Are cast iron pans unsafe?
Cast iron pans are popular, especially for searing, and are generally safe to use. But they can leach iron, which is a strong pro-oxidant. Those genetically at risk for iron overload should learn more about cast iron safety.
Studies have shown that supplement buyers generally trust the supplements they buy. That might not be the safest assumption, as dietary supplements that are presumed helpful or neutral may sometimes cause serious side effects, as quantified by this study.
How can I safely consume seaweed?
It is relatively easy to consume most seaweeds safely, but high intakes of raw Kelp (Kombu, or any seaweed starting with Laminaria) are a very significant concern for iodine toxicity. For daily Kombu intake, proper cooking techniques should be followed for safety.