Association of Out-of-Hospital Cardiac Arrest with Exposure to Fine Particulate and Ozone Ambient Air Pollution from Case-Crossover Analysis Results: Are the Standards Protective?
Ensor, Katherine B.
About 300,000 cardiac arrests occur outside of hospitals in the United States each year; most are fatal. Studies have shown that a small but significant percentage of cardiac arrests appear to be triggered by exposure to increased levels one of two air pollutants: fine particulate matter and ozone. We analyzed seven key studies to determine if Environmental Protection Agency (EPA) standards protect the public from out-of-hospital cardiac arrests (OHCA) triggered by exposure to fine particulate matter and ozone. Using Houston, Texas, data, we found evidence of an increased risk of cardiac arrest on the order of 2% to 9% due to an increase of fine particulate levels (a daily average increase of 10 µg/m3) on the day of, or day before, the heart attack. The EPA fine particulate standard of 35 µg/m3 (35 micrograms per cubic meter of air) therefore does not effectively protect the public from OHCA triggered by exposure to fine particulates. However, the EPA’s ozone standard does appear to adequately protect public health from OHCA triggered by exposure to ozone.