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

Table 1

Statistical comparison between characteristics and risk factors of patients and controls.

Variables	Group
	Cases		Controls
		%		%
Gender
Male	84	84.0%	74	74.0%	0.083
Female	16	16.0%	26	26.0%
Age group
<6 years	45	45.0%	44	44.0%	0.887
≥6 years	55	55.0%	56	56.0%
Age
Mean ± SD	6.24	2.43	6.80	3.04	0.152^‡
Dental amalgam during pregnancy
Positive	34	34.0%	15	15.0%	0.002
Negative	66	66.0%	85	85.0%
House age
>30 years	43	43.0%	1	1.0%	0.001
<30 years	57	57.0%	99	99.0%
Aluminum pans
Positive	90	90.0%	75	75.0%	0.005
Negative	10	10.0%	25	25.0%
Vaccination
Yes	99	99.0%	100	100.0%	1.00
No	1	1.0%	0	0.0%
Rho(D) immune globulin
Positive	25	25.0%	5	5%	0.001
Negative	75	75.0%	95	95%
Fish consumption per month
None	0	0.0%	11	15.7%	0.0001
Once	19	27.1%	19	27.1%
2–4 times	51	72.9%	36	51.4%
>4 times	0	0.0%	4	5.7%
Nearby gasoline stations
Positive	4	5.7%	2	2.9%	0.681
Negative	66	94.3%	68	97.1%
Smoking
Positive	32	32%	10	10%	0.0001
Negative	68	68	90	90%

Chi-square test, Fisher’s exact test, and ^‡Student’s -test.