Due to unfortunate circumstances, the reckless use of tear gas for crowd control has been employed with blatant disregard over the safety of anyone caught amongst the impending chaos. Though we at the Infant Risk Center sincerely wish that no pregnant woman ever gets exposed to tear gas, we intend to inform you of the risks and treatment available if the worse-case scenario presents itself.
Current tear gas methodology has lead to increased usage of ortho-chlorobenzylidene malononitrile (CS), which is 10 times more potent than chloroacetophenone (CN) at producing tears, but supposedly less toxic. There are many other different types of tear gases that were used in the past, but CS seems to be the tear gas of choice nowadays.
As the name implies, tear gas invokes rapid and debilitating effects by causing extreme eye irritation and lacrimation along with blepharospasms (eye-lid spasms). A burning sensation is very common and not limited to just the eyes. The nose, throat, skin, and respiratory tract are all subject to irritation and inflammation.
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Table 1. Clinical manifestations and potential complications (1,2,3)
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Area affected
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Clinical manifestations
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Potential complications
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Potential sequelae
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Eyes
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Tearing, burning sensation; blepharospasm; photophobia; corneal oedema (OC)
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Keratitis (CN); corneal erosion (OC); intraocular haemorrhage
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Cataract; glaucoma
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Respiratory tract
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Severe rhinorrhoea (CS); sneeze, cough, dyspnoea (CS); pharyngitis; tracheal bronchitis
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Bronchospasm, hypoxaemia (CN); delayed pulmonary oedema (CS)
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Reactive airways dysfunction syndrome; asthma (possibly)
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Cardiovascular system
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Hypertension (CS)
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Heart failure; cerebral haemorrhage
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Not described
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Skin
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Rash; oedema; erythema; blistering (CS)
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Irritant dermatitis (CN); facial oedema (CN); aggravation of dermatitis
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Allergic dermatitis (CN)
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Digestive tract*
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Buccal irritation, salivation (CS); odynodysphagia; abdominal pain; diarrhoea; nausea; vomiting (DM)
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Liver toxicity (CS)
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Not described
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Nervous system
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Trembling (DM)
Agitation, anxiety
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Hysterical reaction
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Not described
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As the name implies, tear gas invokes rapid and debilitating effects by causing extreme eye irritation and lacrimation along with blepharospasms (eye-lid spasms). A burning sensation is very common and not limited to just the eyes. The nose, throat, skin, and respiratory tract are all subject to irritation and inflammation.
The effects of CS tear gas showed no harm during pregnancy in several animal studies. (4,5) One study also mentioned that there were no teratogenic effects associated with exposure to CS during pregnancy, even when injected intraperitoneally. (4) However, there are no adequate and well-controlled studies done in humans. Thus, we have no way of knowing for sure what the hidden effects of CS tear gas during pregnancy may be. Caution is advised until further information is obtained. There has been report of increased risk of miscarriage and stillbirths due to direct exposure of CS gas during pregnancy in the war-torn Middle East; it is uncertain if these risks were caused directly by CS gas exposure or by other confounding variables in that particular area of turmoil. (6,7)
If exposed to tear gas, it is important to minimize contact and exposure time. Once safely out of reach, remove any contaminated clothing. Then, rinse eyes and skin with water thoroughly (10-15 minutes). It is important that the patient does not touch their face or rub their eyes; this will only make things worse. If irritation persists after considerable rinsing, seek medical attention immediately. (3)
References:
1. Olajos E, Salem H. Riot control agents: pharmacology, toxicology, biochemistry and chemistry. J Appl Toxicol 2001;21:355-91.
2. OMEGA Foundation. Crowd control technologies (an appraisal of technologies for political control). European Parliament. 2000. (www.europarl.europa.eu/stoa/publications/studies/19991401a_en.pdf)
3. Smith J, Greaves I. The use of chemical incapacitant sprays: a review. J Trauma 2002;52:595-600.
4. Upshall, DG. Effects of o-chlorobenzylidene malononitrile (CS) and the stress of aerosol inhalation upon rat and rabbit embryonic development
(1973) Toxicology and Applied Pharmacology, 24 (1), pp. 45-59.
5. Sam Shen. Riot-control agent attack. In: Ciottone GR, Anderson PD, Auf Der Heide E, Darling RG, Jacoby I, Noji E, Suner S, eds. Disaster Medicine. 3rd ed. Philadelphia, PA: Mosby/Elsevier; 2006:Chap 98, 593-595.
6. The Casualties of Conflict: Medical Care and Human Rights in the West Bank and Gaza Strip. Somerville, Mass: Physicians for Human Rights; 1988.
7. Report on the Status of Palestinian Children: Uprising in the Occupied Territories (9 Dec 1987-9 Dec 1988). East Jerusalem, Israel: Save the Children. In press.
