Particulate matter (PM), formaldehyde (HCHO) and total volatile organic carbon (TVOC) are the prime air pollutants that cause serious air pollution problems and ultimately affect the human life enhancing several types of health risks.
Particulate matter (PM):
PM stands for particulate matter: the expression for a combination of solid particles and liquid droplets present in the air, often called particle pollution. Many of the objects, such as ashes, soot, or smoke, are huge or dark enough for the naked eye to see. Others are so small that only an electron microscope can be used to locate them.
They are categorized into two forms PM10 and PM2.5, PM1.0 are the particles having the diameter less than 10 micrometers while PM2.5 are the particles having a diameter less than 2.5 micrometers, while PM1.0 is referred to as the particles having diameters less than 1 micrometer. Coarser particle concentrations (> PM2.5 μm) are typically correlated with indoor activity, while finer particle concentrations (< PM1.0 μm) are associated with equivalent outdoor concentrations.
In the environment these particles come from different sources such as construction sites and unpaved roads, as well as they can be formed in the environment due to the reactions of different chemicals like sulfur dioxide and nitrogen oxides. These particles can be inhaled directly and cause serious health risks. Because of their very small size, they can enter the lungs and even directly penetrate to the bloodstream causing serious lung diseases and even cancer. They also cause poor visibility and cause haze