Dear would be welder.

Everyone will look at the possibility of your eventual exposure to the so called heavy metals. BS. Iron. Do yourself a favor and look up the key words "Iron Toxicity" on the net. Never mind "heavy metals".

As highlights:

Orthodox statements:
There is no known way for the body to excrete iron in a greater volume, than is absorbed through the diet.

Iron is an essential nutrient to all microorganisms. In fact, the body does its best to hide away any free iron in the body in case of infections, be it acute, or chronic. It is one of a few immune responses.

Iron is absorbed through diet, through skin exposure and through inhalation.

You may go from there.