Date of Degree


Document Type


Degree Name



Earth & Environmental Sciences


Zhongqi Cheng


Peter Groffman

Committee Members

Michael Menser

Howard Mielke

Subject Categories

Environmental Health and Protection | Sustainability


urban soil, urban agriculture, soil contamination, constructed soil, environmental remediation, New York City


Lead (Pb) in soil is a global environmental issue. The particularly high lead concentrations found in surface soils have been emplaced by humans and bring with them life-altering and life-shortening effects for our species and countless others. While much of the general population is unaware of lead lurking in our soils, scientists from a range of backgrounds have generated a body of research documenting this ubiquitous phenomenon, arising from sources such as lead in gasoline, paint, industry, and incineration. Scientists have also explored ways to remediate soil and continue calling for efforts to limit toxicant exposure. Why, then, does this issue persist? What can be done about it? What role can biogeochemical research play in not only describing the issue, but also in conducting experiments and gathering data on alternative life-affirming outcomes?

In response to these questions, the research comprising this dissertation develops and utilizes a systems framework with four separate chapters: 1) The first chapter articulates a systems research framework, exploring systemic interactions, interventions, and applied experiments between humans and soil Pb at micro-, meso-, and macro-scales; 2) The second chapter is a micro-scale investigation of soil Pb at the root zone, a literature review for the USDA’s Phytoremediation Database exploring misconceptions with regard to plants extracting or stabilizing Pb in soil; 3) The third chapter is a meso-scale investigation, a field trial collaboration with the NYS Department of Health and Cornell University, exploring the potential to limit Pb deposition on urban-grown crops; and 4) The fourth chapter is a macro-scale investigation, the first pilot study for the NYC Mayor’s Office of Environmental Remediation’s Clean Soil Bank (CSB), consisting of a field study exploring the use of excavated glacial sediments mixed with compost as a safe growing medium in urban community gardens. This CSB research created the foundation for numerous follow-up studies and efforts aimed at limiting soil Pb exposure and promoting the many benefits of urban growing, including a range of ecosystem services, waste reduction, community cohesion, and food justice in NYC and beyond.