Challenging the status quo

Professor Barbara Maher looking at young growing trees in an urban space
Professor Barbara Maher

Lancaster University’s first female science professor gains international recognition for ‘proven leadership’ in her field, crowning a career challenging the status quo as an often-lone woman in a male-dominated world.

Professor Barbara Maher harnesses the magnetic properties of particles as a tool to increase our understanding of a range of environmental processes, from climate change to how pollution impacts human health.  

She has broken a series of glass ceilings: as well as becoming the University’s first female professor in the Institute of Environmental and Naturals Sciences in 2000, she was the first female head of the Geography Department, the first female deputy dean and the first female University Orator.  

Now she has been honoured by the American Geophysical Union (AGU), the world’s largest earth and space science society. She’s been invited to present the Edward Bullard Lecture at the AGU’s annual ‘Fall Meeting’ in December, which attracts 25,000 attendees from 100 countries. It’s part of a distinguished lecture series by scientists who have made ‘a signification contribution’ in their field.  

Barbara, who retired from the Lancaster Environment Centre at the end of July, remains as an Emerita professor and is still working on her ground-breaking research into the role pollution particles play in Alzheimer’s Disease.  

She first became interested in environmental magnetism when studying Geography and Geology at Liverpool University, the city where she grew up.  

“I went to a lecture in my first year by Frank Oldfield, who together with Roy Thompson, at Edinburgh’s Geophysics Department, was first developing environmental magnetism at that time. He was using the magnetic properties of particles to trace their movement through air, rivers and oceans. He was talking about how the development of new instruments and technology was opening up this new field of science”.  

Barbara was fascinated. She did her final year dissertation on the magnetic properties of soils and began to understand the potential of magnetism as a diagnostic tool for environmental research.   

“Because we can measure the properties of magnetic particles and understand where they came from or how they formed, and what has happened to them as they then move through the environment, they offer a very useful tool to help us understand environmental processes,” says Barbara. 

The dissertation led on to a PhD, then a post-doctoral fellowship to work in Edinburgh, with Roy Thompson, and then a Lectureship at the School of Environmental Sciences at East Anglia. One long term project involved studying the ‘fossil soils’ in China’s Loess Plateau, where 32 separate ‘fossil’ soil layers had formed over the last 2 million years. The amount of magnetic material in the soil can be used to calculate the changing amounts of monsoonal rainfall, right through past interglacial and glacial climate stages.  

“We can calculate what the rainfall was 125,000 years ago or 10,000 years ago from the magnetic properties of these fossil soils. The only other people who are estimating this are climate modellers. So, our data provides a way for climate modellers to see how good their models are at predicting past rainfall, and so how good they might be at predicting future rainfall as the climate changes.” 

“Our data showed that the rainfall was much less than the models indicated, especially for glacial periods. Millions of people depend on rain-fed agriculture: anything we can do to help predict how rainfall might change with global warming is of paramount importance in terms of feeding the human population.” 

This was not to be the last time Barbara’s research would challenge the accuracy of models.  

In 2000, Barbara moved to a professorial position at Lancaster University, setting up the Centre for Environmental Magnetism & Palaeomagnetism. With her PhD students, she used the magnetic properties of North Atlantic Ocean sediments to track the transport of icebergs by ocean surface currents, to test ocean/atmosphere models of ocean circulation during the last glacial stage.  

She also pinpointed the precise riverine source of eroded particles silting up the fish breeding grounds of Bassenthwaite Lake.  

And she became interested in roadside pollution, which was becoming a major area of concern for its detrimental impact on people’s health. She wondered if magnetism could be used to measure airborne particulate pollution, and its health impacts.  

“In many cities there are a lot of trees at the roadside, and we had the idea they might be acting as passive monitors of pollution as pollution particles settle on their leaves – leaves should not be magnetic in ‘clean’ atmospheric conditions. Strongly magnetic particulates are always in the pollution mix and so can act as a proxy for the level of particulate pollution in the air. We found it was really quick to measure and map the magnetic properties of leaves. 

“While the idea of magnetic leaves been around earlier, no-one had done these measurements in a systematic way.” 

The Environment Agency (EA), responsible for monitoring industry pollution, funded a PhD student to magnetically measure airborne particulate pollution around a coal-fired power station. This work showed that the EA’s models were substantially under-estimating particulate pollution.  

Barbara and her team wanted to find out if different plant species might have different capacities for intercepting pollution particulates depending on leaf characteristics. The hunch proved right.  

“We found that airborne pollution particulates are much more likely to attach to a leaf if the leaf is rough, hairy, sticky and/or there are lots of small leaves.” 

Barbara thought this knowledge could be used to reduce the level of damaging particulates and so protect vulnerable people. First, she did a trial with birch trees in pots along a busy Lancaster Street , which showed that levels of particulates in homes were reduced substantially when the trees were present. More recently, she has been working with Manchester City Council and Transport for General Manchester to erect hedges of small trees – which she calls ‘tredges’ - around primary schools next to busy main roads. The results are impressive. 

“When the wind is blowing from the road into the playground, having tredges can reduce particulate pollution by up to 50%: even when the wind is in the other direction it can reduce it by 15-25%.” 

Once again, Barbara results have been challenging what the models predict. “It’s been quite controversial. The modellers don’t believe trees will take out more than 10% or 15% of the particulate pollution, because they don’t take into account the individual characteristics of the leaves.  

“But, in fact, every amount of particulate matter that the tredges remove, rather than getting inhaled by those tiny children, is going to benefit their brains and hearts.” 

Barbara hopes that the pilot project will now be rolled out across Manchester: “It will be a fantastic legacy to have a role in greening up and protecting the most vulnerable areas and people, whilst we move to less polluting electrical vehicles.” 

Barbara also became interested in whether pollution might have a role to play in dementia.  

“I’d been aware for a while, that biological researchers were saying there is more magnetic iron in certain regions of an Alzheimer’s’ brain than a normal brain, which they attributed to the disease causing mishandling of iron in the brain. But I wondered if some of the magnetic nanoparticles, so abundant in airborne pollution, might be able to get into the brain and contribute to iron-related toxicity.” 

She contacted Professor David Allsop, a Lancaster University colleague and expert in Alzheimer’s disease. Together they examined the post-mortem brains of 37 Alzheimer’s sufferers in Manchester and Mexico City looking for magnetic particles. 

‘We found abundant, tiny magnetite particles, some with distinctive spherical shapes, along with ‘exotic’ metals that should not be in the brain, like platinum, for example. They looked exactly the same as the magnetite particles we’d been measuring at the roadside.’  

This work has attracted media and scientific attention all around the world…but follow-up funding has been difficult to get. “Despite the known toxicity of iron in the brain, and the growing evidence for increased brain and heart disease associated with particulate air pollution, we’ve sometimes been portrayed as mavericks, or left field. We’ve been so ahead of the wave…” 

Despite this, Barbara and her colleagues have pushed ahead with further research to try to establish if there is a causal link between these metal-rich roadside particulates and Alzheimer’s. They are currently carrying out laboratory experiments examining the impact on heart and brain cells of ultra-fine particulates, extracted from roadside dust in Lancaster, Birmingham, and Mexico City.   

Barbara has won many prizes and medals for her research. Her teaching has been recognised too: she won the Pilkington Award for her distinctive approach to teaching. She would play Fat Boy Slim music (‘very loud!’) as students came into lectures, and was constantly asking them questions, encouraging them to interact rather than be passive listeners.  

She also felt it was important to take on leadership roles, particularly as a woman.  “Women were very poorly represented at senior levels: on many occasions I would be the only woman at important faculty meetings, with some people trying on occasion to marginalise me, but I’ve never backed off making the arguments I felt were important. It has taken a long time to get that minority status overcome.  

“It seems to be shifting now and quickly. There has been a big improvement in the past few years, and maybe we have now passed a threshold where things will be different.” 

Looking back, she is very proud of what she has achieved at Lancaster. “It’s demonstrably a substantial, incisive body of work: and I’ve done all of that despite contributing more than my fair share in terms of senior management and teaching duties.” 

Despite her official retirement, Barbara is continuing her connection with the Lancaster Environment Centre. She is staying on as an emerita professor and is still working on several research projects, particularly focussing on pollution and health. 

She is also sending more time on creative writing, which she has done on and off throughout her life.   

“I have always worked hard on writing really well in my scientific work – if the reader can’t access it easily you are not doing your job. But I love the freedom of creative writing, being able to express all sorts of things.” 

She now intends to write a novel, which “may be very loosely based on some recollections from my career.”

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