Chronic Low-Level Cyanide Intoxication in an Electroplating Plant in Taiwan

Objective This study aimed to investigate clinical symptoms among electroplating workers exposed to cyanide. Methods In this study, 26 silver-plating and 51 gold-plating workers completed questionnaires and were tested for urinary thiocyanates. Air cyanide, urinary thiocyanates, and clinical symptoms were compared between workers using Student t and χ2 test and further analyzed by multivariate linear regression. Results Air cyanide and urinary thiocyanate were higher in the silver-plating plant than the gold-plating plant. In both plants, a dose-response relationship was observed between exposure status and thiocyanate levels. Silver-plating workers reported a higher frequency of almond odor detection, nasal bleeding, excessive salivation, skin scalding, and corrosion. Urinary thiocyanates were associated with the plant and exposure status, but not with smoking. Conclusions Our study suggests that silver-plating workers had higher exposure and more symptoms. Urinary thiocyanate may be a useful biomarker for cyanide exposure.