EPA/600/F-18/382
science in ACTION
INNOVATIVE RESEARCH FOR A SUSTAINABLE FUTURE
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METALS FROM NATURAL AND
ANTHROPOGENIC SOURCES IN
PUERTO RICO SOILS
The Issue
A number of diverse issues impact the health of
communities in EPA Region 2's Caribbean
territories, such as the lack of sufficiently treated
source waters in small, remote communities;
inadequately closed landfills; and, compared to the
U.S. mainland, greater risks of asthma and a greater
likelihood of preterm births. Puerto Rico is currently
home to over 50 contaminated sites under the
Superfund and Resource Conservation and
Recovery Act (RCRA) Corrective Action Cleanup
programs. Research that improves contaminated
site cleanups on the island is a priority for EPA.
Some soils in Puerto Rico have concentrations of
arsenic and other metals that may be above
regulatory limits due to natural or anthropogenic
sources such as local geology, tropical soil
chemistry, or past agricultural activities. Data on soil
concentrations of arsenic and other metals, both
natural and anthropogenic, for areas throughout
Puerto Rico are necessary to implement effective


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Concentrations of inorganics in soil may be due to natural or
anthropogenic sources such as local geology, tropical soil
chemistry; or past agricultural activities.
U.S. Environmental Protection Agency
Office of Research and Development
EPA records were reviewed for all Superfund (red triangles) and RCRA
Corrective Action sites (green squares) to identify existing background
soil data.
cleanups that protect human health and the
environment.
To distinguish between substances directly
attributable to releases at a contaminated site and
those from naturally occurring or widespread
anthropogenic sources, samples need to be
collected in the appropriate locations. This
background sampling can be time consuming and
expensive and can sometimes result in misleading
information if not conducted properly.
The purpose of this project was to investigate
background concentrations of metals in the soils of
Puerto Rico and create a database to help
contaminated-site practitioners make informed
decisions to protect human health and the
environment.
Approach
A literature and database search was conducted to
identify existing data. EPA records were reviewed
for all Superfund and RCRA Corrective Action sites
on the island to identify data for arsenic, barium,
cadmium, chromium, lead, silver, mercury, and
selenium. Records from initial site investigations
that were conducted to determine CERCLA National
Priorities Listing candidates were also reviewed for
background data.
Juiy 2018

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EQulS™ and GIS were used to compile data and
create maps and other products to graphically
depict the data and compare it to known
contaminated sites and the underlying geology. The
data were analyzed and data gaps were identified.
Results
The data were limited since background samples
were found for only 18 of the 50 CERCLA/RCRA sites
on the island. Samples from 301 locations at these
18 sites were evaluated and 2,058 results were used
for this study. The distribution of available data was
limited to roughly five geographical areas:
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1.	the San Juan metropolitan area,
2.	the northern coast extending to the west of San
Juan,
3.	southwest Puerto Rico extending west to east
from Cabo Rojo to Guayanilla,
4.	the east coast of Puerto Rico in the Humacao
municipality, and
5.	northeast Puerto Rico in the municipality of
Fajardo.
Since geology plays an important role in the
inorganic content of surrounding soils, the rock
types underlying or outcropping in the areas where
the samples were collected were identified using a
geology map. The geologic units include
sedimentary rock in the San Juan and the northern
coast areas, volcanic (Cabo Rojo) and sedimentary
(Guayanilla) rock in the southwest, and interlayered
sedimentary and volcanic rock in the eastern
regions of Puerto Rico (Humacao and Fajardo).
The results were presented in a user-friendly
interactive Story Map so that stakeholders,
including the community and site
assessment/remediation practitioners, will be able
to access the data.
Data Gaps and Next Steps
This study represents the first compilation of soil
background data in Puerto Rico. Since data for the
island were limited, additional work is needed to fill
data gaps.
Next steps include:
•	determine locations for sampling based on soil
types/geology, and current and past land use,
•	collect additional background samples,
•	add the data to the Region 2 EQulS™ database,
and
•	analyze the data to determine representative
island-wide background inorganic
concentrations,
•	update the Story Map and make available to the
public.
Contacts
This project was a collaboration between EPA's
Office of Research and Development (ORD), EPA
Region 2, and the University of Puerto Rico/Medical
Sciences Campus/School of Public Health and was
funded by ORD's Regional Applied Research Effort
(RARE) Program.
•	Jesse Aviles, EPA Region 2 (currently w/
Region 8), aviles.jessejS)epa.gov
•	David Cuevas, EPA Region 2,
cuevas.david(5)epa.gov
•	Diana Cutt, EPA ORD/Region 2,
cutt.diana(5)epa.gov
•	Mark Maddaloni, EPA Region 2*
•	Katherine Mishkin, EPA Region 3,
mishkin.katherine@epa.gov
•	Charles Nace, EPA Region 2,
nace.charles(5)epa.gov
•	Richard Wilkin, EPA ORD National Risk
Management Research Laboratory,
wilkin. rick(5)epa.gov
•	Rodolfo Seda, University of Puerto Rico-
Medical Sciences Campus, School of Public
Health
*No longer with EPA
2
U.S. Environmental Protection Agency
Office of Research and Development
July 2018

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