"Scientists know little about how CS affects the general public. The most comprehensive studies were conducted by the U.S. military on thousands of recruits who were exposed to tear gas during training exercises. Afterward, it left them at higher risk for contracting influenza, pneumonia, bronchitis and other respiratory illnesses.
"The soldiers were generally healthier than the average person, with fewer underlying conditions like asthma or heart disease. Studies of civilians in Turkey found that people who are repeatedly exposed to tear gas are more likely to have chronic bronchitis or chest pains and coughing that can last for weeks. It may also be linked to miscarriages."
-- Lisa Song, "Tear gas is way more dangerous than police let on", 2020-06-04