Pollution

Faculty of Arts & Science

Statistical Sciences

U of T Mississauga

With the increasing popularity of electric vehicles, car-related air pollution will be less of a concern, right? Think again, say a group of ��߲ݴ�ý researchers who are studying the effects of air pollution from brakes and tires.

While the push to mandate EV aims to reduce tailpipe emissions such as carbon dioxide – the federal government has set a target of complete EV adoption by 2035 – swapping every vehicle on the road still won’t eliminate all the sources of air pollution that can impact human health.

That’s because brake pads, rotors and tires grind down over time and erode. This results in tons of particulate matter like heavy metals and microplastics polluting the air.

Matt Adams

“Millions of tires being driven on the road breaking down –that’s a problem,” says Matt Adams, an assistant professor in U of T Mississauga’s department of geography, geomatics and environment. “It’s an emerging question in the field – it’s hard to know where the particles end up.”

Adams and Greg Evans, a professor of chemical engineering and applied chemistry in U of T’s Faculty of Applied Science & Engineering, belong to a team of U of T researchers who are conducting a three-year study to learn more about tailpipe vs. non-tailpipe emissions. The study is for a U.S.-based organization called the Health Effects Institute, which gathers research on the effects of air pollution. Other researchers include: Professor Marianne Hatzopoulou and Associate Professor Arthur Chan in the Faculty of Applied Science & Engineering; Associate Professor Meredith Franklin in the department of statistical sciences in the Faculty of Arts & Science; and McGill University’s Scott Weichenthal and University of Barcelona visiting professor Maria Pérez.

Evans says the source of vehicle pollution has shifted in recent years.

“Because of changes in vehicle technology, tailpipe emissions particularly from cars has dropped off a lot over the last two decades,” Evans says. “What we found with research we’ve done in Toronto is that, since 2013, non-tailpipe emissions have exceeded tailpipe emissions.”

While tires are made from a combination of plastics and rubber, brakes are made of heavy metals, including iron, barium and copper.

Particles of heavy metals, microplastics and micro rubber from tires and brakes pollute the air and can contribute to a range of negative health outcomes. Some heavy metals like copper can cause oxidative stress when inhaled. Lungs suffer from inflammation and an immune response is triggered.

“There is not an organ in your body that’s not impacted by air pollution,” Adams says. “We know your health risk is increased. We know a lot of these pollutants are carcinogens. [It] can contribute to cardiorespiratory issues.”

Evans says the researchers hope the study will improve methods of gathering vehicle pollution data.

“At the end of it, we’re hoping to have better methods to able say how much is coming from tailpipe and how much is non-tailpipe, and how do we identify hot spots,” he says.

The findings could potentially result in regulations for tire and brake emissions. In late 2022, the EU proposed new Euro 7 standards to reduce vehicle emissions and improve air quality. The new proposals were the first worldwide emissions standards to set additional limits for emissions from tires and brakes.

Greg Evans, a professor of chemical engineering and applied chemistry, says his research shows that non-tailpipe emissions have exceeded tailpipe emissions in Toronto since 2013 (supplied photo)

Adams says there are additional considerations when switching over to EVs, including the source of electric power, lithium sourcing and related infrastructure.

“We’re trying to translate the links of how and where you are in the urban environment to your exposure [to air pollution], and then using that to plan cities better for our health,” Adams says.

Planning more healthy cities means building urban areas where people can walk, cycle and take public transit in addition to adopting EVs.

“Air pollution is tricky,” Adams says. “It’s invisible for the most part –we don’t smell it. We’re trying to quantify the intangible for the average person.”

U of T researchers design microfluidic device to understand how air pollution affects lungs

geoff.vendeville — Thu, 04 Nov 2021 14:33:06 +0000

U of T researchers design microfluidic device to understand how air pollution affects lungs

geoff.vendeville Thu, 11/04/2021 - 10:33

Cutline

Edmond Young, of the Faculty of Applied Science & Engineering, and his research team have developed a microfluidic lung-on-a-chip that mimics breathing in human lungs (photo courtesy of Edmond Young)

Qin Dai

Topic

Institute of Biomedical Engineering

Health

��߲ݴ�ý researchers in biomedical engineering have developed a new technology that combines a microfluidic device with a novel airflow system to mimic lung airways. The technology enables scientists and engineers to perform particle exposure experiments to examine the pathological effects of air pollutants on respiratory health.

Siwan Park, a PhD candidate at the Institute of Biomedical Engineering in the Faculty of Applied Science & Engineering, and Edmond Young, an associate professor in the department of mechanical and industrial engineering, recently published their findings in Advanced Materials Technologies.

The microfluidic device-on-a-chip – known as E-FLOAT, short for Extractable Floating Liquid gel-based Organ-on-a-chip for Airway Tissue modelling under airflow – is an easily modifiable system where scientists can grow lung cells in a suspended hydrogel that resembles lung tissue.

The researchers developed the device by micro-milling and bonding layers of thermoplastic. It incorporates a special channel geometry for growing the cells. An airflow system connected to the device can generate various flow rates of warm and humidified air to simulate human breathing.

“We showed that lung airway tissue can be micro-engineered in the lab, exposed to various environmental conditions, including airflow and pollutants, and then be extracted for further interrogation as if it were a real lung tissue sample,” Young says.

In the E-FLOAT device, lung cells are suspended in a hydrogel to mimic how they would grow in normal lung tissue. The microfluidic devices simulate breathing and exposure to air pollutants (images courtesy Siwan Park and Edmond W. K. Young)

In many existing iterations of the technology, cells grown on microfluidic devices are limited to ‘on-chip’ analysis to assess the effect of external stimuli, such as airflow, on the health of the cells. This limits the analysis that can be carried out: while scientists can remove these cells from the device, this process changes the spatial location of the cells in relationship to the tissue, potentially skewing the results.

“One of the advantages of E-FLOAT is the ability to extract the biomimetic airway tissue that allows us to develop an in-depth knowledge through a wide array of imaging technologies,” Park says.

The researchers successfully delivered airborne particles onto the airway cells via controlled airflow to mimic how air pollutants would interact with lung cells. They then extracted the entire hydrogel and analyzed particulate and cell interactions.

“We were especially excited to obtain the stunning images of histology sections using the extracted hydrogel. Not only does it look beautiful, we believe that it may also be significant in histological and pathological perspectives. Also, depending on how we design the cell-matrix interactions in E-FLOAT, we may obtain a more physiologically accurate representation of multicellular airway tissue.”

“In the future, the plan is to use this technology to study the development of lung diseases like asthma – especially in the presence of air pollution – and to also use it as a preclinical model during drug development,” Young says.

“There is obviously a lot more work to be done, but we hope to collaborate with lung researchers and partner with pharma down the road to realize this plan.”

This U of T-designed lab on wheels roams the city, gathering data on air pollution

geoff.vendeville — Fri, 26 Feb 2021 17:39:03 +0000

This U of T-designed lab on wheels roams the city, gathering data on air pollution

geoff.vendeville Fri, 02/26/2021 - 12:39

Cutline

From left : Associate Professor Marianne Hatzopoulou, Keni Mallinen (in vehicle) and Arman Ganji with the UrbanScanner (photo by Phill Snel)

Phill Snel

Topic

A vehicle with flashy chrome finishes and high-tech, roof-mounted scanners is getting a lot of admiring looks as it rolls around Toronto.

Meet UrbanScanner, a mobile testing laboratory on wheels developed by researchers in the ��߲ݴ�ý Faculty of Applied Science & Engineering. Built and driven by researchers in the Transportation and Air Quality group led by Marianne Hatzopoulou, an associate professor in the department of civil and mineral engineering and Canada Research Chair in transportation and air quality, the vehicle takes detailed measurements of air pollution as it varies over space and time.

Hatzopoulou and her team, including research associate Arman Ganji and master's candidate Keni Mallinen, have partnered with Scentroid, a Toronto-based company developing sensor-based systems for urban air pollution monitoring, to create UrbanScanner.

The vehicle includes a 360-degree visual camera, a lidar (light detection and ranging) system, a GPS transponder and an ultrasonic anemometer, as well as sensors for temperature, relative humidity, particulate matter and certain gas-phase pollutants.

A platform on the roof of the vehicle streams data to a cloud server, with air pollution measured every second and paired with the camera and lidar images. The ability to collect detailed location information enables air pollution data to be overlaid on city maps.

UrbanScanner can compare its real-time measurements of air pollution with features of a particular street or neighbourhood, such as traffic flow, number and height of trees and local building forms. It can also reveal patterns over time, whether it’s the daily rush hour or seasonal variations.

“Since September 2020, UrbanScanner has been collecting air quality data across Toronto, both along major roads and within Toronto neighbourhoods,” Hatzopoulou says.

Over the course of a single month UrbanScanner can log more than 2,280 kilometres of driving, or more than 100 hours of data collection. That adds up to over 250,000 data points.

“This massive database will continue to grow as UrbanScanner collects data across seasons and will help us predict air quality in space and time, providing crucial information about population exposures in the city,” Hatzopoulou says.

Pregnant Inuit women exposed to higher levels of chemicals found in consumer products: U of T study

Christopher.Sorensen — Mon, 02 Nov 2020 17:16:39 +0000

Pregnant Inuit women exposed to higher levels of chemicals found in consumer products: U of T study

Christopher.Sorensen Mon, 11/02/2020 - 12:16

Cutline

A U of T study found that pregnant Inuit women had concentrations of PFAAs, found in non-stick coatings for cookware and cleaning products, that were twice as high as those in a representative sample of Canadian women (photo by Halfpoint via Getty Images)

Don Campbell

Topic

Physical and Environmental Sciences

Inuit

Quebec

U of T Scarborough

Pregnant women living in Nunavik in northern Quebec are increasingly being exposed to potentially harmful chemical compounds commonly found in consumer products.

This is one of the findings of new study by a group of Canadian researchers including Élyse Caron-Beaudoin, an assistant professor in the department of health and society and the department of physical and environmental sciences at the ��߲ݴ�ý Scarborough.

The study, published in the journal Environment International, focused on perfluroalkyl acids (PFAAs), which are used in a wide range of consumer products including non-stick coatings for cooking ware, water and stain repellents, food packaging, paints, cosmetics and cleaning products. It found that PFAA concentrations in pregnant Inuit women were twice as high as those in a representative sample of Canadian women.

“It’s an environmental injustice because people’s food in the Arctic is being contaminated by chemicals made far away from their homes,” says Caron-Beaudoin, an expert on toxicology as well as public and environmental health.

PFAAs do not biodegrade easily, and as a result, can persist for a long time in the environment. They can also be carried over long distances in the atmosphere and in oceans, where they accumulate in the tissues of living organisms in the Arctic food chain, according to Caron-Beaudoin.

She says that exposure to these compounds, including during fetal development, is associated with changes in hormonal, kidney, cardio-metabolic and immune function.

The study involved measuring changes in the concentration of PFAAs in the blood of 279 pregnant women living in the Nunavik region of northern Quebec from 2004 to 2017. The researchers found that one of the likely sources of PFAAs concentrations in the blood is the consumption of country foods, particularly marine wildlife.

Caron-Beaudoin says that many living in the north experience food insecurity and rely on the nutritional and cultural value provided by country foods, which make up the traditional Inuit diet.

“The benefit of consuming traditional foods still outweigh the negatives,” she says. “[But] we need adequate regulations that protect these country foods from harmful contaminants because these communities rely on them, especially pregnant women who need the nutritional value.”

While most PFAAs are regulated in North America, they do get imported by consumer products that contain them. The researchers found there’s been a drop in concentrations of legacy PFAAs – those banned by various international and North American treaties – but found that concentrations of long-chain PFAAs, which are more recent and can come from the degradation of other currently-used similar compounds such as Fluorotelomer alcohols (FTOHs), are on the rise.

“These long-chain PFAAs are even more persistent and have an even greater potential to accumulate in the food chain than the older PFAAs,” says Caron-Beaudoin.

Caron-Beaudoin says compounds like FTOHs not only travel long distances from their site of production, they also travel in consumer and industrial products that get imported into North America.

“It’s important to stay on top of this and make sure these new chemical compounds are tightly regulated as well,” she says.

U of T researchers develop early warning system for water pollution using tiny water fleas

Christopher.Sorensen — Fri, 29 Nov 2019 19:17:08 +0000

U of T researchers develop early warning system for water pollution using tiny water fleas

Christopher.Sorensen Fri, 11/29/2019 - 14:17

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The health of common water fleas like this one are being examined by U of T researchers using a powerful instrument called a tandem mass spectrometer (photo by Don Campbell)

Don Campbell

Topic

U of T Scarborough

Researchers at the ��߲ݴ�ý are developing an early warning system for water quality and pollution that combines tiny water fleas and an instrument so sensitive it’s able to detect changes at the molecular level.

The technique being developed by Myrna Simpson, a professor in U of T Scarborough’s department of physical and environmental sciences, and post-doctoral researcherTae-Yong Jeong uses something called metabolomics to study the health of common water fleas (Daphnia). It uses a powerful instrument called a tandem mass spectrometer to offer a window into biochemical processes taking place inside Daphnia when they’re exposed to different water conditions.

“Metabolomics is really dynamic – it allows you to detect biochemical changes in tissues and cells almost instantaneously,” says Simpson.

The technique can be incorporated into what’s called the Biological Early Warning System for water pollution, which involves looking at how organisms respond biologically to changes in water quality. The organisms used in the system usually have a fast response to pollutants and changes in nutrients, so the technique is useful for the continuous monitoring of water quality.

“The health of lakes, rivers and streams is under continuous threat from human-caused activities, and that can rapidly change the nutrient conditions, pH and water quality of ecosystems,” says Simpson.

Professor Myrna Simpson and postdoctoral fellow Tae-Yong Jeong are developing an early warning system for water pollution that uses tiny water fleas (photo by Don Campbell)

The challenge is there hasn’t been a quick and easy method to routinely monitor these environments. Current reproductive tests on Daphnia can take up to 21 days to complete, Simpson says. A metabolomics-approach, on the other hand, can be done within minutes to hours, and even over the lifespan of the organism.

“Current monitoring techniques are long and labour intensive,” says Simpson, whose research looks at the impact of environmental change in soil and water at the molecular level.

“In Ontario there are so many freshwater lakes and river that you can’t just collect and process samples quickly enough.”

Metabolomics approaches to monitoring human and environmental health have been developed in the past, but this is the first time it’s been tested for use in the Biological Early Warning System.

The technique is so granular it can detect picogram-levels (one trillionth of a gram) of metabolites in a sample. Simpson says compared to other highly sensitive “omics” measures like genomics (genes) or proteomics (proteins), metabolomics is cheaper, easier and faster.

Time and sensitivity are crucial when it comes to monitoring water quality, notes Jeong. Once Daphnia are exposed to pollutants, the toxicity can start to fundamentally alter them at a molecular level, affecting energy levels, ability to reproduce and causing genetic changes.

“If Daphnia aren’t happy because they’re affected by pollution, you will see it cascade throughout the food web,” he says.

“They are ideal to use in studying water pollution because, as a keystone organism, they’re representative of what’s happening in their surrounding environment.”

The research, which received funding from the Krembil Foundation and Ontario’s Ministry of the Environment, Conservation and Parks, is published in the journal Water Research.

The pair also authored a second paper looking at how metabolites may fluctuate over the lifespan of Daphnia, which is published in the journal Environmental Science & Technology.

Since metabolomics is so sensitive, an important next step for the researchers is to figure out how to tell the difference between slight metabolic changes that are caused by pollution and more extreme variations.

“We need to define what is a small change in metabolism versus a really big change that we know is going to manifest itself in something much worse,” Simpson says.

National air pollution report highlights rush-hour traffic, diesel truck emissions as major areas of concern

Christopher.Sorensen — Wed, 30 Oct 2019 16:35:09 +0000

National air pollution report highlights rush-hour traffic, diesel truck emissions as major areas of concern

Christopher.Sorensen Wed, 10/30/2019 - 12:35

Cutline

Nearly 30 per cent of Canadians live near major roads and heavy traffic, which a national study led by U of T researchers says are the source of a “soup” of pollutants – particularly during winter (photo by Steve Russell/Toronto Star via Getty Images)

Liz Do

Topic

Chemical Engineering

Almost one-third of Canadians live near a major roadway – and this means they go about their everyday lives exposed to a complex mixture of vehicle air pollutants.

A new national study led by researchers at the ��߲ݴ�ý’s Faculty of Applied Science & Engineering reveals that emissions from nearby traffic can greatly increase concentrations of key air pollutants, with trucks making a major contribution. Canada’s cold winters can also increase emissions while particle emissions from brakes and tires are on the rise.

The report, released today, is the culmination of a two-year study monitoring traffic emissions in Toronto and Vancouver – the two Canadian cities with the highest percentage of residents living near major roads.

“There’s a whole soup of pollutants within traffic emissions,” says Greg Evans, a professor in the department of chemical engineering and applied chemistry who led the study in collaboration with Environment and Climate Change Canada, Ontario’s Ministry of the Environment, Conservation and Parks, and Metro Vancouver.

Evans says that this “soup” of pollutants includes nitrogen oxides, ultra-fine particles, black carbon, metals, carbon monoxide and carbon dioxide. Exposure to these emissions has been associated with a wide range of health issues, including asthma, cancer and cardiovascular mortality.

“The areas of concern we identified raise important questions about the health of Canadians living near major roadways,” says Evans.

The national report’s findings complement a parallel report on air quality in the Vancouver region that will soon be released by Metro Vancouver. Both reports underscore the need to assess and enact new measures to mitigate exposure to air pollutants.

Traffic in cities

Busy roads are detracting from nearby air quality, especially during morning rush hour.

The researchers measured concentrations of ultra-fine particles – the smallest airborne particles emitted by vehicles – and found that average levels of ultra-fine particles near highways were four times higher than at sites far removed from traffic.

“These particles are less than 100 nanometres in size, much smaller than red blood cells. They can travel and trans-locate around the body,” says Evans. “We don’t know yet what the health impacts of these particles are, but we do know that near roads they are a good indicator of exposure to traffic pollution.”

The concentrations of most traffic pollutants varied by factors of two to five across the cities.

Large trucks

The report highlights the dangers of diesel trucks, which represent a minority of the total trucks on roads and highways, but emit diesel exhaust at disproportionately high levels.

“If there’s a high proportion of trucks, people who spend a lot of time near these roadways – drivers, workers, residents – are being more exposed to diesel exhaust, which is a recognized human carcinogen,” says Evans.

Though there’s currently no standard for public exposure to diesel exhaust in Canada, black carbon, more commonly called soot, is used to monitor exposure in workplaces. Based on black carbon, the concentrations of diesel exhaust beside the major roads exceeded the guidelines proposed in the Netherlands for workers, implying that they are too high for the public.

“If these highly polluting diesel trucks were repaired, retrofitted, removed or relocated, it would make a significant difference,” says Evans. “You can’t move your nearby schools or homes, but we can do something about these highly-polluting trucks that are a small proportion of the truck traffic, and yet causing a lot of the trouble.”

Wind and winter

Air quality is not just a concern during the summer driving season. Winter weather brings an increase in near-road concentrations of nitrogen oxides and ultra-fine particles.

The researchers’ data suggest emission treatment systems on diesel vehicles become less effective at colder temperatures. “The systems appear to not be well designed for cold weather,” says Evans. “It’s concerning when you consider most of Canada faces cold temperatures and long months of winter; Toronto and Vancouver are nowhere near the coldest parts of Canada.”

Wind conditions also affect pollutant levels: The researchers found that concentrations were up to six times higher when monitoring the downwind side of a major road.

Tire and brake wear

As brake pads on cars and trucks are worn down, the materials they’re made of turn to dust – and that dust goes straight into the air.

“These non-tailpipe emissions, from brakes, tires and the road itself, are increasing and we believe that this is because our cars are getting larger and heavier,” says Cheol-Heon Jeong, a senior research associate in Evans’s lab whose analysis revealed the growing issue with non-tailpipe emissions.

“People are buying more trucks and SUVs than small cars and that trend has been growing in recent years. The heavier it is, the more energy it takes to stop, and the more brake dust gets emitted,” he says.

The report concludes by offering recommendations to all levels of government. Evans hopes the report will lead to establishing a nation-wide road pollution research network that can advise policy-makers, engage companies and the public, and lead to standards and laws that will ultimately protect the health of Canadians.

“We’d like to see this report and future studies help launch new monitoring stations across Canada so that all Canadians can get a better picture of the implications of our transportation choices and how these influence what we’re breathing in,” he says.

“Our transportation will be changing very quickly in the coming decade and we’ll need ongoing monitoring to help us stay on a path towards increased sustainability.”

The findings of this report and its recommendations will be discussed at a national meeting in Toronto Nov. 4. The research received support from the Natural Sciences and Engineering Research Council of Canada and Canada Foundation for Innovation.

“Nobody monitors air quality here”: U of T researcher returns home to study Trinidad and Tobago emissions

Christopher.Sorensen — Wed, 05 Dec 2018 16:59:17 +0000

“Nobody monitors air quality here”: U of T researcher returns home to study Trinidad and Tobago emissions

Christopher.Sorensen Wed, 12/05/2018 - 11:59

Cutline

PhD candidate Kerolyn Shairsingh at one of the 10 air quality monitoring sites she set up across Trinidad and Tobago (photo courtesy of Kerolyn Shairsingh)

Liz Do

Topic

Global Lens

A new study by a graduate student in the ��߲ݴ�ý's Faculty of Applied Science & Engineering measured significant concentrations of traffic-related air pollution near roadways in the small island nation of Trinidad and Tobago, reaching levels comparable to highways in major urban centres like Toronto and Detroit.

The study of local emissions conducted on the two islands of Trinidad and Tobago is among the first of its kind. It was led by PhD candidate Kerolyn Shairsingh under the supervision of Professor Greg Evans in the department of chemical engineering and applied chemistry.

The team focused primarily on black carbon – also known as soot – which has been linked to negative health outcomes, including lung conditions and cancer. Their findings were recently published in the journal Science of the Total Environment.

Shairsingh, who is from Trinidad and Tobago, said she was motivated to research local concentrations of black carbon after years of experiencing asthma attacks every time she travelled back home.

“I have nephews who also have asthma. Sometimes they can’t go outside and play because they would be wheezing,” said Shairsingh. “I always knew that the air quality was poor, but nobody monitors air quality here at all.”

Air pollution in Point Lisas, a major industrial area in Trinidad and Tobago (photo courtesy of Kerolyn Shairsingh)

Shairsingh decided to pack air-quality monitoring equipment when she visited last February. She set up 10 monitoring sites across Trinidad and Tobago over a three-week period – near oil and gas refineries, urban residences, and major roads, including highways and bus routes.

She found levels of black carbon around industrial areas on the islands were comparable to levels found near Ontario’s Highway 401, North America’s busiest highway. Levels near major roads in Trinidad were significantly higher.

“That’s what shocked me – that it’s actually traffic that is more of the culprit than the industries here, at least for this particular pollutant,” says Shairsingh.

One site, a commercial area in Trinidad with frequent sidewalk traffic, showed black carbon levels 1.1-times higher than Health Canada’s proposed limit for long-term black carbon exposure. Long-term exposure to black carbon has been shown to pose health risks such as asthma, respiratory infections, lung cancer, strokes and cardiovascular mortality.

Shairsingh points out that the major source of black carbon is diesel exhaust. At half the price of gasoline, diesel fuel is prevalent in many of the half-million vehicles driven daily in Trinidad and Tobago.

Although the country passed air pollution legislation in 2014, Shairsingh points out that the guidelines were mostly geared towards industry. “There’s nothing for the monitoring of vehicles at all,” she says.

Shairsingh hopes the study into local emissions will be the first step towards improving the air quality – either through cleaner fuel sources or through retrofitting of large vehicles such as buses and trucks.

Shairsingh is also working on a documentary, Clearing the Air, to further spread awareness of the issue among the residents of Trinidad and Tobago and beyond.

“This paper is one way to spread the news, and the documentary is another avenue to showcase this issue,” she says. “Until people are aware, there will be no drive for change.”

The documentary will feature interviews in Trinidad and Tobago as well as Canada, including with Evans, who leads the Southern Ontario Centre for Atmospheric Aerosol Research (SOCAAR) at U of T. In addition to Shairsingh’s study, researchers at SOCAAR have recently released their findings on near-road air pollution in Toronto and Vancouver, and on the emerging issue of non-exhaust emissions from brakes, tires and road dust.

Large trucks are biggest culprits of near-road air pollution: U of T study

noreen.rasbach — Mon, 10 Sep 2018 20:24:11 +0000

Large trucks are biggest culprits of near-road air pollution: U of T study

noreen.rasbach Mon, 09/10/2018 - 16:24

Cutline

A new study led by Professor Greg Evans shows that trucks and larger vehicles contribute disproportionately to air-pollutant emissions (photo by Nigel Tadyanehondo via Unsplash)

Liz Do

Topic

City & Culture

Cities

Health

Traffic

Subheadline

For the 30 per cent of Canadians who live within 500 metres of a major roadway, the type of vehicles rolling past their homes can matter more than total traffic volume in determining the amount of air pollution they breathe, a new ��߲ݴ�ý study says.

A two-year study involving researchers at the Faculty of Applied Science & Engineering has revealed large trucks to be the greatest contributors to black carbon emissions close to major roadways. Professor Greg Evans of the department of chemical engineering and applied chemistry hopes the study results get city planners and residents thinking more about the density of trucks, rather than the concentration of vehicle traffic, outside their homes, schools and daycares. The study was recently published in the journal Environmental Science & Technology.

“I’ve been asked by people, ‘We live near a high-traffic area, should we be worried?’ My response is that it’s not so much about how much traffic there is, it’s more about the percentage of trucks, older trucks in particular.”

The comprehensive study – led by Evans (pictured right) and collaborators at Environment and Climate Change Canada, and the Ontario Ministry of the Environment, Conservation and Parks, as well as the Metro Vancouver Regional District – involved measuring vehicle emissions near roads in Toronto and Vancouver, including the 401, North America’s busiest stretch of highway.

The difference between emission levels across the sites was more correlated with the number of large trucks on the road rather than number of cars.

Researchers found that air pollution levels right beside a major trucking route within a city were close to levels seen beside Highway 401, despite the road carrying less than one-tenth of the vehicle traffic. “This was in part due to differences in wind and proximity to the road but, surprisingly, the number of vehicles didn’t make that much of a difference,” said Evans.

The data also revealed a significant drop in emissions on the 401 on the weekends, when personal vehicle traffic is still very high, but the volume of large truck traffic is low.

Research consistently links traffic emissions to negative effects on both the environment and human health. “Whether it be cancer, respiratory problems, cardiac problems or neurodegenerative problems, there are numerous adverse health effects associated with the chemicals in these emissions,” said Evans. “If we were able to reduce emission of pollutants like black carbon, we would also see an immediate climate benefit.”

Black carbon – commonly called soot – is a marker for exposure to diesel exhaust which is known to have negative health effects.

Evans points out that modern trucks have made large improvements in their emissions – it’s the older diesel trucks that are the real culprits. “Those big, 18-wheeler diesel trucks last for a long time. We need to push to retrofit these old trucks with better emission treatment systems. Simply retrofitting the worse offending trucks, or getting them off the road, is a tremendous opportunity to improve air quality in our cities.”

The study will be part of a larger report in December that will stress the importance of implementing long-term monitoring of traffic-related air pollution in Canada, and indicating that targeting high-emitting vehicles such as old trucks can provide a path towards improving near-road air quality.

In the meantime, Evans hopes the study gets Canadians thinking about the effects of working, playing and living near truck-related air pollution.

“When a cyclist is riding near a large truck and they see a large plume of soot coming out – it’s important for them to be aware. Although shipping freight and construction by truck are critical to our economy, people need to know about the negative effects. There are ways that we can achieve a better balance.”

The research was supported by Environment and Climate Change Canada and the Canada Foundation for Innovation.

Environment more important to respiratory health than genetics: U of T researcher

noreen.rasbach — Tue, 06 Mar 2018 19:09:08 +0000

Environment more important to respiratory health than genetics: U of T researcher

noreen.rasbach Tue, 03/06/2018 - 14:09

Cutline

The study linked genetic, health and disease data of participants from Montreal, Quebec City and Saguenay to environmental information such as air pollution, walkability and access to food (photo by Eric Titcombe via Flickr)

Topic