However, several scientists objected to the “infallible” pronouncements made by the laboratories. For instance, Dr. Rosalie David of the Manchester Museum has performed autopsies on Egyptians mummies, and has used carbon dating to corroborate the age of them; however, sometimes carbon dating indicates a date a thousand years younger than the actual date of the mummy known through other archeological evidence. Such a discrepancy would be caused by some source of contamination.
Contamination to the shroud could alter the accuracy of the carbon dating. Exposure to years of candle soot in the cathedral and Turin pollution, the drenching with water during the fire, and the accumulation of minuscule fragments of deteriorating ceiling frescos would give the shroud a coating which could in turn skew the carbon-dating results. Moreover, a corner sample which over the years had been handled by many individuals would probably be contaminated. Such items enrich the carbon content and would make the shroud appear substantially younger than its true age when carbon-dated.