I stopped drinking my beloved Rosamonte especial (smoky) mainly out of concern for carcinogenic compounds (PAHs) and less for the boiling temperatures.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3525749/As for the present prospective cohort survey https://onlinelibrary.wiley.com/doi/full/10.1002/ijc.32220, I'm surprised the actual tea (processing method/brand) was not listed as a confounding factor. They mention PAHs but to the extent of their generic use of the term 'tea' throughout the Discussion section makes me question the utility:
"However, tea also contains several other compounds with unknown effects, and some potentially carcinogenic compounds may be introduced to tea when being processed (such as possible contamination of black tea with PAHs)"