Use the Echo system, www.epa-echo.gov/echo/index.html, to locate the firms that have permits for emissions in your zip code. What is the ratio of large to small firms? What is the ratio of "notice of violations" (NOV) to other enforcement actions? Who are the biggest polluters? Look at www.peri.umass.edu/Toxic-100-Table.265.0.html for one compilation of results from the Toxics Release Inventory. Are these also the largest industrial firms in the United States? Which entries do you find surprising?