Table 2.

Pearson Correlation Coefficient Matrix of Continuous Variables Significantly Correlated (P < 0.05) With (Logged) House-Dust Nicotine Concentration, Northern California Childhood Leukemia Study, 1999–2007

	Lognormal (House-Dust Nicotine Concentration)	Cigarette Consumptiona of Father 3 Months Before Conception	Cigarette Consumption of Mother 3 Months Before Conception	Cigarette Consumption of Mother While Pregnant	Cigarette Consumption of Mother After Birth	Household Cigarette Consumption at Dust Collection	Mother's Age	Father's Age	Mother's Education	Father's Education	Household Annual Income	Age of Residence	Breastfeeding Duration	Size of Sampling Area	Vacuum Use Frequency
	469	454	463	462	462	467	463	459	469	458	469	413	462	385	457
Lognormal (house-dust nicotine concentration)	1	0.37**	0.24**	0.17*	0.31**	0.29**	−0.26**	−0.16*	−0.27**	−0.28**	−0.24**	0.13*	−0.18**	−0.16*	0.15*
Cigarette consumption of father 3 months before conception		1	0.41**	0.20**	0.46**	0.29**	−0.14*	−0.05	−0.18*	−0.21**	−0.16*	0.00	−0.08	−0.05	0.12*
Cigarette consumption of mother 3 months before conception			1	0.75**	0.87**	0.30**	−0.13*	−0.04	−0.11*	−0.09*	−0.01	−0.04	−0.07	−0.02	0.04
Cigarette consumption of mother while pregnant				1	0.63**	0.26**	−0.09*	−0.08	−0.06	−0.03	0.00	−0.01	−0.06	0.03	−0.01
Cigarette consumption of mother after birth					1	0.38**	−0.15*	−0.07	−0.14*	−0.12*	−0.04	−0.04	−0.10*	−0.08	0.08
Household cigarette consumption at dust collection						1	−0.12*	−0.03	−0.16*	−0.15*	−0.14*	0.04	−0.07	−0.03	0.09
Mother's age							1	0.75**	0.42**	0.39**	0.37**	0.11*	0.24**	0.11*	−0.26**
Father's age								1	0.36**	0.34**	0.32**	0.09	0.20**	0.05	−0.23**
Mother's education									1	0.69**	0.60**	0.06	0.17*	0.06	−0.35**
Father's education										1	0.59**	0.03	0.23**	0.09	−0.37**
Household annual income											1	−0.05	0.11*	0.13*	−0.33**
Age of residence												1	0.10*	−0.14*	−0.04
Breastfeeding duration													1	0.00	−0.21**
Size of sampling area														1	0.09
Vacuum use frequency															1

* P < 0.05; **P < 0.0001.

^aCigarettes smoked per day.