Laser Photometry air quality monitoring system near Skagway’s cruise ship docks. (Reuben Cash photo)
Over the last three years, Skagway’s tribal government has been studying the town’s air quality and how it may be affected by cruise ship-based tourism. It appears that there was less air pollution during the pandemic when fewer cruise ships were visiting.
The Skagway Traditional Council’s air quality study got the go-ahead in 2020, it was inspired by an earlier joint effort with the council, the municipality, and the Alaska Department of Environmental Conservation. Even though cruise ships didn’t visit due to pandemic-related shutdowns in 2020, the study moved forward. Environmental Coordinator Reuben Cash says the lack of ships gave his team a unique opportunity to develop baseline data.
“If you compare 2020 and 2021, they’re very, very similar. But in 2022, particulate matter doubled,” said Cash.
He says the particles they are studying are 2.5 microns or smaller. That’s tiny. Most dust particles are twice that size.
“We are solely looking at fine particulate matter because that is a pretty influential part of what is going to impact human health because these are not only inhalable particles, but they’re small enough that they can get into your bloodstream,” said Cash.
He says those particles are typically a result of fossil fuel combustion which could be from cruise ships, vehicles, or wildfires. But they can also come from chemical processes that take place in the atmosphere.
Smoke from wildfires in 2019 inundated Skagway. (Mike Swasey photo)
“So you get secondary particles like sulfur dioxide, nitrous oxides,” said Cash.
These particles can have a significant impact on people with asthma or related respiratory issues.
The study utilizes laser photometry which brings air into a chamber and then measures particulates using lasers. The equipment is roughly the size of a suitcase and is elevated off the ground to five or six feet. The team put three monitors up in Skagway, one on the south end of town, one in mid-town, and one at the north end. Cash says he was most surprised by the location of the highest particulate readings.
“We saw higher emissions on the north side of town pretty far away from where any potential sources would be,” said Cash.
He says that could be explained by a variety of reasons including elevation or wind direction.
The monitoring project will continue in 2023 and a complete report from the first three years is expected later this spring. Cash also says a real-time air quality index dashboard will be set up in the first half of this year to allow residents to monitor air quality day by day. Cash says his team will be looking for community feedback on what should be included in the dashboard.
