field study
['HHE determination report no. HHE-79-9-615, Arapahoe Aluminum and Brass Foundry, Inc., Englewood, Colorado', 'lead', 'field study', 'National Institute for Occupational Safety and Health', 'HHE determination report no. HHE-79-9-615, Arapahoe Aluminum and Brass Foundry, Inc., Englewood, Colorado']