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)




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


Argemi, B., 2000. Exploration biologique de la fonction thyroïdienne. L’indispensable, le confortable, le superflu. Revue de l’ACOMEN, 6 (1), 15 - 21.

Bledsoe, M.L., Pinkerton, L.E., Silver, S., Deddens, J.A., Biagini, R.E., 2011. Thyroxine and Free Thyroxine Levels in Workers Occupationally Exposed to Inorganic Lead. Environ health insights, 5, 55 - 61.

Boas, M., Feldt-Rasmussen, U., Skakkebæk, N.E., Main, K.M., 2006. Environmental chemicals and thyroid function. Eur J Endocrinol, 154 (5), 599 - 611.

Cullen, M.R., Kayne, R.D., Robins, J.M., 1984. Endocrine and reproductive dysfunction in men associated with occupational inorganic lead intoxication. Arch Environ Health, 39 (6), 431 - 440.

Delecourt, F., Forzy, A., Tilly, G., 1999. Variation de la TSH (thyroid stimulating hormone) en fonction de l’âge. Ann Biol Clin, 57 (6), 739 - 40.

Dundar, B., Öktem, F., Arslan, M.K., Delibas, N., Baykal, B., Arslan, Ç., Gultepe, M., Ilhan, I.E., 2006. The effect of long-term low-dose lead exposure on thyroid function in adolescents. Environ Res, 101 (1), 140 - 145.

Dursun, N., Tutus, A., 1999. Chronic occupational lead exposure and thyroid function. J Trace Elem Exp Med, 12 (1), 45 - 49.

Erfurth, E.M., Gerhardsson, L., Nilsson, A., Rylander, L., Schütz, A., Skerfving, S., Börjesson, J., 2001. Effects of lead on the endocrine system in lead smelter workers. Arch Environ Health, 56 (5), 449 - 455.

Gennart, J.P., Bernard, A., Lauwerys, R., 1992. Assessment of thyroid, testes, kidney and autonomic nervous system function in lead-exposed workers. Int Arch Occup Environ Health, 64 (1), 49 - 57.

Gidlow, D.A., 2004. Lead toxicity. Occup Med, 54, 76 - 81.

Hoermann, R., Eckl, W., Hoermann, C., Larisch, R., 2010. Complex relationship between free thyroxine and TSH in the regulation of thyroid function. Eur J Endocrinol, 162 (6), 1123 - 1129.

Hoermann, R., Midgley, J.E.M., 2012. TSH Measurement and Its Implications for Personalised Clinical Decision-Making. J thyroid res, 1 - 9.

Kim, H.S., Park, Y.C., Choi, J.W., Rho, W.W., Kim, D.S., Park, J.T., 1999. A Study on Thyroid Function among Male Workers Occupationally Exposed to Inorganic Lead. Korean. J Occup Environ Med, 11 (2), 153 - 160.

Klee, G.G., Hay, I.D., 1993. Role of thyrotropin measurements in the diagnosis and management of thyroid disease. Clin Lab Med, 13 (3), 673 - 82.

Kreutzer, H., Tertoolen, J., Thijssen, J., Der Kinderen, P., Koppeschaar, H., 1986. Analytical evaluation of four sensitive assays of thyrotropin, including effects of variations in patient sampling. Clin Chem, 32 (11), 2085 - 2090.

Lipson, A., Nickoloff, E.L., Hau, T.H., Kasecamp, W.R., Drew, H.M., Shakir, R., Wagner, H.N., 1979. A study of age-dependent changes in thyroid hormone tests in adults. J Nucl Med, 20, 1124 - 1127.

Lopez, C.M., Pineiro, A.E., Nunez, N., Avagnina, A.M., Villaamil, E.C., Roses, O.E., 2000. Thyroid hormone changes in males exposed to lead in the Buenos Aires area (Argentina). Pharmacol Res, 42 (6), 599 - 602.

Maes, M., Mommen, K., Hendrickx, D., Peeters, D., D’Hondt, P., Ranjan, R., De Meyer, F., Scharpe, S., 1997. Components of biological variation, including seasonality, in blood concentrations of TSH, TT3, FT4, PRL, cortisol and testosterone in healthy volunteers. Clin Endocrinol (Oxf), 46 (5), 587 - 598.

Marteau, C., Madre-Pichon, F., Chivot, J.J., 1996. Etude du taux sérique de l’hormone thyréotrope (TSH) par une méthode ultra sensible chez 91 sujets âgés de plus de 70 ans. Spectra biologie, 15 (79), 28 - 30.

Onalaja, A.O., Claudio, L., 2000. Genetic susceptibility to lead poisoning. Environ Health Perspect, 108 Suppl 1, 23 - 28.

Pekcici, R., KavlakoÈlu, B., Yilmaz, S., Ÿahin, M., Delibaêi, T., 2010. Effects of lead on thyroid functions in lead-exposed workers. Cent Eur J Med, 5 (2), 215 - 218.

Pearce, E.N., 2013. The Relationship between Serum TSH and Free T4 Is Not Log-Linear and Varies by Age and Sex. Clin Thyroidol, 25, 156 - 157.

Refowitz, R.M., 1984. Thyroid function and lead: no clear relationship. J Occup Environ Hyg Med, 26 (8), 579 - 583.

Robins, J.M., Cullen, M.R., Connors, B.B., Kayne, R.D., 1983. Depressed thyroid indexes associated with occupational exposure to inorganic lead. Arch Intern Med, 143 (2), 220 - 224.

Sandstead, H.H., 1967. Effect of Chronic Lead Intoxication on in vivo I131 Uptake By the Rat Thyroid. Exp Biol Med, 124 (1), 18 - 20.

Sandstead, H.H., Stant, E.G., Brill, A.B., Arias, L.I., Terry, R.T., 1969. Lead intoxication and the thyroid. Arch Intern Med, 123 (6), 632 - 635.

Sapin, R., Schlienger, J.L., 2003. Dosages de thyroxine (T4) et tri-iodothyronine (T3): techniques et place dans le bilan thyroïdien fonctionnel. Ann Biol Clin, 61 (4), 411 - 420.

Schumacher, C., Brodkin, C.A., Alexander, B., Cullen, M., Rainey, P.M., van Netten, C., Faustman, E., Checkoway, H., 1998. Thyroid function in lead smelter workers: absence of subacute or cumulative effects with moderate lead burdens. Int Arch Occup Environ Health, 71 (7), 453 - 458.

Siegel, M., Forsyth, B., Siegel, L., Cullen, M.R., 1989. The effect of lead on thyroid function in children. Environ Res, 49 (2), 190 - 196.

Singh, B., Chandran, V., Bandhu, H.K., Mittal, B.R., Bhattacharya, A., Jindal, S.K., Varma, S., 2000. Impact of lead exposure on pituitary-thyroid axis in humans. Biometals, 13 (2), 187 - 192.

Soltani, S., Sharifiyan, A., Ghasemi, M., Chavoshi, F., Sadeghniiat, K., Bahaedini, L., Aminian, O., Meisami, A.P., 2012. Assessment of Thyroid Function in Male Workers of Battery Recycling Factory Occupationally Exposed to Lead. J Pharmacol Toxicol, 7 (7), 338 - 343.

Tiwari, I., Timms, P., Rothe, P., 1985. Lead poisoning and euthyroid hyperthyroxinaemia. The Lancet, 325 (8444), 1508 - 1509.

Tuppurainen, M., Wägar, G., Kurppa, K., Sakari, W., Wambugu, A., Fröseth, B., Alho, J., Nykyri, E., 1988. Thyroid function as assessed by routine laboratory tests of workers with long-term lead exposure. Scan J Work Environ Health, 14 (3), 175 - 180.