Table 1 Air pollutants and their effect on epilepsy

Farahmandfard et al. 2022, Iran [19]

Ecological Study

Total cases: 894

Men: 498

Women: 396

PM_2.5

RR (95% CI): 1.0017 (0.9977–1.0057). For a mean concentration of 27.46 µg/m3, no significant association with hospital admissions

PM₁₀

RR (95% CI): 1.0037 (1.0024–1.0050)

For a mean concentration of 71.11 µg/m3, a positive significant association with hospital admissions

NO₂

RR (95% CI): 1.0266 (1.0168–1.0364). A positive, significant association with admissions was found for a mean concentration of 15.82 ppb.

O₃

RR (95% CI): 0.9816 (0.9756–0.9877). For a mean concentration of 30.21ppb, there was no association with hospital admissions.

CO

RR (95% CI): 0.9008 (0.7906–1.0263). For a mean concentration of 1.07ppm, there was no significant association with hospital admissions.

SO₂

RR (95% CI): 0.9978 (0.9945–1.0011). For a mean concentration of 26.12 ppm, there is no significant association with admissions.

Chen Z et al. 2022, Australia [20]

Time-stratified case-crossover

Total cases: 49

Males: 22

Females: 27

PM₁₀

RR (95% CI): 1.00 (0.97, 1.03). For a median concentration of 15 µg/m3, there was no association with epileptic seizures.

NO₂

RR (95% CI): 1.04 (0.98, 1.10). For a median concentration of 6.78ppb, there is a positive but not significant association with epileptic seizures.

O₃

RR (95% CI): 0.99 (0.94, 1.05). For a median concentration of 14.74 ppb, there was no association with epileptic seizure.

CO

RR (95% CI): 1.04 (1.01, 1.07). For a median concentration of 0.15ppm, there was a positive significant association with epileptic seizures.

SO₂

RR (95% CI): 0.98 (0.95, 1.00). For a median concentration of 0.30ppb, there is no association with epileptic seizures.

Xu C et al., 2016, China [21]

Time series

Total cases: 20,368

Males: 12,041

Females: 8327

PM_2.5

95% CI: 0.20 (-0.23, 0.62). A 10 µg/m3 increase was associated with positive but insignificant outpatient visits of epilepsy patients.

PM₁₀

95% CI: 0.14 (-0.13, 0.41. A 10 µg/m3 increase was associated with positive but insignificant outpatient visits of epilepsy patients.

NO₂

95% CI: 3.17 (1.41, 4.93). 10 µg/m3 increase was associated with significantly positive outpatient visits of epilepsy patients.

O₃

95% CI: -0.84 (-1.58, -0.09). 10 µg/m3 increase was associated with significantly decreased outpatient visits of epilepsy patients.

CO

95% CI: 0.11 (-0.37, 0.59). A 0.1 mg/m3 increase was associated with positive but not significant outpatient visits.

SO₂

95% CI: 3.55 (1.93, 5.18). A 10 µg/m3 increase was associated with significantly positive outpatient visits.

Bao X et al. 2019, China [22]

Time-stratified case-crossover

Total cases: 51,523

Men: 30,908

Women: 20,615

PM_2.5

95% CI: 0.6 (-0.7,1.9). The increase in IQR (56.9 µg/m3) was positively but not significantly associated with hospitalization.

PM₁₀

95% CI: 0.1 (-1.3,1.5). IQR (77.5 µg/m3) increase was positively but not significantly associated with hospitalization

NO₂

95% CI: 2.0 (0.5,3.6). An IQR (25.9 µg/m3) increase was positively and significantly associated with hospitalization.

CO

95% CI): 1.1 (0.1,2.1). An IQR (0.5 µg/m3) increase was positively and significantly associated with hospitalization.

SO₂

95% CI: 0.8 (-0.5,2.1). An IQR (18.9 µg/m3) increase was positively but not significantly associated with hospitalization.

Cakmak S et al. 2010, Chile [23]

Time series

Total cases: 290,500

PM_2.5

RR (95% CI): 1.065 (1.002, 1.132). An IQR (32.48 µg/m3) increase in PM_2.5 was associated with increased hospitalizations.

PM₁₀

RR (95% CI): 1.083 (1.038, 1.13). An IQR (72.24 µg/m3) increase in PM₁₀ was associated with increased hospitalizations.

NO₂

RR (95% CI): 1.108 (1.021, 1.204). An IQR (44.74ppb) increase in NO₂ was associated with increased hospitalizations.

O₃

RR (95% CI): 1.100 (1.025, 1.181). An IQR (93.26ppb) increase in O₃ was associated with increased hospitalizations.

CO

RR (95% CI): 1.098 (1.045, 1.155). An IQR (1.11ppm) increase in CO was associated with increased hospitalizations.

SO₂

RR (95% CI): 1.085 (1.03, 1.144). An IQR (9.32ppb) increase in SO₂ was associated with increased hospitalizations.

Cheng J et al. 2022, China [24]

Time-stratified case-crossover

Total cases: 8181

Age: 0–18 years

Boys: 4860

Girls: 3321

PM_2.5

OR (95% CI); A: Warm season: 1.001 (0.979, 1.022); B: Cold season: 1.014 (1.002, 1.025). 10 µg/m3 increase was not significantly associated with increased hospitalization for either season

PM₁₀

OR (95% CI); A: Warm season: 0.996 (0.985, 1.008); B: Cold season: 1.014 (1.005, 1.022). 10 µg/m3 increase was not associated with increased hospitalization for the warm season but was a significant positive increase for the cold season.

NO₂

OR (95% CI); A: Warm season: 1.004 (0.968, 1.041); B: Cold season: 1.035 (1.011, 1.059). 10 µg/m3 increase was not significantly associated with increased hospitalization for either season

O₃

OR (95% CI); A: Warm season: 1.011 (0.997, 1.025); B: Cold season: 1.004 (0.981, 1.027). 10 µg/m3 increase was not significantly associated with increased hospitalization for either season

SO₂

OR (95% CI); A: Warm season: 1.006 (0.889, 1.138); B: Cold season: 1.046 (0.965, 1.134). 10 µg/m3 increase was not significantly associated with increased hospitalization for either season