Indices of Thyroid Function and Antibodies in Occupationally Lead-Exposed Workers in Egypt

Mohamed Mahmoud El Batanouni1, Sanaa Sayed Abd-El Shafi2, Sanaa Aboul Rizk3,
Noha Mohamed Hegazi3, Ahmed Hussein Abd El-Karim3, and Heba Mahdy Abd-allah3

1 Department of Industrial Medicine and Occupational Diseases, Cairo University, Cairo, Egypt
2 Department of Chemical and Clinical Pathology, Beni-Suef, Cairo University, Cairo, Egypt
3 Department of Environmental and Occupational Medicine, National Research Center, Dokki, Cairo, Egypt

Corresponding author: Dr. Heba Mahdy Abd-allah
    Department of Environmental and Occupational Medicine
    National Research Center
    El-Bohouth Street, Dokki
    Giza, Egypt
    Fax numbers: 202 3370931, 202 3601877
    E-mail: hebamahdy2003@yahoo.com

CEJOEM 2004, Vol.10. No.3.: 252–258

Key words:
Lead, occupational exposure, thyroid gland function, antithyroid and antinuclear antibodies

Abbreviations:
Anti Sm
FT3
FT4
RNP		 = Anti smith
= Free triiodothyronine
= Free tetraiodothyronine (Thyroxine)
= Ribonucleoprotein		 Scl-70 
T3
T4
TSH		 = Scleroderma
= Total triiodothyronine
= Total tetraiodothyronine (Thyroxine)
= Thyroid Stimulating Hormone

Abstract:
The effect of lead (Pb) exposure on the thyroid gland was studied in 100 male workers employed in a lead smelter (mean duration of exposure 16.99 ± 5.6 yr) and as a control group in 60 non-exposed male workers matched for age and socioeconomic status. The participants of both groups filled in a detailed questionnaire including medical and occupational history. For all participants, full clinical examination was done. Occupational exposure to lead was verified by history and measuring of blood lead level. In all participants thyroid function tests comprising T3, FT3, T4, FT4 and TSH were performed. Determination of antithyroid and antinuclear antibodies was performed in 38 of the exposed workers.
    In the exposed group the level of blood Pb was significantly elevated as compared to the controls. No statistically significant difference was detected between the exposed and control groups as regards the measures of thyroid function. The blood lead levels above 50 µg/dl negatively correlated with FT4. Antithyroid antibodies were detected in the sera of 22 out of 38 of the exposed workers. The study revealed the existence of antinuclear antibodies in some of the exposed workers.
    The results suggest the necessity of monitoring thyroid hormones and TSH levels in lead-exposed workers.

Received: 10 June 2004
Accepted: 22 October 2004
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