Selecting Features by Spatial Location

One of the most practical uses of GIS is the ability to select information based on location.  One example, show below, highlights this technique.  The map seeks to answer the questions: How many New Jersey schools are in regions with the greatest health risks from air pollution?  Where are they located?  This map uses information from the EPA National Air Toxics Assessment to explore areas with the greatest risks for cancer due to air pollution.  Using GIS, I superimpose schools over these areas to identify which schools are within the top ten percent risk areas for the state.  Within these schools, I further narrow my search to display high schools within these risk areas.  Of 3,753 schools cataloged in New Jersey’s database of schools, 258 are in census tracks with the top ten percent risk of cancer due to air pollution.  Among these, 21 are high schools, and eight of these are show in the map bordering New York.  Recent research has explored the association between air pollution and neurotoxic risks, in relation to schools across the U.S, and educators have also contributed their concerns about air pollution and student health and success.

More recent data, published in August 2018, estimated carcinogenic risks by census tract for 2014.  The map below identifies the school locations in the top decile and in the top census tract.