Sooner or later final summer season, there have been simply too many studies of protesters who had skilled irregular menstrual cycles after being uncovered to tear gasoline for Britta Torgrimson-Ojerio, a nurse researcher on the Kaiser Permanente Heart for Well being Analysis in Portland, to dismiss them as coincidence.
A preschool instructor informed Oregon Public Broadasting that if she inhaled a big quantity of gasoline at night time, she’d get her interval the subsequent morning. Different Portland residents shared stories of intervals that lasted for weeks and of surprising recognizing. Transgender males described sudden intervals that defied hormones that had stored menstruation at bay for months or years.
Dr. Torgrimson-Ojerio determined she would strive to determine whether or not these anecdotes had been outliers or consultant of a extra widespread phenomenon. She surveyed round 2,200 adults who mentioned they’d been uncovered to tear gasoline in Portland final summer season. In a research revealed this week within the journal BMC Public Well being, she reported that 899 of them — greater than 54 {9408d2729c5b964773080eecb6473be8afcc4ab36ea87c4d1a5a2adbd81b758b} of the respondents who probably menstruate — mentioned they’d skilled irregular menstrual cycles.
“Regardless that we can not say something scientifically definitive about these chemical brokers and a causal relationship to menstrual irregularities,” Dr. Torgrimson-Ojerio mentioned, “we will definitively say that in our research most individuals who had menstrual cycles or a uterus reported menstrual irregularities after reporting publicity to tear gasoline.”
Downstream results, just like the impression on fertility, usually are not recognized, however “that is our name to motion to ask our scientific group to show their eye to this subject,” she mentioned.
Dr. Torgrimson-Ojerio was additionally enthusiastic about whether or not individuals had skilled different issues quite a lot of hours after being uncovered to tear gasoline. She discovered that 80 {9408d2729c5b964773080eecb6473be8afcc4ab36ea87c4d1a5a2adbd81b758b} of survey members had, with problem respiration being among the many most prevalent complaints.
Kira Taylor, a professor of epidemiology and inhabitants well being on the College of Louisville College of Public Well being and Data Sciences who’s conducting a similar study, said that Dr. Torgrimson-Ojerio’s study provided “some of the first solid evidence” that tear gas might be linked to menstrual abnormalities. It is also “the first study to document the longer-term effects of tear gas exposure in a large population,” she said.
Sven-Eric Jordt, a professor of anesthesiology, pharmacology and cancer biology at the Duke University School of Medicine, who was not involved in the study, applauded the work.
Most of the research that police agencies and the government rely on to inform them about tear gas safety “are outdated, often 50 to 70 years old, and don’t measure up to modern toxicological approaches,” he said. “Most of these studies were conducted in young healthy men at the time, either police or military, and not in women, or in a general civilian population representing protesters.”
Dr. Torgrimson-Ojerio and her colleagues recruited survey participants through social media and links on the websites of The Oregonian and the Oregon Health Authority in July and August.
The researchers asked participants to explain precisely how their periods had been affected after exposure to tear gas. Increased cramps, unusual spotting and uncharacteristically intense or long bleeding were the most common reactions. A number of people who don’t usually have periods because of hormone therapy or age reported unexpected bleeding and spotting, Dr. Torgrimson-Ojerio said.
This study has limitations. It is not a random sample.
“It is possible that people who feel that their health was damaged by tear gas might have been more likely to respond than people who were also exposed, yet did not feel such harmful effects,” Dr. Taylor said. “This means that some of the numbers might be exaggerated.”
Given that subjects were permitted to participate anonymously, researchers could not verify their accounts.
Nor can the study answer how or why tear gas might be contributing to menstrual irregularities or to what extent other factors are also involved. The authors acknowledge that the high levels of stress and anxiety among protesters, for example, could also have contributed to the physical response.
“It is possible that pain, stress, dehydration and exertion play a role,” Dr. Jordt said. Alternatively, tear gas may act as an “endocrine disrupter,” interfering with normal hormonal function.
“The tear gas agent CS, sometimes used by police, is a chlorinated chemical compound and produces additional chlorinated byproducts when burned in the canisters used by the police,” he said. “Exposure to chlorinated chemicals can affect menstrual health.”
Alexander Samuel, a molecular biologist in France, has been investigating similar questions since French protesters began reporting menstrual irregularities.
He mentioned two additional areas for exploration: whether tear gas is metabolized into cyanide, which may cause heavy menstrual bleeding, and the role a traumatic event may play in altering menstrual cycles.
Suspicions about tear gas and menstruation first came up more than a decade ago, during the Arab Spring protests, Dr. Jordt noted.
In 2011, Chile also banned the use of tear gas after a study suggested that CS gas could cause miscarriages and harm young children. Three days later, the Chilean police lifted the ban, insisting that the type of tear gas they used was perfectly safe.
