Wildfires result in greater emissions in polluted areas than in pristine regions, a new study shows. Biomass grown in locations that experience greater concentrations of air pollution release a greater amount of pollutants when burned, researchers determined.
All plant matter release gases and aerosols into the air when burned. This new study suggests that when wildfire rages in areas such as Los Angeles, where air pollution is prevalent, the burning of the biomass releases a greater-than-normal level of pollutants into the air.
Factories, automobiles and power plants produce nitrogen as a waste product. This gas is the most common component of the atmosphere. A certain amount of the gas is essential for the healthy functioning of plants. However, too much of the gas can result in a condition known as nitrogen saturation, which can lead to a reduction in biodiversity, water contamination, acidification of the surrounding soil and other environmental challenges.
University of California, Riverside researchers examined samples from the San Bernardino Mountains east of Los Angeles. Locations 55 miles apart were examined, revealing how pollutants alter the chemistry of plants.
"This study, and specifically the concern that biomass grown and burned in polluted areas is potentially more toxic to human health, is additional evidence that human activities have consequences not yet explored and therefore not understood," Akua Asa-Awuku from the Bourns College of Engineering at UC Riverside said.
Material from the forest floor, called litter, was studied. Researchers found material collected closer to the city contained a greater concentration of pollutants than samples found further east. When burned, this litter released higher levels of nitrogen oxides and small particles than cleaner samples.
When forest service personnel carry out controlled burns, they try to predict the quantity of pollutants that will be released in the process. However, these estimates are based on burning clean biomass. This new study suggests the degree of pollution in locations where fires are planned will need to be accounted for in future prescribed burns. Researchers have stated this is another example of human beings having a poorly understood impact on the environment.
Research into how air pollution may affect emissions into the atmosphere was published in the journal Environmental Research Letters.
