Ew, gassy!

[FTJoshua]

Anyone have writeups or can point to a 4th Ed. book with write ups of VX, mustard, and/or sarin gas? Thanks!

 

(If you're following the DC Assault thread, you know where this is going.)

[Vondy]

Well,since we're talking about the DC thread... I don't think the government would bother with mustard gas. It was generally damaging to lung tissue, but was seldom lethal, and compared to modern chemical weapons is completely obsolete.

 

Sarin and VX gas are actually variations of the same chemical compounds, but VX gas has a different consistency [read delivery method] and is considered far more lethal. The scientific name for VX gas is Acetylcholinesterase.

 

The Effects of VX Gas

 

VX gas may be absorbed ocularly (through the eyes), percutaneously (through skin), and by inhalation. Upon absorbtion, the phosphorous atom of VX covalently binds to a serine hydroxyl group in the active site of acetylcholinesterase (compare the two structures below).

 

This binding stops the hydrolysis of acetylcholine, causing constant stimulation that "fatigues" the post-synaptic neurone. The lack of acetylcholine also exhausts the pre-synaptic neurone's acetylcholine reserves.

 

This constant nerve stimulation causes the characteristic symptoms of VX Gas poisoning. These include:

 

Ataxia (lack of muscle control), Slurred speech, Coma, reflexia (loss of reflexes), Generalized convulsions, Cessation of breathing i.e. death,

 

Lower doses of VX cause similar effects, but may allow complete recovery in hours. Both VX and it's [highly toxic] breakdown products are persistent and of low votility (0.0007mmHg). This means they do not evaporate or decompose, so contaminated sites may take months to become habitable. Dispersed VX is usually broken down by rain-induced hydrolysis to an ethoxide (CH3CH2O-) ion and the nerve gas EA1292.

 

Though VX Gas is quick-acting and highly toxic, antidotes to the compound do exist.

 

So... I would break VX Gas into the following [defense for NND is correct immunity, preadministered vaccine, or a shot of atropine [a chemical weapon in its own right oddly enough] directly into the heart, which would stop the effects in progress] -- this presumes a lethal dose was received:

 

A) 2d6 Major Transform [seeing person to blind person], NND, Cumulative, Uncontrolled, 1 Charge [Lasts 1 Minute]

2d6 Dexterity Drain, Maximum Effect +78, Uncontrolled, Recover Every Hour, 1 Charge [Lasts 1 Minute]

C) 10d6 RKA, NND, Gradual Effect (5 Minutes), 0 End

 

This would likely be delivered in an area effect attack that would coat the area with an aerosol gel of VX. Chem warfare suits would be useful for the PCs, but my understanding is that there are two problems with this:

 

1) VX gas has been known to penetrate the standard issue chem warfare suits in small, non-lethal, but incapacitating doses.

 

2) We have corrosive agents that we introduce before the gas that will render the chem warfare suits useless. If the government knows the PCs have such suits they would likely follow this course of action.

 

Antidotes to VX Gas

 

Pyridostigmine bromide enhances the effects of other antidotes by competitively inhibiting (binding to) acetylcholinesterase, and is taken in tablet form.

 

Pralidoxine is infused intravenously (1.5mg over 15 minutes) and continually repeated after 10 minutes until muscle control returns.

 

Soap and water. Despite sounding old fashioned, if VX in liquid form can be wiped off the skin quickly enough, victims have a chance of survival, particularly if they are taken to hospital and treated immediately.

 

Unfortunately, none of these three antidotes are useful in a widespread situation as they are all slow acting and require the assistance of a second party.

 

Atropine is a nerve gas itself, but is a suitable antidote to VX gas. Atropine acts by competitivly binding to the muscarinic (acetylcholine) receptors in the muscles. This prevents acetylcholine from binding to the receptors and sending impulses to the muscles. VX stimulates the muscles, so as atropine ceases the constant stimulation it acts as an antidote. With no acetylcholine reaching or binding to the receptors it is unimportant that the acetylcholinesterase is being destroyed by the VX Gas.

 

Atropine

Atropine is injected intramuscularly (into the thigh) in 2mg doses every 3-8 minutes. If faster action is required, a direct injection into the heart will prevent death, effectively neutralising the effect of VX.

 

Each marine is supplied with three autoinjectors. If VX exposure is indicated, a fellow soldier uses one autoinjector in the victim's thigh every six minutes.

[Lord Liaden]

Steve Peterson wrote up various drugs and poisons in the Hero System Almanac II, including a sample nerve gas. I won't reproduce it exactly so as to avoid breaking copyright (and you would probably want to tailor it to suit your scenario, anyway), but it worked as a series of Linked Drains: a 1D6 Continuous Uncontrolled STR Drain with Charges, Recovery 5 pts./day, plus DEX, CON and BODY Drains with the same BP, AP, Advantages and Charges, all of them Linked to the STR Drain. You could of course increase the BP on these if you want them faster acting/more lethal, add Area of Effect, etc.

 

Edit: having read D-Man's very informative post above, it would seem that the Drain approach would cover most of the symptoms that he describes. In reference to Steve Peterson's writeup, I'd suggest that any of the treatments that D-Man describes would be appropriate to stop the Uncontrolled effect.