Participants
A total of 2,450 persons accessed the survey (Figure 1). Of those, 2,257 (92.1%) met qualifying criteria and were eligible for our analysis. Of the 2,257 persons, 1,998 (88.5%) fully completed the survey. The majority self-identified as females/cisgender women (1,151; 51.0% of 2,257), White/non-Hispanic (1,615; 71.6%), and aged 18–33 years (1,199; 53.1%) (Table 1). The vast majority reported being exposed to tear gas at a protest (2,099; 93.0%); of those, most reported two to four days of exposure (1,391; 62.7%). A small number were exposed to tear gas only at their homes or elsewhere 158 (7.0%). Twenty-eight respondents (1.2%) reported a recent positive COVID-19 test.
Table 1. Participants’ characteristics
Category
|
n
|
%
(N=2,257)
|
Age, years
|
|
|
18–33
|
1,199
|
53.1
|
34–50
|
706
|
31.3
|
≥51
|
122
|
5.4
|
Prefer Not to Answer
|
230
|
10.2
|
Gender Identity
|
|
|
Female/Cisgender Woman
|
1,151
|
51.0
|
Male/Cisgender Man
|
587
|
26.0
|
Genderqueer, not exclusively female or male
|
162
|
7.2
|
Transgender woman
|
20
|
0.9
|
Transgender man
|
33
|
1.5
|
My gender identity is not listed here
|
27
|
1.2
|
Prefer Not to Answer
|
277
|
12.3
|
Race/Ethnicity
|
|
|
White, non-Hispanic
|
1,615
|
71.6
|
All other race/ethnicity
|
377
|
16.7
|
Prefer not to answer
|
265
|
11.7
|
Race/Ethnicity (not mutually exclusive)*
|
|
|
White
|
1,831
|
81.1
|
Black
|
58
|
2.6
|
American Indian or Alaska Native
|
93
|
4.1
|
Asian/Pacific Islander
|
115
|
5.1
|
Hispanic
|
174
|
7.7
|
Prefer not to answer
|
265
|
11.7
|
Place of exposure to tear gas
|
|
|
At a protest
|
2,099
|
93.0
|
Other (i.e., homes, community)
|
158
|
7.0
|
Intensity of exposure in days overall
|
|
|
1
|
398
|
17.6
|
2 to 4
|
1,391
|
61.6
|
≥5
|
468
|
20.7
|
*Respondents may be counted in multiple race/ethnicity categories.
Post-exposure health effects
Overall, 2,116 (93.8%) respondents reported physical (2,114; 93.7%) and/or psychological (1,635; 72.4%) health issues following tear gas exposure. Besides menstrual health issues, physical health issues were reported by 2,105 (93.3%) persons immediately after the exposure, abating to 1,750 (77.5%) after 1–2 days (i.e., delayed health issues). Respondents more frequently reported eye, nose, mouth, skin, and/or lungs/chest issues immediately after the exposure vs. 1–2 days following (Table 2). A slightly higher proportion experienced delayed health issues related to head or gastrointestinal tract, compared with immediate complaints.
Table 2. Proportions of persons reporting health issues
Health issues categories
|
Number of persons expressing health issues†
|
Change from immediate to delayed issues
|
Either immediate or with a delay
|
Immediately
|
Delayed
|
n
|
%
|
n
|
%
|
n
|
%
|
n
|
%
|
Any physical or psychological health issues
|
2,116
|
93.8
|
2,105
|
93.3
|
1,944
|
86.1
|
-161
|
-7.6
|
Any physical health issues*
|
2,114
|
93.7
|
2,105
|
93.3
|
1,823
|
80.8
|
-282
|
-13.4‖
|
Eyes
|
2,001
|
88.7
|
1,995
|
88.4
|
594
|
26.3
|
-1,401
|
-70.2‖
|
Nose
|
1,802
|
79.8
|
1,790
|
79.3
|
437
|
19.4
|
-1,353
|
-75.6‖
|
Mouth
|
1,542
|
68.3
|
1,510
|
66.9
|
378
|
16.7
|
-1,132
|
-75.0‖
|
Lungs and/or Chest
|
1,674
|
74.2
|
1,569
|
69.5
|
1,063
|
47.1
|
-506
|
-32.2‖
|
Skin
|
1,312
|
58.1
|
1,238
|
54.9
|
495
|
21.9
|
-743
|
-60.0‖
|
Gastrointestinal
|
808
|
35.8
|
453
|
20.1
|
638
|
28.3
|
+185
|
+40.8‖
|
Head
|
920
|
40.8
|
610
|
27.0
|
626
|
27.7
|
+16
|
+2.6
|
Menstrual‡§
|
899
|
54.5
|
N/A
|
|
899
|
54.5
|
N/A
|
|
Psychological health issues
|
1,635
|
72.4
|
N/A
|
|
1,635
|
72.4
|
N/A
|
|
N/A – not applicable
* Total count for the delayed physical issues includes menstrual health/breast health
† Denominator was 2,257 for any health issues, except 1,650 for menstrual health
‡ Excludes cisgender men/males and transgender women
- For details for each menstrual/breast health change, see Figure 2 and Additional file
‖ p < 0.01 for the change
Immediate physical health issues
Almost all respondents (2,105; 93.3%) reported having eye, nose, lungs/chest, mouth, and/or skin-related issues immediately after the exposure (Table 2 and Additional file). Of 1,995 persons (88.4% of 2,257) reporting any eye issues, the largest group experienced eye burning (1,895; 95.0%), followed by excessive tearing (1,713; 85.9%), blurred vision (1,392; 69.8%), and eye redness (1,078; 54.0%). Many participants reported issues related to the upper and lower respiratory tract and mouth. Of 1,790 (79.3% of 2,257) individuals reporting any nose-related issues, most reported having a burning sensation (1,529; 85.4%) or runny nose (1,520; 84.9%). Of 1,569 persons (69.5%) with lung/chest issues, the largest group reported coughing (1,442; 91.9%), followed by shortness of breath (1,041; 66.3%), chest tightness (1,038; 66.2%), and choking sensation (872; 55.6%). Mouth issues were reported by 1,510 (66.9%) of respondents, most commonly irritation (1,157; 76.6%), burning (1074; 71.1%), or sore throat (1,064; 70.5%). Skin issues were reported by 1,238 respondents (54.9%), primarily burning sensation (1,189; 96.0%), rash (280; 22.6%), and burns (180; 14.5%).
Fewer individuals reported any gastrointestinal- and head-related issues immediately after the exposure (453; 20.1%). The most common gastrointestinal issues were nausea (371; 81.9% of 453) and gastrointestinal cramping (263; 58.1%). Of 610 persons reporting any head-related issues, respondents commonly cited headache (482; 79.0%), disorientation (407; 66.7%), and dizziness (356; 58.4%).
Delayed physical health issues
Most participants (1,823; 80.8%) reported delayed physical health issues after exposure (Table 2). The most commonly reported delayed issues were related to lungs and/or chest (1,063; 47.1%) and menstrual changes (899; 54.5% of 1,650 respondents who potentially menstruate), followed by gastrointestinal (638; 28.3%), head (626; 27.7%), and eye issues (594; 26.3%).
Delayed health issues differed in frequency when compared to those endorsed immediately after the exposure. Respondents less frequently reported eye, nose, mouth, skin, and/or lungs/chest issues days following exposure vs. immediately after the exposure (Additional file). For example, 1,713 persons reported experiencing excessive tearing immediately; that number was 163 one to two days later (90.5% decline). Similar declines were seen for mouth burning (91.0% decline), drooling (96.7% decline), blurred vision (88.8% decline), eye burning (82.8% decline) nose burning (87.3% decline), and choking sensation (86.4% decline). All changes were significantly significant (p < 0.01).
Although the frequency of most symptoms decreased within a few days, we observed a statistically significant increase in the frequency of composit gastrointestinal issues by 40.8% (453 [20.1%] reported immediate gastrointestinal issues vs. 638 [28.3%]) reported delayed issues; p < 0.01). The frequency of composit head-related issues have increased by 2.6% (from 610 [27.0%] endorsed to 626 [27.7%]); however, this increase was not statistically significut 2.6% (p = 0.59). The most common increased gastrointestinal issues were new cases of diarrhea, gastroinstentinal cramping, and issues in the “Other” category (all p < 0.01). An additional 200 persons reported diarrhea—a 137.9% increase compared with the day of exposure (p < 0.01). Gastrointestinal cramping was reported by an additional 161 persons—a 61.2% increase (p < 0.01). An additional 18.5% of respondents reported having headaches one or two days following the exposure (p < 0.01).
Of 1,650 persons identified as female/cisgender woman, transgender man, genderqueer (not exclusively female or male), and those who did not specify their sex or gender identity, more than half—899 (54.5%)—reported some menstrual health disruption or breast/chest tenderness. The most reported issues were increased menstrual cramping in 604 (36.6%), unusual spotting in 459 (27.8%), increased bleeding in 389 (23.6%), and more days of bleeding (312; 18.9%) (Figure 2). Respondents age 18–33 were most likely to report menstrual/breast changes (69.7%; 604 of 866). A majority of respondents age 34–50 years reported symptoms (59.2%; 271 of 458).
The frequency of any physical (except mouth-related) and/or psychological delayed health issues increased with a higher exposure to tear gas (p < 0.01) (Table 3). We also observed a positive dose-response trend for all menstrual/breast health issues (p < 0.01), except those in the “Other” category.
Table 3. Proportions of respondents reporting health changes by intensity of exposure
Delayed health issues categories
|
Participants reporting health issues
by intensity of exposure†
|
Test of trend
|
1 day of exposure
|
2–4 days of exposure
|
≥5 days of exposure
|
n
|
%*
|
n
|
%*
|
n
|
%*
|
p value
|
Z value
|
Any physical or psychological health issues
|
309
|
13.7
|
1,215
|
53.8
|
420
|
18.6
|
<0.01
|
-3.8
|
Any physical health issues*
|
290
|
12.9
|
1,126
|
49.9
|
407
|
18.0
|
<0.01
|
-4.7
|
Eye
|
91
|
4.0
|
356
|
11.8
|
147
|
6.5
|
<0.01
|
-3.0
|
Nose
|
62
|
2.8
|
257
|
11.4
|
118
|
5.2
|
<0.01
|
-3.8
|
Mouth
|
59
|
2.6
|
232
|
10.3
|
87
|
3.9
|
0.16
|
-1.4
|
Lungs and/or Chest
|
126
|
5.6
|
648
|
28.7
|
289
|
12.8
|
<0.01
|
-8.3
|
Skin
|
57
|
2.5
|
294
|
13.0
|
144
|
6.4
|
<0.01
|
-5.8
|
Gastrointestinal
|
77
|
3.4
|
358
|
15.9
|
203
|
9.0
|
<0.01
|
-8.5
|
Head
|
91
|
4.0
|
385
|
17.1
|
150
|
6.7
|
<0.01
|
-2.8
|
Menstrual‡
|
116
|
7.0
|
566
|
34.3
|
217
|
13.2
|
<0.01
|
-6.0
|
Psychological health issues
|
204
|
9.0
|
1,041
|
46.1
|
390
|
17.3
|
<0.01
|
-8.2
|
* Total count for the delayed physical issues includes menstrual health/breast health
† Denominator was 2,257 for any health issues, except 1,650 for menstrual health issues
‡ Excludes cisgender men/males and transgender women
Psychological health issues
Of 2,257 respondents, 1,635 (72.4%) reported increased anxiety, startle response, fear, fatigue, or sadness/depressive feelings after the exposure. These issues were more common among protesters (73.7%; 1,546 of 2,099) than those otherwise exposed (56.3%; 89 of 158). Respondents who self-identified as persons of Black, American Indian/Alaska Native, Native Hawaiian/Pacific Islander, Asian or Hispanic race and/or ethnicity compared to White/non-Hispanic were equally likely to report mental health issues (81.4%; 307 of 377 vs. 79.0%; 1,276 of 1,615; p = 0.29, negligible association Cramer’s V = 0.02).
Open-ended responses
Overall, open-ended responses align with observed quantitative results; however, these provide insights into the duration of health issues and their severity. Additional health issues identified were sleep disturbances (e.g., insomnia, nightmares), prolonged fatigue, appetite suppression, and smell and taste disturbances.
Of the 923 respondents who provided open-ended feedback, 71 commented on new headaches that were severe and lasted for weeks in some. Forty-one commented on being nauseous for days. Thirteen persons reported having diarrhea, with blood in some persons, ranging from one day to over a month. Overall, open-ended responses on menstrual health changes from 163 persons align with the quantitative data. Many respondents noted that after their exposures, their menstrual cycle started days or weeks earlier or later and lasted longer, compared to their typical cycle. Seventy-three persons commented on being exhausted and unable to carry out their regular work for up to 5 days; a few wrote that fatigue lasted up to two weeks.
Thirty-two persons indicated worsening of an existing health condition after being exposed to tear gas. Conditions and symptoms included allergies, asthma attacks that required multiple or sustained treatments or symptoms that were not resolved with treatment, flares of eczema, fibromyalgia, Hashimoto’s thyroiditis, rheumatoid arthritis, and herpes simplex virus. Sixteen persons reported injuries from projectiles (bruising, swelling, broken skin), two of which required staples or stitches.
Healthcare utilization
The majority (1,233; 54.6%) of respondents reported receiving or planning to seek medical or mental healthcare for their tear gas-related health issues.
Receiving formal medical care (i.e., care provided by a clinician) or informal medical help (i.e., care provided by a non-clinician or a person with unknown training) was reported immediately after the exposure by 41.8% (944 of 2,257) of respondents. Volunteer medics were the most commonly reported immediate providers of medical attention after exposure (504; 53.4% of 944 receiving immediate care). Forty-one percent (383 of 944) reported getting medical attention from a protester who identified as a medic, nurse, doctor, or other healthcare providers. A similar proportion of individuals (421; 44.6%) reported receiving medical help from a protester who did not self-identify as a trained health provider, and six (0.6%) respondents reported care at an onsite medical utility vehicle.
Six percent (136) reported receiving professional medical care with some delay after the exposure. Of those, 69 (50.7%) reported visiting a health provider in-person or via telehealth, 30 (22.0%) called an advice nurse, 20 (14.7%) visited urgent care, and 14 (10.3%) visited an emergency room. An additional 84 (3.7%) persons reported planning to seek professional medical care.
Overall, 373 respondents (16.5%) reported receiving mental healthcare following exposure to tear gas agents, and 249 (11.0%) planned to seek mental care. We observed that a slightly higher proportion of respondents exposed at a protest reported receiving mental healthcare than those who were exposed other ways (355 [16.9%] vs. 18 [11.4%]; p = 0.07, negligible association Cramer’s V = 0.04). Among respondents exposed other ways, persons of Black, American Indian or Alaska Native, Native Hawaiian or Pacific Islander, Asian, or Hispanic race and/or ethnicity were twice as likely to report receiving mental care as White/non-Hispanic respondents (6 [28.6%] vs. 12 [12.5%]; p = 0.09, weak association Cramer’s V = 0.18). This difference did not reach statistical significance.