Capability for Detection of Chemical Warfare Agents in Field Drinking Water
The standard method for monitoring chemical warfare (CW) agents in field drinking water is the M272 Chemical Agents Water Testing Kit developed by the Department of the Army (U.S. Army, 1983). Combat drinking-water standards established in 1975 (U.S. Army, 1975) were in effect at the time the M272 kit was first distributed for use in the field (May 1984). Concentrations of CW agents reliably detected by the kit are as follows: 20 µg/L (0.02 mg/L) for organophosphate nerve agents; 2,000 µg/L (2 mg/L) for vesicants (sulfur mustard and lewisite; lewisite measured as As+3); and 20,000 µg/L (20 mg/L) for hydrogen cyanide (measured as CN-). The M272 kit does not test for Agent BZ or T-2 toxin.
These detection limits are adequate to measure concentrations at the current short-term field drinking-water standards for organophosphate nerve agents (20 µg/L), lewisite (2,000 µg/L or 2.0 mg/L), and cyanide (20 mg/L) (U.S. Army, 1986). However, the kit's sensitivity is not adequate to measure concentrations at the current short-term standards for sulfur mustard (200 µg/L; difference of an order of magnitude (U.S. Army, 1986)) or any concentrations of Agent BZ or T-2 toxin.
Of the subcommittee's recommended field drinking-water guidelines (Table B-1), only those for the organophosphorus agent GA (70 µg/L for 5 L/day water consumption and 22.5 µg/L for 15 L/day water consumption) can be detected by the current protocol using the M272 kit. There
is a clear need for development of protocols and instrumentation to reliably detect the agents under review at the proposed field drinking-water concentrations.
TABLE B-1 Summary of the Subcommittee's Recommended Field Drinking-Water Guidelines for Selected CW Agents in Field Drinking Watera
Recommended Guidelines |
||
CW Agent |
5 L/day |
15 L/day |
BZ (µg/L) |
7.0 |
2.3 |
Organophosphorus nerve agents |
||
Agent GA (µg/L) |
70.0 |
22.5 |
Agent GB (µg/L) |
13.8 |
4.6 |
Agent GD (µg/L) |
6.0 |
2.0 |
Agent VX (µg/L) |
7.5 |
2.5 |
Sulfur mustard (µg/L) |
140.0 |
47.0 |
T-2 toxin (µg/L) |
26.0 |
8.7 |
Lewisite (µg/L) (arsenic fraction)b |
80.0 |
27.0 |
Cyanide (mg/L) |
6.0 |
2.0 |
aAssumes a water consumption of up to 7 days. bBased on detection of the arsenic fraction of lewisite in water; the corresponding concentration of lewisite is about 2.75 times greater. |
REFERENCES
U.S. Army. 1975. Sanitary Control and Surveillance of Supplies at Fixed and Field Installations. TB MED 229. Department of the Army Headquarters, Washington, D.C.
U.S. Army. 1983. Technical Manual, Operator's Manual-Water Testing Kit, Chemical Agents: M272. TM 3-6665-319-10 . Department of the Army Headquarters, Washington, D.C.
U.S. Army. 1986. Occupational and Environmental Health: Sanitary Control and Surveillance of Field Water Supplies. TB MED 577. Department of the Army Headquarters, Washington, D.C.