Table1.

Major bio-contaminants of indoor air, their sources, lifestyle and health effects

Causative organism	Health effect	Lifestyle of organism	Sources in indoor area
Bacteria
M. tuberculosis	Tuberculosis (T.B.)	Obligate parasite	Human
Legionella spp.	Pneumonia	Facultative parasite	Hot water sources
Y. pestis	Plague	Facultative parasite	Infected fleas
B. anthracis	Anthrax	Facultative parasite	Animal handlers, veterinarians
Fungi
Alternaria spp.	Asthma, rhinitis	Saprophytes	Outdoor air, damp surfaces
Histoplasma spp.	Histoplasmosis	Facultative parasite	Bird droppings
Aspergillus (aflatoxin)	Cancer		Damp surfaces
Penicillium spp.	Penicilliosis	Facultative parasite	Mold contaminated building
Viruses
Influenza virus	Respiratory infection	Obligate parasite	Human
Variola virus	Chicken pox	Obligate parasite	Human
Coronavirus (SARS-CoV-2)	Coronavirus disease	Obligate parasite	Human
Algae
Chlorococcus spp.	Asthma, rhinitis	Autotrophic	Outdoor air