PatnaDaily The indoor environment becomes a concern when it gets contaminated due to Chemical, Biological and Radiological (CBR) pollutants. The monitoring of indoor environments becomes necessary in order to evaluate and manage the health and hygiene around such polluted area. This distresses everyone to some extent, but it is particularly harmful to residents around metropolitan areas with large industrial settings, children whose immunity is still developing, the elderly with known medical conditions and of course, people with compromised immune systems. The Sources of CBR Pollutants CBR related issues of the indoor environment may induce due to a number of activities within the building or as a result of outside infiltration or the combination of both. Some common and frequent CBR agents/of the indoor environment is described below: