The Influence of Sustained Mercury Exposure on Prothrombin Time and Partial Thromboplastin Time among Sudanese Gold Mining Workers

Abstract

Background: Gold mining is the world's leading source of anthropogenic mercury pollution, negatively impacting not only miners but also the surrounding inhabitants; it has many effects on human health, especially cardiovascular problems, which lead to coagulation disorders and an increase in morbidity and mortality rate. The present study aimed to determine the prothrombin time (PT) and partial thromboplastin time (PTT) among Sudanese gold mining workers exposed to mercury. Methods and Results: This cross-sectional study was carried out among mining workers in the Red Sea state. A total of 50 mining workers were enrolled in the case group, and 50 non-mining apparently healthy subjects were the control group. About 5 ml of whole blood samples were collected in 3.2% sodium citrate blood collection tubes. Platelet poor plasma (PPP) for prothrombin time (PT) and partial thromboplastin time (PTT) measurements was obtained by using high-speed centrifugation. PT and PTT tests were performed using a standard method (Practical-Haemostasis.com.) with a Helena C2 coagulometer (Germany) and reagents manufactured by the Bio-med trademark (China). The mean age of miners was 33.5±11.5 years and occupation time - 1.94±2.1 years. The mean value of PTT was greater in the case group than in the control group (42.43±6.18 sec vs. 37.76±5.33 sec, P=0.000). In the age subgroup <40 years, the PT level was longer than in the age subgroup >40 years: 14.04±1.38 sec vs. 13.15±1.35 sec (P=0.045), respectively. The correlation analysis revealed a significant, direct correlation between PTT and occupation time (r=0.357, P=0.011). Conclusion: Prolonged coagulation time, notably PTT, has been revealed among mining workers, implying that these workers may have a clinically silent state of coagulation abnormalities.