It is difficult to predict the likelihood or scale of biological attack.

So for a biological attack, experts agree, warning systems are crucial.

However, this may also have an impact on policy planning for a biological attack with a disease such as smallpox.

Under the bill, states would get $1.5 billion in federal grants to prepare for a biological attack.

What would happen, for instance, if the military were asked to quarantine an area after a biological or nuclear attack?

Even fewer said they were ready for a chemical, biological or nuclear attack.

Scientific knowledge about biological attacks is limited because so few have occurred.

Nevertheless, he said food could be used in a biological attack.

Moreover, there are no measures to routinely check for biological attack.

But in the event of a biological attack, many might go home to their own families.