All metals can be toxic or cause adverse conditions if too much is ingested. Too much silver will turn you blue. Too much lead will make you dead (in two very different ways). So many salts can be poisonous. Hexavalent Chromium causes several types of cancer and that was used as primer on aluminum alloys for corrosion resistance, so if you get hold of yellow aluminum parts, wash your hands well.
When my kids were in scouts, we participated in the annual beach sweep. We were given gloves and a bucket to collect trash. The trash everyone found the most of was cigarette butts.
And… About 40 years ago, someone had the great idea of repurposing old tires as an offshore fish reef. Hundreds of tires strung up with steel cables and weighted down. 10-15 years later, the steel cables had rusted through so now, every time we have a big storm, tires wash up onto the beach.
Asparagus will turn your pee green.