891
Dermal cobalt and a trend for increasing urine metals during Workweek Year 1 , but not in Year 2 , indicated reduced exposure after preventive actions.ConclusionGravimetric analyses showed low total and inhalable dust exposure in AM operators .
 material: cobalt; concept or principle: trend; material: metals; concept or principle: exposure; concept or principle: exposure; manufacturing process: AM
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 material: cobalt; concept or principle: trend; material: metals; concept or principle: exposure; concept or principle: exposure; manufacturing process: AM