SUMMARY
Background: Many workers, particularly those working in manufacture of fertilizers, explosives, rubber, pesticides, textiles, and employees of petrochemical industries are exposed to ammonia in their workplaces. Toxic responses of hematopoietic system and kidney following occupational exposure to this chemical have not been thoroughly investigated.Objective: To determine the relationship between long-term occupational exposure to low levels of ammonia and hematological parameters and kidney function.Methods: In this cross-sectional study, 119 randomly selected, male petrochemical workers and 131 office employees (comparison group) were examined. Urine and blood samples were taken from all participants for urinalysis, complete blood count (CBC), serum calcium level, and blood urea nitrogen (BUN) and plasma creatinine. Personal, environmental, and peak ammonia exposure were also measured.Results: The median personal, environmental, and peak occupational exposure to ammonia were 0.23, 0.16, and 65.50 mg/m3, respectively, among the exposed group. No significant difference was observed between the exposed and unexposed participants in terms of hematological parameters and urinalysis. Conversely, calcium and BUN, while within the normal range, were significantly higher in the exposed than in the comparison group.Conclusion: Occupational exposure to low atmospheric concentrations of ammonia was associated with subtle, sub-clinical, pre-pathologic changes in kidney function. Possible longterm consequences and ramifications of these effects require further investigation.