Quirks & Quarks

You can help researchers monitor air pollution by collecting moss

Bob McDonald's blog: Scientists are asking for people across Canada to collect their local mosses and send them in for analysis, so that they can monitor heavy metals such as arsenic, cadmium, lead, and zinc accumulated in them.

Bob McDonald's blog: Scientists are asking Canadians to collect moss to help them monitor air quality

Researcher Tanner Liang sampling stair-step moss on Baffin Island in Canada's Arctic. Because moss is so widespread, it makes for a perfect way to monitor pollutants across the country. (Submitted by Kayla Wilkins)

Environmental scientists from across Canada are asking for public participation to monitor air pollution — and it can be as easy as taking a walk in the woods and picking a few plants. 

Air quality measurements are normally taken by complex instruments that must be positioned outdoors to take air samples, then analyzed to determine the chemical composition. But there aren't nearly enough monitoring stations to cover the vast area of our huge country. 

But thankfully, nature has provided us with abundant tools that collect air samples every day: mosses. Which is why scientists are asking citizens to sign up for what they call the bryomonitoring survey, to collect these fluffy mosses — also known as bryophytes — from across Canada to act as a biomonitoring tool.

Researchers analyze red-stemmed feather moss in the lab, where they can detect a long list of contaminants such as arsenic, cadmium, lead, zinc, accumulated over the past several years. (Submitted by Kayla Wilkins)

"We don't often notice moss, but it's everywhere, and can tell us lots about air quality," said Kayla Wilkins, a graduate researcher at Trent University and part of the project. "This is especially helpful in Canada's remote regions where it would be challenging to set up and maintain air pollution monitoring equipment."

Mosses have no roots, and draw their moisture and nutrients from the air rather than the soil. In the process, they also collect any chemical contaminants in the air and store them in their tissues for several years. This makes them natural air quality samplers.

All the scientists need are volunteers to pick some samples and send them in for analysis.

Universities across the country are participating in the survey, from the University of British Columbia to the Université de Moncton, and several in between. At Trent University in Ontario for example, lab equipment can detect a long list of contaminants such as arsenic, cadmium, lead, zinc and others accumulated in the moss over the past two to three years.

When you register on their website, you select an area you would like to sample based on a numbered grid that has been laid over the entire country. You are sent a collecting kit consisting of brown paper lunch bags, gloves, field sheets and identification guides to know which mosses to pick, along with a return envelope.

The survey is asking volunteers to collect two specific types of moss: stair-step moss and red-stemmed feather moss. They are usually found in open areas, such as places recovering from the clear-cutting of trees, areas near hydro transmission lines, or where the forest canopy has opened up due to fallen trees.

The scientists suggest you choose an area that is away from buildings, roads, and even pathways so the samples aren't just capturing pollutants from those specific local sources.

You will be asked to collect at least five samples within a 50-by-50 metre area. Using the GPS on your phone you mark the location and time, then place your specimens in paper bags (plastic bags will promote the growth of mould which destroys the samples) and mail it to the closest laboratory.

The bryomonitoring survey is intended to add Canada to the much larger ICP vegetation moss biomonitoring survey, which is an international research project involving 50 countries to investigate the effects of air pollution on crops and other vegetation. It was established in 1987 under the United Nations Convention on Long Range Transboundary Air Pollution.

Kayla Wilkins collects moss to check for nutrients and heavy metals. Because moss doesn't have roots, it absorbs everything in the air, making it a natural air quality monitoring station. (Submitted by Kayla Wilkins)

Heavy metal pollution comes from industry and affects biodiversity, as well as human health. Getting a clear picture of how widespread that pollution is in a country as large as Canada would be difficult and expensive without public participation, according to Wilkins.

If you enjoy taking hikes into remote areas, why not make a scientific contribution along the way? You will learn about mosses, heavy metals and contribute real data to a national survey.

As they say on their website, "Reserve your turf and sign up to sample."

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