Airborne fine particulate matter (PM2.5) is not associated with cardiac emergencies, report German researchers.
A study published in the journal Science of the Total Environment reports no correlation between ambient PM2.5 measurements in Leipzig, Germany and cardiac emergencies for the period February 2002 – January 2003. A purported associated between PM2.5 exposure and cardiac emergencies is a major basis for the U.S. EPA’s ever-tightening air quality standards.
Possibly in an effort to atone for their failure to associate PM2.5 with cardiac emergencies, the researchers instead attempt to make much of a reported weak correlation between ambient ultrafine particles (<100 nanometers) and a subset of cardiac emergencies (i.e., hypertensive crises).
But aside from the absence of any assessment of actual personal exposures to ultrafine particles and the failure to medically confirm that such exposures caused or contributed to the hypertensive crises, the reported correlation could possibly be the result of the multiple comparisons fallacy as many types of cardiac emergency over many days and multiple particle types were tested.
Additionally, we are always suspicious of seemingly cherry picked data — why limit the analysis to Leipzig during 2002?