Garza’s experience is common among Hanford workers; in July 2021, a new state report found that a shocking 57 percent of Hanford workers have reported exposure to hazardous materials. But as dangerous as they are, the toxic vapors Garza’s crew encountered aren’t necessarily the tanks’ worst hazard. It wouldn’t take much for a tank to fuel a massive explosion, one that Tom Carpenter, executive director of the watchdog group Hanford Challenge, says could spread radiation over a staggering area: Washington, Idaho, Oregon, “probably Utah and maybe Canada, depending on the wind direction and speed.”