Occupational Renal Dysfunction Among Asphalt Workers In Sharkia Governorate: An Epidemiological Study

Abstract

Background: Occupational exposure to bitumen fumes emitted during hot application of asphalt carries the risk of exposure to significant amount of hydrocarbon compounds that may cause toxic nephropathy. Objectives: Investigation of renal dysfunction among asphalt-exposed workers and identification of some factors that may be associated with these renal effects. Subjects and methods : A cross-sectional study was carried out at one of the road paving sation in Sharkia Governorate. Ninety-four male asphalt workers and seventy-three non exposed workers, as controls, were included in the study. All participants were interviewed and answered a preconstructed questionnaire including personal and occupational characteristics, present and past medical history suggesting renal involvement. Weight, height and blood pressure were measured. Fasting blood and urine samples were collected from all participants. Urine was examined for presence of red blood corpuscles, leukocytes, total protein, microalbumin and pimicroglobulin. Serum creatinine was also estimated. Results: the results of this study revealed a significantly higher prevalence of renal manifestations among asphalt workers when compared with controls (OR = 50.1). Furthermore asphalt workers had significantly higher prevalence of abnormal renal nephrotoxic markers serum creatinine: 23.4%, total proteinuria 17%, microscopic hemaiuria: 11.7%, leukocyturia : 17%, microalbuminuria : 31.9% and p; microglobulinuria: 31.9%). The presence of both microglbuminuria and urinary cellular sediment seemed to occur nearly 9.5 times more than the presence of urinary sediment alone. Asphalt workers were more likely to have irreversible glomerular damage about 8.5 times more than the control subjects, while there was no statistically significant difference between. the two groups regarding the presence of irreversible tubular damage (P > 0.05). Duration of employment > 15 years was the only factor associated with occurrence of renal dysfunction. Conclusion: occupational exposure to asphalt during road paving was associated with renal dysfunction and may be responsible for diverse effects on both glomeruli and renal tubules. These dysfunctions were mostly related to the duration of exposure lo asphalt. So, it was recommended dial preplacement and periodic medical examinations, biological monitoring for workers, periodic environmental assessment, personal cleanliness, and regular use of protective equipments can be of a great help in minimizing the risk of renal dysfunction among asphalt workers. Key words: renal dysfunction, asphalt workers, nephrotoxin, glomerular damage