Fellow 2021-22

Vishal Verma

Civil & Environmental Engineering

Verma imageHealth-Relevant Properties of Ambient Particulate Matter—Targeted Studies in Air Polluted Cities across the World

Worldwide, 4.2 million deaths were attributable to ambient PM2.5 pollution in 2015, which represented 7.6% of total deaths from all causes. Most of these deaths were in the developing countries of Southeast Asia and Africa. Unlike other air pollutants such as ozone, NOx or SO2, ambient PM2.5 is not a single chemical compound but rather a mixture of several chemical

(both organic and inorganic) species. Currently, there are at least 10 properties of the ambient PM2.5 which can be relatively easily measured. However, the key knowledge on the most important property which is responsible for the observed health effects is still missing. There is also substantial spatial heterogeneity in the physical and chemical composition of the ambient PM2.5 across the world. Despite the available technologies to measure these properties, the regulatory standard to control PM2.5 pollution in both the developed and developing world is still solely based on mass concentrations of the particles.

During his CAS appointment, Professor Verma plans to develop a global cohort for the measurement of a comprehensive suite of ambient PM2.5 properties. He plans to develop an international collaboration with aerosol engineers, chemists, toxicologists and epidemiologists located in countries such as India, China, Pakistan, Bangladesh, Egypt and Sudan to launch an intensive PM2.5 sampling campaign. These countries are among the ones which are most badly impacted by air pollution. With his research team, he will build a global database on multiple properties of the ambient PM2.5 through these efforts, which will then be used in the follow-up epidemiological and toxicological studies to look at the association of each property with the adverse health effects. The outcome of these studies will ultimately help to revisit the current mass-based standards and establish the most important property of the ambient PM2.5 related with the health effects.