The traditional concern on the production side is worker safety. After a severe mine disaster in 1968, regulation was revised in the Coal Mine Health and Safety Act of 1969. Safety regulation was made more stringent and regulations of health effects were added. Moreover, administration was transferred from the U. S. Bureau of Mines of the DOI to a newly created Mine Safety and Health and Safety Administration, which was initially a part of the DOI but was transferred in 1977 to the Department of Labor.
Regulation has involved both setting rules for operating mines and federal inspection of the mines. The 1969 act both tightened the rules and increased the frequency of inspection. New rules required that no mine work occur under unsupported roofs; improved ventilation; use of curtains and watering to ensure reduction of ‘‘respirable dust’’ levels and increase the flow of air to the ‘‘face’’ (i. e., where mining was occurring); and increases in the monitoring of mines to determine levels of methane, dust, and other dangerous material. The number of inspections increased greatly. In the early years, many mines had daily inspections because of special problems or because they were so large that only daily visits sufficed to ensure that the required tasks could be completed.
Simultaneously with the passage of the Act, underground coal mining productivity began declining from a peak of 1.95 short tons per worker hour in 1969 to a low of 1.04 short tons in 1978. Then a reversal occurred so that by 2000, the level was up to 4.17 short tons.
Much effort was devoted to determining the role of the Act in the initial productivity declines. Evaluation was hindered by the standard problems of multiple, interrelated influences on which data were unavailable. In particular, the passage of the Act coincided with (and perhaps was a major cause of) an influx of inexperienced miners. As a result of the Act, more labor use in mines appears to have been necessary. The need to increase inspections contributed to the need for new workers because experienced miners were recruited as inspectors. The effects that this had on mine productivity are unclear, but whatever they were, they have been substantially reversed.