Even at low-level exposure, arsenic is not just a class I carcinogen, but may also impair our immune function and increase our risk of cardiovascular disease and diabetes. When people hear about arsenic, they think of it as an acute poison, and, indeed, a tiny amount—a hundred milligrams, about one-tenth the weight of a paperclip—could kill you in an hour. But, there is also chronic arsenic poisoning, where even a dose 10,000 times as small can be harmful if you’re exposed day-after-day for years at a time as I discuss in my video “The Effects of Too Much Arsenic in the Diet.” Chief among the concerns is cancer. As a class I carcinogen, arsenic is classified at the highest level of things known to cause cancer in humans. Other class I carcinogens are asbestos, cigarette smoke, formaldehyde, plutonium, and processed meat (the consumption of bacon, ham, hot dogs, deli meat, and the like). So, arsenic is pretty bad, to say the …