Mustard gas, also known as sulfur mustard, is a potent chemical warfare agent. Classified as a vesicant, it causes severe blistering on contact with skin and mucous membranes. Though notorious from World War I, sulfur mustard is an oily liquid, not a true gas. It can be dispersed as a mist or vapor, permeating clothing and affecting individuals through skin absorption or inhalation.
Cellular Mechanism of Damage
Sulfur mustard damages cells as a highly reactive alkylating agent. It forms cyclic sulfonium ions that modify biological molecules like DNA, RNA, and proteins, disrupting their function and replication. DNA disruption can cause strand breaks and cross-links, preventing cell division and initiating programmed cell death (apoptosis). Damaged DNA can also lead to inflammation and potentially cancer. Symptoms often appear hours to a day after contact, as cellular damage accumulates.
Acute Effects on Body Systems
Mustard gas exposure causes acute effects across various body systems. The skin develops redness, intense itching, and painful blisters resembling second or third-degree burns. These fluid-filled blisters appear hours to days after exposure, with liquid contact causing more severe burns than vapor.
The eyes are highly sensitive to vapor, showing irritation, pain, tearing, and light sensitivity. Conjunctivitis is common, and corneal damage can cause blurred vision or temporary blindness due to eyelid and corneal swelling.
Inhaled vapors irritate the nose, throat, and lungs, leading to coughing, hoarseness, and shortness of breath. Severe cases can progress to pulmonary edema, where fluid in the lungs may cause fatal respiratory failure.
Systemic absorption or ingestion affects the gastrointestinal system, causing nausea, vomiting, abdominal pain, and diarrhea. Higher doses can suppress bone marrow function, decreasing white blood cell counts and increasing infection susceptibility.
Long-Term Health Complications
Chronic health complications can develop years or decades after exposure. Persistent respiratory issues include chronic coughing, bronchitis, emphysema, and increased susceptibility to infections. Some individuals also develop lung fibrosis.
Ocular problems can become chronic, such as persistent conjunctivitis, recurrent corneal ulcers, and cataracts. These may lead to permanent vision impairment, though complete blindness is rare.
Skin issues include scarring, pigmentation changes, and chronic dermatitis. There is an increased risk of skin cancers like basal cell and squamous cell carcinoma in affected areas.
Mustard gas’s mutagenic properties elevate the risk of other cancers, including respiratory cancers (lung, larynx, pharynx) and leukemia. Chronic health problems can also lead to psychological effects like post-traumatic stress disorder, anxiety, and depression.
Emergency Response and Treatment
Immediate action is crucial after mustard gas exposure. Rapid decontamination is the first step: remove contaminated clothing and wash exposed skin thoroughly with soap and water. Eyes should be rinsed immediately and copiously with saline or clean water.
There is no specific antidote for mustard gas poisoning. Treatment is supportive, managing symptoms and preventing secondary complications.
Supportive care includes pain management, meticulous wound care, and respiratory support (oxygen, mechanical ventilation). Antibiotics may combat infections. Eye care involves lubricating drops and specialized treatments. Ongoing medical surveillance is necessary for chronic conditions.