Several students are participating in SWAPIT, a large winter air quality study, run by Environment and Climate Change Canada

Who would imagine a bright, sunny winter day could have higher concentrations of some air pollutants than a hazy summer day?

Not only is it uncommon for people to consider air quality during the coldest months of the year, but scientists rarely conduct winter air quality testing, says chemistry PhD student Daniel Persaud of 91亚色鈥檚 Faculty of Science. This is likely especially true during a polar vortex like Toronto, and the rest of Canada, is currently experiencing.

Even more unusual, though, is the possibility that Toronto鈥檚 cold winter air could be worse than in summertime, adds 91亚色鈥檚 Lassonde School of Engineering master鈥檚 degree student Samir Singh.

Researchers won鈥檛 know for sure which pollutants are worse until all measurements and analysis are done for the (SWAPIT), led by (ECCC). That data analysis is currently underway for last year鈥檚 campaign and SWAPIT scientists plan to meet next week to share initial results with each other to generate new insights and plan the release of the findings publicly.

鈥淭he unique thing about this study is that it's occurring during the winter months when there are different sources of pollutants from indoor heating to the de-icing of highways, which could have impacts. It is now evident that the levels of some pollutants are elevated in the winter months,鈥� says Persaud. 鈥淢ost of the other studies focused on smog, which normally occurs during the summer months.鈥�

Persaud and Singh are two of several 91亚色 grad students taking part in the SWAPIT study to better understand the mix of pollutants in Toronto鈥檚 urban winter air and why known pollutants haven鈥檛 declined as expected over the years. Persaud is under the supervision of Professor with Associate Professor , both atmospheric chemists in the Faculty of Science, while Singh is supervised by Associate Professor , director of the Graduate Program in Earth and Space Science at Lassonde and the Air Pollution Lab.

, air quality research scientist at ECCC, is leading the study, with 91亚色 as one of the collaborators. 鈥淪tudies like this can lead to improved tools for testing air quality and provide better information about our urban cities across the country,鈥� she says.

ECCC calls it the largest urban study of its kind in Canada with more than 90 scientific and technical experts with some 44 sub-projects. The winter phase of the study took place over an intensive six-week field measurement campaign last winter.

鈥淭here is a need to understand what pollutants are most prevalent in the air in the winter as different sources of contaminants become more prevalent during that time compared to the summer, things like high particulate matter from forest fires which is unlikely during winter,鈥� says Young.

It鈥檚 not the first time 91亚色 has been a partner in large atmospheric projects. A couple of summers ago, Young and VandenBoer led (Toronto Halogens, Emissions, Contaminants and Inorganics Experiment) in collaboration with the (AEROMMA) project organized by NASA and the National Oceanic and Atmospheric Administration.

SWAPIT, like THE CIX, uses 91亚色鈥檚 rooftop Air Quality Research Station to monitor air quality, but this time it also included another 91亚色 research station perched on the east edge of the Keele Campus, plus several other non-91亚色 stations spread out across the GTA.

鈥�In both of these studies, we are looking at the mix of pollutants and their source. It鈥檚 one thing to know there is a particular level of a toxic gas in the atmosphere, but how that might combine with another pollutant to create a whole new contaminant is one of the things we鈥檙e working on,鈥� says VandenBoer.

As part of the instrumentation used to gather air quality data for this study, Singh and Gordon installed a spectrometer on the roof of one of 91亚色鈥檚 administrative buildings to measure the distribution of particle sizes, along with a particulate matter sensor, an anemometer to measure wind speed and direction, and two cameras to measure the amount of traffic. In addition to particulate matter, some of the pollutants measured are per- and polyfluorinated substances (PFAS), ozone and , such as benzene, as well as trace contaminants like flame retardants and plasticizers. Given the sheer number of pollutants to be measured, it is considered the largest study of its kind globally.

鈥淚t will be interesting to see the variation over time, spatially, as well as how the pollutants vary throughout the city, from one testing site to another,鈥� says Singh, who routinely checks on the 91亚色 sites and collects initial raw data along the way to gauge how things are progressing or if there is anything significant.

鈥淯ntil we investigate what kind of pollutants and in what amounts are circulating at various times throughout the year and where they are coming from, whether that鈥檚 vehicle emissions in the country鈥檚 major cities or emissions from the oil sands facilities in the west, we don鈥檛 know what effect they may be having,鈥� says Gordon. 鈥淭his type of information has not been readily available, which makes combating air quality issues difficult.鈥�

The 91亚色 students involved in the study also worked with ECCC scientists at additional locations, including Pearson International Airport, High Park, and the Evergreen Brickworks. Both Singh and Persaud say they appreciate the opportunity to be involved in this study and to collaborate with external partners.

鈥淚t鈥檚 a unique opportunity to use our skills, resources and data with various groups, not only here at 91亚色, but with Environmental Canada, and hopefully we get some good data out and it can lead to changes that would benefit human health and air quality,鈥� says Persaud, who adds it gives him the opportunity to gain hands on experience in environmental monitoring and data analysis.

The goal, he adds, is to hopefully influence policy in the end, but for now they need to identify what鈥檚 responsible for pushing up the air quality index whether that鈥檚 in the winter or summer months. In addition to human health, it鈥檚 also important for the health of the environment, including the Great Lakes.

As Singh points out, the data they collect can help understand what pollutants are in the air and the direction they鈥檙e coming from, which the wind sensor they installed will help to do. The results will hopefully illuminate some of the impacts these pollutants might have on people鈥檚 health during the winter. They can be also be an indicator of the influence of a changing climate and be compared to similar research to give them a bigger picture of the issues.

Persaud not only helped deploy custom built wet deposition samplers for this study, but also went on to co-author a paper, , with VandenBoer, Young and others, about the instrument in the peer-reviewed journal Atmospheric Measurement Techniques. (See the .)

Wet deposition includes rain, sleet and snow, which can all carry contaminants. He will collect and analyze those samples for things like PFAS, which don鈥檛 break down in the environment and can travel thousands of kilometres away from their source and accumulate in soil, water and snow. Traces can even be found in wildlife, including fish, and even people.

鈥淲e hope to understand, to get an idea of the concentration and spatial distribution of these compounds,鈥� says Persaud, who has been studying atmospheric deposition for the past six years. 鈥淲e look for trends, we correlate them with atmospheric tracers, and we hope that we can compare our measurements to measurements that other groups are making in the study so we can truly understand the big picture with atmospheric transport and deposition.鈥�

A different project Persaud participated in with Young was investigating the presence of these compounds in ice cores, which were collected and analyzed from Ellesmere Island, Nunavut in Canada鈥檚 High Arctic 鈥� 鈥� published in the peer-reviewed journal Environmental Science: Processes and Implications. They were able to date perfluoroalkyl acids going back to about 1967.

鈥淲e could see a gradual increase as more industrial revolution happened,鈥� says Persaud, who has always been interested in chemistry and interactions with the environment.

Persaud realized during his undergrad that he wanted to pursue a career investigating contaminants in the environment. That passion led him to 91亚色 where he is now part of the group run by Young, one of the few research groups that use and develop analytical techniques to understand environmental issues, he says. 鈥淚'm fortunate to be a part of Dr. Young鈥檚 group. We use and develop analytical techniques to solve environmental issues. PFAS is a hot topic in environmental chemistry.鈥�

For Singh, he saw 91亚色 as having the best professors and programs in atmospheric science, which made the decision to move to this University for his graduate work easy. As part of Gordon鈥檚 Air Pollution Lab, students like Singh can study emissions and the mixing of pollutants caused by city and highway traffic, emissions from oil sands production facilities, and how pollutants interact with forest environments and mix within the forest canopy.

It's the kind of academic work both students are excited about and eager to apply their new knowledge to the real world, such as participating in the SWAPIT project, toward making a difference in the health of people and the environment.

鈥淭his can generate meaningful insights and develop evidence-based solutions for improving air quality,鈥� says Persaud.

The post 91亚色 grad students take the measure of Toronto鈥檚 winter urban air appeared first on News@91亚色.

91亚色 researchers find meteorology played an important and unaccounted role

TORONTO, Nov. 16, 2021 鈥� Observational data shows air pollution in India decreased drastically in the first COVID-19 lockdown when emissions from vehicles naturally declined, but 91亚色 researchers say those numbers only tell part of the story 鈥� blue skies and an absence of visible smog can be deceiving and hide pollutants that could potentially cause health issues.

Air pollution results from a complex mix of interactions between emissions, meteorology, such as wind direction and rain, as well as chemistry, but looking only at observational data as many recent studies have done without take meteorology into account, skews the numbers.

The researchers found that some air pollutants didn鈥檛 drop nearly as much as first thought and even more surprising was that ozone levels increased even as other pollutants decreased. The air looked much cleaner, but that allowed more sunshine to get through, creating conditions for ozone (0₃) to increase up to 30 per cent.

鈥淭o accurately quantify the impact of the COVID-19 lockdown on air pollutant levels, meteorology and atmospheric chemistry needs to be considered in addition to emissions,鈥� says 91亚色 postdoctoral researcher Leigh Crilley, who led the Faculty of Science research along with 91亚色 Associate Professor and team. 鈥淥ur research shows the decline in local emissions had less influence on the decrease in air pollutants than first thought.鈥�

Cora Young

As the national lockdown in India reduced major urban sources of air pollution, such as traffic, industry and construction, it gave the researchers an opportunity to study the contribution of local sources of air pollutants during normal meteorological conditions.

To get a clearer picture of potential decreases in air pollution, Crilley and Young focussed their study on nitrogen oxides (NOx), fine particulate matter (PM_2.5) and 0₃, as well as what was happening meteorologically at multiple locations within two cities in India 鈥� Delhi and Hyderabad 鈥� during the start of the first lockdown, from March 24 to April 24, 2020.

Air pollution is a known health risk and India has some of the worst air pollution globally resulting in a disproportionally high level of mortality and disease. It is estimated that air pollution exposure, particularly PM_2.5, resulted in the death of 1.27 million people in 2017.

Cities in India also have some of the highest 0₃ levels in the world, which can be formed from a complexity of sources and chemistry, either NOx-limited or volatile organic compounds (VOC)-limited.

The researchers used hourly data from air quality monitoring stations for levels of PM_2.5, NOx and 0_3, and hourly meteorological and visibility data. They compared that data to the same dates from the previous three years to evaluate changes due to the lockdown. A boosted regression tree model was built to account for the influence of meteorology on observed levels.

When only taking observational data into account, NOx and PM_2.5 fell by up to 57 per cent and 75 per cent respectively, but when meteorology was factored in, those percentages fell to less than eight per cent for PM_2.5 and between five and 30 per cent in both cities, while 0₃ increased.

They found that local sources of emissions, such as vehicles and the burning of fuels, had less influence on air pollution levels than regional emissions sources, while weather events and atmospheric chemical processes contributed independently to air pollutant levels.

鈥淲e demonstrate that regional sources, such as rural and agriculturally based emissions, that may have been less affected by the lockdown, have a significant influence on PM_2.5 levels in Delhi and Hyderabad after weather-normalization. This indicates that future PM_2.5 mitigation strategies should focus on national-scale, as well as local sources,鈥� says Young.

鈥淥verall, this study highlights the impact of emissions, meteorology and chemistry on air pollution and that all three should be considered when assessing the effects of any short-term intervention on air pollutants.鈥�

In addition, the research team found that ozone production in Delhi is likely VOC-limited and, as such, attempts to mitigate it should focus on dominant VOC sources.

The researchers say this really points to the need regulators to understand the complex factors involved in air pollution if they are going to make policies to reduce pollutants and ozone.

The paper, , was published in the journal Environmental Science: Processes & Impacts.

-30-

91亚色聽is a modern, multi-campus, urban university located in Toronto, Ontario. Backed by a diverse group of students, faculty, staff, alumni and partners, we bring a uniquely global perspective to help solve societal challenges, drive positive change and prepare our students for success. 91亚色's fully bilingual Glendon Campus is home to Southern Ontario's Centre of Excellence for French Language and Bilingual Postsecondary Education. 91亚色鈥檚 campuses in Costa Rica and India offer students exceptional transnational learning opportunities and innovative programs. Together, we can make things right for our communities, our planet, and our future.

Media Contact:

Sandra McLean, 91亚色 Media Relations, 416-272-6317,聽sandramc@yorku.ca

The post Air pollution decrease in India during COVID-19 lockdown not as high as originally thought appeared first on News@91亚色.

91亚色 researchers find meteorology played an important and unaccounted role

TORONTO, Nov. 16, 2021 鈥� Observational data shows air pollution in India decreased drastically in the first COVID-19 lockdown when emissions from vehicles naturally declined, but 91亚色 researchers say those numbers only tell part of the story 鈥� blue skies and an absence of visible smog can be deceiving and hide pollutants that could potentially cause health issues.

Air pollution results from a complex mix of interactions between emissions, meteorology, such as wind direction and rain, as well as chemistry, but looking only at observational data as many recent studies have done without take meteorology into account, skews the numbers.

The researchers found that some air pollutants didn鈥檛 drop nearly as much as first thought and even more surprising was that ozone levels increased even as other pollutants decreased. The air looked much cleaner, but that allowed more sunshine to get through, creating conditions for ozone (0₃) to increase up to 30 per cent.

鈥淭o accurately quantify the impact of the COVID-19 lockdown on air pollutant levels, meteorology and atmospheric chemistry needs to be considered in addition to emissions,鈥� says 91亚色 postdoctoral researcher Leigh Crilley, who led the Faculty of Science research along with 91亚色 Associate Professor and team. 鈥淥ur research shows the decline in local emissions had less influence on the decrease in air pollutants than first thought.鈥�

Cora Young

As the national lockdown in India reduced major urban sources of air pollution, such as traffic, industry and construction, it gave the researchers an opportunity to study the contribution of local sources of air pollutants during normal meteorological conditions.

To get a clearer picture of potential decreases in air pollution, Crilley and Young focussed their study on nitrogen oxides (NOx), fine particulate matter (PM_2.5) and 0₃, as well as what was happening meteorologically at multiple locations within two cities in India 鈥� Delhi and Hyderabad 鈥� during the start of the first lockdown, from March 24 to April 24, 2020.

Air pollution is a known health risk and India has some of the worst air pollution globally resulting in a disproportionally high level of mortality and disease. It is estimated that air pollution exposure, particularly PM_2.5, resulted in the death of 1.27 million people in 2017.

Cities in India also have some of the highest 0₃ levels in the world, which can be formed from a complexity of sources and chemistry, either NOx-limited or volatile organic compounds (VOC)-limited.

The researchers used hourly data from air quality monitoring stations for levels of PM_2.5, NOx and 0_3, and hourly meteorological and visibility data. They compared that data to the same dates from the previous three years to evaluate changes due to the lockdown. A boosted regression tree model was built to account for the influence of meteorology on observed levels.

When only taking observational data into account, NOx and PM_2.5 fell by up to 57 per cent and 75 per cent respectively, but when meteorology was factored in, those percentages fell to less than eight per cent for PM_2.5 and between five and 30 per cent in both cities, while 0₃ increased.

They found that local sources of emissions, such as vehicles and the burning of fuels, had less influence on air pollution levels than regional emissions sources, while weather events and atmospheric chemical processes contributed independently to air pollutant levels.

鈥淲e demonstrate that regional sources, such as rural and agriculturally based emissions, that may have been less affected by the lockdown, have a significant influence on PM_2.5 levels in Delhi and Hyderabad after weather-normalization. This indicates that future PM_2.5 mitigation strategies should focus on national-scale, as well as local sources,鈥� says Young.

鈥淥verall, this study highlights the impact of emissions, meteorology and chemistry on air pollution and that all three should be considered when assessing the effects of any short-term intervention on air pollutants.鈥�

In addition, the research team found that ozone production in Delhi is likely VOC-limited and, as such, attempts to mitigate it should focus on dominant VOC sources.

The researchers say this really points to the need regulators to understand the complex factors involved in air pollution if they are going to make policies to reduce pollutants and ozone.

The paper, , was published in the journal Environmental Science: Processes & Impacts.

-30-

91亚色聽is a modern, multi-campus, urban university located in Toronto, Ontario. Backed by a diverse group of students, faculty, staff, alumni and partners, we bring a uniquely global perspective to help solve societal challenges, drive positive change and prepare our students for success. 91亚色's fully bilingual Glendon Campus is home to Southern Ontario's Centre of Excellence for French Language and Bilingual Postsecondary Education. 91亚色鈥檚 campuses in Costa Rica and India offer students exceptional transnational learning opportunities and innovative programs. Together, we can make things right for our communities, our planet, and our future.

Media Contact:

Sandra McLean, 91亚色 Media Relations, 416-272-6317,聽sandramc@yorku.ca

The post Air pollution decrease in India during COVID-19 lockdown not as high as originally thought appeared first on News@91亚色.