Climate change could impact omega-3 levels worldwide, U of T researchers find

Christopher.Sorensen — Thu, 26 Sep 2019 16:25:39 +0000

Christopher.Sorensen Thu, 09/26/2019 - 12:25

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Most people get DHA, an essential omega-3 fatty acid, from eating fish, which in turn get it from eating algae. But a U of T study suggests climate change will result in less need for algae to produce DHA (photo by Stock Colours via Getty Images)

Branden Wesseling

Topic

Breaking Research

Chemical Engineering

Climate Change

Earth Sciences

Faculty of Applied Science and Engineering

Faculty of Arts & Science

Research & Innovation

Sustainability

Climate change won’t just bring rising sea levels and more extreme weather — it could also impact your dinner plate.

A new ��Ƶ study suggests that a warmer world will decrease the availability of a nutrient that is key to development and brain health. The study, published in the journal Ambio, investigates worldwide production of docosahexaenoic acid (DHA), a naturally occurring essential omega-3 fatty acid. The group of molecules is needed for higher-level brain functioning and cognition, memory, eyesight, particularly at crucial stages in fetal brain development.

Most humans get their DHA from eating fish, which in turn get it from the algae that they eat. But Tim Rodgers, a PhD candidate in the department of chemical engineering and applied chemistry, says that as ocean temperatures rise, the need for algae to produce DHA decreases.

“To counteract the effect of higher temperatures, which can make their cell membranes too fluid, algae typically produce fewer polyunsaturated fats (such as DHA) in a process known as homeoviscous adaptation,” says Rodgers (left), who is a first co-author of the study along with Stefanie Colombo of Dalhousie University.

“Algae is the bedrock of aquatic food chains, so this decrease in DHA production works its way right up to the fish we eat, which make up a significant source of the long chain omega-3 fatty acids in the global diet.”

Rodgers, who is also a graduate student in U of T’s Diamond Environmental Research Group under supervisor Professor Miriam Diamond, used a form of computer modelling known as Monte Carlo uncertainty analysis to predict the amount of DHA that will be available under various scenarios of climate change developed by the United Nations Intergovernmental Panel on Climate Change.

Under the worst case scenario – known as RCP 8.5, which assumes that greenhouse gas emissions continue to rise at current rates indefinitely – the team found that, over the next 80 years, the amount of DHA available in the food chain would decrease by 10 percentage points to 58 per cent.

The team also estimated the results on the diets of humans around the world. If the loss of DHA were spread out evenly, the team suggests that up to 96 per cent of humans would not be able to obtain enough DHA to maintain a healthy diet.

But that scenario may understate the impacts on vulnerable populations, the researchers say, because wealthy countries such as Canada, which doesn’t produce enough DHA domestically and relies upon trade to supplement this need, would likely push to the front of the line.

“As global DHA levels decrease, it’s not difficult to envision a situation where rich countries use their economic advantages to increase their access to naturally occurring sources and with more expensive supplements,” says Rodgers.

This means that the impacts of a shortage would likely be felt by the most vulnerable populations in poorer countries, as well as by more vulnerable people, such as infants and developing fetuses.

“Even at the low end of the model, meaning the less extreme scenarios, the impact of declining DHA will still be significant,” says Rodgers. “Based on the current trajectory of the climate, even the most optimistic projections have us heading towards a pretty alarming loss in human potential.”

The study, a collaboration among U of T researchers from chemical engineering in the Faculty of Applied Science & Engineering, Earth sciences in the Faculty of Arts & Science and nutritional sciences in the Faculty of Medicine, as well as researchers from Ryerson University and Dalhousie University, is the first comprehensive look at DHA declines due to global warming specifically.

The research received support from the Natural Sciences and Engineering Research Council of Canada.

U of T study of oil sands monitoring suggests poor understanding of emissions – and their impact

Christopher.Sorensen — Thu, 11 Jul 2019 19:59:17 +0000

U of T study of oil sands monitoring suggests poor understanding of emissions – and their impact

Christopher.Sorensen Thu, 07/11/2019 - 15:59

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The review of Canada's Joint Oil Sands Monitoring Program by U of T's Jeffrey Brook sought to identify progress and limitations in knowledge around emissions and potential ecosystem effects (photo by Mark Ralston/AFP via Getty Images)

Topic

Dalla Lana School of Public Health

Faculty of Applied Science & Engineering

Jeffrey Brook, a ��Ƶ expert in air quality and health, spent nearly a year reviewing data from Canada’s Joint Oil Sands Monitoring (JOSM) program, which aims to quantify and assess the short and long-term impact of Alberta’s oil sands operations by monitoring air quality, water contamination and biodiversity disturbances.

His findings, recently published in the Journal of the Air & Waste Management Association, suggested some air contaminants are not well quantified and that emissions levels for a range of air contaminants – including greenhouse gases – are underestimated.

Organic toxins, known as polycyclic aromatic compounds (PACs), are also an environmental concern.

“They are in the air, water and the biota and there is evidence that some of the negative changes in the health of some of the species studied are associated with PACs,” says Brook (left), who is an assistant professor in U of T’s Faculty of Applied Science & Engineering and the Dalla Lana School of Public Health.

While the environmental impact of Alberta’s oil sands industry has long raised concerns in the global scientific community, there have been questions about how to apply the data gathered through initiatives such as JOSM.

Brook’s review – which focused on results generated from Environment and Climate Change Canada’s research on air, water and wildlife contaminants and toxicology – covered the current state of oil sands monitoring in order to identify progress and limitations in knowledge around emissions and potential ecosystem effects. Ultimately, the review aimed to initiate dialogue on areas needing future scientific work.

When it comes to his findings about PACs, Brook stresses that, “Multiple environmental factors are at play. Contaminants from oil sands development is only one of the factors affecting plant and animal species in the area.”

Nevertheless, he also points out that Indigenous populations could potentially be impacted – from changes in their way of life to health effects from exposure to contaminants.

“These risks are presently not well understood, which limits the ability to set short and long-term environmental standards that appropriately recognizes the health and ecological effects.”

Brook says an enhanced monitoring and integrated assessment of the knowledge of oil sands is necessary “to understand its effects and protect important Canadian environments.” That includes northeast Alberta’s Peace-Athabasca Delta, the largest freshwater inland river delta in North America.

Taking stock of lessons learned in oil sands monitoring is also an essential step towards helping to identify potential new areas of study and future policy development.

Brook says a more complete understanding of the oil sands could be on the horizon.

“Tools to predict the current and future impacts of atmospheric emissions on the local and more-distant environment have made a significant leap forward.”