10
Pesticides, Organic Contaminants, and Pathogens in Air
characteristic of nerve gas: the sheep were dazed, heads tilted to one side,
and movements were uncoordinated (Boffey, 1968).
Nearby residents suspected the Dugway Proving Ground, a U.S. military
chemical and biological weapons research and testing facility, which was
only 27 miles away. The military’s role in the incident was confrmed a week
later when a report was released stating that a high-speed jet had malfunctioned during a test and sprayed 320 gallons of nerve gas Venomous Agent X
(VX) at a much higher altitude than expected (Boissoneault, 2018).
Most Western countries banned the use of chemical weapons following the First World War, which incurred 90,000 deaths and 1 million injuries due to chemical weapons; however, the United States did not enter into
the agreement. The United States offcially ended its use, development,
and stockpiling of chemical weapons in 1997 when a treaty signed at the
Convention on the Prohibition of the Development, Production, Stockpiling and Use
of Chemical Weapons and on their Destruction came into full effect (U.N. Offce
for Disarmament Affairs, 2021). VX is a semivolatile (vapor pressure = 0.09
Pa) organophosphorus chemical similar in structure and mode of action to
organophosphate (OP) insecticides.
OP insecticides originated from compounds developed as nerve gases
during World War II. The nerve gas-inspired insecticides, such as tetraethyl pyrophosphate (TEPP) and parathion, have high mammalian toxicities
(LD 50 < 20 mg/kg). They act by inhibiting the enzyme acetylcholinesterase
(AChE) (shown in Figure 2.2) that breaks down the neurotransmitter acetylcholine (ACh) at the nerve synapse, blocking impulses and causing hyperactivity and tetanic paralysis of the insect, and fnally death. Most are not
persistent and do not bioaccumulate in animals or have signifcant long-term
environmental impacts.
FIGURE 2.2
Mode of action of OPs and also carbamates is inhibition of the nerve signal via the vital enzyme
AChE. (Adapted from Wiener and Hoffman, 2004.)
Pesticides, Organic Contaminants, and Pathogens in Air
characteristic of nerve gas: the sheep were dazed, heads tilted to one side,
and movements were uncoordinated (Boffey, 1968).
Nearby residents suspected the Dugway Proving Ground, a U.S. military
chemical and biological weapons research and testing facility, which was
only 27 miles away. The military’s role in the incident was confrmed a week
later when a report was released stating that a high-speed jet had malfunctioned during a test and sprayed 320 gallons of nerve gas Venomous Agent X
(VX) at a much higher altitude than expected (Boissoneault, 2018).
Most Western countries banned the use of chemical weapons following the First World War, which incurred 90,000 deaths and 1 million injuries due to chemical weapons; however, the United States did not enter into
the agreement. The United States offcially ended its use, development,
and stockpiling of chemical weapons in 1997 when a treaty signed at the
Convention on the Prohibition of the Development, Production, Stockpiling and Use
of Chemical Weapons and on their Destruction came into full effect (U.N. Offce
for Disarmament Affairs, 2021). VX is a semivolatile (vapor pressure = 0.09
Pa) organophosphorus chemical similar in structure and mode of action to
organophosphate (OP) insecticides.
OP insecticides originated from compounds developed as nerve gases
during World War II. The nerve gas-inspired insecticides, such as tetraethyl pyrophosphate (TEPP) and parathion, have high mammalian toxicities
(LD 50 < 20 mg/kg). They act by inhibiting the enzyme acetylcholinesterase
(AChE) (shown in Figure 2.2) that breaks down the neurotransmitter acetylcholine (ACh) at the nerve synapse, blocking impulses and causing hyperactivity and tetanic paralysis of the insect, and fnally death. Most are not
persistent and do not bioaccumulate in animals or have signifcant long-term
environmental impacts.
FIGURE 2.2
Mode of action of OPs and also carbamates is inhibition of the nerve signal via the vital enzyme
AChE. (Adapted from Wiener and Hoffman, 2004.)