Which heavy metals might kelp absorb and concentrate from polluted seawater environments?

Arsenic, lead, cadmium, and mercury.

Kelp acts as a natural accumulator, drawing minerals and compounds directly from the surrounding seawater. While this mechanism allows it to gather beneficial iodine, it unfortunately also leads to the absorption and concentration of environmental contaminants, particularly heavy metals, if the harvesting location is polluted. The specific toxins identified as risks that can accumulate in the body over time include arsenic, lead, cadmium, and mercury. Unlike beneficial minerals that the body manages for excretion, these heavy metals pose a long-term health hazard as they can settle and accumulate within bodily tissues and organs, leading toward chronic toxicity issues if exposure is prolonged.