The air we breathe

Q: Amidst all of the new climate worries and terminology, I have been thinking about the old problem of air pollution and wondered how closely it’s connected to environmental concerns.

A: You are quite right to notice a link between air pollution and the health of the climate, even human health, because many of the causes and consequences overlap.

“Over the last one hundred years or so, even before that, we have been experiencing the effects of air pollution on human health,” explains Professor Patrick Goodman, Senior Lecturer at TU Dublin in the School of Physics, Clinical and Optometric Sciences, who has worked as an expert advisor on air quality for WHO, the EU and USEPA. If we think of “big ticket items,” he says, like the Great Smog of London in 1952 or the pollution event in Dublin in 1982, when smoky coal caused a number of deaths, “this all kind of sparked an interest in how air pollution is not good for your health.”

It took time for scientists to figure out that the lower we can keep air pollution, the better, he explains, with WHO setting guidelines which are not enforceable but usually more stringent than EU limits. Another thing we do know, based on data from the smoking ban in pubs and the ban on smoky coal in Dublin in the 1990s and Cork in 1995, is that “air quality has improved and we see a big health benefit from the general population.”

You may have heard of particle size and why it matters: PM10 are particles up to 10 microns in diameter, the size that can get past your nose and into your respiratory system or upper airway. PM2.5 are smaller and can get into your lungs and bloodstream. Goodman points to the example of someone who smokes: “You get high from smoking fairly quickly, and clearly stuff is going from the cigarette into the blood stream into the brain.”

“If you are breathing air with nasty things in it, it will get in your bloodstream,” and can lead to breathing troubles and other cardiovascular effects. With “high pollution events,” he says, “particles interact with blood vessels and cause plaque build-up, and heart attacks can be triggered in people who are already ill.” A few bad days of air pollution might trigger breathing problems for those with asthma, or elderly with respiratory conditions; but an extended period – for example the effect of those Canadian wildfires in the U.S. last summer – can lead to longer-lasting and more serious health problems. Indoor products like household cleaners and aerosol sprays can also be local trigger for asthmatics.


The connection between air pollution and the environment gets explicit when we ask where it comes from.

“The bulk of pollution is from combustion processes, burning things, petrol or diesel in the vehicle or diesel or kerosene in heating systems or coal or turf or wood in home heating. They are all from combustion,” says Goodman. Even more, “when burning any of these carbon-based fuels, we are producing greenhouse gases,” he adds. “The most effective way to effect global human health is to get away from burning, produce much less air pollution and reduce our carbon footprint,” he says, pointing to the “double benefit if we can reduce combustion processes.”

Goodman notes, “By and large, Ireland would be one of the cleaner places,” but “it doesn’t mean we need to be complacent.” A few things work in our favor, including wet and windy weather, when pollution levels are generally low, with clearer days and “high pressure centers” bringing a greater risk.

The biggest sources for air pollution for Ireland is road traffic and home heating. “Curiously, monitoring by the EPA often finds far higher pollution levels in some of the smaller towns around the country rather than cities because of the heating of the houses, especially with turf or coal,” Goodman notes. “We were taken aback by the difference between the smaller town and the big city in annual reports from the EPA on air quality.”

It turns out, the strategies for limiting air pollution are much the same as those for challenging climate change, including getting away from solid fuel usage, even moving to a heat pump if possible, turning to electric vehicles, insulating your home to use less energy to heat it, and, for older people in the cold weather, heating one or two rooms instead of the whole house, or going to a library or shopping centre for a few hours to avoid using your own heating.

Goodman also warns that we need to be aware of unintended consequences, for example the turn to solid fuels in the ‘80s, a response to oil shortages, led to even greater air pollution, and the switch to diesel in the 2000s, which was well-intentioned, diesel supposedly emitting fewer greenhouses gases, was followed by the scandal that emissions were being misreported, diesel indeed emitting nitrogen oxides.

“Going forward, what can we do?” asks Goodman.

“We can burn less. If we have to burn something, make sure it’s clean, newer, certified fuels, and it’s not just burning rubbish. If loads of people do it, it makes a huge difference.”

Much of the wisdom about what’s good for the climate is also what’s good for air quality and for your own health.