Sentence:  Manganism has been known about since the 19th century, when miners exposed to ores containing manganese...began to totter, slur their speech and behave like someone inebriated. The poisoning was irreversible, and soon ended in psychosis and death. Nowadays workers are exposed to far lower <WSD>doses</WSD> and manganism is rare. 
Meaning of the word marked with <WSD> tags:  The quantity of an agent (not always active) substance or radiation administered at any one time.