Objectives:To study heavy metals status in children with autism spectrum disorder

Study design: Cross-sectional study, done during July 2015 to June 2016. Children with autism between 3-10 years of age, fulfilling the DSM V criteria were recruited. Control group included age and sex-matched children from the same environment. Whole blood and hair were analyzed for heavy metals using ICP-MS.

Results: 72 children with autism,34 siblings and 72 controls were enrolled in the study. Autism group had significant exposure history of PICA(p=0.001), batteries(p=0.001) and scented body products(p=0.001) when compared to controls. They had higher blood levels of lead(0.001), mercury(p=0.001), arsenic(p=0.024), manganese(p=0.001) and cobalt(p=0.001), higher hair levels of lead(p=0.045), mercury(p=0.034) and arsenic(p=0.046) and lower hair levels of copper(p=0.019) and selenium(p=0.016) as compared to  controls. Children with autism showed significantly elevated blood levels of lead(p=0.001), mercury(p=0.023), manganese(p=0.002) and cobalt(p=0.001); elevated hair levels of nickel(p=0.013), cadmium(p=0.045) and cobalt(p=0.05) and significantly lower levels of selenium(p=0.014) in hair when compared with their siblings. Blood levels of arsenic and hair levels of lead had significant positive correlation with autism severity. Blood levels of copper, zinc and magnesium had negative correlation with autism severity.

Conclusion: This study suggests that there might be an association between high levels of blood and hair heavy metals and ASD.