About 50 types of cancer have been added to the list of diseases eligible for coverage in a compensation program for people who became sick after the World Trade Center collapse on September 11, 2001, AFP reports citing officials.
The National Institute for Occupational Safety and Health said it had confirmed a recommendation made in June to include the cancers, which break up into 14 categories.
"The final rule adds to the list of WTC-related health conditions each of the types of cancer proposed," World Trade Center health program administrator John Howard said in a statement.
A $4.3 billion fund is available for 9/11 health victims but until now cancer sufferers -- believed to be in the many hundreds -- have not been able to place claims of their own. The new rule will take effect in mid-October.
Until now, most of the aid recipients, including local residents and emergency services personnel, have received compensation for respiratory diseases linked to the toxic dust and fumes from the fallen towers.
In the ruling, some cancers are excluded, but 14 broad categories, containing dozens of different types, are included and sufferers would qualify for free treatment and compensation.
Despite huge sympathy and political backing for victims of 9/11, the compensation decision has been held up by the scarcity of evidence of a direct link between the World Trade Center tragedy and cancer.
The pool of money for the overall health program will not be expanded.
New York Mayor Michael Bloomberg welcomed the news, which came on the eve of the 11th anniversary of 9/11.
"We have urged from the very beginning that the decision whether or not to include cancer be based on science," he said.
"Dr Howard's decision, made after thorough consideration of the latest available research and data, will continue to ensure that those who have become ill due to the heinous attacks on 9/11 get the medical care they need and deserve."
Three New York congressional representatives -- Carolyn Maloney, Jerrold Nadler and Peter King -- said the announcement was "great news" ahead of the 9/11 anniversary.