By Carl Dimitri Sr.

BU School of Public Health

Editor’s Note: Brown University researcher Erica Walker explores the hidden health impacts of wood pellet production in her home state of Mississippi.

As the global demand for clean energy alternatives surges, the wood pellet industry, often touted as a sustainable fuel option, is projected to nearly double in size by 2026. In the United States, the industry’s growth is most pronounced in the rural South, where 91 wood pellet manufacturing plants are situated, constituting 75% of U.S. production. But this growing industry is facing scrutiny over its environmental, health, and social impacts; similar to fossil fuel refineries, wood pellet plants are more than twice as likely to be located in predominantly Black and poor communities.

A new study led by Erica Walker, RGSS Assistant Professor of Epidemiology at Brown University’s School of Public Health, alongside Krystal Martin of Greater Greener Gloster Project and students from Tougaloo College and Brown, highlights the environmental health effects of wood pellet manufacturing on public health. The study concentrates on the emissions from the industry in the state of Mississippi, specifically noise, particulate matter, black carbon, ozone, nitrogen dioxide and volatile organic compounds (VOCs), which potentially exceed the thresholds established by the Clean Air Act by up to five times. 

Concurrently, the researchers are enrolling families with children – collecting survey and biological information – with the hopes of understanding how these emissions are impacting these children across their life course. 

“Our cumulative effects longitudinal cohort study, centered on children living in close proximity to wood pellet manufacturing, is much needed,” Walker said. “We are excited to spearhead this work with our community partners.”

Mississippi already has more than its share of public health problems. It ranks second to last in overall health and is last nationwide regarding childhood respiratory diseases. Today, Mississippi is home to seven wood pellet plants, four fully operational and three soon to open (or in early development) that are anticipated to be the largest in the world. Walker and her team focused on the town of Gloster, home to 897 people, of which 71% are Black and 38.6% live in poverty, with an annual median income of $22,131.

“The practice of placing wood pellet facilities in underserved communities is not uncommon,” the authors write in their report. “Typically, in the United States, the closest an urban residential area is to a wood pellet manufacturing facility is approximately 2 km. Gloster represents an extreme case, where the closest residences to the wood pellet industrial area are less than 500 meters away.” 

Wood pellet manufacturing involves processing full green trees into dried pellets, a process that emits significant amounts of black carbon and VOCs. These emissions contribute to ground-level ozone formation, posing severe health risks. Particularly alarming is the release of toxic PAHs (polycyclic aromatic hydrocarbons) during wood preparation, which are known carcinogens.

Walker and her team point out that vulnerable populations and children in particular are impacted by air pollution emitted from wood pellet production. Proximity to these plants is associated with a statistically significant higher risk of hospitalization for respiratory illnesses and increased asthma-like symptoms in children.

During a community-listening session with the Environmental Protection Agency in 2023, Gloster residents expressed their need for a consistent, localized and community-engaged air pollution monitoring program. Beginning in August of that year, Walker and her team answered that call, working with a local nonprofit to launch an unfunded community-driven assessment of air pollution in the town.

“Dr. Walker was sent to us from heaven,” said Martin. “The air, noise, and health research studies that she is conducting will help us to better inform our residents and government officials on the harmful impacts of the wood pellet industry in the Gloster community. This collaborative partnership with Dr. Walker will identify pathways needed to help improve the health and quality of life for all of us.”

Their preliminary findings are the first air-quality measurements taken in a Mississippi-based wood pellet-impacted community. They measured their results against an air pollution monitoring campaign in Mendenhall, Mississippi, a town with no current industrial activity. In Mendenhall, 34% of residents are Black, 35.8% live in poverty, and residents have an annual median income of $35,956. 

“When comparing air pollution concentrations in Gloster to those in Mendenhall,” the authors state in their report, “air pollutant concentrations in Gloster are magnitudes higher, even after adjusting for meteorological conditions.”

Researchers also discovered that the time-of-day matters, identifying a spike in pollution levels during the night. Additionally, while average pollution levels were not out of the ordinary, the team found that the maximum concentration of air pollutants, especially in particulate matter and total volatile organic compounds, is a cause for concern. 

The research team is also monitoring noise pollution in the area. “Regulatory agencies do not pay attention to the sound levels being emitted from these plants,” Walker said. “We have been measuring noise pollution in Mississippi-based wood pellet communities. From our preliminary data, when comparing noise levels in Gloster to background communities, emissions are 10-12 decibels higher – that 10 dB difference is a doubling of perceived loudness.”

In-light-of these discoveries, Walker, and her team plan to continue monitoring air and noise pollution in the two Mississippi towns for a minimum of one year. This longer study will help create detailed plans to better understand what affects pollution levels in Gloster. It will also enable the team to see how their results stack up against EPA guidelines.

Researchers are additionally going to take a closer look at specific pollutants linked to wood pellet production, such as benzene and formaldehyde. These can be released when wood pellets are made or burned, especially if chemicals are added.

“Working closely with our community partners in Gloster and Mendenhall, we have recently enrolled our first cohort of children,” Walker said. “We’re pushing this issue forward. “As a person born and raised in Mississippi, I am honored to be able to do this work.”

www.sph.brown.edu

Carl Dimitri: 

(carl_dimitri@brown.edu)

Erica Walker: 

(erica_walker@brown.edu)