"Millions of K–12 students in America spend several hours a day learning in schools that are more than 50 years old and in need of extensive repair and where children may be exposed to mold, poor ventilation, uncomfortable temperatures, inadequate lighting, and overcrowded, excessively noisy conditions."
Emphasizes the scale of the issue--this is not a Philadelphia or Santa Ana or Azusa problem, it is a national issue for all public schools. Also emphasizes the breadth of the issues--there are so many different forms of environmental hazards in schools.