Critics have questioned whether the city should have moved people onto the island in the first place. While the Navy knew it would need to undertake an environmental cleanup before the island could be developed, the military and city of San Francisco didn’t wait for that cleanup to be completed before moving people there: About 2,000 families have lived in former military housing on the island and nearby Yerba Buena Island since 1999.

The Navy didn’t publicly acknowledge that there was radiological contamination until 2007 but has long known about other contaminants in the housing area, including asbestos and lead paint in the half-century-old homes and the arsenic, pesticides, lead, PCBs and other chemicals left over in the soil from when the housing area was used as a trash pit…..

The Navy said the radiation is left over from the decontamination of radioactive ships and from dials, gauges and deck markers left behind from a time when the military used radioactive paint to make objects glow in the dark.http://www.sfgate.com/bayarea/article/Navy-to-test-Treasure-Island-homes-for-radiation-5345049.php