It has already been established that fine and ultra-fine particles are those causing the most serious respiratory and heart illnesses.
The new study was designed based on this information, allowing the scientists to apply source-oriented sampling strategy of these particular particles.
The findings were released yesterday (19th Feb) by the California Air Resources Board and the Electric Power Research Institute, and they were presented at a public seminar, hosted by the Air Board in Sacramento.
The study outlines the key sources of toxic pollutants. Specifically for the study site in Fresno, emissions from vehicles, wood burning and residential cooking were recognised as the most common causes for asthma.
The conclusions were based on data collected in summer and winter, so that seasonality is taken into account. Using a single particle mass-spectrometer, they were able to analyse and separate ambient particles. The scientists then conducted a laboratory experiment with mice.
According to Anthony Wexler, the principal investigator, director of the Air Quality Research Center at UC, Davis, and developer of the spectrometer, current air quality standards should be customized to cover only the toxic sources, which will save money to the regulators.
Pediatrics professor Kent Pinkerton, who was responsible for the monitoring of the responses to pollutants in the experimental mice, added that the method reveals the different degrees of toxicity of the different particles. This brings science one step closer to finding a solution to air pollution problems.