Fleurpepper
There used to be very strict guidelines and checks until very recently (won't mention THE word)- none now- anything goes. Same for so many other products.
Lindt:
"Our quality products are made in 11 production sites in Switzerland, Europe and the US"
I doubt that they make chocolate specially for the UK market which contains heavy metals. It will be all their chocolate.
The source:
Dark chocolate’s reputation as a relatively healthy treat stems mostly from the cocoa solids. These are packed with flavanols, which are antioxidants linked to improved blood vessel function, reduced inflammation, and lower cholesterol. Dark chocolate is also lower in sugar and higher in fiber than milk chocolate, and it has magnesium and potassium. Unfortunately, cocoa solids are also where the heavy metals, especially cadmium, lurk. That makes it tricky to balance dark chocolate’s risks and benefits.