[ad_1]
Yale researchers have discovered that a type of air pollution is much more complex than previous studies.
The researchers were able to analyze air samples in great detail using very powerful devices analyzing the molecular composition of organic aerosols, which have a significant presence in the atmosphere. In presenting risks to health and climate, these suspended particles generally fall into two categories: primary organic aerosols that can form during combustion, such as exhaust gases from cars and trucks, and secondary organic aerosols resulting from the oxidation of organic gases and airborne particles.
For the study, published November 2 in Nature's Communications chemistrythe researchers used a combination of liquid chromatography, which separates thousands of compounds from a sample, and a mass spectrometer, which identifies and analyzes these compounds.
"Here we can actually distinguish molecules that otherwise seem to be very similar," said lead author Drew Gentner, assistant professor in chemical and environmental engineering. "In previous studies, they had less information about molecular identities in the complex mixtures present. With these instruments, we can determine molecular formulas more accurately. "
The researchers point out that this is an important step forward because it is essential to know what harmful elements are in the air to find ways to reduce them, added Gentner.
"If you develop an air pollution control policy based on less specific information about organic aerosols, the molecular composition may vary much more than you would expect, which could affect the properties and impacts of aerosols." Said Jenna Ditto, Ph.D. candidate in Gentner's laboratory and lead author of the study.
Collected for three weeks at each site in summer, samples were taken from a Michigan forest and in urban environments in Atlanta and New York. According to the researchers, the variations observed in the samples taken from the same sites were the most surprising. In most cases, up to 70% of the compounds present at one site were distinct from each other in consecutive samples.
Although some causes remain constant, according to the researchers, several factors could be at the origin of the variability. "The different types of compounds emitted by cars and plants can vary from one car to another or from one tree to another," said Ditto.
Other factors, such as weather conditions and chemical oxidation conditions may also change. Individually, these variations are usually minimal, but they can add up to important differences, said the researchers.
In support of this study, the researchers said they plan to further analyze the results to better understand the types of effects that these variabilities could have on health and climate.
"There is a wealth of information in these details to use by the field," said Gentner. "You can leverage valuable data to understand what's happening throughout the complex system."
More information:
Jenna C. Ditto et al, Ubiquitous diversity and variability in the chemical composition of functionalized organic aerosols in the atmosphere, Communications chemistry (2018). DOI: 10.1038 / s42004-018-0074-3
Yale researchers have discovered that a type of air pollution is much more complex than previous studies.
The researchers were able to analyze air samples in great detail using very powerful devices analyzing the molecular composition of organic aerosols, which have a significant presence in the atmosphere. In presenting risks to health and climate, these suspended particles generally fall into two categories: primary organic aerosols that can form during combustion, such as exhaust gases from cars and trucks, and secondary organic aerosols resulting from the oxidation of organic gases and airborne particles.
For the study, published November 2 in Nature's Communications chemistrythe researchers used a combination of liquid chromatography, which separates thousands of compounds from a sample, and a mass spectrometer, which identifies and analyzes these compounds.
"Here we can actually distinguish molecules that otherwise seem to be very similar," said lead author Drew Gentner, assistant professor in chemical and environmental engineering. "In previous studies, they had less information about molecular identities in the complex mixtures present. With these instruments, we can determine molecular formulas more accurately. "
The researchers point out that this is an important step forward because it is essential to know what harmful elements are in the air to find ways to reduce them, added Gentner.
"If you develop an air pollution control policy based on less specific information about organic aerosols, the molecular composition may vary much more than you would expect, which could affect the properties and impacts of aerosols." Said Jenna Ditto, Ph.D. candidate in Gentner's laboratory and lead author of the study.
Collected for three weeks at each site in summer, samples were taken from a Michigan forest and in urban environments in Atlanta and New York. According to the researchers, the variations observed in the samples taken from the same sites were the most surprising. In most cases, up to 70% of the compounds present at one site were distinct from each other in consecutive samples.
Although some causes remain constant, according to the researchers, several factors could be at the origin of the variability. "The different types of compounds emitted by cars and plants can vary from one car to another or from one tree to another," said Ditto.
Other factors, such as weather conditions and chemical oxidation conditions may also change. Individually, these variations are usually minimal, but they can add up to important differences, said the researchers.
In support of this study, the researchers said they plan to further analyze the results to better understand the types of effects that these variabilities could have on health and climate.
"There is a wealth of information in these details to use by the field," said Gentner. "You can leverage valuable data to understand what's happening throughout the complex system."
More information:
Jenna C. Ditto et al, Ubiquitous diversity and variability in the chemical composition of functionalized organic aerosols in the atmosphere, Communications chemistry (2018). DOI: 10.1038 / s42004-018-0074-3
Source link
