Using GIS to Interpret Environmental Justice Data in Portland

By Sofia Linden, Georgia Reid and Marissa Weileder


Due to myriad research methods in studies, environmental justice is a murky area to study.  Researchers can test siting hypothesis – if minorities/ people of lower socioeconomic status are disproportionally living in areas with closer proximity to toxic facilities – or risk hypotheses – if minorities/people of lower socioeconomic status are disproportionally at risk from toxic facilities. (Davidson, 2003).  There is a lot of ambiguity involved in studying these hypothesis.  Who works in these areas that do not live in these areas?  Are the areas with closer proximity to the sites more heavily affected, or do wind and water routes cause a high impact somewhere else?  Finding the answers to these questions can be tricky.


Our study group looked specifically at the toxic sites in Portland to try to understand how environmental justice plays out locally.  Using GIS to map out data allows us to visualize what is happening.



First we downloaded Portland spatial data from We then downloaded TRI (Toxic Release Inventory) data from the EPA website and the Meta Data for TRI’s to help interpret the information we were looking at, such as what the units of measurement were, and what abbreviations meant. After creating folders for this study, we created to sub-folders for downloaded data and anything we personally created.  We opened the shape file for Portland spatial data in QGIS and each worked on individual maps, so that we could interpret a wider amount of data.  We each added different TRI data to our maps and color coded the different data on our maps in what e found a suitable manner.  We color coded the maps the showed unemployment rates in relation to the amount of onsite total releases and off-site total releases the same to make them more easily comparable.  For these two maps we also downloaded from the shape file for the Urban Development Boundary in Portland, to help see how this relates to the data we were observing.  Once we finished our maps, we prepared them to be completed in QGIS composer, adding the appropriate tittles and legends.




The most TRI sites are within the Urban Development Boundary, most likely a result from law regulations.  The largest quantities of sites are along the river.

Percent White and TRI Sites (1)

The above map shows the percentage of white people in the different geographic blocks in Portland and the location of different TRI sites.  Most sites are located in geographic blocks with the middle range to lighter purples, indicating these TRI sites are located mostly in areas that are 50-100 percent white.

HH Income and TRI Sites

The green map above differentiates between TRI sites that are releasing carcinogenic and non-carcinogenic toxins and the weighted average household income.  The TRI sites are mostly located in the lighter greens (lower income) regions, between $24, 329-106,012.  However, the darkest two greens blocks, showing household incomes between $106,012-159,087 are in multiple cases locations directly next to the facilities.  The carcinogenic facilities are primarily in light green areas, however, like with the total of facilities, high income areas are shown nearby the geographic blocks in which these facilities are located.

Percent Unemployed-releases

The sites, as shown above, are primarily located within the Urban Development Boundary.  This likely relates to law regulations.  Most sites have between 0-3450 lbs of total on site releases.  Most of the geographic blocks where facilities are located have a substantial amount of employment, mostly within the middle purple shade.  This could be a result of the facilities supplying jobs.  This could also be a result of Portland overall not having a large amount of variation in employment rates for the most part.  The majority of the Portland area is has a percent of unemployment between 5.6 and 15.8.


Final Toxic off-site releases

Looking at offsite releases, we can see how much of the toxic/polluting effects of the facilities do not directly impact the neighboring areas, but other areas that would require more research to find out about.  The majority of the Portland TRI facilities have between 0-1,824 lbs of total offsite releases.



The data we collected is not enough to properly test the risk hypotheses.  We do not know exactly where chemicals are being released.  Many of the facilities are located on the river, and chemicals could be carried to various locations because of this.  It seems that carcinogenic facilities are located in areas with lower household incomes, but we cannot say for sure that these are the areas most heavily affected by the carcinogens, do to river transportation, wind, and other factors.  We can gather some idea of the siting hypothesis from this data.  It’s unclear looking at these maps if neighborhoods with higher percents of minorities host the most TRI facilities, because while many of the facilities are in higher minority areas, the area along the river is predominantly white and hosts a large quantity of Portland’s TRI facilities.  It appears that the facilities are more commonly located in areas with lower income rates, but more analyses of the data is needed to be sure.


Further analyses will allow for a better understanding how environmental justice hypotheses play out in Portland.  By proving or disproving environmental justice hypotheses in Portland, we can see how these trends in Portland may play out elsewhere.



Davidson, Pamela.  2003.  “Risky Business? Relying on
Empirical Studies to Assess
Environmental Justice.” In Our Backyard: A quest for environmental justice, Edited by Gerald R. Visgilio and Diana M. Whitelaw, 83-99. Oxford; New York; Boulder; Lanham: Rowman & Littlefield.

The Environmental Protection Agency, Office of Environmental Information, Office of Information Analysis and Access, Toxics Release Inventory Program Division, Information and Outreach Branch.  2013. “Toxic Release Inventory Basic Data File Format Documentation v12.”

Metro Data Resource Center. “Portland 2010 Block Groups.” Geo.lclark.

Toxic Release Inventory (TRI) Program. 2015. “2015 Preliminary Dataset – Basic Data Files.” EPA.



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