Occupational Lead Poisoning in Workers of Traditional Tile Factories in Mashhad, Northeast of Iran

M Balali-Mood, S Shademanfar, J Rastegar Moghadam, R Afshari, M Namaei Ghassemi, H Allah Nemati, MR Keramati, J Neghabian, B Balali-Mood, G Zare


Background: Occupational lead poisoning is a health problem in Iran. It has not previously been studied in traditional tile makers.

Objective: To determine the prevalence of lead poisoning and its complications in traditional tile workers in Mashhad, Northwest of Iran.

Methods: We visited workers in two traditional tile factories and collected data by direct history taking and physical examination. Blood and urine lead concentrations were measured by heated graphite atomization technique.

Results: Overall, 108 men with mean±SD age of 37±7.8 years were studied. The mean±SD length of daily lead exposure was 9.8±6 years. The mean±SD blood lead concentration was 520.5±323.2 μg/L. The main objective clinical findings were the presence of lead line (64.8%), peripheral neuropathy of the upper extremities (37%), depressed deep tendon reflexes in the upper extremities (25.7%), tremor (23.3%), peripheral neuropathy of the lower extremities (17%) and abdominal tenderness (15.1%). The subjective findings were mainly attributed to the central nervous system and included loss of memory (57%), moodiness (56.1%), agitation (47.7%), drowsiness (36.4%) and headache (29.9%). There was no statistically significant correlation between the blood lead concentration and glomerular filtration rate. However, there were significant correlations between the blood lead concentration and each of the urine lead concentration (p<0.001), diastolic blood pressure (p=0.04), serum triglyceride level (p=0.043), high density lipoprotein level (p=0.012), and basophilic stippling (p=0.048). Blood lead level, however, did not have any significant correlation with the presence of lead line.

Conclusion: In traditional tile workers, lead toxicity is not uncommon and the toxic effects of lead were found more often on the teeth (bone), central and peripheral nervous system, hematological and lipid profiles than on the renal function.


Occupational exposure; toxicology; lead poisoning; nervous system; Iran

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 pISSN: 2008-6520
 eISSN: 2008-6814

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