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

Table 5 Associations between land use in recharge areas for homogenous drinking water supplies and breast cancer.

Fraction of Recharge Area in Specified Land Use	Cases	Controls	Adjusted OR (95% CI)^a	Adjusted OR (95% CI)^b
Residential
0 to < .5	201	211	1.0 (reference)	1.0 (reference)
.5 to < 1	234	184	1.4 (1.0–1.9)	1.1 (0.8–1.6)
1 to < 1.5	139	122	1.2 (0.8–1.6)	0.9 (0.6–1.3)
1.5 to < 2	99	90	1.2 (0.8–1.7)	0.9 (0.6–1.4)
≥ 2	9	16	0.7 (0.3–1.6)	0.5 (0.2–1.2)
Commercial
0 to < .5	587	533	1.0 (reference)	1.0 (reference)
.5 to < 1	49	54	0.9 (0.6–1.4)	0.8 (0.5–1.3)
1 to < 1.5	12	8	1.6 (0.6–4.1)	1.7 (0.7–4.4)
1.5 to < 2	10	7	1.4 (0.5–3.9)	1.4 (0.5–3.7)
2 to < 2.5	7	3	2.6 (0.6–10.3)	2.3 (0.6–9.3)
2.5 to < 3	17	18	1.0 (0.5–2.0)	0.9 (0.4–1.8)
Pesticide application area
0 to < .5	234	243	1.0 (reference)	1.0 (reference)
.5 to < 1	178	140	1.3 (1.0–1.8)	1.2 (0.8–1.6)
1 to < 1.5	229	203	1.2 (0.9–1.6)	0.9 (0.7–1.4)
≥ 1.5	41	37	1.2 (0.7–2.0)	0.9 (0.5–1.6)
Total^c
0 to < .5	70	93	1.0 (reference)	1.0 (reference)
.5 to < 1	87	72	1.7 (1.1–2.6)	1.5 (0.9–2.4)
1 to < 1.5	69	64	1.5 (0.9–2.4)	1.3 (0.7–2.2)
1.5 to < 2	90	81	1.6 (1.0–2.6)	1.3 (0.7–2.3)
2 to < 2.5	187	149	1.9 (1.3–2.8)	1.4 (0.8–2.6)
2.5 to < 3	46	40	1.5 (0.9–2.6)	1.2 (0.6–2.3)
3 to < 3.5	98	87	1.7 (1.1–2.6)	1.2 (0.6–2.4)
≥ 3.5	35	37	1.4 (0.8–2.5)	1.0 (0.5–2.2)

^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.
^c Residential plus pesticide use area plus commercial.

ISSN: 1476-069X