Indoor air quality (IAQ) healthy and safety or not

Indoor air quality has become an important health and safety concern.
Common issues associated with include:
Improper or inadequately maintained heating and ventilation systems
Contamination by construction materials, glues, fibreglass, particle boards, paints, chemicals, etc.
Increase in number of building occupants and time spent indoors.
Handheld particle counter let you know good or bad indoor environment which you living.