Size-resolved chemical properties and sources of PM2.5 at urban Gwangju

Abstract

Environmental pollution has caused us to take drastic measures to reduce its global impact and protect the climate and effects on the lives of people and other animal and marine life. Recently, different studies have been proposed (Xing et al., 2016; Wang et al., 2016; Lin et al., 2018) to reduce the environmental impacts by adopting various strategies. Air pollution continues to be a growing problem in major cities around the world (WHO, 2016). Megacities, such as Beijing, New Delhi, Ulaanbaatar, Los Angeles and even cities in the Korean peninsula have been found to be affected by either local or long range transport (K. Park et al., 2012; J. Park et al., 2013). This pollution has resulted in growing increase of health problems around the world leading to cardiovascular diseases, pulmonary diseases, respiratory problems, lung and skin cancer, stroke and heart attack to be named among a few. Some studies have also explored their wider effects on the brain by neurological disorders and birth defects in new born children (Woodward et al., 2015; Zhang et al., 2018). The short term and long term health effects have caused to develop scientific methods to quantify their health effects and provide measures to mitigate such health outcomes. One of the promising scientific method developed over the last few decades is the ‘source apportionment” (SA). Source apportionment is carried out to identify possible sources of air pollution in a geographical region and quantify their contribution towards the overall environmental burden by taking measurements and chemical analysis and using scientific algorithms to identify major components or ‘sources’ responsible for it, either natural or anthropogenic (i.e. caused by human). vi

A receptor model will not predict the future, however, it helps to identify major pollutants; hence roll-back techniques are employed to reduce the effects of air pollution in a receptor model studied area. For example, if traffic emissions are high, stricter controls on type of fuel used; flow of traffic or emission controls could be implemented to reduce air pollution. This could help in substantial savings in health and its associated costs. Costs can be in terms of saving human lives (mortality) or long-short term illnesses (morbidity), hence the global burden of disease (GBD), which is a new and developing area in the field of science, can be explored. This study also explains the results obtained from chemical speciation of size-resolved ambient data by Micro-Orifice Uniform Deposition Impactor (MOUDI) at Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea. By understanding the effect of aerosols and their chemical constituents at different sizes, better understanding of sources can be obtained, as has been explained in previous studies (Gao et al., 2016; Taiwo et al., 2014). However, complete source apportionment for MOUDI data will be obtained by using 2 MOUDIs set up side by side. One MOUDI will be used for gravimetric, ionic and elemental species analysis, while the other will be used for OC-EC speciation. In this way we can obtain the results as have been produced in Gao et al., 2016. In our MOUDI results, in addition to source characterization, cancer health risk (Excess Lifetime Cancer Risk (ELCR) and non-cancer health risk (Hazard Quotient) were also determined for metal species at the measurement site.