This book explores the relationships between biological contaminants and human health, as well as providing in-depth information of numerous biological contaminants found in diverse settings such as homes, hospitals, businesses, and schools. The current literature study has provided qualitative and quantitative data on bio-contaminants in these diverse indoor contexts. The main objective of this book is to investigate the pattern of morbidity among the people living in industrial, commercial, and residential due to poor air quality. Furthermore, biological sampling data obtained from indoor sites in different seasons provides seasonal adverse health problems explainations. The current study's findings may aid in the development and implementation of preventative public health programs, as well as the creation of recommendations aimed at creating better indoor settings.