Profile: Up Close with Associate Professor Steve Yim

By Sanjay Devaraja, Editor, The LKCMedicine

Holding a dual appointment with LKCMedicine and the Asian School of the Environment at NTU, Associate Professor Steve Yim specialises in atmospheric science. His expertise lies in the realm of air pollution, where his research is dedicated to unravelling the intricate connections between climate and air quality, with a particular focus on their implications for public health.

A/P Yim's endeavours are centred on advancing our understanding of the mechanisms responsible for the formation and removal of air pollutants arising from emissions, climate variations, and changes in land cover. His work involves a comprehensive examination of the characteristics and pathways of transboundary air pollution, coupled with an assessment of population exposure and the health effects of air pollution. Ultimately, A/P Yim's research aims to offer effective solutions for safeguarding human health and promoting sustainable development.

1. You were recently reappointed a member of the Global Air Pollution and Health–Technical Advisory Group (GAPH-TAG) of the World Health Organization (WHO). Please tell us more about this position and your contributions. 

This WHO advisory group consists of international air pollution and health experts to review, advise, and support the WHO’s efforts on air pollution and health issues. My research mainly focuses on the interactions between climate and air quality, and the human health impacts. The reappointment is encouraging because it internationally recognises my air pollution and health research. I am devoted to incorporating my latest research findings into global environmental policies for protecting human health.

2. What is your most recent paper about and what are the implications highlighted in it with regards to Population Health in Southeast Asia?

One of my recent published papers comprehensively assessed the local, transboundary and sectoral contributions in haze months of Southeast Asia in the recent years. We found the strong association between climate variability and haze pollution in Southeast Asia, particularly in Singapore. Fire and residential sources respectively affected maritime and mainland Southeast Asia. We also systemically found that the combined effect of El Niño and positive Indian Ocean Dipole exacerbated haze in Southeast Asia.

3. How has or will climate change impact human health and what can be done to mitigate associated health concerns/risks? Why is the study of Public Health important in today’s context? 

Our findings have a strong implication on population health protection, especially in Southeast Asia region which is vulnerable to climate change and transboundary air pollution. One good example was the transboundary haze episode in October 2023. During the case, Maritime Southeast Asia was under strong influences by the co-occurrence of El Niño and positive Indian Ocean Dipole. Both created a dry and hot climate over Southeast Asia that was favourable for air pollutant accumulation and long-range transport. Based on our research, our team gave an early warning to the public and governments. Public awareness was enhanced, and government actions were timely such that the haze pollution was largely reduced in terms of intensity and duration, compared to that in 2015. The next potential period of haze pollution is expected to take place between July and November this year. Our research can improve haze forecast and emission controls, and will continue to closely monitor the air quality.

4. As an Associate Professor, what do you teach and how do you make your lessons engaging and interesting for students?

My teaching field mainly focuses on urban environmental problems and their health effects. My course introduces four major problems in urban areas covering air pollution, urban climate issues, noise pollution and water pollutions. In my teaching, I use a lot of daily life examples to describe and explain the fundamental knowledge of the four problems, the assessment methods and how to manage these problems. I take keen interest in sharing with students my latest research findings and my experience in serving international organisation committees such as the WHO working group. These are very effective ways to enhance students’ interests in the class. Students always give me very positive feedback.

5. What are some of the key research projects that you are/will be working on? 

My team is currently working on several projects addressing how air quality and its health impacts respond to the projected changes of climate in Southeast Asia and the rest of the world. As the lead Principal Investigator (PI) in the climate and health cluster of our Tier 3c grant (Climate Transformation Programme) funded by the Ministry of Education (MOE), my team assesses the characteristics of O₃ sensitivity in future climate emission scenarios. We found that future emission reduction policies have to be more stringent for particular species so as to properly mitigate future O₃ pollution and health burdens in Southeast Asia. One project is currently establishing a 3-dimensional monitoring system in Singapore, called the 3-DimensionalReal-Time Atmospheric Monitoring System (3DREAMS) which is the first-of-its-kind doppler LiDAR system in Southeast Asia. 3DREAMS monitors wind and aerosol in the atmosphere up to 12km above ground in real-time across different locations in Singapore simultaneously. This new monitoring system will support our observation and forecast of transboundary haze, which will allow us to issue early warning of any air pollution episode, thus protecting population health.

6. Your multiple roles must keep you busy! What do you enjoy doing in your free time?

In addition to research, I love exercising and coffee. I enjoy playing soccer, jogging and hitting the gym. Exercising daily helps me to reduce stress and train my mind to think positively. Some research ideas even come up during my exercises.

I do not only drink coffee but make hand-drip coffee in my office. Making a perfect cup of coffee requires concentration and controlling different factors such as coffee grind size, water temperature, etc. Making a good cup of coffee is something I quite enjoy doing!