The market is full of paints, carpeting, and other materials that are low in VOC s (volatile organic compounds)
. Recently more attention has been paid to the effects of such compounds on the people who live and work in traditional buildings. For instance, VOCs can trigger asthma, one of the biggest causes of absenteeism in schools. Studies have found that students in "green" schools have fewer absentee days. They also tend to do better on standardized tests, in part because natural light is healthier, causes less eye strain, and helps them stay more alert.