"Up to 400,000 New Yorkers breathed in the most toxic polluting cloud ever recorded after the twin towers were brought down three years ago, but no proper effort has been made to find out how their health has been affected. [A] US government study provides the latest evidence of a systematic cover-up of the health toll from pollution after the 9/11 disaster [3], which doctors fear will cause more deaths than the attacks themselves," the Independent writes. The Government Accountability Office report "September 11: Health Effects in the Aftermath of the World Trade Center Attack [4]" concludes that programs monitoring the long-term health effects of the attacks may not be "in operation long enough to adequately capture information about new conditions, chronic conditions, and diseases whose onset may occur decades after exposure to a harmful agent, such as many cancers."