"Invisible Threat" by Kae Shummoogum addresses the critical and often overlooked issue of indoor air pollution, particularly in enclosed spaces like parking garages and multi-unit residential buildings. The book argues that current building codes and practices, often prioritizing energy efficiency over health and safety, lead to dangerous levels of pollutants such as carbon monoxide (CO) and nitrogen dioxide (NO2). Through case studies and research findings, Shummoogum exposes the "Cost vs. Safety Paradox" and highlights the vulnerability of building occupants, including children and pets, to these "invisible but potentially hazardous gases." The central thesis is that "Clean air should not be a luxury or an afterthought—it’s a fundamental right and a foundational part of a healthy building." The author, with over 40 years of experience in gas de ...