The environmental health hazard exposure index summarizes potential exposure to harmful toxins including carcinogenic, respiratory, and neurological hazards. Values are percentile ranked and range from 0 to 100, with higher values corresponding to less exposure to harmful toxins. Data is computed for U.S. counties by applying summary statistics across all census tracts present in a county and is current as of 2015.

Above charts are based on data from the U.S. Department of Housing and Urban Development | Data Source | ODN Dataset | API - Notes:

1. ODN datasets and APIs are subject to change and may differ in format from the original source data in order to provide a user-friendly experience on this site.

2. To build your own apps using this data, see the ODN Dataset and API links.

3. If you use this derived data in an app, we ask that you provide a link somewhere in your applications to the Open Data Network with a citation that states: "Data for this application was provided by the Open Data Network" where "Open Data Network" links to http://opendatanetwork.com. Where an application has a region specific module, we ask that you add an additional line that states: "Data about REGIONX was provided by the Open Data Network." where REGIONX is an HREF with a name for a geographical region like "Seattle, WA" and the link points to this page URL, e.g. http://opendatanetwork.com/region/1600000US5363000/Seattle_WA