Updated 5 hours ago NBC Universal, Inc. As employees and students prepare for their return to offices and classrooms, an NBC Bay Area investigation reveals a surprising lack of oversight regarding indoor air quality, which may have led to more COVID-19 infections and deaths. Experts argue the problem existed well before the pandemic and continues to threaten workplaces and schools across the country. A lack of education, awareness, and accountability may be leading to hazardous indoor air conditions inside a wide array of buildings throughout the nation. One study found 85% of classrooms had inadequate air ventilation, allowing toxins to accumulate. Download our mobile app for iOS or Android to get the latest breaking news and local stories.