Study shows burning trash leaves toxins in soil

STATE COLLEGE — Burning trash in the backyard has long been known to cause air quality concerns, but a recent Penn State study sponsored by the Centre County Recycling and Refuse Authority has found that the longtime practice of burning trash also puts harmful toxins in the soil.

Of the 35 municipalities in Centre County, only 12 have mandatory trash collection, said Joanne Shafer, deputy executive director of the authority. Of those 35, only 14 municipalities have ordinances that prohibit the burning of garbage.

“There are people out there who, believe it or not, think they are doing us a favor by reducing the amount of trash by burning it down. So, we wanted to take a look at what the effects of a burn barrel are when someone has it on their property,” said Shafer.

“Open trash burning is a common practice in rural areas, not only in our county, but across the state, and it is well established that air emissions of toxic materials are common per open burning, but there hasn’t been any work done about the level of toxin in the ground,” said Richard Stehouwer, a Penn State professor of environmental soil science whose student Kylie Hint conducted the study. 

The study looked at 24 sample sites around the county and tested the soil for increases in toxic metals. The test found a significant increase in levels of known toxins — arsenic, lead and cadmium — all increased above normal background concentration, said Stehouwer.

“They do run up into ranges where they start to cross some thresholds that have been established by various regulatory agencies,” said Stehouwer. The concentrations of metals also were shown to increase the longer the burn site was in use. Not all the sites reached above the established regulatory thresholds, but at least a quarter of the sites were above the threshold for the metals.

Copper and zinc, while not toxic to humans, are toxic to plants, and they also showed an increase in the test sites.

Stehouwer said it takes about 25 years of burning at a site for the level of the toxins to get up to the threshold of concerns, but any burning does increase the levels.

The ultimate recommendation is to not burn trash, he said, and it also is important to keep children away from the burn sites.

“When a burn site is retired, it should be covered with non-contaminated soil. You don’t want to convert it into a play area, for sure, or probably not a garden, because you could have plant toxity at some of the sites,” Stehouwer said.

“I think the biggest incentive for homeowners to stop burning trash is that, sooner or later, you are going to want to sell that property. And, it is a liability when (a potential buyer is) looking at it,” said Shaffer. “And, 25 years might seem like a long time, but your incentive is your kids, your grand kids, down the line somewhere, nobody wants to find out that when they are putting that house on the market that they have a toxicity issue going on.”

Shafer said the CCRRA recommends people don’t burn trash, and the authority plans to go to municipalities to share the study.