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Industrial Legacies & Open Space

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Lead Contamination Level of Philadelphia's Green Spaces 

by Junyi Yang

Junyi is a second-year student at the University of Pennsylvania pursuing a dual degree in Master of
Landscape Architecture and Master of City Planning with a concentration in Smart Cities. With a B.S. in Molecular Environmental Biology and a B.A. in Landscape Architecture from UC Berkeley, she has a professional background in design, planning, and data analysis for research and design firms. She believes in the potential of multi-discipline collaborations and is always prepared to learn new things. Her current work and interests range from front-end web development, urban spatial analytics, and parametric modeling to urban design, planning, and landscape design.


With a long industrial history, present-day Philadelphia still contends
with soil contamination despite the closure of most of the industries. Among
the various pollutants lingering in the soil, lead stands out as one of the most
challenging contaminants to remediate due to two primary factors. Firstly,
lead found in soil can originate from multiple sources. Before standards were
established to regulate lead levels in industrial products, lead was commonly
found in paints, gasoline, metals, and other materials; not only associated with industries but also prevalent in people’s daily lives. Lead from these sources dissolved in the topsoil and accumulated over time. Unlike other heavy metal pollutants, lead exhibits exceptional stability in the soil, adhering tightly to the surface of organic particles. It does not dissolve in water but can adhere to skin and clothing upon contact.

Due to these factors, lead contamination is a widespread issue in post-indus-
trial, aging cities. This problem is particularly severe for younger age groups, as children often come into contact with soil during outdoor play. According to CDC standards, “a blood lead level of 5 micrograms per deciliter (μg/dL) is the blood lead reference value, which means the maximum blood lead amount that can be considered “normal” for the human body. However, for children, the CDC employs a blood lead reference value of 3.5 micrograms per deciliter (μg/dL).” [1]. Research conducted by the University of Pennsylvania’s Center of Excellence in Environmental Toxicology (CEET) in 2018 revealed that “3.2% of the 37,584 children screened by the Philadelphia Public Health Department had Elevated Blood Lead Levels (EBLLs) between 5-9 μg/dL.” [2].  This result indicates that more than 1,200 children in Philadelphia have a blood lead level that is almost double that of the CDC’s lead reference value.


The purpose of this online dashboard tool is to assist individuals, particularly parents with young children, in assessing the lead levels in Philadelphia’s green spaces. The assessing standard is based on EPA’s regulation that states “400 ppm for lead in bare soil in play areas,” and the lead data utilized in this tool is sourced from the CEET sample base [3]. Users can either input an address into the search box or explore the list of green spaces. When searching by address, the tool will automatically identify the nearest park and the route to it, while searching by park name will zoom in on the selected park. In all instances, the chart at the bottom right of the screen will display the lead level of the selection and compare it to the EPA’s 400 ppm standard. 

[1Centers for Disease Control and Prevention. “Guidelines for the Identification and
Management of Lead Exposure in Pregnant and Lactating Women.” CDC, Accessed February 20, 2024.

[2] Center of Excellence in Environmental Toxicology. “Lead Soil Contamination Map-
ping.” University of Pennsylvania, Accessed February 15, 2024.

[3Agency for Toxic Substances and Disease Registry. “Safety Standards for Lead in
Soil.” CDC, Accessed February 12, 2024.

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