Lead nitrate is used in small quantities in the gold recovery circuit.
Lead is extremely toxic. It is a cumulative poison and so a dangerous exposure level would not necessarily show an immediate result, but continuous exposure at this level would maybe show as serious problems after a month. View a lead nitrate MSDS.
Ingestion of lead must be avoided. Rubber gloves and masks should be worn while mixing up lead nitrate solution.
Rubber gloves should be worn when adjusting the lead nitrate flowrate.
Eating, drinking and smoking should not occur in a plant where lead salts are present, and operators should wash their hands thoroughly before eating, drinking or smoking.
Should lead poisoning be suspected a doctor should be consulted.
https://www.911metallurgist.com/sodium-cyanide-safety-poisoning-hcn-vapor