Teens Are Using Moss To Push For Cleaner Air in Seattle’s Duwamish Valley

In Seattle neighborhoods historically devoid of reliable government-sanctioned air monitors, community moss sampling has successfully led to new air monitoring sites in pollution hotspots.

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When Nico Vargas spent her time mentoring teenage girls in South Seattle last year, they were just trying to make it through another day in high school – all while disproportionately burdened with air pollution.

Vargas, then a senior at Western Washington University studying environmental policy, walked them through neighborhoods in the Duwamish Valley to collect moss that the United States Forest Service (USFS) would later screen for air toxin concentrations. They asked about how to find viable trees to access the moss, but they also asked why navigating high school felt so impossible. It reminded Vargas of lived experiences outside of datasets often reflected in academic papers.

“The experts don’t have to just be someone in a white lab coat. Science can be used as a tool to help people with their advocacy rather than a tool of gatekeeping,” says Vargas, who now works at a salmon recovery non-profit. “Involving the community directly in research about their own neighborhood is a matter of justice. It’s not just numbers in a study, people are really living this.”

That’s one of the reasons why Duwamish River Community Coalition (DRCC) Executive Director Paulina Lopez worked with the USFS to train community scientists to investigate heavy metals around them. More than 73% of people who live in Duwamish Valley’s neighborhoods, Georgetown and South Park, are Black, indigenous and people of color. In the local government’s science-based agencies, they’ve historically been excluded from evidence collecting and evaluation in their own community.

“We wanted to define the future of the community by the people who are being impacted on a daily basis and change the way science has been approached,” Lopez says. “We’ve been prioritizing communities as a way of giving them that power to learn and make informed decisions.”

Members of the Duwamish River Cleanup Coalition work on a local community moss sampling project. (Photo courtesy Duwamish River Cleanup Coalition)

Lopez is sharing what a team of 55 community scientists learned from measuring pollutants in moss tissues from these industry-adjacent neighborhoods. Through a complex air quality investigation, including a newly published study of heavy metal concentrations in the air, they hope to bring environmental justice to an underinvested area with a long history of environmental contamination. After reviewing their data, the government has already agreed to fund several temporary air monitors in the Duwamish Valley this summer.

The area’s injustice is deep with ties that go back to the displacement of the villages of the Duwamish Tribe, which is still federally unrecognized. To make way for industrialization, the U.S. Army Corps of Engineers excavated and straightened the winding Duwamish River that was once a diverse ecosystem of floodplain forests and marshes. That process began in 1913. Now, with more than a century of environmental degradation, the legacy of pollutants has left the city’s only river Superfund Site, a cleanup accountability program by the Environmental Protection Agency.

While Duwamish Valley residents can see Mount Rainier on a clear day, smokestacks still obstruct its glaciated peak with plumes of chemical-filled exhaust. For those who live along it, they have higher rates of asthma and lower life expectancies, according to a health impacts analysis conducted in part by advocacy group Just Health Action. With the threats exacerbated by Covid-19, and now heat waves and sea level rights brought by climate change, Lopez knew her community needed to take action into their own hands.

Despite the well-documented reports of gentrification pushing low-income people into the city’s pollution pocket, Lopez needed to provide measure metals in the air’s particulate matter to get meaningful action and funding from the government. Both Georgetown and South Park each have one air pollution monitor, which doesn’t measure for toxins. Low-cost air monitors that Lopez’s organizations could purchase themselves, like Purple Air, also can’t screen for metals like arsenic and chromium.

Lopez, along with more than 15 community partners, heard of research happening about 300 miles south in Portland, Oregon, where USFS ecologists looked to a natural source for monitoring.

Mapping hotspots with moss

Sarah Jovan had spent her career studying moss in the pristine wilderness. The lush air plants drape over branches in some parts of the Pacific Northwest as if they are heavy, centuries-old curtains in the castles that are the region’s temperate rainforests. Unlike a rooted plant, moss gets nutrients from the air, rain and other decomposed matter. It essentially breathes in what is around it. That includes pollutants.

“A lot of people, including Europe, have used moss and lichen as indicators of heavy metals since the 60s, but most people haven’t heard of that research,” says Jovan. “In Europe, and in some places on the East Coast where there’s more sulfur pollution, it can kill off the moss in urban areas. In Portland, as well as in Seattle, this particular moss we’re using is extremely abundant. And it seems very tolerant to different kinds of pollution. So you can be in the most polluted part of the city, and if you have hardwood trees, you’re going to find it.”

The species of moss is called Orthotrichum lyellii, and it grows in small, cushy green patches. Jovan and her colleague built a grid-based sampling strategy and collected 346 pieces of moss across Portland. After the samples were processed in a lab, they found high cadmium levels specifically near stained-glass manufacturers. In response to the findings, the Oregon Department of Environmental Quality placed screening instruments in the industrial area. Additionally, it contributed to a new state program called Cleaner Air Oregon.

“Paulina and the DRCC approached us and told us ‘Hey, you know the Duwamish area has been polluted for more than 100 years and maybe you’ve heard about the health disparities for the folks who live here. We haven’t been able to get any traction with local regulators,’” Jovan recalls. “And so we all came together to sample moss and look at heavy metals, but instead of it being two scientists, there were over 50 people involved to physically collect the data.”

Jovan and Lopez called on the community’s environmentally conscious youth, like Faith Villalobos, to help. A three-day training showed them how to collect, clean and map valid samples. They then sent the moss to a lab, which found 21 chemical elements measured in moss, including arsenic, cadmium, chromium, cobalt, lead and nickel.

According to their peer-reviewed case study published in June, lab work found that the metals peaked near the Valley’s central industrial core, and tended to be much higher than values seen in the earlier Portland study.

“It’s something that gives us an idea of the quality of the air,” says Villalobos, now a nursing student at Seattle Pacific University. “We are surrounded by the industry, and maybe a lot of people don’t pay attention to how much pollution is down there, but I feel like this gives us that credit and helps us understand more about pollution in the Duwamish Valley.”

Villalobos, along with a small team, presented their findings to decision makers including the Seattle City Council. They hoped for similar action that the Oregon government took in response to Portland’s fine-scale maps of air pollution. While new policies are a work in progress, their study landed regional air agency funding to estimate potential cancer risk based on new air toxin measurements.

Finding the health correlations from the moss study

Local youth, trained as community scientists, gather moss samples in Duwamish Valley neighborhoods. (Photo by Monika Derrien, courtesy of USDA Forest Service)

After submitting a proposal to the EPA with data from the moss study, the Puget Sound Clean Air Agency received a $700,000 grant to place temporary monitoring sites in the Duwamish Valley.

The agency is using hotspots identified by the moss study to select locations for monitoring. They have been monitoring for metals at a hotspot near a community college since March and plan to sample four more hotspots over the summer. The equipment that can correctly monitor for the 400 types of pollutants that fall into air toxics category will cost around $100,000 per site.

“They’re very expensive, and we can only shift around our resources so much. What’s great about the work that the DRCC and Forest Service has done with the moss method is it’s relatively inexpensive as an indicator to show where these areas may be where we want to take samples,” says Graeme Carvlin, an air resource specialist with the agency.

“Now, we’re able to bring in instruments to measure the metals in the air, and then those measurements have a direct health correlation. We’ll be analyzing data in the fall, and then we’ll be sharing them with the community and talking about what the results show and then what some follow up steps might be.”

While the county public health department offers various programs that address asthma and indoor air ventilation, there is not a program that specifically addresses legacy pollution in the Duwamish Valley. It will take a layered approach with direct programs in the Duwamish Valley to address its air pollution and subsequent ecological and health effects.

Over the last two years, Governor Jay Inslee signed two major laws related to environmental justice: The Healthy Environment for All (HEAL) Act – requiring agencies like the Department of Ecology to conduct environmental justice assessments – and The Climate Commitment Act, which directs a statewide cap-and-invest program to cut carbon pollution.

But that will take time – likely up to five years to even begin meaningful change. In the meantime, Lopez and her organization are pushing for better regulation in the upcoming state legislative session that could bring action sooner.

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Ashli Blow is a freelance journalist who covers environmental science and policy.

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Tags: seattlepollutionair quality

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