Has climate change been contributing to rising numbers of asthma attacks?
That’s something scientists hope to shed more light on, with the first analysis in more than three decades of the amount of pollen flowing through our air.
As allergy sufferers know all too well, the fine pollen particles released by trees and plants over spring and early summer can be a hayfever headache - leaving us with watery eyes, runny noses, and relentless bouts of sneezing.
Hayfever, or allergic rhinitis, is also an extremely common trigger for children and adults with asthma, with an estimated 80 per cent of asthmatics suffering from it.
While there’s now plenty of health data to show New Zealand has comparably high rates of childhood asthma – and that asthma attacks have been generally increasing – less clear are the specific drivers behind it, with damp homes and air pollution among the suspected drivers.
In a new project, a team of researchers aim to learn more about how a warming climate and other recent environmental shifts fit into the picture.
Atop the Auckland War Memorial Museum Tāmaki Paenga Hira, they’ve just installed a spacecraft-like pollen trap, providing them with near real-time data on pollen and spores known to trigger a range of allergic reactions.
Given our current information is modelled on trends measured decades ago, the work was well overdue, University of Auckland pharmacist and asthma researcher Dr Amy Chan said.
“We simply don’t have current - or recent - data that tells us about how these pollen triggers may have changed in recent decades in response to changes in climate, land use and vegetation patterns,” she said.
“So, there’s a real need to look at pollen and how this relates to health. This is the first time in 35 years we’ve been able to do it using pollen capture, which is why it’s really exciting.”
The project, funded by Auckland Medical Research Foundation, Health Research Council and Life AI Corp, would also track about 300 patients to record any correlations between their asthma and what the team were finding in the trap.
Chan said there were many burning questions to answer – particularly whether there’s a clear climate change connection.
“With climate change and warmer temperatures, plants produce more pollen over longer growing seasons,” she explained.
“This means the duration that people may be exposed to pollen triggers is now longer, which may be why we have seen an increase in asthma attacks.”
In one just-published study, Chan and colleagues revealed there’d been a one-third increase in total asthma attacks in the decade to 2019 in New Zealand, with half of hospital admissions being Māori or Pacific people.
“Carbon pollution also fuels photosynthesis so plants will grow larger and produce more pollen too and worsen pollen triggers.”
In recent times, researchers have raised concerns that New Zealand might be at more risk of “thunderstorm asthma” - where big weather events coincide with high-pollen periods.
“The combination of more pollen in the air over a longer duration with more severe weather events could make for a dangerous combination.”
Likewise, there’d been a growing number of studies exploring links between asthma rates and green spaces, which have undergone dramatic change since the last pollen analysis in the late 1980s.
One such paper, involving nearly 50,000 Kiwi kids, suggested exposure to green natural environments - especially those with a diverse mix of vegetation - could protect against the condition.
“The richness and diversity of trees may facilitate exposure to a range of pollen types which could be protective for developing symptoms of respiratory disease.”
Another open question was whether there now might be new or emerging pollen allergens that weren’t detected in the last assessment in 1988.
Working alongside Chan is University of Auckland optometrist and scientist Dr Stuti Misra, who’s investigating whether seasonal bursts of pollen can affect inflammatory cells within the eyes of people with allergies.
Both researchers are now keen to see New Zealand follow other countries and set up permanent, automated pollen monitoring stations across the country, giving people instant information about what’s in the air.
Having hosted a trap in the 1980s, the museum’s elevated position and clear surroundings in Auckland Domain made it an ideal monitoring site.
“Auckland Museum is one of the oldest research institutions in Aotearoa and we are happy to support researchers, especially if it helps us better understand our surrounding environment,” Auckland Museum asset manager Edward Howell said.
Joining Chan and Misra on the project – itself part of a wider programme to better understand New Zealand’s high asthma incidence - are Victoria University palynologist Professor Rewi Newnham, Massey University senior lecturer Dr Katherine Holt, and University of Auckland researchers Laura McDonald and Natasha Ngadi.
Outside of asthma, Chan anticipated the fresh data would unlock a world of invaluable new insights.
Could it possible, she asked, that shifts in pollen concentrations were linked to changes in our cognitive performance, productivity, sleep and quality of life – or even respiratory and cardiovascular deaths?
“We know from overseas research that pollen can have a significant impact on health, not just allergic diseases,” she said.
“Now, we’re finally able to have data on pollen types and amounts in Auckland.”
Jamie Morton is a specialist in science and environmental reporting. He joined the Herald in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.