The Impact of Black Lung and a Methodology for Controlling Respirable Dust

Abstract

Coal workers' pneumoconiosis (CWP), commonly known as black lung, is caused by the inhalation of respirable coal mine dust and is a disabling and potentially fatal lung disease with no cure. Historically, CWP has taken a tremendous human and financial toll in the US coal mining industry. Recent health surveillance data indicates that CWP continues to occur at elevated levels. Respirable coal dust exposure must be controlled to prevent the development of CWP. The Pittsburgh Mining Research Division of the National Institute for Occupational Safety and Health (NIOSH) conducts laboratory and mine-site research to identify control technologies that can be used to successfully reduce respirable dust levels. Various technologies, using multiple methods of control, can be applied in order to reduce dust levels. An overview of CWP's impact and a general methodology for controlling respirable dust in underground coal mines are discussed in this paper.

Keywords: Coal workers’ pneumoconiosis; Engineering controls; Respirable dust; Underground coal mining.

Fig. 1

Chest radiographs of healthy lungs (left), simple CWP Category 2 (center), and PMF Category C (right) (source: International Labour Office)

Fig. 2

Percentage of examined miners with CWP Category 1 or greater by tenure in mining

Fig. 3

Percentage of miners filing for federal black lung benefits by decade that were found to have PMF

Fig. 4

Efficient cutting with proper bit design (left), undercut roof rock (center), and reduced drum rpm (right)

Fig. 5

Full-cone spray pattern (left), typical spray locations on a shearer drum (center) and a continuous miner (right)

Fig. 6

Enclosed stageloader/crusher (left) and schematic illustrating internal spray locations (right)

Fig. 7

Miner removing filter from scrubber (left) and graph showing respirable dust reductions with different density filters (right) (source: NIOSH)

Fig. 8

Cleaning dust from collector box (left), collector bag (center), and dust captured in bag (right)

Fig. 9

Canopy air curtain provides filtered air to operator (left) and commercially available unit (right)

Fig. 10

Intake air flowing into gob at headgate (left) and gob curtain turning airflow down the face (right)

Fig. 11

Directional spray system on longwall shearer with venturi sprays mounted on the splitter arm and hollow-cone sprays on shearer body (left) and tailgate-side sprays (right)