KUOW says preliminary findings released Monday night suggest trains carrying coal are emitting coal dust into the atmosphere.
Researcher Dan Jaffe measured air quality at two locations along train tracks, in the Columbia River Gorge and a Seattle neighborhood. His team found a significant increase in large particles after coal trains passed, compared with other train types.
Coal dust contains arsenic, mercury and other contaminants. Little is known about how dust from trains could impact people who live nearby.
BNSF Railway spokeswoman Courtney Wallace questioned the study and it hasn't been reviewed by peers.
Jaffe dismisses those concerns. The study has been submitted to an online journal and is in the peer review process.
Jaffe raised $24,000 for the study through an online crowd-funding website.