Allegheny County’s Toxic Ten

* Blank fields indicate that toxicity weighting information for this chemical is unavailable. See methodology.

* Blank fields indicate that toxicity weighting information for this chemical is unavailable. See methodology.

Some releases round to zero.

Some releases round to zero.

Data from the TRI 2021 National Analysis were downloaded via the Envirofacts TRI Form R & A Download page at https://enviro.epa.gov/facts/tri/form_ra_download.html on 1 November 2022. Only facilities with non-zero values for “air total releases” with locations in Allegheny County were included in this analysis.

Reporting facilities are able to amend their TRI reporting on a continuous basis. The National Analysis data used in this analysis was “frozen” in October 2022 and does not include revisions made by facilities after that date. As a result, the figures cited in this analysis may not match data currently available on some pages of the EPA web site.

The industry categories used in this analysis were obtained by matching the North American Industry Classification System (NAICS) codes available in the TRI data download with 2017 NAICS code definitions from the U.S. Census Bureau, downloaded 16 May 2022 from https://www.census.gov/naics/?48967.

The EPA’s Risk Screening Environmental Indicators (RSEI) provide toxicity-weighted measures with which to assess the level of potential hazard or risk to public health posed by chemical releases reported under the TRI. In this analysis, we used toxicity weights used to produce the EPA’s “RSEI Hazard” metric to compare the toxicity of air releases from facilities in Allegheny County. The RSEI Hazard metric provides a screening-level indicator useful for comparing releases but does not account for potential routes of human exposure to toxics released by industrial facilities.

EPA had not yet released RSEI Hazard data for the 2021 TRI reporting year as of the date of this analysis. We calculated Hazard-based results for each facility, following EPA methodologies and using the EPA’s RSEI Toxicity Weighting Spreadsheet v.2.3.10, downloaded from https://www.epa.gov/rsei/rsei-documentation-and-help, 1 November 2022. In most cases, Hazard-based results were calculated by multiplying the facility’s release of a particular chemical in pounds by the inhalation toxicity weight (ITW) of that chemical. 

In two cases, calculation of the Hazard-based result required an additional step:

• Dioxin and dioxin compounds – Different forms of dioxin vary in their toxicity. To account for this, EPA requires facilities reporting releases of dioxin and dioxin compounds to report separately the releases of 17 individual dioxin congeners. This detailed reporting is then used by the EPA to calculate a facility-specific toxic equivalency (TEQ), which represents the quantity of the most-toxic member of the dioxin class that would need to be released to have a similar toxic effect to the specific mix of dioxin congeners released by that facility. For this analysis, we obtained TEQs for the two facilities in Allegheny County with reported air releases of dioxin (Cheswick Power Plant in Springdale and Calgon Carbon Corp.’s Neville Island plant) and replaced the reported dioxin releases from those facilities (reported in grams) with the TEQ value.² We then multiplied the TEQ by the ITW for dioxin and dioxin compounds in the EPA’s RSEI Toxicity Weighting Spreadsheet to arrive at the Hazard-based toxicity value.   
• Chromium and chromium compounds – Facilities that emit chromium typically emit a combination of two types, or valences, of the element: chromium (III), also called trivalent chromium, and chromium (VI), also called hexavalent chromium. Facilities reporting to TRI, however, report under the umbrella category, “chromium and chromium compounds,” which includes releases of both valences. Trivalent chromium has “a very low toxicity,” according to the EPA’s RSEI model methodology documentation, and therefore is assumed to have no toxicity in the RSEI model.³ EPA bases each facility’s ratio of trivalent to hexavalent chromium emitted on industry-specific factors from the 2017 National Emissions Inventory (NEI).  ⁴

To calculate the Hazard-based result for each facility, we multiplied the reported air releases of chromium and chromium compounds (in pounds) by the percentage of each facility’s releases made up of chromium (VI). Each facility’s chromium VI percentage was derived from industry-specific factors obtained in the U.S. EPA’s TRI-based Chromium Speciation Excel spreadsheet, downloaded from https://gaftp.epa.gov/air/nei/2017/doc/supporting_data/TRI_based_chromium_speciation.zip  , 7November 2022. Each facility’s primary NAICS code was used to identify the appropriate chromium speciation profile for each facility. The percentage of chromium VI in that profile was then multiplied by the facility’s reported releases of chromium and chromium compounds to obtain an adjusted release figure, which could then by multiplied by the appropriate RSEI toxicity weight. Facilities without an industry-specific profile were assigned the default value of 34% chromium VI, as described in the EPA’s RSEI Methodology.⁵

EPA’s RSEI Toxicity Weighting Spreadsheet does not include a weighting factor for every chemical with releases reported under the TRI. Consistent with EPA methodology, those releases are not assigned a RSEI Hazard value and do not count toward a facility’s ranking.⁶

Each toxic substance reported as released by a facility was evaluated to determine if it was associated with cancer, developmental harm or reproductive toxicity. The assessment of the health effects of the substances is based on analysis conducted for the Environment America Research & Policy Center report, Wasting Our Waterways, published in September 2022, updated to include substances released to air by Allegheny County polluters that were not included in that report. ⁷

The information used to assign health effects to toxic releases was primarily obtained from two datasets. The first was the EPA’s TRI Toxics Tracker tool at https://edap.epa.gov/public/extensions/ TRIToxicsTracker/TRIToxicsTracker.html, downloaded on 10 May 2022. We used the “Potential Health Effects” option under the “Chemicals” tab and selected all reporting years in the filter options. The other dataset was California’s Proposition 65 list of known harmful chemicals and their effects, downloaded on 9 May 2022 at https://oehha.ca.gov/proposition-65/proposition-65-list (and reviewed for updates on 21 February 2023) Health effects for chemicals indicated in the “Prop 65” list as having been “delisted” or for which a given health effect was “removed” were excluded from the dataset. The following rules were followed in assigning health effects to toxic substances:

• Chemicals listed as known to cause cancer, reproductive or developmental toxicity in the Prop 65 list were assigned those health effects.
• Toxic substances that were not listed as tied to a given health effect on the Prop 65 list, but that were tied to that effect on the EPA list, were evaluated further using the EPA’s CompTox Chemicals Dashboard, which aggregates chemical warnings and toxicity determinations by authorities in the United States, Europe, Japan, Australia and other jurisdictions across the globe.⁸ Chemicals included on the EPA Toxics Tracker for a health effect that at least one other authority found “may cause” that health effect were included in the list used in this report. Substances listed by authorities as “suspected” of causing a health effect were not included.
• Releases of certain chemicals are reported to the EPA by class, instead of, or in addition to, reported releases of the individual substance, thus requiring a determination of whether the class of chemicals is linked to a particular health effect. Because different compounds within a class may have differing levels and forms of toxicity, because there is no way to distinguish among which compounds in a class are being released, and because the EPA and Prop 65 lists are sometimes unclear as to which health effects are associated with particular chemicals, we applied the following rules in assigning health effects to chemicals and related chemical classes:
  • If, in the Prop 65 list or other sources, health effects were associated with a substance and its compounds, those health effects were assumed to be associated with releases of the substance and its compounds as reported to TRI.
  • If health effects in the Prop 65 list or other sources were associated with either a type of compounds as a class, or specific compounds of an element (usually a metal), but not specifically with the elemental form of the substance, those health effects were assumed to be associated with the “[ELEMENT] and [ELEMENT] Compounds” category in TRI if the substance and its compounds had the same toxicity weight in RSEI.
  • Reported releases of “Chromium and chromium compounds” (TRI class N090) were associated with cancer, developmental harm and reproductive health effects of hexavalent chromium compounds as indicated on the Prop 65 list. Reported releases of “Chromium” (Chemical Abstracts Service number 7440-47-3) were not assigned the health effects of chromium compounds.

In some cases, groups of chemicals or individual chemicals were listed with associated health effects in the Prop 65 list but with no corresponding Chemical Abstracts Service (CAS) number. In these cases, CAS numbers were obtained from the EPA’s listing of TRI chemicals or obtained from other sources and assigned as described in the footnote.⁹

The Cheswick power plant ranked eighth for toxicity of its air releases in 2021. However, the facility closed in the spring of 2022 and was therefore excluded from the Toxic Ten list. McConway & Torley, which had ranked 11th for toxic air releases in 2021, was then included in the Toxic Ten.

Harsco Metals in Natrona Heights has appeared in all previous editions of the Toxic Ten, ranking second for the toxicity of its releases to Allegheny County’s air in 2019. The facility, which processes steel slag from the neighboring ATI Flat Rolled Products plant, released compounds of chromium, lead, manganese and nickel to the region’s air in 2019 and 2020, but as of the time of publication of this website, had not reported toxic releases for 2021 to the EPA’s Toxics Release Inventory. It is unknown whether Harsco is no longer required to report to TRI (for example, by reducing its use or releases of toxic substances below reporting thresholds) or has simply failed to report. The company’s 2020 releases would have ranked it among the Toxic Ten in this report. 

The population within three miles of each facility was obtained from the U.S. EPA, which calculates this figure for each facility in its Enforcement and Compliance History Online (ECHO) database.

The number of schools and hospitals within three miles of each facility was determined via GIS analysis. A shapefile with the locations of hospitals in the commonwealth was obtained from the Pennsylvania Department of Health via Pennsylvania Spatial Data Access on 29 December 2022. A listing of public and public charter schools in Allegheny County was obtained from the Pennsylvania Department of Education, Educational Names & Addresses (EdNA) database on 29 December 2022. The addresses from the EdNA database were geocoded using the U.S. Census Bureau’s public batch geocoding tool, with schools that did not produce matches then manually geocoded using Google Maps searches. Parochial and private schools are not included in the number of schools reported for each facility.

The authors are grateful to John Graham, senior scientist at Clean Air Task Force for his review and suggestions, and to the Heinz Endowments for making this project possible.

1. Defined as days on which the EPA’s Air Quality Index for either pollutant exceeded 50, a level the EPA defines as “moderate,” but has been associated with threats to public health. For more information on the health effects of air pollution, please see PennEnvironment Research & Policy Center and Frontier Group, Trouble in the Air, October 2021.
2. TEQs for stack or point air emissions (Section 5.2 of TRI Form R) were used. The TEQ for Cheswick was obtained from U.S. EPA, Envirofacts, Form R Reports: Cheswick Power Plant, accessed at https://enviro.epa.gov/enviro/tri_formr_partone_v2.get_details?rpt_year=2021&fac_id=15024CHSWCPITTS&ban_flag=Y, 3 November 2022; the TEQ for Calgon Carbon was obtained from U.S. EPA, Envirofacts, Form R Reports: Calgon Carbon Corp. Neville Island Plant, accessed at https://enviro.epa.gov/enviro/tri_formr_partone_v2.get_details?rpt_year=2021&fac_id=15225CLGNC200NE&ban_flag=Y, 3 November 2022.
3. U.S. Environmental Protection Agency, EPA’s Risk-Screening Environmental Indicators (RSEI) Methodology, RSEI Version 2.3.10, May 2022, archived at https://web.archive.org/web/20221122185535/https://www.epa.gov/system/files/documents/2022-06/RSEI%20Methodology%20V2.3.10.pdf, p. 18.
4. U.S. Environmental Protection Agency, EPA’s Risk-Screening Environmental Indicators (RSEI) Methodology, RSEI Version 2.3.10, May 2022, archived at https://web.archive.org/web/20221122185535/https://www.epa.gov/system/files/documents/2022-06/RSEI%20Methodology%20V2.3.10.pdf, p. 18.
5. U.S. Environmental Protection Agency, EPA’s Risk-Screening Environmental Indicators (RSEI) Methodology, RSEI Version 2.3.10, May 2022, archived at https://web.archive.org/web/20221122185535/https://www.epa.gov/system/files/documents/2022-06/RSEI%20Methodology%20V2.3.10.pdf, p. 18 at note 18.
6. U.S. Environmental Protection Agency, EPA’s Risk-Screening Environmental Indicators (RSEI) Methodology, RSEI Version 2.3.10, May 2022, archived at https://web.archive.org/web/20221122185535/https://www.epa.gov/system/files/documents/2022-06/RSEI%20Methodology%20V2.3.10.pdf, p. 12.
7. Bryn Huxley-Reicher, et al., Environment America Research & Policy Center, U.S. PIRG Education Fund and Frontier Group, Wasting Our Waterways: Toxic pollution and the unfulfilled promise of the Clean Water Act, September 2022, available at https://environmentamerica.org/center/resources/wasting-our-waterways/. The following chemicals that were not included in Wasting Our Waterways were evaluated for their health effects using the same methodology as described in this section, using the same sources: hydrochloric acid, 2,4-dinitrotoluene, sulfuric acid, 2,6-dinitrotoluene, aluminum. In addition, we reviewed the California Proposition 65 list for any changes since publication of Wasting Our Waterways.
8. U.S. Environmental Protection Agency, CompTox Dashboard, available at https://comptox.epa.gov/dashboard/.
9. Bis(2-chloro-1-methylethyl)ether, technical grade” assigned CAS number 108-60-1 as found 31 May 2022 at https:// iris.epa.gov/ChemicalLanding/&substance_nmbr=407#:~:text=Bis(2%2Dchloro%2D1,%7CIRIS%7CUS%20EPA%2C%20 ORD; “3,3’-Dimethoxybenzidine-based dyes metabolized to 3,3’-dimethoxybenzidine” assigned CAS number 119-90-4 as found 31 May 2022 at https://pubchem.ncbi.nlm.nih.gov/compound/3_3_-Dimethoxybenzidine#section=Other-Identifiers; “3,3’-Dimethylbenzidine-based dyes metabolized to 3,3’-dimethylbenzidine” assigned CAS number 119-93-7 as found 31 May 2022 at https://cameochemicals.noaa.gov/chemical/16097; “Dinitrotoluene (technical grade)” and “Dinitrotoluene mixture, 2,4-/2,6-” assigned CAS number 25321-14-6 as found 31 May 2022 at https://cameochemicals.noaa.gov/chemical/612; “Lindane and other hexachlorocyclohexane isomers” assigned CAS number 58-89-9 as found by searching TRI release data for lindane; “Pentachlorophenol and by-products of its synthesis (complex mixture)” assigned CAS number 87-86-5 as found by searching TRI release data for pentachlorophenol; “Perfluorononanoic acid (PFNA) and its salts” assigned CAS number 375-95-1 as found by searching TRI release data for perfluorononanoic acid; “Perfluorooctane sulfonic acid (PFOS) and its salts and transformation and degradation precursors” assigned CAS number 1763-23-1 as found by searching TRI release data for perfluorooctane sulfonic acid; “Polychlorinated biphenyls” and “Polychlorinated biphenyls (containing 60 or more percent chlorine by molecular weight)“ assigned CAS number 1336-36-3 as found by searching TRI release data for polychlorinated biphenyls; “Quinoline and its strong acid salts” assigned CAS number 91-22-5 as found by searching TRI release data for quinoline.