Scientists are a step closer to understanding what controls the fine particle in the Earth's atmosphere after new connections between the natural pollutants and the pollutants created by the man are found.
A fine particle is an air pollutant that can adversely affect human health when air levels are too high and can affect the climate.
Research could lead to stronger, more precise legislation related to climate and cleaner air. The international team, led by the University of Manchester and Forschungszentrum Jülichhung in Germany, explored the influence of secondary organic aerosols (SOA) in our air.
SOAs are extremely small particles and are created in an atmosphere of natural and artificial emissions. They are produced by complex interactions between sunlight and volatile organic compounds from trees, plants, cars or industrial emissions.
These tiny particles seriously affect the physical and mental health of people and are the major factor of premature deaths of approximately 5.5 million people worldwide every year. The influence of these particles on the climate is also responsible for the greatest contributory uncertainty of the effects the man has made on the balance of radiation affecting climate change.
The international team has been studying the creation of fine SOA particles from different pairs emitted from natural plants and from a mixture of artificial and natural pairs reacting to the lab. In all cases, they found that a smaller particle mass occurred when the same amount of steam reacted to the mixture than when it reacted itself.
The leading author, Professor Gordon McFiggans of Manchester School of Earth and Environmental Sciences, explains: "It has long been known that we need to take into account the full blend of vapors when predicting the quantity of secondary pollutants such as ozone.
"Our results now show that we also need to know what human and natural compounds are present in the real atmosphere to quantify particle contamination."
The study is the first study of this kind that deals with the influence of these complex vapor mixtures on the concentration of atmospheric particles.
Professor Thomas Mentel, a FZJ co-author, added: "By carefully designing the experiment, we have been able to understand two different ways of reducing the amount of particles created in the blends. We found that trace compounds did not compete for the reactant alone, but the products of these reactions can also react to prevent efficient particle formation.
"By incorporating this experimentally observed effect into a global air quality model, we have shown that fine particles can be significantly affected by real atmospheric conditions, not just those in the lab."
This observational quantification of the interaction between particles that can form particle provides a first insight into how pollutants will act in complex mixtures that are in the real atmosphere.
Professor McFiggans concluded: "Our work provides guidelines for understanding the future contribution of matter particles to air quality and climate. By incorporating these results and those from further experiments into numerical models, we will be able to provide real advice to policy makers."