ALA is also very good for arsenic. For example this is from a doctor who is also mother of a formerly autistic boy.
http://onibasu.com/archives/am/6608.html

DMSA is very good for lead according to Cutler. It is FDA approved for this even in kids.

Results of DMSA Treatment Study, James Adams,et al
http://www.scribd.com/doc/15120628/Results-of-DMSA-Treatment-Study
Conclusions - benefits
•DMSA greatly increases excretion of lead, and some increase in excretion of tin, mercury,thallium.
•1 round of DMSA dramatically normalized glutathione levels for at least 1-2 months, and helped normalize platelet levels (marker of inflammation) for at least 4 months
•Severity of Autism Scale. Significant improvement in both groups

Conclusions - safety
•DMSA increases excretion of potassium and
chromium; suggests need for more vegetables/fruit
and modest chromium supplementation during chelation
•DMSA had little effect on other essential minerals
•DMSA had no adverse effect on liver enzymes, kidney function, or complete blood count (CBC)
•DMSA possibly raised triglycerides – concern to watch for
•Check cysteine levels, since 90% of DMSA is excreted bound to 1-2 cysteine

DMPS tends to produce a smoother feeling while chelating with ALA when Hg and As are involved.

Cutler indicates that cadmium is tough to remove; however my Cd has gradually gone from in the red on my hair test after 1 yr detox with DMSA + ALA to very low in the green after roughly 5 years.

Lead has very gradually come down from in the red after 1.5 yrs detox to low side of the yellow after 5 years; however I apparently had a bad lead and cadmium problem due to decades of work related exposure. It was bad enough that I broke my leg without any contact--it just snapped like chalk at age 43!

Thankfully my bone density and kidney numbers have normalized and I've gotten less impressive gains in many other areas-- food sensitivities , fatigue, eye floaters, more pleasant and extroverted personality, etc.

Followup tests are tricky. A person with a PhD in environmental engineering who was using a variation of Cutler's protocol tracked her hair tests during her years of detox.
http://mercuryandmore.weebly.com/lab-results.html