EVERYDAY SCIENCE

Detailed explanation-1: -Particle pollution is produced by both primary and secondary sources. Primary particulate matter is emitted directly from construction sites, wildfires, wood burning, gravel pits, agricultural activities, and dusty roads. Secondary particulate matter is formed in the atmosphere through complex chemical reactions.

Detailed explanation-2: -Secondary sources let off gases that can form particles. Power plants and coal fires are examples of secondary sources. Some other common sources of particle pollution can be either primary or secondary-for example, factories, cars and trucks, and construction sites.

Detailed explanation-3: -mobile sources – such as cars, buses, planes, trucks, and trains. stationary sources – such as power plants, oil refineries, industrial facilities, and factories. area sources – such as agricultural areas, cities, and wood burning fireplaces. natural sources – such as wind-blown dust, wildfires, and volcanoes.

Detailed explanation-4: -Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. Others are so small they can only be detected using an electron microscope. PM2.5 : fine inhalable particles, with diameters that are generally 2.5 micrometers and smaller.