I don't know that it is so much these metals being added as part of industrial processes as that these metals are found naturally in the environment in a wide a

I don't know that it is so much these metals being added as part of industrial processes as that these metals are found naturally in the environment in a wide array of common materials. As a result of using these materials in manufacturing, the metals end up in the final product. Test equipment is getting more and more sensitive, and cheaper, so it is getting easier to detect very small amounts of these metals. That doesn't mean they are "safe". It means the metals are pervasive on earth, and as we get better technology, hopefully we can do more to remove them from products where they are a danger.