Table 3 Crude Odds ratio (OR) between independent variables and breast cancer stages.

Education level (Ref: Academic)

 Diploma

1.28 (0.64–2.56)

1.37 (0.72–2.62)

1.35 (0.71–2.58)

0.67 (0.27–1.68)

0.80 (0.34–1.89)

0.62 (0.24–1.57)

 Under diploma

0.26 (0.10–0.63)*

0.66 (0.34–1.31)

0.58 (0.29–1.16)

0.61 (0.24–1.54)

0.94 (0.39–2.21)

1.50 (0.62–3.66)

Marital status (Ref = single)

 Married

1.21 (0.49–2.93)

1.74 (0.75–4.06)

1.57 (0.69–3.59)

†

†

†

 Divorced/ Widowed

1.15 (0.16–8.27)

2.81 (0.50–15.77)

1.39 (0.23–8.51)

†

†

†

Smoking status (Ref = No)

 Yes

0.25 (0.04–1.42)

0.69 (0.20–2.36)

0.64 (0.18–2.35)

0.70 (0.16–3.01)

0.81 (0.22–3.01)

1.10 (0.29–4.21)

 Secondhand smoke

1.00 (0.32–3.10)

0.68 (0.22–2.06)

1.29 (0.46–3.62)

2.46 (0.29–20.95)

2.25 (0.28–17.96)

4.98 (0.63–39.06)

Diabetes (Ref = No)

 Yes

1.34 (0.14–14.04)

2.45 (0.30–20.03)

1.01 (0.11–9.42)

1.67 (0.18–15.42)

4.13 (0.52–32.93)

7.21 (0.90–57.71)

Family history of BC(Ref = No)

 Yes

1.76 (0.85–3.65)*

1.09 (0.55–2.17)

1.02 (0.51–2.05)

0.69 (0.30–1.56)

0.59 (0.28–1.28)

0.85 (0.39–1.85)

Age at first menstruation, year (Ref =  ≤ 12)

 > 12

1.13 (0.62–2.06)

1.52 (0.89–2.56)

1.36 (0.81–2.30)

1.16 (0.58–2.34)

1.19 (0.63–2.27)

1.03 (0.53–2.02)

Age at first pregnancy, year (Ref: < 30)

 ≥ 30

1 (0.27–3.71)

0.62 (0.17–2.19)

0.78 (0.22–2.69)

0.76 (0.18–3.21)

1.70 (0.48–5.99)

1.79 (0.49–6.52)

Number of pregnancies (Ref: No)

 1 and 2

2.58 (1.29–5.13)*

2.92 (1.58–5.39)*

2.12 (1.17–3.83)*

5.46 (1.90–15.71)*

4.07 (1.48–11.19)*

1.10 (0.36–3.32)

 ≥ 3

2 (1.04–3.86)*

2.21 (1.24–3.96)*

1.27 (0.72–2.25)

2.29 (1.02–5.13)*

3.65 (1.76–7.56)*

2.42 (1.18–4.96)*

Number of deliveries (Ref: No)

 1 and 2

2.59 (1.37–4.87)*

2.58 (1.47–4.51)*

1.89 (1.10–3.26)*

4.13 (1.68–10.11)*

3.77 (1.63–8.71)*

1.31 (0.54–3.16)

 ≥ 3

1.96 (0.94–4.07)

1.99 (1.05–3.80)*

1.12 (0.58–2.14)

2.23 (0.97–5.13)

3.65 (1.73–7.72)*

2.79 (1.33–5.88)*

Estrogen/Progesterone receptor status (ERPR status) (Ref: ER−PR-)

 ER + PR + 

1.02 (0.34–3.02)

0.78 (0.27–2.25)

0.73 (0.25–2.09)

†

†

†

 ER + PR-

0.56 (0.08–3.82)

0.68 (0.12–3.89)

1.06 (0.19–5.95)

†

†

†

 ER−PR + 

0.91 (0.08–9.98)

0.31 (0.03–3.59)

0.64 (0.06–6.42)

†

†

†

Number of metastatic lymph nodes (Ref: No)

 < 5

2 (0.11–35.81)

19.33 (2.30–160.2)*

0.68 (0.11–4.19)

0.49 (0.03–8.07)

†

†

 ≥ 5

2.34 (0.21–26.17)

0.81 (0.13–4.97)

0.01 (0.00–0.05)*

†

†

†

Air pollution

 PM₁₀ (μg/m³)**

1.04 (0.97–1.12)

1.01 (0.94–1.07)

1.03 (0.96–1.09)

.98 (0.89–1.07)

1.00 (0.92–1.08)

1.01 (0.93–1.10)

 SO₂ (ppb)

0.99 (0.92–1.06)

1.00 (0.94–1.07)

0.98 (0.93–1.05)

0.93 (0.86–1.02)

0.97 (0.90–1.05)

0.91 (0.84–0.99)*

 NO₂ (ppb)

1.08 (0.97–1.21)

1.03 (0.93–1.14)

1.02 (0.93–1.14)

0.98 (0.85–1.13)

0.97 (0.85–1.11)

0.95 (0.83–1.09)

 NO (ppb)

1.06 (1.01–1.12)*

1.04 (0.99–1.09)

1.03 (0.98–1.08)

0.96 (0.89–1.08)

1.00 (0.94–1.07)

1.01 (0.94–1.07)

 NO_X (ppb)

1.02 (0.99–1.05)

1.00 (0.98–1.03)

0.99 (0.97–1.02)

0.98 (0.95–1.02)

0.99 (0.97–1.02)

0.98 (0.96–1.02)

 Benzene (μg/m³)

3.78 (1.22–11.78)*

2.04 (0.72–5.80)

0.97 (0.33–2.82)

0.69 (0.19–2.52)

1.27 (0.40–4.05)

1.43 (0.44–4.71)

 Toluene (μg/m³)

1.54 (1.05–2.24)*

1.25 (0.88–1.76)

1.13 (0.80–1.59)

0.88 (0.56–1.39)

1.16 (0.77–1.74)

1.22 (0.81–1.58)

 Ethylbenzene (μg/m³)

9.98 (1.85–58.82)*

3.18 (0.67–15.03)

1.57 (0.33–7.51)

0.48 (0.07–3.21)

1.41 (0.26–7.62)

2.08 (0.36–11.75)

 P-xylene(μg/m³)

6.61 (0.89–48.55)

2.14 (0.34–13.44)

1.36 (0.22–8.63)

0.44 (0.05–3.53)

1.93 (0.35–10.75)

1.79 (0.31–10.49)

 O-xylene(μg/m³)

4.21 (0.94–18.89)

1.63 (0.41–6.55)

1.31 (0.33–5.27)

0.63 (0.09–4.19)

1.44 (0.26–7.99)

2.77 (0.48–16.16)

 m-xylene(μg/m³)

2.55 (1.15–5.67)*

1.52 (0.72–3.19)

1.09 (0.52–2.31)

0.83 (0.33–2.04)

1.28 (0.57–2.90)

1.29 (0.56–2.99)

 TBTEX (μg/m³)

1.24 (1.05–1.46)*

1.09 (0.94–1.27)

1.07 (0.92–1.24)

0.95 (0.79–1.13)

1.06 (0.92–1.23)

1.04 (0.89–1.22)

Multipollutant level (Ref: Quartile 1-low)

 Quartile 2

0.77 (0.37–1.63)

0.81 (0.43–1.53)

1.02 (0.54–1.92)

1.02 (0.42–2.05)

0.92 (0.41–2.05)

0.98 (0.42–2.27)

 Quartile 3

1.03 (0.49–2.15)

0.78 (0.40–1.48)

0.95 (0.49–1.81)

1.48 (0.58–3.78)

1.51 (0.63–3.57)

1.82 (0.75–4.44)

 Quartile 4-high

2.75 (1.18–6.39)*

2.29 (1.06–4.95) *

2.07 (0.95–4.52)

1.05 (0.43–2.57)

0.90 (0.39–2.05)

0.99 (0.42–2.34)

Highway proximity (Ref: > 800 m)

 < 400 m

1.03 (0.51–2.08)

1.27 (0.67–2.41)

0.78 (0.41–1.47)

0.94 (0.39–2.24)

1.08 (0.49–2.38)

1.68 (0.74–3.82)

 400–800 m

0.81 (0.41–1.58)

1.14 (0.62–2.09)

0.86 (0.47–1.55)

1.12 (0.51–2.49)

0.88 (0.42–1.83)

1.26 (0.52–2.45)