Case Study · Environmental Health & Justice

Environmental Exposure Analysis to Identify Cancer Risk Hotspots in Harris County

FocusIndustrial air-toxics exposure & cancer risk
MethodsEPA AirToxScreen · EJ indices · benchmarking
PresentedTPHA 2024 Annual Meeting & Expo
0
national percentile for cancer risk
0
of total cancer risk from EtO
0
state percentile for cancer risk
TPHA 2024
presented at annual meeting & expo

Cancer-risk profile - Census Tract 48201252600

national percentile ranking
0th percentile 0 100
Risk ranking vs. all U.S. census tracts
>50% EtO
Ethylene Oxide (EtO) - over 50% of total cancer risk
All other air toxics combined
Figures from this analysis. Tract 48201252600 ranked in the 95th percentile (state) and 97th percentile (national) for cancer risk; EtO contributed over 50% of total cancer risk in the area.
Client Profile

Public health and environmental stakeholders focused on evaluating the impact of industrial emissions on community health outcomes in high-risk regions of Harris County, Texas.

The Challenge

Communities located near industrial corridors in Harris County face ongoing exposure to hazardous air pollutants, particularly Ethylene Oxide (EtO), a known carcinogen.

Despite the potential risks, there was limited clarity on:

  • Which communities were most affected
  • The magnitude of cancer risk attributable to EtO exposure
  • How environmental exposure intersects with demographic and socioeconomic vulnerability

The need was to identify high-risk “hotspots” and quantify exposure-driven cancer risk to inform regulatory and public health action.

Key Requirements
  • Identify high-risk census tracts using environmental exposure data
  • Quantify cancer risk associated with EtO and other air toxics
  • Integrate demographic and environmental justice indicators
  • Benchmark risk at state and national levels
  • Translate findings into actionable insights for decision-makers
The Solution
1

Exposure Data Integration

Utilized EPA AirToxScreen data to identify high-exposure census tracts and quantify air toxic concentrations.

2

Risk Quantification

Applied statistical analysis to estimate cumulative cancer risk and isolate the contribution of Ethylene Oxide.

3

Environmental Justice Analysis

Integrated U.S. Census and Environmental Justice (EJ) indices to assess demographic disparities, including income, insurance status, and population composition.

4

Benchmarking and Ranking

Evaluated census tracts against state and national percentiles for cancer risk and criteria pollutants (PM2.5 and ozone).

5

Visualization and Interpretation

Developed clear visual outputs (as shown in the TPHA poster) to communicate exposure-response relationships and highlight high-risk communities.

The Impact
  • Identified census tract 48201252600 as a high-risk environmental hotspot
  • Determined that EtO contributes over 50% of total cancer risk in the area
  • Highlighted extreme risk levels, with the tract ranking in the 95th percentile (state) and 97th percentile (national)
  • Revealed disproportionate impact on low-income, minority populations
  • Provided evidence to support targeted regulatory oversight and intervention strategies
Key Insight

Industrial emissions are not impacting all populations equally. This analysis demonstrates that environmental exposure risk is strongly aligned with socioeconomic vulnerability, reinforcing the need for targeted environmental justice interventions.

Outcome

This work was presented at the Texas Public Health Association (TPHA) 2024 Annual Meeting and Expo, supporting broader awareness of environmental exposure risks and informing future public health strategies.

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