Evaluation of kidney function and oxidative stress biomarkers in prolonged occupational exposure with mercury in dentists

Abstract

Inorganic mercury (Hg), which predominant component in dental amalgam, is one of the primary sources of Hg inhalation exposure with several systemic toxicities in dental staff. This research investigated occupational Hg exposure and its effects on kidney function biomarkers (KFBs) and superoxide dismutase (SOD) as an oxidative stress index in dental workers. The participants were classified into two matched groups as an exposed group (G1: n = 30), which occupied in endo, pediatric and restorative wards, and non-exposed (G2: n = 27) occupied in the administrative wards. Blood and urinary level of Hg(B-Hg and U-Hg), SOD blood level(SODB), and KFBs including urinary N-acetyl-β-D-glycosaminidase;U-NAG, microalbumin; U-Micro- Alb, immunoglobulin G; U-IgG, and creatinine; U-Cr were measured in 24 collected urine and blood samples and the correlations of B-Hg and U-Hg concentrations with these markers were analyzed. The mean of BHg and UHg concentrations in G1 with significant difference was higher than G2 (p < 0.05). The SODB in G1 and G2 was 59.40 ± 8.75 IU/L and 64.69 ± 8.56 IU/L, respectively, which had significant difference (p < 0.05). UIgG in G1 was higher than the G2 group with non- significance difference (p = 0.341). U-Hg and B-Hg concentrations had not significant correlation with KFBs and SODB in G1 and G2. Using dental amalgam can lead to the accumulation of Hg in blood and urine and may pose perturbation in oxidative stress index and relevant dysfunctions. So, monitoring of Hg concentration and its influences on kidney function and oxidative stress index in exposed groups is hardly suggested for health status prediction of these groups.