886
Here , metal exposure in an AM facility with large-scale metallic component production was investigated during two consecutive years with preventive actions in between.MethodsGravimetric analyzes measured airborne particle concentrations , and filters were analyzed for metal content .
 material: metal; concept or principle: exposure; manufacturing process: AM; material: metallic; machine or equipment: component; concept or principle: particle; application: filters; material: metal
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: metal; concept or principle: exposure; manufacturing process: AM; material: metallic; machine or equipment: component; concept or principle: particle; application: filters; material: metal