scanne, while I understand your concerns, a little knowledge on the subject will go a long way towards calming your fears.
A large scale attack on the US is highly improbable. This is because in order for anything to be done on a large scale, a large amount of whatever needs to be developed. This is far from easy. Once whatever has been developed, it has to be weaponized. Also not easy. Each chemical and biological agent has its own properties that make mass dispersal difficult to say the least. The water supply can't be tampered with because there is just too much water to keep the integrity of the agent intact. The idea of releasing something into the air works in the movies, but in real life, a release is more likely in an enclosed space. These chemicals have distinct smells. If you're in a confined space and you suspect something has been released, hold your breath (as best you can) and get outside as fast as possible. If you are outside and something has been released, get away from it. Notice which direction the wind is blowing and go the other way. Stand as tall as possible as all of these things are heavier than air (don't hit the ground). Put something over your mouth and nose (wet, preferrably). Get to a safe place, and remove your clothes, and wash completely. If your safe place is home, put your clothes in a sealed bag.
If it's a biological attack, relax. The fact that it is biological means that it's going to effect a small (relatively speaking) group of people. Once the initial group has been diagnosed, med staff will know what they are dealing with, and take heart, most of it is completely curable. Again, soap and water are your best defense. Be especially mindful of any body oraface including your eyes.
Try to stay away from mass transit if there has been an attack as you could become contaminated by someone, or you could contaminate someone else.
While none of this is a guarantee, it does help to understand what you are dealing with. As Hunt said, a fatal car accident is more likely than this.
I hope that this helped.
Erin
