The Global Symposium on Soil Pollution #GSOP18 | 2 - 4 May 2018 | FAO Hq Ms. Anna Paltseva, Brooklyn College of The City University of New York, US

1. Application of GIS to Characterize
Garden Soil Contamination
in New York City
Anna Paltseva
anya@usi.nyc
Zhongqi Cheng

2. Background
• New York City is now home to commercial
farms and numerous community gardens
growing food.
• Soil contamination may pose significant health
risks to urban residents and particularly to
gardeners.
• Urban soil is a sink for anthropogenic lead (Pb).
• Knowledge about absorption of the
contaminants in organisms exposed to soils is
limited.
• Previous researches have emphasized the need
for a large-scale GIS map for a better health-
based assessment in NYC.
Cheng et al. (2015) were first to
create a map of NYC soil Pb
map

3. Objectives
• to assess pollution and ecological risk
indices;
• to examine the spatial distribution of Pb
levels in NYC gardens using GIS;
• to identify gardens at risk from historical and
current contaminants sources

4. Methodology
List of data sources:
• Brooklyn College Soil Research
Lab,
• ESRI ArcGIS,
• NYC Open data,
• EPA website,
• the ToxiCity Mapping Project,
• Sanborn maps,
• BetaNYC’s Community Data
Portal,
• NYC Department of Health and
Mental Hygiene Environment &
Health Data Portal.
Geoanalysis:
• Geoprocessing - Model Builder
Buffer
Intercept
Clip
• Regression models:
OLS
Autocorrelation
GWR
• Spatial analysis:
Interpolation (Kriging)
• Geostastical analysis:
Statistics
Summary
Pearson correlation coefficient
Soil data collection:
• Garden soil samples have been collected
since 2009 by Brooklyn College Soil Lab
and NYC Urban Soils Institute
• Screened by a pXRF analyzer and ICP-MS
• 2079 garden soil samples are used

5. Summary Statistics of the Contaminant
Factors (CF)
Degree of contaminant factors: Pb > Cd > Cu> Zn > Cr > As > Ni
CFi is the contamination factor for the same metal
CFi=Cm/Bm
where Cm is the measured concentration of the examined metals in the soil samples,
Bm is the background concentration in unpolluted soils.
Low (CF<1)
Moderate (1<CF<3)
Considerable (3<CF<6)
Very high (CF>6)

6. Single Ecological Risk Index
Ei=Ti*CFi,
where Ti is the toxic-response
factor for a given metal
 The ecological risk comes mainly from
the soil pollution with Pb and Cd.

7.  The ecological risk comes mainly from the soil pollution with Cd
Makeup of the Mean Potential
Ecological Risk Index (565)

8. Pollution Load Index (PLI)
 The PLI gives simple comparative means for assessing
a site quality.
 All 126 samples found to be polluted based on Pb, Ni,
Zn, Cu. PLI > 1 (polluted soil quality).
PLI=(CF1 *CF2 *…*CFn)(1/n), where n – the number of
metals studied.
Mean 9.08
Median 7.56
Min 1.06
Max 64.01
Std dev 8.36

9. Soil Pb contamination
level in NYC gardens
 Soil Pb contamination is mostly
concentrated in Brooklyn with the
highest values in the northern and
middle parts of the borough
 Total Pb is up to 45,000 ppm
(mean - 640 ppm), a typical range
for garden soils from New York
City
 Pb content decreases from the
inner center towards outskirts,
which is commonly seen in
industrial cities
 The highest Pb level was found in
Greenpoint with the highest mean
Pb of 584 ppm per zip code
Greenpoint
n=2079

10. Historical and Current
Contaminant Sources
 33 gardens are at risk from
historical contaminant sources
(smelters, coal yards, factories,
refineries, lead companies) existed
between 1768 and 2004.
 46 gardens are at risk from current
contaminant sources (smelters,
factories, superfund sites, waste
transfer stations) and major roads.
 28 gardens are at risk due to both
historical and current contaminant
sources.
 Buffers represent 1.6 km
potentially contaminated areas
from the sites.
 Data collected from EPA website,
the ToxiCity Mapping Project and
Sanborn maps.
Garden n=126

11. Conclusion
• Soil quality assessment indices were calculated based on
individual metals (Pb, Zn, Cd, As, Cu, Cr, Ni) for 126 garden
samples.
• The majority of soils is contaminated and poses significant risks
to human health and ecological systems, particularly by Pb and
Cd.
• A consolidated garden soil Pb database was compiled with 2079
garden samples.
• The highest Pb levels were found in northern and central
Brooklyn. Generally, Pb levels became lower toward the
suburban areas.
• The Pb contamination map would be valuable not only to guide
remediation efforts but also for urban planning such as
developing gardens and green spaces or sitting of new parks.

12. Acknowledgments
The authors thank Tatiana Morin, George Lozefski, Zulema Blanco Garcia,
Michael Grinshtein, Igor Bronz, Kayo Green, Donna Cao, Kristen Walsh,
Norma Sutton, Ololade Thomas for their lab assistance and data collection
and Rocky Garcia for GIS consultation.
An interactive story map of this work is available at https://arcg.is/0W9Cqi