In the wake of the September 11 attacks, the US Department of Health is pushing ahead with plans to build at least five maximum security laboratories to study deadly diseases like Ebola, anthrax and smallpox. Five of these "level 4" labs already exist in the US. The government feels that the labs are essential in the war on terror. "To know that we can do this research and not do it would be irresponsible," says Rona Hirschberg, of the National Institutes of Health.

A lab in Boston has drawn fierce opposition from community activists -- and even from 150 scientists, including two Nobel laureates from Harvard. They query whether housing dangerous pathogens in an urban setting is safe. "There's no way of having a system that's 100% foolproof," said Penn Loh, executive director of Alternatives for Community and Environment in Roxbury, an inner city, mainly black, Boston neighbourhood near the site. "Should something occur, you don't want it to happen in a densely populated area."