Asking for any experiences on soil remediation using plants (tips on testing heavy metals in soil, especially using sunflower to remediate)

Hi everyone! My team and I are working on a prototype to use sunflowers and AMF fungi to clean up soil contaminated with heavy metals. But none of us come from agricultural backgrounds, we’re just passionate youth trying to help remediate soil in conflict-affected areas. So it’s been quite a challenge to work on this and looking for someone from this field. Recently, saw several posts about soil remediation on reddit, so we got some hopes to find practical insights here!

I’d love to hear from anyone with experience or advice on:

(1) How did you test whether concentration of heavy metals in the soil after planting hyperaccumulator plants is lower?

(2) Any useful tips on growing sunflowers for soil remediation?

My team and I will be super duper grateful for any of your insights!