Table 2.

Spearman correlation coefficients (r _s ) among ADHD scores and ADHD-related variables

N = 243	BLLs	BCLs	IA score a	HI score b	Total score c
Age	–0.118	0.066	–0.259**	–0.155*	–0.227**
Sex	–0.196**	0.021	–0.154*	–0.263**	–0.246**
Ferritin	–0.069	–0.055	–0.137*	–0.148*	–0.158*
BLLs	--	0.141*	0.246**	0.317**	0.309**
BCLs	0.141*	--	–0.030	0.024	0.015
Inattentive score	0.246**	–0.030	--	0.581**	0.883**
Hyperactive/Impulsive score	0.317**	0.024	0.581**	--	0.879**
Total score	0.309**	0.015	0.883**	0.879**	--
Father’s education level	–0.247**	–0.025	0.012	0.041	0.019
Mother’s education level	–0.206**	0.048	–0.114	–0.084	–0.115
Monthly household income	–0.182**	–0.019	–0.075	–0.034	–0.060
Father’s work relating to e-waste	0.202**	0.113	0.177**	0.106	0.145*
E-waste workshops around the house	0.147*	0.142*	0.232**	0.169**	0.219**
Household tobacco smoke exposure	0.138*	–0.102	0.090	0.069	0.081

*p < 0.05; **p < 0.01.

^aIA score: inattentive score.

^bHI score: hyperactive/impulsive score.

^cTotal score: sum of inattentive and hyperactive/impulsive scores.