Victims of the dust cloud

The legal fight over the health risks posed by the giant dust plume that formed when the World Trade Center in New York City collapsed may come to an end before the scientific dust settles.

The city’s lawyers had challenged some of the claims that the cloud swirling around the wreckage damaged the health of rescue and clean-up workers. Now the city is offering a $657.5 million settlement, so the cases may never go to court. If the plaintiffs approve, the city will award payments according to the severity of a person’s condition and their exposure to debris.

However, we still don’t know what was behind the adverse health effects, such as lung problems, stomach ailments and possibly cancer. Larger, high pH particles of cement, glass and pulverised debris are the likely cause of respiratory problems, says Paul Lioy at Rutgers University in Piscataway, New Jersey. But the gases and particles mixed in novel ways, making it hard to pick out “smoking guns”.