Emory soil analysis project leads to EPA site investigation
By Carol Clark | Dec. 6, 2019
Emory professor Eri Saikawa (left) in the field with Historic Westside Gardens member and Westside resident Rosario Hernandez (center) and Xinyi Yao (right), an Emory student pursing a master’s degree in environmental sciences who is involved in the research project.
An Emory University collaboration with members of Atlanta’s Westside community, to test urban soil for contaminants, has led to a site investigation by the U.S. Environmental Protection Agency (EPA). The ongoing community collaboration is funded by Emory’s HERCULES Exposome Research Center, dedicated to understanding how environmental exposures affect health and community well-being.
The EPA told the Atlanta Journal-Constitution that it is continuing to collect samples and has so far identified 64 sites where the soil contains elevated levels of lead — a dangerous neurotoxin. The agency plans to begin decontaminating properties, possibly by removing and replacing soil, in the first quarter of next year, at no expense to residents or homeowners, according to the AJC. The report also appeared in Georgia Health News.
“It’s important for people to know that soil contamination by heavy metals can be serious,” says Eri Saikawa, an associate professor of environmental sciences at Emory and the lead researcher on the original project that sparked the EPA investigation. “If you are thinking about gardening in an urban area, or if children are playing in your yard, it makes sense to test your soil and make sure that it’s not contaminated.”
The Emory project began in the spring of 2018. Sam Peters, a PhD student at Rollins School of Public Health and a member of Saikawa’s lab, decided to investigate levels of heavy metal and metalloids (HMM) in the soil of urban gardens, based on community need. The project was co-designed with Historic Westside Gardens, a HERCULES partner in the community that installs gardens in residents’ yards and provides training, mentorship and a food market collective. Residents wanted more information about the condition of their soil.
“This is true community-engaged, community-based research, driven by what the community is interested in — testing and improving their soil to help them grow healthy food,” Saikawa says. “They are passionate about improving their community.”
More than a dozen other Emory students from Saikawa’s lab, including undergraduates and graduate students, soon became involved in the labor-intensive effort, which included making and distributing flyers to explain what they were doing and why they were doing it. In collaboration with community members, 355 soil samples from neighborhood home gardens and yards were collected and analyzed for lead, arsenic, chromium, cadmium and other HMMs.
The samples were analyzed via X-ray fluorescence, a handheld instrument that can test for more than 25 heavy metals in 90 seconds. The results showed that most of the samples were above the University of Georgia’s low-risk levels for agriculture of 75 parts per million (ppm). And a few were above the EPA’s low-risk residential screening level of 400 ppm. The samples above 400 ppm were generally near older housing and not used for growing food. Samples from garden beds and active growing sites were lower than those without beds or anything growing.
Sharing data among the project members led to small remediation efforts. One community member, for example, was able to lower the concentration of lead in one garden bed from above 400 ppm to below 75 ppm by adding in new soil and plants.
A type of industrial smelting waste known as slag, a possible source of lead contamination, was also identified in at multiple vacant lots in the area, further raising concerns. “Children ride their bikes up these piles of dirt containing slag in vacant lots,” Saikawa says.
The potential for heavy metal contamination of soil is not just an Atlanta issue, Saikawa stresses, but an urban problem in general. “Emissions from industry and power plants, lead-based paints, fertilizer, sewage sludge, pesticides and deposits from the atmosphere are some of the ways that heavy metals can make their way into soil,” she says. Many studies have also shown the increased risk of exposure to heavy metals among youth in low-income families in urban areas, Saikawa adds.
The project members from Emory and the community met with the EPA and Georgia Department of Public Health to discuss strategies.
The EPA initiated an investigation which expanded the area of potential contamination to 368 properties. The agency is still in the process of collecting soil samples. It is offering free soil testing for residents and property owners in the Westside area encompassing properties between Joseph E. Boone Boulevard NW, Chestnut Street NW, James P. Brawley Drive, Cameron Alexander Boulevard NW and an old CSX rail line.
The decontamination process, set to begin early in 2020, could involve removing and replacing soil. The initial costs are capped at $2 million over 12 months, according to a memo of the state Environmental Protection Division, obtained by the Atlanta Journal-Constitution.
Community collaboration continues
Meanwhile, Emory continues to support efforts by the community, funded by HERCULES. Sam Peters has since graduated and works for an agricultural company in Boston. A dozen other Emory students from the Saikawa lab, both undergraduates and graduate students, are currently working with members of the community on awareness and remediation efforts.
“We want to ensure that people know about ways to reduce their risk, by washing their hands and removing dust from their clothing after coming in contact with soil and removing their shoes before entering a residence,” Saikawa says. “It’s especially important that children do not play in contaminated soil.”
Although lead exposure has been substantially reduced during the past few decades, elevated blood-lead levels are still linked to intellectual disabilities in more than half a million children globally every year, she notes.
The project team members are recruiting families with children under the age of 12 to provide toenail clippings from the children to analyze how much exposure they may have had to heavy metals.
Another ongoing study by Emory and the community is testing whether growing various species of plants in the soil can reduce some of the contamination to less risky levels — a process known as phytoremediation. Preliminary results from experiments conducted in the field and in a greenhouse on the Emory campus show that growing sunflowers in the soil may help to significantly reduce heavy metal concentrations, but more research is needed, Saikawa says.
The experience of working closely with a community has changed the perspective of students involved in the project, Saikawa says.
Xinyi Yao, a graduate student in environmental sciences, had originally planned to just get a master’s degree and work in industry. “This project showed me how research can directly help improve people’s lives,” Yao says. “I find that really rewarding.”
Yao now plans to pursue a PhD and a career in public health research.
“Talking with residents has helped us think differently and more creatively about our work as scientists,” Saikawa says. One community member who is an artist, for example, suggested using art to help raise community awareness.
“We’re putting together a grant proposal to include the work of local artists to educate residents about the need to test soil for contamination and how to avoid exposure to heavy metals,” Saikawa says. “We’d also like to involve local middle school and high school students in the project so that they learn more about the issue, while also learning what scientists do.”