Applying a Systems Approach to the Legacy of Lead in Soil

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

The concurrent decline of soil lead and children’s blood lead in New Orleans

Lead (Pb) is extremely toxic and a major cause of chronic diseases worldwide. Pb is associated with health disparities, particularly within low-income populations. In biological systems, Pb mimics calcium and, among other effects, interrupts cell signaling. Furthermore, Pb exposure results in epigenetic changes that affect multigenerational gene expression. Exposure to Pb has decreased through primary prevention, including removal of Pb solder from canned food, regulating lead-based paint, and especially eliminating Pb additives in gasoline. While researchers observe a continuous decline in children’s blood lead (BPb), reservoirs of exposure persist in topsoil, which stores the legacy dust from leaded gasoline and other sources. Our surveys of metropolitan New Orleans reveal that median topsoil Pb in communities (n = 274) decreased 44% from 99 mg/kg to 54 mg/kg (P value of 2.09 × 10−08), with a median depletion rate of ∼2.4 mg·kg·y−1 over 15 y. From 2000 through 2005 to 2011 through 2016, children’s BPb declined from 3.6 μg/dL to 1.2 μg/dL or 64% (P value of 2.02 × 10−85), a decrease of ∼0.2 μg·dL·y−1 during a median of 12 y. Here, we explore the decline of children’s BPb by examining a metabolism of cities framework of inputs, transformations, storages, and outputs. Our findings indicate that decreasing Pb in topsoil is an important factor in the continuous decline of children’s BPb. Similar reductions are expected in other major US cities. The most contaminated urban communities, usually inhabited by vulnerable populations, require further reductions of topsoil Pb to fulfill primary prevention for the nation’s children

Potential ecosystem services provided by constructed Technosols

International audienceWaste generation and management is a global issue receiving increasing attention. Construction and Demolition (C&D) debris generate high percentages of a country’s total solid waste, and has been estimated to contribute to 35% of the solid waste generated worldwide. Construction of Technosols is an innovative process based on the association of organic and mineral wastes to construct fertile soils that are favorable environment for plant growth. Such an approach could be a relevant solution to recycle significant amount of C&D materials as these waste could provide valuable properties such as bearing and drainage capacities and buffer capacity to the constructed Technosols. Technosols in various situations around the world are discussed as well as the actual and potential ecosystem services provided by such artificial soils. The presentation focuses on their designs and biotic choice. We explain and predict the assembly and function of Technosols under varieties of environmental conditions. Humans have total control over such soils and play a dominant role on every aspect and stages, providing a lot of opportunities. However, wrong choices can have tremendously negative consequences: every action should be weighted and evaluated carefully when manipulating these systems, to maximize Technosols ecological benefits while minimizing the ecological risk

Review of the last two decades experiences of technosols construction for urban greening

International audienceWith the rise in urban population and the urban sprawl come demand for solutions to offset the environmental burden in cities. Green infrastructures are interconnected urban spaces that provide multi-ecological functions and that mainly rely on their soils component. However, because of either the consumption of such natural resources as neighboring topsoil or the poor design and implementation of soil materials, actual approaches are questionable.Constructed Technosols, consisting of rational associations of organic and mineral wastes, are artificial soils designed to meet specific requirements. Such innovative solution based on circular economy may appear as valuable contribution to sustainable urban design. This presentation has two objectives: 1) to present the methods to create Constructed Technosols adapted for various greening purposes and 2) to present and discuss the various existing published experiences about Constructed Technosols for different land-uses (i.e. parks, street-side trees, stormwater management, urban farming, and derelict land reclamation).Our work aims at answering to the following questions: What are the main steps for the construction of Technosols? What materials and which formula should be used to design functional Constructed Technosols? What are the technical constraints to consider when using Constructed Technosols? What are the levels of ecosystem functions provided by Constructed Technosols? How fast and intense is the pedogenesis of Constructed Technosols and what are the consequences in terms of sustainability?Even though there is no optimal formula, this review provides key elements to both scientists, green spaces departments and actors involved in the management of urban soils. This review also confirms that Constructed Technosols are promising solutions for greening cities and producing potential interdisciplinary benefits for urbanites.Disclosure of Interest: None declare

Review of the last two decades experiences of technosols construction for urban greening

International audienceWith the rise in urban population and the urban sprawl come demand for solutions to offset the environmental burden in cities. Green infrastructures are interconnected urban spaces that provide multi-ecological functions and that mainly rely on their soils component. However, because of either the consumption of such natural resources as neighboring topsoil or the poor design and implementation of soil materials, actual approaches are questionable.Constructed Technosols, consisting of rational associations of organic and mineral wastes, are artificial soils designed to meet specific requirements. Such innovative solution based on circular economy may appear as valuable contribution to sustainable urban design. This presentation has two objectives: 1) to present the methods to create Constructed Technosols adapted for various greening purposes and 2) to present and discuss the various existing published experiences about Constructed Technosols for different land-uses (i.e. parks, street-side trees, stormwater management, urban farming, and derelict land reclamation).Our work aims at answering to the following questions: What are the main steps for the construction of Technosols? What materials and which formula should be used to design functional Constructed Technosols? What are the technical constraints to consider when using Constructed Technosols? What are the levels of ecosystem functions provided by Constructed Technosols? How fast and intense is the pedogenesis of Constructed Technosols and what are the consequences in terms of sustainability?Even though there is no optimal formula, this review provides key elements to both scientists, green spaces departments and actors involved in the management of urban soils. This review also confirms that Constructed Technosols are promising solutions for greening cities and producing potential interdisciplinary benefits for urbanites.Disclosure of Interest: None declare

Review of the last two decades experiences of technosols construction for urban greening

International audienceWith the rise in urban population and the urban sprawl come demand for solutions to offset the environmental burden in cities. Green infrastructures are interconnected urban spaces that provide multi-ecological functions and that mainly rely on their soils component. However, because of either the consumption of such natural resources as neighboring topsoil or the poor design and implementation of soil materials, actual approaches are questionable.Constructed Technosols, consisting of rational associations of organic and mineral wastes, are artificial soils designed to meet specific requirements. Such innovative solution based on circular economy may appear as valuable contribution to sustainable urban design. This presentation has two objectives: 1) to present the methods to create Constructed Technosols adapted for various greening purposes and 2) to present and discuss the various existing published experiences about Constructed Technosols for different land-uses (i.e. parks, street-side trees, stormwater management, urban farming, and derelict land reclamation).Our work aims at answering to the following questions: What are the main steps for the construction of Technosols? What materials and which formula should be used to design functional Constructed Technosols? What are the technical constraints to consider when using Constructed Technosols? What are the levels of ecosystem functions provided by Constructed Technosols? How fast and intense is the pedogenesis of Constructed Technosols and what are the consequences in terms of sustainability?Even though there is no optimal formula, this review provides key elements to both scientists, green spaces departments and actors involved in the management of urban soils. This review also confirms that Constructed Technosols are promising solutions for greening cities and producing potential interdisciplinary benefits for urbanites.Disclosure of Interest: None declare

Using constructed soils for green infrastructure – challenges and limitations

International audienceWith the rise in urban population comes a demand for solutions to offset environmental problems caused by urbanization. Green infrastructure (GI) refers to engineered features that provide multiecological functions in urban spaces. Soils are a fundamental component of GI, playing key roles in supporting plant growth, infiltration, and biological activities that contribute to the maintenance of air and water quality. However, urban soils are often physically, chemically, or biologically unsuitable for use in GI features. Constructed Technosols (CTs), consisting of mixtures of organic and mineral waste, are man-made soils designed to meet specific requirements and have great potential for use in GI. This review covers (1) current methods to create CTs adapted for various GI designs and (2) published examples in which CTs have been used in GI. We address the main steps for building CTs, the materials and which formulae should be used to design functional CTs, and the technical constraints of using CTs for applications in parks and square lawns, tree-lined streets, green buffer for storm water management, urban farming, and reclaimed derelict land. The analysis suggests that the composition and structure of CTs should and can be adapted to available wastes and by-products and to future land use and environmental conditions. CTs have a high potential to provide multiple soil functions in diverse situations and to contribute to greening efforts in cities (and beyond) across the world