Table 8a The Estimated Risk of Childhood Leukemia Associated with Blood Levels of Persistent Pesticide Levels (ng/g lipid) HYPERLINK \l "note1" * for Cases Compared with Controls Living in Churchill County

Persistent Pesticide Odds Ratio HYPERLINK \l "note3" ‡P-Value HYPERLINK \l "note4" §

Odds Ratio

P-Value

DDE, p,p,-

0.53

0.26

0.79

0.25

Hexachlorobenzene

0.70

0.06

1.35

0.52

TransnonachlorNC HYPERLINK \l "note5" ║

NC

1.40

0.41

Hexachloro-cyclohexane, beta

NC

NC

1.27

0.32

Oxychlordane

NC

NC

1.24

0.40

* Nanogram per gram lipid

† Family members include parents/guardians only.

‡ The odds ratio is the estimated relative risk of leukemia associated with one standard error of the geometric mean increase in the blood or urine level of each chemical. Odds ratios are not reported if fewer than 60% of cases and controls had detectable levels of the chemical in their blood or urine.

§ The P-value estimates the probability that the deviation of the odds ratio from 1.0 (no difference in risk) is due to chance. A P-value less than 0.05 suggests that chance is unlikely to explain the deviation.

║ Not calculated. Less than 60% of the study population had detectable levels of this chemical.

Persistent pesticides that were analyzed in the Churchill County investigation but that were detected in fewer than 60% of the participants were:

DDT, o,p,- Mirex

DDT, p,p,- Heptachlor epoxide

Dieldrin Hexachloro-cyclohexane, gamma