Potentially 90 Percent of Crime Rate Changes Explained by...

IN 1994, RICK NEVIN WAS A CONSULTANT working for the US Department of Housing and Urban Development on the costs and benefits of removing lead paint from old houses. This has been a topic of intense study because of the growing body of research linking lead exposure in small children with a whole raft of complications later in life, including lower IQ, hyperactivity, behavioral problems, and learning disabilities. But as Nevin was working on that assignment, his client suggested they might b...

 Los Angeles's Air Quality Regulations

Los Angeles air quality has improved in recent years because of new regulations on automobile and plant emissions, but the American Lung Association still ranks the Los Angeles area as the metropolitan region in America most polluted by year-round particles, short-term particles, and ozone. This persistent ranking contrasts with other data on Los Angeles's environmental progress. For example, the number of "exceedance" days in the Los Angeles / Long Beach area of southern California (days tha...