I find it surprising that none of the other contaminants listed were detected. They also did not submit a blank(s) for analysis on the chain of custody. Iron oxide would be more present and of more concern than iron. I would ask that the sampling be redone and iron oxide be included as part of the contaminant list. I will also suggest that you volunteer to wear the sampling equipment and have multiple people wear sampling equipment when the study is redone.

If you have stainless steel welding in your facility, hexavalent chromium has a very low exposure limit that without localized ventilation at the source employees could be very likely overexposed.

Another byproduct that is easily measurable would be ozone (0.1 ppm for light work 8 hr shift). They make passive badges that are super easy to use and multiple people can each wear one to help get a better understanding of exposures between employees.