What happened after US police teargassed protesters – a visual investigation

The model is the first of its kind to calculate the chemical concentrations in the air and deposits on the ground during a major teargas event in the US. It builds on existing reports and litigation alleging the months-long teargas use during the summer of protests caused severe injuries, long-term health problems, menstrual irregularities and environmental hazards.

The research renews pressure on the scandal-ridden police department and raises significant public health and civil rights concerns at a time when law enforcement agencies in the US and across the globe are escalating their use of teargas on crowds, including against protesters for abortion rights and police accountability.