| Material – Structure or Location | Relative Shielding Strength |
|---|---|
| Outside | No reduction in exposure |
| Vehicle | No reduction in exposure |
| Wooden frame house | Slight reduction in exposure |
| Basement of wooden house | Almost 50% reduction in exposure |
| Masonry home | Almost 50% reduction in exposure |
| Basement of masonry house | >50% reduction in exposure |
| Large office or industrial building (inner areas, away from windows) |
80% reduction in exposure |
Source: Adapted from Management of Terrorist Events Involving Radioactive Material, Report 138, Table 8.5, p. 109. Bethesda, MD: National Council on Radiation Protection and Measurements; October 2001. Used with permission.