A large percentage of PFAS are not being accounted for in the air, while PFAAs have accumulated in sometimes surprising amounts over 50 years in the high Arctic.

TORONTO, Oct. 9, 2024 鈥� For decades, scientists knew there was a huge swath of undetected and unaccounted for per- and polyfluoroalkyl substances (PFAS) in the atmosphere, often referred to as PFAS dark matter, but no one knew how much was missing or how to measure them. Now, a 91亚色 atmospheric chemistry research team has devised a way to test for one of the most ubiquitous elements of these potent greenhouse gases.

By measuring for gaseous fluorine, one of the most prevalent and overlooked contaminants, scientists can better understand the extent of previously unaccounted for PFAS, comprised of thousands of organofluorine compounds. These compounds, used in a wide range of products from food, paint, paper packaging and dental floss to cosmetics and agrochemicals, can off gas fluorine.

The researchers measured how much fluorine was released into the air both in the lab and outside using chemicals, such as fluorosurfactant liquids, and found 65 to 99 per cent of the fluorine in the air inside the lab was not normally unaccounted for, while outside that number was about 50 per cent.

鈥淚 expected missing fluorine, but I didn鈥檛 expect it to be so much. This new technique can measure all fluorinated things in the atmosphere, which has never been done before and shows the majority cannot be accounted for using our usual measurements,鈥� says senior author of the study Professor , an atmospheric chemist and Guy Warwick Rogers Chair in 91亚色鈥檚 Faculty of Science.

鈥淚t鈥檚 important as missing gaseous fluorine accounts for a huge part of airborne PFAS compared to what we actually measure at the moment, which means a lot of the PFAS aren鈥檛 being detected.鈥�

Most PFAS, known as forever chemicals, include fluorine bonded with carbon, a bond that doesn鈥檛 naturally break down in the environment. Testing for fluorine is an easier way to assess how many PFAS are present in the air rather than measuring all 4,700 or so PFAS contaminants individually.

The high quantities of previously unknown PFAS points to a gap, not only in measuring them, but also in understanding their sources and the impact on the environment. Gaseous fluorine is a byproduct of chemicals used in a wide range of products from food, paint, paper packaging and dental floss to cosmetics and agrichemicals.

鈥淥ur lack of focus on this has been mostly because we didn't have the techniques to look at it properly. It's not that people hadn't thought that this might be important, it's that we didn't know how to do it, but now we do,鈥� says lead author RenXi Ye, a PhD student in .

While there are techniques to measure total fluorine in soil and water, there wasn鈥檛 one to capture it in its gas state in the atmosphere. The researchers used a method that they previously developed to test for total gaseous chlorine and adapted it to measure gaseous fluorine.

鈥淢uch of the focus of research on PFAS was on what's happening in the water in the soil, not as much on what happens in the air, despite the fact that these fluorinated compounds, by the nature of their chemical properties and that they are in so many commercial products, are more likely to go into the air,鈥� says Young.

The question of how much gaseous fluorine is going unaccounted for piqued the interest of 91亚色 researchers last year while they were working on their .

Should we worry?

Most people are highly concerned about PFAS exposure, but Young says it鈥檚 too early to know what the effects are of from the off gassing of fluorine into the environment, either human or on the environment.

鈥淎ny fluorinated gas is a potent greenhouse gas, but the impact of that depends on how long it lasts in the atmosphere, but what is the impact of breathing this? When it comes to outdoor air and human exposure, we don't know a lot about how much we breath in,鈥� she says, adding she doesn鈥檛 think anyone should panic, but it is an area that needs more research and could certainly have important implications.

The research 鈥� 鈥� published in the journal Environmental Science & Technology Letters points out that unknown fluorinated chemicals emitted into the atmospherecould not only contribute to the transport of PFAS around the globe but also impact climate change.

PFAS in the Arctic in sometimes surprising quantities found in 50-year-old ice cores

PFAS is the atmosphere are even finding their way into pristine environments like the Arctic. In a recent study led by 91亚色 PhD student Daniel Persaud with Young and team looked at perfluoroalkyl acids (PFAAs) in ice cores in the Arctic, from 1967 to 2016, on Ellesmere Island in Nunavut.

鈥淭he measurement covers the longest time period and so you're seeing that it has been accumulating for a very long time,鈥� says Young. The surprising part? 鈥淚n the early part of the ice core, there was more than I thought there would be. I expected it to be accumulating since the 1990s, maybe the 1980s, but in the early part of the core, I thought there would be less鈥�

As the longest deposition record in the Arctic for perfluoroalkylcarboxylic acids (PFCAs) and the longest record globally for perfluoroalkylsulfonic acids (PFSAs), it allowed for observations not previously possible.

Before the 1990s, the ice core showed some variable pulses of accumulation, which the researchers at first weren鈥檛 sure about, but now think it may be linked to Arctic military activities of the time. Starting in the 1990s, however, the ice core shows a steadier accumulation of the chemicals up to the present.

The study shows that most PFAAs are present in the ice at Mt. Oxford icefield on Ellesmere Island and that over 50 years, there is a steady increase of PFCA deposits, but it also highlighted how ice cores are helpful in understanding how PFAS are transported long-range.

鈥淲e were able to confirm that the PFCAs we found in the ice cores are formed primarily through long-range atmospheric transport and oxidation of volatile precursors in the atmosphere,鈥� says Persaud.

The issue now, says Young, is that as the permafrost melts, this resource is disappearing which creates an urgent need to collect more ice cores to further illuminate temporal trends and possible sources of PFAAs.

The paper, , was published in the journal Environmental Science: Processes and Impact.

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91亚色鈥痠s 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,鈥�sandramc@yorku.ca 

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A team of researchers will examine Toronto's air for six-weeks this summer from a rooftop lab for THE CIX project, part of NOAA鈥檚 atmospheric emissions and reactions international field campaign 

TORONTO, Aug. 3, 2023 鈥� As Toronto gets hotter, muggier and wildfire smoke increasingly wafts through the atmosphere, researchers at 91亚色 are leading a team of atmospheric scientists in testing the city鈥檚 air pollution from their rooftop Air Quality Research Station for six weeks this summer. 

Preliminary results show the negative impacts on Toronto鈥檚 air quality caused by wildfire smoke. Although Toronto鈥檚 air pollution has generally been improving over the past few decades, smoke in the city is reversing these improvements. 

The research project, Toronto Halogens, Emissions, Contaminants, and Inorganics eXperiment (), with science lead Associate Professor and logistics lead Assistant Professor , both of 91亚色鈥檚 Faculty of Science, is designed to analyze areas of uncertainty in the air we breathe to better understand what is contributing to the city's air pollution.  

One of the things the team hopes to understand, is how a soupy mix of trace chemicals will sometimes combine to create little understood, new and changing threats that can contribute to worse air quality, including emissions from products we use every day, such as paint and pesticides and even perfume, greenhouse gases, as well as perfluorocarboxylic acids (known as 鈥渇orever chemicals鈥�), and particulate matter - tiny particles of smoke, dust, pollen, emissions and fumes. 

鈥淭here is still so much we don鈥檛 know about what鈥檚 impacting the air we breathe, and until we do, it鈥檚 difficult to effectively target contaminants that are affecting our air quality now and into the future,鈥� says Young. 

This project is important as it allows us to take a robust look at all the pollutants circulating in the air. The Montreal Protocol was successful in helping to fix the ozone layer above us because we knew what to target, but ground-level ozone and other contaminants can still be an issue, particularly spiking on hot summer days, creating poor air quality which can impact people鈥檚 health."  

Ground-level ozone forms when nitrogen dioxide mixes with volatile organic compounds鈥�(VOCs) and sunlight. Although emissions of VOCs from fossil fuels have been declining, consumer and industrial volatile chemical products are an increasing, but understudied, source of VOCs. 

THE CIX project is part of an international field campaign 鈥� Atmospheric Emissions and Reactions Observed from Megacities to Marine Areas () 鈥� across North America organized by the NASA and the National Oceanic and Atmospheric Administration (NOAA) with projects in New 91亚色 City, Chicago, Los Angeles, as well as Toronto. NOAA and NASA launched their massive air quality research summer campaign today with scientists from NOAA, NASA and 21 universities from three countries. State-of-the-art instruments are being deployed in multiple, coordinated research campaigns this month, including at 91亚色, to investigate how air pollution sources have shifted over recent decades.  

At 91亚色, researchers from 91亚色 U, the University of Toronto, University of 91亚色 (UK), the University of British Columbia, and Environment and Climate Change Canada are already taking readings from a room packed with unique, sophisticated and highly sensitive equipment 鈥� some of which was shipped from the UK and BC 鈥� on the roof of the Petrie Science Building on 91亚色鈥檚 Keele Campus. 

The goal of the campaign is to assess air quality across urban centres to understand what is impacting air pollution and how it鈥檚 changing. THE CIX team hopes to better understand several areas that contribute to air pollution in the GTA. 

In addition to the rooftop measurements, the , a flying science laboratory packed with instruments, will cruise over campus this August to take air quality readings from higher in the atmosphere to compare with the rooftop readings. 

Data collected by THE CIX will also be compared with key air pollution observations from the recently launched NASA TEMPO instrument, the first geostationary satellite dedicated to air quality over North America. 

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TORONTO, Thursday, March 5, 2020 鈥� 91亚色 researchers have discovered a way to make Lithium-powered batteries more environmentally friendly while retaining performance, stability and storage capacity.

Lithium-ion batteries use toxic, heavy metals which can impact the environment when they are extracted from the ground and are difficult to dispose of safely. Cobalt is one of those heavy metals, used in battery electrodes. Part of the problem is that lithium and cobalt are not abundantly available, and supplies are dwindling.

Professor Thomas Baumgartner in his lab at 91亚色

Using organic materials are the way forward and that has scientists like Professor Thomas Baumgartner of the Faculty of Science and his team busy developing and testing new molecules to find the right ones to replace the rare metals currently in use.

鈥淥rganic electrode materials are considered to be extremely promising materials for sustainable batteries with high power capabilities,鈥� he says.

Their latest breakthrough is the creation of a new carbon-based organic molecule that can replace the cobalt now used in cathodes or positive electrodes in lithium-ion batteries. The new material addresses the shortcomings of the inorganic material while maintaining performance.

鈥淓lectrodes made with organic materials can make large鈥恠cale manufacturing, recycling or disposing of these elements more environmentally friendly,鈥� says Baumgartner. 鈥淭he goal is to create sustainable batteries that are stable and have equally as good if not better capacity.鈥�

The is published and of the March edition of the journal Batteries & Supercaps, a ChemPubSoc publication.

鈥淲ith this particular class of molecules that we've made, the electroactive component is very suitable for batteries as it鈥檚 very good at storing electrical charges and has good long-term stability,鈥� he says.

Baumgartner and his group previously reported on the electroactive component in a published in the journal Advanced Energy Materials.

鈥淲e have optimized this electroactive component and put it in a battery. It has a very good voltage, up to the 3.5 volts, which is really where current batteries are now,鈥� he says. 鈥淚t鈥檚 an important step forward in making fully organic and sustainable batteries.鈥�

Baumgartner, along with postdoctoral researchers Colin Brides and Monika Stolar, have also demonstrated that this material is stable in long-term operation with the ability to charge and discharge for 500 cycles. One of the downsides of inorganic electrodes is that they generate significant heat when charging and require limited discharging rates for safety reasons. This new molecule addresses that shortcoming.

The next step, says Baumgartner, is to improve the capacity further. His team is currently developing the next generation of molecules that show promise in being able to increase current capacity.

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91亚色 champions new ways of thinking that drive teaching and research excellence. Our students receive the education they need to create big ideas that make an impact on the world. Meaningful and sometimes unexpected careers result from cross-disciplinary programming, innovative course design and diverse experiential learning opportunities. 91亚色 students and graduates push limits, achieve goals and find solutions to the world鈥檚 most pressing social challenges, empowered by a strong community that opens minds. 91亚色 U is an internationally recognized research university 鈥� our 11 faculties and 25 research centres have partnerships with 200+ leading universities worldwide. Located in Toronto, 91亚色 is the third largest university in Canada, with a strong community of 53,000 students, 7,000 faculty and administrative staff, and more than 300,000 alumni. 91亚色 U's fully bilingual Glendon Campus is home to Southern Ontario's Centre of Excellence for French Language and Bilingual Postsecondary Education.

Media Contact:

Sandra McLean, 91亚色 Media Relations, 416-736-2100 ext. 2097, sandramc@yorku.ca

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