Black Carbon Health Effects
In the PM family, black carbon is a major contributor to the fine particle (PM2.5) burden in the air. It is small enough to be easily inhaled into the lungs and has been associated with adverse health effects. Whether black carbon is itself toxic or functions as an indicator of other co-pollutants is currently under debate. But, clearly, black carbon is associated with asthma, and other respiratory problems, low birth weights, heart attacks and lung cancer. EPA scientists study the effects of particles including black carbon on human health through clinical and animal testing.
Using human and animal exposure data, researchers can estimate the amount of black carbon deposited into lungs under a variety of breathing conditions. When compared with lung tissue samples from coal miners, smokers and nonsmokers, correlations and predictions can be drawn between the exposure and potential risk of adverse lung outcomes. Such research has contributed to global awareness of black carbon's health effects.
Research to investigate children's asthma in Detroit, Michigan, is examining the impact of diesel exhaust from roadways. As part of this research effort, the Near-Road EXposures to Urban Air Pollutants Study (NEXUS) is evaluating the impact of vehicle emissions, including black carbon, on near-road exposures and asthma outcomes.
Similarly, controlled clinical studies in adults are being conducted to examine the health effects from exposure to different air quality scenarios: diesel exhaust, clean air, ozone, or a mixture of diesel exhaust and ozone.
Peat-burning wildfires, as occurred in a large wildfire in the summer of 2008 in rural eastern North Carolina, released enormous amounts of PM, especially black carbon, which were linked to increased risk of heart failure and respiratory hospital visits in the affected region.
EPA research will continue to evaluate the health effects wildfires, involving black carbon, have on disadvantaged groups.