Spatial variations in the incidence of breast cancer and potential risks associated with soil dioxin contamination in Midland, Saginaw, and Bay Counties, Michigan, USA

Table 3 Frequency distribution of the levels (ppt TEQ) for dioxins in soil classified by depth and location

Categories	Sample size	Mean	Min	Max	Stdev	25^th P	75^th P	Med
Depth (in inches)
0 – 3	307	500	0	15,300	1,440	15	442	83
3 – 6	112	350	0	2,790	590	5.56	525	56.3
6 – 15	102	355	0	5,660	799	3.14	356	44.3
15 – 24	3	576	6.9	1,620	909	6.9	1,620	97.5
24 – 36	3	56.9	13.9	133	65.9	13.9	133	23.9
36 – 48	3	24.1	1.12	64	34.6	1.12	64	7.34
48 – 60	2	6.77	1.42	12.1	7.57	1.42	12.1	6.77
Locations
Midland	53	1,140	0	15,300	3,040	69.6	111	727
Floodplain
1-year	191	564	0	5,660	725	62.1	923	308
2-year	80	364	0.17	3,140	632	30.4	438	99.3
5-year	29	39.8	0.18	294	74.2	5.63	32.5	16
10-year	32	34.6	0	244	62.2	3.53	41.2	7.17
50-year	44	206	0	5,070	792	2.23	34.1	8.74
100-year	43	481	0	6,450	1,130	1.1	531	26.4
500-year	15	13.7	0.23	69.7	20.1	3.45	11.6	4.5
Outside	35	13.9	0	76.8	20.3	1.8	22.4	4.55
Saginaw	10	96.3	0.73	450	136	9.81	142	50.4
Total	532

ISSN: 1476-069X