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What do we know about outdoor air quality in T&T? One researcher's journey


Air pollution in Point Lisas, a major industrial area in Trinidad and Tobago. A new U of T Engineering study led by alumna Kerolyn Shairsingh (ChemE 0T8, PhD 1T8) measured local traffic-related emissions on Trinidad and Tobago. (Photo courtesy of Kerolyn Shairsingh)

“Change takes time. Have patience and don’t give up. Sometimes an idea is born before its time but that doesn’t mean it’s not feasible, it just means you need to give the population time to grow into the future” is the advice given by PhD. researcher Dr. Kerolyn Shairsingh of the University of Toronto who is also a Trinidad and Tobago National with a passion for the sustainable development of her home country. Dr. Shairsingh, under the supervision of Professor Greg Evans of the University of Toronto recently conducted the first study of local emissions in T&T, focusing primarily on the airborne pollutant black carbon — also known as soot — which has been linked to negative health outcomes including lung conditions and cancer. Their groundbreaking findings shows how vehicular traffic, primarily through the widespread usage of diesel can have a significant impact on air quality and has been shown to pose health risks such as asthma, respiratory infections, lung cancer, strokes and cardiovascular mortality.

Dr. Shairsingh’s findings represent a new way of problem solving in Trinidad and Tobago, an approach that’s based on research. We reached out to Dr. Shairsingh to comment on her motivation for publishing her work as well her advice for other researchers who have a similar passion.



Kerolyn Shairsingh received her BASc. with honours in Chemical Engineering and Applied Chemistry from the University of Toronto in June 2008. After which she worked as a Chemical Engineer at the Caribbean Industrial Research Institute (CARIRI), in Trinidad and Tobago, from 2008 to 2014. In 2013 she obtained her MSc. with distinction in Chemical and Process Engineering from the University of the West Indies in Trinidad and Tobago. Her PhD. research at the University of Toronto focussed on improving land-use regression (LUR) model estimates of traffic-related air pollution when extending these models over space and time. LUR models are commonly used in epidemiological studies to examine if there is an association between specific traffic-related air pollution and adverse health outcomes. Currently she is developing Greater Toronto Area LUR models for use in future epidemiological studies at the Southern Ontario Centre for Atmospheric Aerosol Research.
Mrs. Kerolyn Shairsingh, Ph.D. (Toronto), M.Sc. (UWI), B.A.Sc.

Dr. Kerolyn Shairsingh received her BASc. with honours in Chemical Engineering and Applied Chemistry from the University of Toronto in June 2008. After which she worked as a Chemical Engineer at the Caribbean Industrial Research Institute (CARIRI), in Trinidad and Tobago, from 2008 to 2014. In 2013 she obtained her MSc. with distinction in Chemical and Process Engineering from the University of the West Indies in Trinidad and Tobago. Her PhD. research at the University of Toronto focussed on improving land-use regression (LUR) model estimates of traffic-related air pollution when extending these models over space and time. LUR models are commonly used in epidemiological studies to examine if there is an association between specific traffic-related air pollution and adverse health outcomes. Currently she is developing Greater Toronto Area LUR models for use in future epidemiological studies at the Southern Ontario Centre for Atmospheric Aerosol Research.

Interview with Kerolyn


What do you like most about T&T? What are your top 5 things?


Trinidad and Tobago is home, it’s where I grew up and it’s where my family lives. When I think of Trinidad I think of yummy homecooked food and fun family gatherings. There’s a warmth you find only in the Caribbean islands, and I’m not just talking about the sunshine. In North America you can become so busy trying to sustain you way of life that you sometimes forget about the human connections that are the most important thing in life. My top five things about Trinidad would be having my family so close by, being able to try such an eclectic mix of food any day of the week, our music, beautiful beaches less than an hour away, and endless sunshine.


What are your ambitions for the future?


I would like to help our future generations make the planet they will inherit more livable. The actions we take or fail to take in some cases will determine the kind of world our children will have to live in. It’s my hope that I can help to develop policies that are more environmental conscious even if it makes our current lives a bit more difficult.


What inspired you to write this paper?


Writing the journal article is the most common way that researchers get their findings out to the world. The more important question was what was I hoping to find by conducting this research that was not part of my PhD research. At the end of the day, I would say the sampling campaign was an intersection of curiosity and opportunity. I have always been curious about the quality of our air in Trinidad. I remember when I was doing my undergraduate degree, my sister told me that she could not let my nephew go outside and play because the Sahara dust was aggravating his asthma. At that time, I was using a program called HYSPLIT which allowed me to examine the origin of air masses. When I used the program, I realized that the air masses that Trinidad was experiencing wasn’t from the Sahara which meant that something else was aggravating my nephew’s asthma. Fast forward 10 years later, I came back to the University of Toronto to do my PhD and I had access to portable equipment that could measure a variety of air pollutants which gave rise to the opportunity to explore the question that has been at the back of my mind for over a decade.


What problems did you intend to solve?


I recently spoke to a group of grade 9 students (i.e. approximately age 13/14) about what it means to be an engineer. Engineers like to solve problems but before we can solve any problem, we need to thoroughly understand the system. This was the objective of the first traffic-related air pollution study in Trinidad. I wanted to understand what were the dominant sources of air pollution which is why I designed the campaign to give us a snapshot (24-hour averages) of pollutant concentrations at sites where the land is being used for different purposes (i.e. industrial vs residential vs near roadways).


What are some other challenges we should be looking to address?


In my first air quality sampling campaign, I only monitored two pollutants. While black carbon was observed to be higher near roadways than the oil and gas industrial facilities, it should be noted that this pollutant is derived from the combustion of diesel fuel and therefore it will be more informative of our transportation sector. That being said, the black carbon levels recorded near to our major roads are higher than the levels recorded in one of the busiest highways in North America (i.e. highway 401). What’s even more alarming is that the elevated black carbon tends to be higher as you get closer to the priority bus route which means that commuters are regularly subjected to pollution levels that are higher than Health Canada’s recommended exposure limit. While the first study showed us that we’re being exposed to high levels of black carbon from diesel exhaust, we still need to understand what is causing these high levels. Is it the diesel fuel or the diesel engine? In other parts of the world, countries use low-sulphur content diesel fuel which results in cleaner exhaust emissions. I read that Jamaica has this type of fuel but I’m not sure what kind of fuel we use in Trinidad. Another aspect is the type of diesel engine. Low emission diesel vehicles do exist, and we should consider importing such vehicles especially for our public transportation sector.

While Trinidad and Tobago has taken a progressive step forward by enacting the air pollution rules in 2014, we need to also develop laws that tackle traffic-related air pollution, not just industry-related air pollution. For example, in Ontario it is illegal to tamper with your vehicle’s catalytic converter, yet in Trinidad, people do this regularly in an effort to gain more power from the vehicle. Catalytic converters are essential for converting harmful pollutants such as nitrogen oxides into less toxic gases. If vehicle emission laws were passed, we could expand upon existing car inspections in Trinidad to also include inspection of catalytic converters and possibly emission testing. A simple test that was conducted on heavy-duty vehicles in Ontario is the opacity test. That is, if the exhaust coming from your vehicle is so smoky that it obscures the view, then that vehicle needs to be serviced before it can rejoin the on-road vehicle fleet.


Did you receive support at your University to conduct this research?


My supervisor, Professor Greg Evans, was very supportive of this air quality sampling campaign and was happy to loan me the University’s equipment to conduct the sampling. Since the sourcing of equipment can be the most prohibitive part of any sampling campaign, once I had the University’s equipment, I covered all other arrangements/costs for the field campaign.


How was the reception back at home, what were the highs and lows?


I think most people were sad to hear that the air quality was poor but at the same time happy to finally know. I think we all had our suspicions that the air quality was bad, but we didn’t really know what was driving the poor air quality. I was quite happy that a lot of people reached out to me personally to find out more the published research, and if I planned to do any follow-up work. At the end of the day my goal is to bring awareness to the people of Trinidad and Tobago.


Who is your role model and why?


Different people for different things. Sometimes doing the right thing isn’t easy or popular. Whether it is like Erin Brockovich (for the town), Nelson Mandela (for the country) or Julian Assange (for the world). Going against the grain takes strength. And in the fight against climate change, we certainly will need a lot of people who can make tough choices. I have often heard the argument from one side that India and China need to reduce their greenhouse gas emissions if we are to not pass that tipping point. On the other side, I’ve heard that the USA and Europe had their chance to become industrialized and it’s their fault that we’re so close to the tipping point so why must India and China not have their chance. While both of these statements are true, so too is the inevitability of climate change. If each of us could put the planet’s needs ahead of our own needs, we could give ourselves and nature more time to adapt to climate change.


What advice would you give to others who want to address challenges in T&T?


Change takes time. Have patience and don’t give up. Sometimes an idea is born before its time but that doesn’t mean it’s not feasible, it just means you need to give the population time to grow into the future. Trinidad and Tobago is heavily reliant on oil and gas but the rest of the world is starting to shift towards renewable energy. In Costa Rica, the country was able to obtain enough energy from renewable sources to supply the country needs for 300 days. That’s amazing! In Europe we are seeing countries shifting away from conventional gasoline and diesel fuels to electric vehicles. Change is coming, and we can choose to either embrace the change or be dragged into the future kicking and screaming.


Can we expect more from you?


I recently completed a second air quality sampling campaign over the Christmas season. Using the knowledge from the first campaign, this follow-up campaign seeks to understand more about our vehicles by comparing emission factors for our vehicles to emission factors in different countries. Emission factors tell us how much kg of a particular pollutant is created for every kg of fuel burnt. This information can give us more insight into what is driving the elevated vehicle exhaust emissions. Is it just a few vehicles in our fleet that is responsible for most of the emissions or is the fuel adversely affecting all the vehicles? Hopefully by the end of this year, I would be able to share that information with the citizens of Trinidad and Tobago.


Further Information on her research:

University of Toronto Article: https://news.engineering.utoronto.ca/first-study-of-traffic-related-pollution-in-trinidad-and-tobago-reveals-high-levels-of-black-carbon/?fbclid=IwAR17os60PCjOvVfg8WSj9w8SpR4f9NYBzNBPMpea_4JQuf0suN6_f8-sGgQ

Publication: https://www.sciencedirect.com/science/article/pii/S004896971834381X?dgcid=coauthor


Contact Info:

Kerolyn Katrina Shairsingh Ph.D. (Toronto), M.Sc. (UWI), B.A.Sc. http://kerolynshairsingh

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