Even tried more protein shakes until I read there was more heavy metal content in these protein powders. (nutritionfacts.org)
However, flaxseed oil has a far lower heavy metal content than flaxseed. (foodforbreastcancer.com)
While studies show that the volume of sludge is expected to rise, disposal options are limited due to stricter environmental regulations including a ban on burying sludge in soil due to its high heavy metal content that could cause adverse impacts to the environment. (sciencedaily.com)