Tear gas may cause a sudden onset of menstruation, as well as other hormonal side effects, according to the findings of new research.
While most people report health effects after tear gas exposure, often involving long-term respiratory problems, a new study warns that more than half of women who were tear gassed last year during Black Lives Matter protests reported abnormal menstrual cycles, researchers from Kaiser Permanente found. The findings were published last week in the journal BMC Public Health.
In 2019, following a slew of high-profile police brutality incidents, social activists took to the streets for widespread protests, rallying against the murders of Black men like George Floyd and Eric Garner at the hands of police.
During and after the protests, many protestors reported experiencing abnormal menstrual cycles associated with tear gas exposure. Similar reports followed other large-scale global protests, such as the Arab Spring, a series of protests against dictatorships in the Middle East, and recent protests held in Chile.
In this latest study, Kaiser Permanente researchers conducted a cross-sectional, self-administered web-based survey of 2,200 adults reporting recent exposure to tear gas in Portland, Oregon, from July 30, 2020, to August 20, 2020.
According to the findings, nearly 94% of protestors who were tear gassed reported physical issues immediately after. Roughly 93% reported psychological changes and 72% reported health issues experienced immediately after or within days of tear gas exposure.
More than half of all protestors capable of menstruating said they experienced abnormal cycles, with some reporting periods which lasted for weeks. Transgender men reported sudden periods despite being on hormones which had stopped their menstruation for months to years.
Protestors report experiencing other side effects as well. About 80% said they had difficulty breathing and 55% said they received or planned to seek medical care or mental care. A large number of protesters also experienced delayed head or gastrointestinal tract issues.
Most research on tear gas is largely considered outdated. The studies are roughly 50 to 70 years old, and most were conducted on young healthy men, the military, and not in women or the general population.
While the new study indicates a link between exposure and changes to hormones and menstruation, the study cannot definitively conclude the chemicals caused menstrual irregularities. However, most people who had menstrual cycles or a uterus reported menstrual irregularities after exposure to tear gas.
It is also possible the high-stress and high-anxiety environment of a protest may contribute to a physical response. Researchers speculate tear gas may act as an endocrine disruptor interfering with normal hormonal function. Other research is being conducted on whether tear gas is metabolized into cyanide.
“Health issues reported increased with the frequency of reported exposure, indicating a potential dose-response; these health effects often led to healthcare utilization,” the researchers concluded. “This study provides evidence of potential unexpected harms of tear gas in civilians.”