM 2.5 microparticles can cause respiratory diseases, heart attacks, strokes and cancer. It should also be noted that according to WHO, 4.2 million people die each year due to air pollution.