Biomedical Engineering Reference
In-Depth Information
garlic, onion, or mustard, hence its name. However,
because of the rapid accommodation to smell,
odor should not be relied on for detection. Under
temperate conditions, mustard evaporates slowly
and thus is primarily a liquid_hazard. However,
its vapor hazard increases with increasing temper-
ature. At 100
F or above, it is a definite vapor
hazard. Of the three vesicant agents, mustard is the
only one that does not cause immediate pain. The
patient is asymptomatic until the lesion becomes
apparent hours later. Lewisite and phosgene oxime,
in contrast, cause immediate pain or irritation to
the eye, skin, or respiratory tract.
mustard (HN), the arsenical vesicants such as
lewisite (L) which may be mixed with HD. Vesi-
cants burn and blister the skin or any other part
of the body they contact. They act on the eyes,
mucous membranes, lungs, skin and bone marrow.
They damage the respiratory tract when inhaled
and cause vomiting and diarrhea when ingested.
Mustard's effects are delayed, appearing hours
after exposure. There is no specific antidote, imme-
diate decontamination is the only way to reduce
damage and management consists of symptomatic
therapy [19-21].
6.4.1 History
Sulfur mustard was first synthesized in the early
1800s and was first used on the battlefield during
World War I by Germany in July 1917. Despite
its introduction late in that conflict, mustard
produced more chemical casualties than all of the
other chemical agents combined. However, less
than 5% of the mustard casualties who reached
medical treatment facilities died. Italy allegedly
used mustard against Abyssinia in the 1930s. In the
1960s Egypt apparently employed mustard against
Yemen, and Iraq used mustard in the 1980s against
Iran and the Kurds. Mustard is still considered a
major threat agent of former Warsaw Pact coun-
tries and third world countries [20].
The nitrogen mustards (HN1, HN2, and HN3)
were synthesized in the 1930s, but were not
produced in large amounts for warfare and
Mechlorethamine (HN2, Mustargen) became the
prototypical cancer chemotherapeutic compound
and
CH
2
CH
2
CI
S
CH
2
CH
2
CI
HD
6.4.3 Mechanism of Toxicity
Mustard has many biological actions and the exact
mechanism by which it produces tissue injury is not
known. According to one prominent hypothesis,
biological damage from mustard results from DNA
alkylation, crosslinking and strand breakage in
rapidly dividing cells, such as basal keratinocytes,
mucosal epithelium, and bone marrow precursor
cells. This leads to cellular death, an inflamma-
tory reaction, and, in the skin, protease digestion of
anchoring filaments at the epidermal-dermal junc-
tion and the formation of blisters.
Mustard vapor and liquid readily penetrate
thin layers of most fabrics reaching underlying
skin where the lipophilicity of mustard guaran-
tees effective absorption through even intact skin.
Penetration is rapid (1-4mcgmin cm
−
2
). Approx-
imately 10% of the amount of mustard that begins
to penetrate the skin will bind to the skin as
“fixed” (reacted) mustard; the remaining 90% of
the dose reaches the circulation and is systemically
distributed as “free,” unreacted and hydrolyzed
mustard. However, mustard penetrates the skin
without causing any acute concomitant clinical
effects, e.g., burning or erythema. Because of the
has
remained
the
standard
part
of
chemotherapy for many years.
Lewisite (L) was synthesized during the late
stages of World War I, but probably has not
been used on a battlefield. The Lewisite antidote,
British-Anti-Lewisite (BAL), finds medicinal use
today as a heavy-metal chelator. Although classi-
fied as a vesicant, phosgene oxime (CX) is a corro-
sive urticant that also has not seen battlefield use.
6.4.2 Physical Characteristics
Mustard is an oily liquid with a color ranging
from light yellow to brown. Its odor is that of
