Children who ride the bus are exposed to particulate matter from diesel fumes. Carbon dioxide exposure for children who ride at the back of the bus frequently hit 5,000 ppm. Firefighters, road maintenance and construction workers have a federal right at these levels to ask for safer working conditions. Yet, children from ages 4-18 are exposed at these levels frequently, on the ride to and from school. At this level, nausea, headaches, and poor concentration are often experienced, and some can even experience permanent loss of cognitive function.
About 1-2 school buses per day in the US are lost due to fire. Most students are able to make it off safely, but smoke inhalation with these concentrated levels of carbon dioxide can lead to life long effects. These types of fumes are linked to cancer and can impair brain development.