Pollen analysis takes flight

Faster analysis of what’s in the air is important for hay fever and asthma sufferers

A device originally developed to counter bioterrorism has been pressed into service in aid of hay fever sufferers and those with asthma. A research team at UCC has further developed the technology and it might also be useful for monitoring airborne bacteria in hospitals.

It gives an almost instantaneous read-out of what pollen types might be floating about but also fungal spores, plant particles, bacteria and even viruses. Success with prototype systems has been enough to temp MeteoSwiss, Switzerland’s met office, to trial the system there.

“The system we have is actually one of a number of prototypes we are moving forward,” says John Sodeau, professor of physical chemistry and director of the Centre for Research into Atmospheric Chemistry at UCC. “We wanted to look at the possibility of identifying biological aerosol particles in near real time.”

Pollen forecasts

The Environmental Protection Agency provided funding for the research via its climate change research programme. Prof Sodeau was aware that Ireland does not have its own pollen and “bio-aerosol” measuring system and wondered if one could be developed.

“For the past number of years Ireland has been buying in its pollen forecasts from a service run near Worcester,” he says. Pollen levels are sampled there and then modelled to forecast for Ireland.

Prof Sodeau decided to develop an alternative based on a radical new technology. “The traditional methods for measuring are extremely laborious,” he says, involving trapping particles in filters over time and then employing a highly trained operative to identify and count them using a microscope. There are also laser-based systems which are commercially available, he says.

Prof Sodeau had heard of an alternative, developed by Prof Paul Kaye and Dr Warren Stanley at University of Hertfordshire. “We were aware of an instrument developed for bioterrorism,” he says. “These are prototype instruments. There are probably three in the world and this is the only one being used in this way.”

They were originally designed to sample air and pick up the presence of bacteria or viruses in near real time (within seconds). The system is based on spectroscopy and fluorescence, measuring the light signal coming from bio-aerosols.

Prof Sodeau wanted to see if it could be used for the detection of less dangerous bio-aerosols, the ones of importance to hay fever and asthma sufferers. “We are the first people to use it to do real time identification of fungal spores and pollen.”

He worked with colleagues in the Cork centre in the Department of Chemistry and the Environmental Research Institute, Dr David Healy and Dr David O’Connor. Together they developed software that allowed the raw light signals coming from the instrument to be processed into meaningful data.

It gave them a great deal of information, for example being able to identify different types of pollen. The device used two different light wavelengths to provide the data and also uses “laser scattering” which helps gauge size and shape. Their system can detect viruses in a sample.

Instrument trials

They decided to trial the instrument in Killarney National Park, testing it against the existing laser and by-hand pollen measuring methods. They found that there were more bio-aerosols in the park environs than in either urban or industrial environments during the summer. This was expected given the park’s abundance of plant sources, but the system delivered data comparable to traditional methods and in a matter of seconds, Prof Sodeau says. This type of data calibration experiment to validate the system was also carried out at the Technical University of Munich, he says.

Prof Sodeau sees commercial potential in the device. “In the long term it can provide a service that isn’t currently available here.” It could give rapid warning of heavy pollen discharge or spore release that might impact on those with asthma or hay fever. A commercial version of the device could be set up near compost and waste facilities to monitor bio-aerosol output. It could also be used indoors, for example in a hospital setting where airborne bacteria and viruses could be monitored.

It also has value in studying aspects of climate change. Aerosols of all types can become nucleation points for ice crystals or water droplets. Bio-aerosols, which include very small plant fragments, may therefore have a more important role than previously thought in influencing climate and hydrological cycles, he says.

The study of airborne pollution is another possibility. “There are chemical pollutants in the atmosphere as well. What happens when chemicals piggy-back on these particles?” It opens up another research approach, he believes.

A new approach to bio-aerosol monitoring in Ireland is at iti.ms/WFljTm