Mercury in the body produces a selenium deficiency state that increases toxicity.
Spiller HA. Rethinking mercury: the role of selenium in the pathophysiology of mercury toxicity. Clinical Toxicology. 2018;56(5):313-326.
This study makes the case that mercury’s multifaceted interactions with selenium are a central feature of mercury toxicity. The authors argue that “the previously suggested ‘protective effect’ of selenium against mercury toxicity may in fact be backwards”—because of mercury’s affinity for selenium, mercury can actually produce a selenium deficiency state that promotes oxidative stress and inhibits the body’s regenerative mechanisms. Depending on the form of mercury and other factors, selenium supplementation may have some benefits for restoring adequate selenium status and mitigating the toxicity of mercury, but it does not appear to promote increased elimination of mercury.
Blood levels of mercury and lead are much higher in autistic children as compared to normal controls.
Yassa HA. Environmental Toxicology and Pharmacology. 2014;38:1016-1024.
The aim of this study was to find out the relation between exposure to lead and/or mercury as heavy metals and autistic symptoms and assess use of chelating agents for dealing with heavy metals and improving autistic symptoms. The results showed significantly higher levels of mercury and lead among children with autism compared to children without autism, and a significant decline in the blood levels of lead and mercury with the use of DMSA as a chelating agent. In addition, there was a decline in autistic symptoms with the decrease in the lead and mercury levels in blood.