Overview
- People who menstruate across multiple cities say they experienced early or heavy periods, severe pelvic pain, spotting and some miscarriages after inhaling police tear gas, with many accounts tied to the October 17 protests.
- The grassroots group Lacrymos de sang collected over 10,000 testimonies in about three weeks and is pressing for an immediate study and suspension of tear‑gas use on the precautionary principle.
- Medical toxicologists say tear gas clearly causes respiratory harm but that no peer‑reviewed epidemiological or toxicological study has yet proven a causal link between single exposures and menstrual or hormonal disruption.
- Official tear‑gas formulations commonly list CS (chlorobenzylidene malononitrile) plus irritants such as capsaicin, and a 2020 toxicology report warned CS can partly break down to cyanide or thiocyanate after heavy or repeated exposure, which could theoretically affect endocrine organs like the thyroid.
- The rapid rise in testimony has put pressure on public authorities to open scientific investigations, and health professionals warn that robust studies must quantify exposure, control for stress and other factors, and test biological mechanisms before causal claims can be confirmed.