Chemical Composition of Air Pollution Particles Varies in Cities
Microscopic particles suspended in the air, known as atmospheric aerosols, are a serious source of pollution. These particles can be produced by combustion, whether from the motors of cars and trucks or from homes and factories. They are also produced as a side effect of agricultural activity. These small particles can settle into the lungs, sometimes spreading to other parts of the body, and cause negative health effects in humans. People who breathe in polluted air for extended periods of time increase their risk of heart disease, worsening asthma, or a variety of pulmonary diseases. Because of the danger these aerosols pose, governments often measure their total mass in the atmosphere to help guide public health policy.
Recently, researchers from France, the Netherlands, and Switzerland were interested in whether the type of chemical in these small particles differed based on location. Specifically, they studied the presence of oxidative chemicals within these particles, since this type of chemical in general is known to react with and damage structures in human cells. They collected data from a series of measurement statements throughout Switzerland and Liechtenstein and found that aerosols in general were fairly evenly dispersed across this region. However, particles containing oxidative chemicals were formed principally in cities and other locations with high population densities. The authors attribute this to more cars and wood burning in these areas, which both produce oxidizing particles.
As a result, the authors note that these high population areas with a high concentration of oxidizing particles could be targeted for public health interventions to help reduce this pollution. Right now, both the WHO and the EPA make health recommendations based only on the total mass of particles rather than the specific chemicals in pollutants. However, further research needs to be done on the specific human health effects of oxidizing particles compared to those without oxidative chemicals, in order to determine whether public health interventions should additionally take the chemical composition into account.
Managing correspondent: Emily Kerr
Image Credit: Wikicommons: Tokyoahead
