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

Table 4 Associations between land use in recharge areas for drinking water wells 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	252	262	1.0 (reference)	1.0 (reference)
.5 to < 1	243	195	1.3 (1.0–1.7)	1.1 (0.8–1.5)
1 to < 1.5	157	136	1.2 (0.9–1.6)	0.9 (0.7–1.3)
1.5 to < 2	125	106	1.3 (0.9–1.7)	1.0 (0.7–1.4)
≥ 2	47	46	1.1 (0.7–1.7)	0.8 (0.5–1.4)
Commercial
0 to < .5	671	611	1.0 (reference)	1.0 (reference)
.5 to < 1	58	61	0.9 (0.6–1.4)	0.8 (0.6–1.3)
1 to < 1.5	17	16	1.1 (0.5–2.2)	1.2 (0.6–2.4)
1.5 to < 2	19	11	1.7 (0.8–3.7)	1.7 (0.8–3.6)
2 to < 2.5	10	5	2.1 (0.7–6.4)	2.0 (0.7–6.2)
2.5 to < 3	25	22	1.2 (0.7–2.2)	1.1 (0.6–2.0)
≥ 3	24	19	1.2 (0.6–2.2)	1.0 (0.5–1.9)
Pesticide application area
0 to < .5	303	309	1.0 (reference)	1.0 (reference)
.5 to < 1	240	187	1.3 (1.0–1.7)	1.1 (0.8–1.5)
1 to < 1.5	238	211	1.2 (0.9–1.6)	0.9 (0.7–1.3)
≥ 1.5	43	38	1.2 (0.8–2.0)	1.0 (0.6–1.6)
Total^c
0 to < .5	86	112	1.0 (reference)	1.0 (reference)
.5 to < 1	120	101	1.6 (1.1–2.4)	1.4 (0.9–2.2)
1 to < 1.5	75	72	1.4 (0.9–2.2)	1.2 (0.8–2.0)
1.5 to < 2	95	84	1.6 (1.0–2.4)	1.3 (0.8–2.2)
2 to < 2.5	196	155	1.8 (1.2–2.6)	1.4 (0.8–2.4)
2.5 to < 3	51	48	1.4 (0.9–2.4)	1.1 (0.6–2.1)
3 to < 3.5	109	97	1.6 (1.1–2.4)	1.2 (0.7–2.2)
≥ 3.5	92	76	1.7 (1.1–2.7)	1.4 (0.8–2.4)

^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