Norman, my brother, and owner of Vintage Tub & Bath answered the question this way:
That is a very broad question and, as such, merits both a technical and practical answer.
Technically, lead is a naturally occurring element. I am sure that the vast majority of material present on the surface of the Earth contains at least some trace of lead. Our tubs aren't excluded from that group. To specifically and technically answer your exact question, we feel that the answer must be yes.
In practical terms, if your question was meant to ask whether or not the tubs you bought present any type of known lead-based health hazard under normal use and conditions, the answer is no (i.e., the tubs are not known to leach hazardous lead into water or emit lead particles into the air, etc.). Furthermore, Vintage Tub & Bath doesn't have any reason to believe any of the materials present in your tub contain a significant amount of lead to present a lead-based health hazard under virtually any condition.
You may have asked us this question because many years ago lead and a host of other harmful materials were significant constituents in paints, surface-smoothing fills, as well as the frits (ground-up glass) that were used to make the porcelain enamel coating used on the inside of cast iron tubs. In fact, in the early 1900s, pure lead was used in major American manufacturing operations to smooth the outside of some clawfoot tubs. The lead would be applied hot, cooled and then ground down by hand by workers with little to no respiratory protection. As a result, lead-based hazards abounded with these older products for workers and consumers alike.
The use of pure lead and significantly lead-based materials in these types of processes and products has long since been abandoned (as in decades ago), and your tubs were manufactured under modern manufacturing conditions no earlier than 2002 to 2003. As a result, we are confident your tubs are quite safe in terms of both lead content and resultant exposure risk. I hope this answers your question.