A total of 7.5 million people are estimated to be exposed at these 406 sites. The median population at risk from all pathways per site is 9,200 with a range of 100 to 400,000 people. Figure 2 presents the population at risk per key pollutant. As a component of the ISS, coordinators and/or in vestigators assessed a variety of environmental media, such as air, soil (residential, agricultural, and industrial), and water (drinking, bathing, irrigation, and fishing). Periodic sampling of blood, urine, and food was also implemented though not a priority. The dominant sampling media however were residential topsoil with a frequency of over 50 %. The usefulness of the ISS however rests in the assessment and reporting of exposure pathways. Table 2 lists each key pollutant and the dominant exposure pathway assessed. Such information may prove useful in designing environmental interventions that are tailored to minimizing health risks. Dust and soil dominated in exposure pathways.