Table 3

Associations between wastewater impacted public drinking water in homogenous supplies and breast cancer.


Cases
Controls
Adjusted OR (95% CI)a
Adjusted OR (95% CI)b

Average annual excess nitrate-N concentration (mg/L)
0 to < .3
280
250
1.0 (referent)
1.0 (referent)
.3 to < .6
163
141
1.0 (0.7 – 1.3)
1.0 (0.7 – 1.3)
.6 to < .9
149
144
0.9 (0.6 – 1.2)
0.9 (0.6 – 1.2)
.9 to < 1.2
78
79
0.8 (0.5 – 1.2)
0.8 (0.5 – 1.2)
≥ 1.2
12
9
1.2 (0.5 – 2.9)
1.2 (0.5 – 3.1)
Sum of annual excess nitrate-N concentrations (mg/L)
0 to < .01
18
17
0.8 (0.4 – 1.6)
0.9 (0.4 – 1.9)
.01 to < .1
43
41
0.9 (0.5 – 1.4)
1.0 (0.6 – 1.7)
.1 to < 1
104
104
0.9 (0.6 – 1.2)
1.1 (0.8 – 1.5)
1 to < 10
390
344
1.0 (referent)
1.0 (referent)
≥ 10
127
117
1.0 (0.7 – 1.3)
0.9 (0.6 – 1.2)
Number of years exposed to excess nitrate-N > 1 mg/L
0
479
433
1.0 (referent)
1.0 (referent)
< 2
50
47
0.9 (0.6 – 1.4)
1.0 (0.6 – 1.5)
2 to < 4
87
69
1.1 (0.7 – 1.6)
1.0 (0.7 – 1.5)
4 to < 6
66
74
0.8 (0.5 – 1.2)
0.7 (0.5 – 1.1)

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.

b Adjusted for variables in analysis [a] and years on Cape Cod and years on the Cape squared.

Brody et al. Environmental Health: A Global Access Science Source 2006 5:28   doi:10.1186/1476-069X-5-28