Table 3. Odds ratios (OR) with lower limit of one-sided 95% confidence interval (CI) for leukemias and assignment to the category of "Krümmel cases," by period^*1.

	< 5 years				< 15 years
Period*1	OR*3	OR*3 without the 30 cases from the Krümmel area	KiKK study patients from the whole Krümmel area*4	KiKK study patients from the Krümmel 5-km zone*5	Cases forming the known "Krümmel cluster"*5
1980–1990	3.00*2 (1.54)	2.78*2 (1.42)	9	1	4
1991–1995	2.10*2 (1.04)	1.79 (0.76)	9	4	5
1996–2003	1.78 (0.99)	1.52 (0.81)	12	3	5
1980–2003	2.19*2 (1.51)	1.96*2 (1.31)	30	8	14

^*1 Analogous to the study periods of the three NPP studies carried out with data from the German Childhood Cancer Registry

^*2 Significant at 5% level, one-sided

^*3 Residential address within 5 km or over 5 km (in parentheses, lower limit of CI)

^*4 "Kruemmel cases" from the "KiKK administrative districts" (Duchy of Lauenburg, Harburg, and Lueneburg)

^*5 From the communities of Geesthacht and Elbmarsch