Ozone is formed when heat and sunlight cause chemical reactions between oxides of nitrogen (NOX ) and Volatile Organic Compounds (VOC), which are also known as Hydrocarbons. This reaction can occur both near the ground and high in the atmosphere.

Ground-level ozone is a secondary pollutant – it is formed through chemical reactions of other molecules already in the air, specifically nitrogen oxides (NOx) and volatile organic compounds (VOCs).

Air pollution is caused by solid and liquid particles and certain gases that are suspended in the air. These particles and gases can come from car and truck exhaust, factories, dust, pollen, mold spores, volcanoes and wildfires. The solid and liquid particles suspended in our air are called aerosols.

The common air pollutants are:

• Particulate matter (PM10 and PM2.
• Ozone (O3)
• Nitrogen dioxide (NO2)
• Carbon monoxide (CO)
• Sulphur dioxide (SO2)

Six Common Pollutants

• Carbon monoxide (CO)
• Lead (Pb)
• Nitrogen dioxide (NO2)
• Ozone (O3)
• Particulate matter (PM), and.
• Sulfur dioxide (SO2)

town of Picher

Bangladesh

Denmark is the topmost greenest country in the world, with an overall score of 82.50. It also ranks 1st with 100 scores in water resources and wastewater treatment category and also holds the first position in Ecosystem vitality.

Here are the five worst U.S. states (plus one not-state) to consider visiting:

• District of Columbia (35 percent of matchups)
• Alabama (38 percent of matchups)
• Mississippi (38 percent of matchups)
• New Jersey (39 percent of matchups)
• Arkansas (39 percent of matchups)
• Iowa (39 percent of matchups)

Hawaii ranks No. 1 for its natural environment, according to the 2021 U.S. News Best States rankings, which considers metrics such as air and water quality and pollution levels.

Here are the 10 most eco-friendly cities:

• Copenhagen, Denmark.
• Amsterdam, Netherlands.
• Stockholm, Sweden.
• Berlin, Germany.
• Portland, Oregon.
• San Francisco, California.
• Cape Town, South Africa.
• Helsinki, Finland.