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Table 2 Associations between wastewater impacted public drinking water and breast cancer.

From: Breast cancer risk and drinking water contaminated by wastewater: a case control study

 

Cases

Controls

Adjusted OR (95% CI)a

Adjusted OR (95% CI)b

Average annual excess nitrate-N concentration (mg/L)

0 to < .3

327

287

1.0 (reference)

1.0 (reference)

.3 to < .6

201

175

1.0 (0.7 – 1.3)

0.9 (0.7 – 1.3)

.6 to < .9

155

152

0.9 (0.6 – 1.2)

0.8 (0.6 – 1.1)

.9 to < 1.2

120

112

0.9 (0.6 – 1.2)

0.9 (0.6 – 1.2)

≥ 1.2

21

19

0.9 (0.5 – 1.7)

1.0 (0.5 – 1.9)

Sum of annual excess nitrate-N concentrations (mg/L)

0 to < .01

19

18

0.8 (0.4 – 1.6)

0.9 (0.5 – 1.9)

.01 to < .1

45

42

0.9 (0.6 – 1.5)

1.1 (0.7 – 1.7)

.1 to < 1

119

118

0.9 (0.7 – 1.2)

1.1 (0.8 – 1.5)

1 to < 10

474

418

1.0 (reference)

1.0 (reference)

≥ 10

167

149

1.0 (0.8 – 1.3)

0.9 (0.7 – 1.2)

Number of years exposed to excess nitrate-N > 1 mg/L

0

562

504

1.0 (reference)

1.0 (reference)

< 2

58

52

1.0 (0.7 – 1.5)

1.1 (0.7 – 1.6)

2 to < 4

93

77

1.0 (0.7 – 1.4)

1.0 (0.7 – 1.4)

4 to < 6

36

44

0.8 (0.5 – 1.2)

0.7 (0.5 – 1.2)

6 to < 8

50

43

1.0 (0.6 – 1.5)

0.9 (0.6 – 1.4)

≥ 8

25

25

0.9 (0.5 – 1.7)

0.9 (0.5 – 1.5)

OR odds ratio.

CI confidence interval.

   
  1. a Adjusted for diagnosis/reference year, age at diagnosis/reference year, birth decade, study, vital status, previous breast cancer diagnosis, age at first birth, family history of breast cancer, and education.
  2. b Adjusted for variables in analysis (a), years on Cape Cod and years on the Cape squared.