Kunal Sindhu: Tear gas is banned in warfare—America should not use it on its own citizens

The use of tear gas by American law enforcement agents against largely peaceful protesters is irresponsible and unacceptable, says Kunal Sindhu

The murder of George Floyd by Derek Chauvin, a now ex-police officer in Minneapolis, Minnesota, on 25 May triggered a massive outpouring of anger in the United States. Within days, large protests erupted in hundreds of American cities against systemic racism and police brutality. While some early protests devolved into looting and rioting, the vast majority of protesters have been peaceful.

Unfortunately, many police officers have responded to these collective expressions of grief with overwhelming and unjustifiable force. In particular, law enforcement agents in cities across America have employed tear gas to disperse crowds. In perhaps the most infamous example, police used it on 1 June to clear peaceful protesters in Lafayette Square in advance of President Trump’s photo opportunity at St John’s Episcopal Church across from the White House.

Tear gas has a long and unfortunate history in the US. After it was first deployed on a massive scale as a chemical weapon during the first world war, tear gas grenades began to be used in the US by local police departments to quash domestic protests. Over the next century, tear gas was used against American civilians on numerous occasions, including during the Bonus Army march in 1932; the May Day protests against the Vietnam War in 1971; and the Occupy protests against economic inequality in 2011.

The use of tear gas in today’s protests is particularly regrettable. It is not harmless. According to the Centers for Disease Control and Prevention (CDC), “riot control agents (sometimes referred to as ‘tear gas’) are chemical compounds that temporarily make people unable to function by causing irritation to the eyes, mouth, throat, lungs, and skin.” While tear gas generally produces transient effects, a 2015 review noted that “more severe ocular injuries have been reported, including hyphema, uveitis, necrotising keratitis, coagulative necrosis, symblepharon, secondary glaucoma, cataracts and traumatic optic neuropathy and loss of sight.” As a result, the American Academy of Ophthalmology condemned its use by law enforcement on 4 June.

Additionally, the widespread use of tear gas by American police departments threatens to accelerate the spread of the novel coronavirus. The US accounts for more than a quarter of the confirmed cases and deaths from covid-19 worldwide. Even now, three months after the first lockdowns began, the number of daily confirmed cases in America has only plateaued. With Trump having chosen to prematurely declare victory over the virus, the prospect of a second wave of infections looms large.

Tear gas can exacerbate the pandemic in two ways. According to the CDC, SARS-CoV-2, the virus that causes covid-19, is primarily spread “between people who are in close contact” via “respiratory droplets produced when an infected person coughs, sneezes or talks.” The protests have already brought tens of thousands of individuals into close proximity with one another. By inciting violent coughing fits, tear gas promotes viral transmission, potentially putting protesters more at risk. 

Secondly, the use of tear gas may also increase an individual’s susceptibility to a subsequent respiratory illness. A 2014 study of 6723 US army recruits found that exposure to tear gas more than doubled their risk of developing an acute respiratory illness over the following three weeks. While it is not clear how these findings would apply to the novel coronavirus, they are worrying and worthy of consideration.

On 25 April 1997, the United States Senate approved the “Convention on the Prohibition of the Development, Production, Stockpiling, and Use of Chemical Weapons and on their Destruction,” also known as the Chemical Weapons Convention (CWC), by a vote of 74 to 26. The CWC, in addition to banning the development, acquisition, and use of chemical weapons, required participants “not to use riot control agents as a method of warfare.” In other words, as one of the 193 state parties subject to the treaty, the US committed to abstain from using tear gas on the battlefield. 

While the CWC did include an exemption for domestic law enforcement purposes, its ban on the use of tear gas as a weapon of war should give us pause. If the US has pledged not to use tear gas against enemy combatants, why are American police departments still using it against their own citizens?

Tear gas is hazardous to human health, risks accelerating the spread of SARS-Cov-2, and has been banned from warfare. Its use by American law enforcement agents against largely peaceful protesters is irresponsible and unacceptable. It must end.

Kunal Sindhu is a radiation oncology resident in New York City. Twitter @sindhu_kunal

Competing interests: I have read and understood BMJ policy on declaration of interests and declare the following interests: None.