Assessment of Hair Aluminum, Lead, and Mercury in a Sample of Autistic Egyptian Children: Environmental Risk Factors of Heavy Metals in Autism

Table 5

The relationship between risk factors and lead level among cases.

Variables	Lead level (mg/kg)		P
	Range	Mean ± SD
Age group
<6 years	0.005–17.130	2.98 ± 4.12	0.811
≥6 years	0.005–21.924	3.24 ± 4.52
Artificial feeding
Positive	0.313–17.130	2.69 ± 3.73	0.590
Negative	0.005–21.924	3.31 ± 4.56
Pica
Positive	0.005–21.924	3.48 ± 4.92	0.507
Negative	0.005–16.711	2.79 ± 3.68
Lead pipes
Positive	0.005–21.924	3.29 ± 4.44	0.175
Negative	0.005–2.557	1.04 ± 0.97
Nearby gasoline stations
Positive	0.739–16.711	7.29 ± 7.41	0.047
Negative	0.005–21.924	2.88 ± 4.02
Fish consumption per month
None	0.313–8.750	3.26 ± 2.73	0.802
Once per month	0.005–21.924	2.62 ± 4.82
2–4 times per month	0.005–17.130	3.49 ± 4.71
>4 times per month	0.744–4.396	2.02 ± 1.66

Mann-Whitney test, Kruskal-Wallis test.