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Federal Register: December 16, 1997 (Volume 62, Number 241, Page 65777)


Mine Safety and Health Administration

30 CFR Parts 56, 57, 62, 70, and 71


Health Standards for Occupational Noise Exposure in Coal, Metal and Nonmetal Mines

AGENCY: Mine Safety and Health Administration (MSHA), Labor.

ACTION: Proposed rule; Availability of report.


SUMMARY: This notice announces the availability of a report from the National Institute for Occupational Safety and Health (NIOSH) entitled ``Prevalence of Hearing Loss For Noise-Exposed Metal/Nonmetal Miners.'' The report, which MSHA received on October 15, 1997, is cumulative evidence concerning the risk to metal and nonmetal miners of noise induced hearing loss (NIHL). The report is relevant to the magnitude of the risk of NIHL among miners. The Agency, therefore, will supplement the rulemaking record with this report and make it available to interested parties upon request.

ADDRESSES: Copies of the report are available from the Office of Standards, Regulations, and Variances, 703-235-1910.

FOR FURTHER INFORMATION CONTACT: Patricia W. Silvey, Director, MSHA, Office of Standards, Regulations, and Variances, 703-235-1910.

SUPPLEMENTARY INFORMATION: On December 17, 1996, MSHA published a proposed rule in the Federal Register (61 FR 66348) revising its health standards for occupational noise exposure in coal and metal and nonmetal mines. In this proposal, MSHA stated that current scientific evidence demonstrates that NIHL constitutes a serious hazard, that evidence exists of continuing harm to miners, and that MSHA standards no longer reflect experience and expert advice. The Agency concluded that regulatory action was necessary to address the continued excess risk of NIHL resulting from mining employment.

MSHA evaluated evidence related to the risk to miners from exposure to harmful levels of noise, and evidence on the level of that risk. MSHA determined that with respect to mine safety and health , any definition of material impairment of hearing should relate to a permanent, measurable loss of hearing which, unchecked, will limit the ability to understand speech, as it is spoken in everyday social (noisy) conditions. This is because speech comprehension is essential for mine safety .

The Agency reviewed the major studies on the level of risk at different noise exposures. The studies consistently indicated that the risk of developing a material impairment became significant over a working lifetime when workplace exposure exceeded average sound levels of 85 dBA. The data further indicated that while lowering exposure from an eight-hour time-weighted average (TWA8) of 90 dBA to one of 85 dBA did not eliminate the risk, it did reduce the risk by approximately half. MSHA also reviewed a large body of data on the effects of varying industrial sound levels on worker hearing. These studies were supportive of the same conclusion. The Agency also focused on the harm that can occur at lower sound levels by reviewing studies of workers in other countries.

To confirm the magnitude of the risks of NIHL among miners, MSHA examined evidence of reported hearing loss among miners from a variety of sources audiometric data bases tracking hearing acuity among coal miners, individual commenter data, hearing loss data reported to MSHA, and workers' compensation data. MSHA also asked NIOSH to examine a body of audiometric data which tracked hearing acuity among coal miners and one which tracked hearing acuity among metal and nonmetal miners. NIOSH completed its analysis of the audiometric data on coal miners and issued a report to MSHA entitled ``Analysis of Audiograms for a Large Cohort of Noise-Exposed Miners,'' (Franks, 1996) which is a part of the existing rulemaking record.

NIOSH has now issued its report to MSHA which analyzes audiometric data on metal and nonmetal miners. This report is entitled ``Prevalence of Hearing Loss For Noise-Exposed Metal/Nonmetal Miners.'' The NIOSH analysis supports the conclusion from earlier scientific studies that miners are losing their hearing sensitivity faster than the general population. It indicates that 49% of the male population of metal and nonmetal miners have a hearing impairment by age 50 as compared with only 9% of the general population.

The report is available to interested members of the public and may be obtained upon request by electronic mail, fax, phone, or mail as follows: (1) Electronic mail: psilvey, (2) Fax: MSHA, Office of Standards, Regulations, and Variances, 703-235-5551, (3) Phone: Patricia W. Silvey, 703-235-1910, and (4) Mail: Mine Safety and Health Administration, Office of Standards, Regulations, and Variances, 4015 Wilson Boulevard, Room 631, Arlington, VA 22203-1984.

Dated: December 9, 1997.
J. Davitt McAteer,
Assistant Secretary for Mine Safety and Health .
[FR Doc. 97-32709 Filed 12-15-97; 8:45 am]