Cadmium is a naturally-occurring component in soil, & many plants take it up as they absorb soil nutrients, which is how it gets into our cocoa beans. According to the CDC, cadmium is commonly found in vegetables, & in relatively high concentrations in leafy greens like spinach. Virtually all dark chocolate should have a prop 65 warning if it is concerned with CDC guidelines.
If you'd like a more nuanced view or want to know more, visit www.P65warnings.ca.gov, send us an email, or give us a call @ (510) 984-4848. We'd be happy to talk.