Urban Air Quality
Urban air has problems from vehicle emissions, one of which is “Black Carbon”. During the 1996 Atlanta Summer Olympics several studies examined urban air quality before, during, and after the Games. The opportunity was unique because the city shut down a lot of traffic during the events. Here’s a graph of pollution levels by Friedman etal (2001):
Significant reductions were seen in ozone, carbon monoxide, and small particulate matter during the traffic shutdown.
High levels of black carbon (small particles of incompletely burned fossil fuels) correlates to 15% higher admissions rates for both pneumonia and heart attacks in winter, according to Zanobetti and Schwartz (2006):
And for summer:
Essentially, the authors connected hospital admissions with pollution levels. Comparing days with high and low pollution levels they found these differences between admissions for these two health problems.
Generally speaking, particulate matter including black carbon causes health problems in urban areas.
Friedman, M.S., et al. 2001. Impact of Changes in Transportation and Commuting Behaviors During the 1996 Summer Olympic Games in Atlanta on Air Quality and Childhood Asthma. Journal American Medical Association 285: 897-905.
Zanobetti, A., and J. Schwartz. 2006. Air pollution and emergency admissions in Boston, MA. J. Epidemiol. Community Health 60: 890-895.