Pollution deaths down amid gains in Twin Cities area air quality

Deaths linked to air pollution declined by 26% from 2008 to 2015 in the Twin Cities metro area, according to new state health estimates, but risks varied substantially by neighborhood, income and race.

Pollution levels caused by PM2.5 fine airborne particles declined by 30% when comparing those two years, reducing related deaths in people 25 and older from 2,152 to 1,588, but state health officials weren't celebrating on Tuesday. Another 10% reduction could have prevented an estimated 185 deaths in 2015, and that was before the rising seasonal air quality problem of forest fires and the COVID-19 pandemic that reduced respiratory health in many Minnesotans.

"To see these negative health effects persist in our state's largest population centers underlines just how important the issue of air quality is, especially for those Minnesotans who are disproportionately affected by pollution," said Craig McDonnell, an assistant commissioner for the Minnesota Pollution Control Agency (MPCA).

Ozone-related pollution in the Twin Cities declined by 10% when comparing 2008 and 2015, according to the state Life and Breath report prepared by the Minnesota Department of Health and MPCA. Cardiopulmonary deaths linked to that source of pollution declined from 23 to 19.

PM2.5 refers to particles produced largely by the combustion of fuel, oil and wood that are small enough to travel down the respiratory tract into the lungs and complicate health problems such as asthma. Ozone measured at the ground level comes from similar sources, along with industrial plants, household paints and solvents.

An estimated 10% of all deaths in the Twin Cities in 2015 were related to air pollution from these two sources.

A companion report looked at pollution levels in Duluth, Rochester and St. Cloud and found that fine particles contributed to an estimated 203 deaths in 2015, or 8.5% of the deaths in those three cities combined that year.

The metro report highlighted ZIP codes in which death rates attributable to fine particles or ozone were substantially elevated, partly because of their proximity to highways and industries. They included the 55428 area of New Hope, Crystal and Brooklyn and the 55436 section of Edina and Richfield surrounding Southdale Center.

The rates of cardiopulmonary deaths related to ozone were higher in those two ZIP codes as well but also in 55395, a fringe metro region including the town of Winsted, and in the 55013 area encompassing Chisago City. While these rates can fluctuate because of the small total number of ozone-related deaths, ZIP codes with higher ozone death rates tended to have elevated PM2.5 levels as well.

Larger elderly populations and other factors also can inflate pollution-related death rates in ZIP codes, said David Bael, an MPCA policy analyst and a co-author of the latest research. "It's not just because there is higher air pollution in those areas. There are many factors that contribute to vulnerability."

Poverty and minority racial status elevated rates of air quality-related hospitalizations and severe outcomes in greater Minnesota and more so in the Twin Cities. The rate of respiratory hospitalizations related to fine particles was almost twice as high in ZIP codes with high populations of racial and ethnic minorities compared with those with low populations. The rate of asthma-related emergency department visits was more than five times higher in the most diverse ZIP codes.

ZIP codes with more disabled or uninsured people also had increased levels of hospital visits related to poor air quality.

Improvements in air quality are linked to new technologies reducing emissions from factories as well as the shutdown of coal-fired power plants, state officials said. Individuals can contribute in many ways as well by reducing wood fires and the use of gas-powered lawnmowers.

Bael urged people to use the MPCA forecasts, including a smartphone app, to reduce their outdoor exposure and exertion levels on poor air quality days.

COVID-19 has added a new complication to pollution issues, exacerbating or causing long-term lung damage in more Minnesotans.

The state on Tuesday reported another 20 COVID-19 deaths and 1,457 coronavirus infections that were identified over the weekend, raising Minnesota's pandemic totals to 12,221 deaths and more than 1.4 million infections. The additions included COVID-19 deaths of a 20- to 24-year-old from Anoka County and two 30- to 34-year-olds from Hennepin and Ramsey counties. There have been 113 COVID-19 deaths in Minnesota of people younger than 35.

Minnesota is emerging from its fifth pandemic wave, with COVID-19 hospitalizations in the state dropping from 1,629 on Jan. 14 to 366 on Monday. The number of Minnesotans with lingering complications who could be more susceptible to poor air quality remains a mystery and target for future research.

"Although this [report] predates the pandemic, we know that, in addition to an increase in wildfires and other events, that we will be confronting this issue," said Kathy Raleigh, a state health epidemiologist and co-author of the pollution report.