Understanding the Great Indoors: A Review on Physical and Chemical Transformations that Occur in Indoor Environments

Many of the reaction mechanisms that occur outdoors, such as radical chemistry, photolysis, and interfacial chemistry are also common reactions that occur in an indoor atmosphere. Though they share similar chemical processes, they are far from identical. Environmental conditions heavily impact the resulting chemical composition. Unlike the outdoors, many pollutants accumulate indoors due to poor ventilation. Pollutants stem from common household products such as perfumes and cleaners, and processes like cleaning. They are also transported through air exchange with outdoor ambient air. Although 90% of a human’s life is spent indoors, few regulations exist to control critical levels of hazardous compounds. Thus, understanding the chemical processes that form hazardous emissions will help us understand how to promote healthy indoor air quality. This review will present common environmental conditions that affect chemical and physical processes.