Effect of inorganic lead on thyroid function of exposed workers

  • Ziadi Boukerma Faculté de Médecine, Service de Médecine du Travail, Université Farhat Abbas Sétif 1, Algérie (Algeria); e-mail: zboukerma@gmail.com
  • Ahmed-Lakhdar Behlouli Faculté de Médecine, Service de Médecine du Travail, Université Farhat Abbas, Sétif 1, Algérie (Algeria)
  • Farida Djabi Faculté de Médecine, Laboratoire de biochimie, Université Farhat Abbas, Sétif 1, Algérie (Algeria)
Keywords: Blood lead exposure, thyroid hormones, FT3, FT4, TSH, endocrine disruption


Background: The effects of long-term exposure to lead on thyroid hormones are not clear. Unlike others, some studies
report deleterious effects of inorganic lead on thyroid function. Methods: the potential endocrine disruption was evaluated
in 141 lead-exposed workers and 141 controls free from any exposure to this toxic. In the exposed group, the exposure-
retained factors are blood lead level (BLL), which reflects recent exposure, the cumulative blood lead, which reflects
the old exposure (from hiring) and zinc protoporphyrin (ZPP), a marker of the intermediate exposure. Regarding the control
group, only blood lead was measured. Results: If TSH and FT4 were significantly higher in the exposed group, however
FT3 was significantly higher in the non-exposed group. In the exposed group, FT3 is inversely correlated with age,
FT4 is positively correlated with BLL and ZPP, and TSH is positively correlated with ZPP. Conclusions: the results suggest
the existence of a deleterious effect of inorganic lead on thyroid function. Furthermore, it appears that only the intermediate
exposure seems to be responsible for this action


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