Diesel Particulate Case Study

Issue Overview

Underground metal and non-metal miners, such as those working in limestone, gold, silver and salt mines, are exposed to the highest levels of diesel particulate matter (DPM) compared with any other occupational group in the United States. Diesel engines power much of the equipment used to extract the ore, and emissions generated from them are a complex mixture, including fine particulate with a carbon core and a surface that adsorbs polycyclic aromatic compounds, including many known carcinogens. "Weight of the Evidence or Wait for the Evidence?", published in the February 2006 issue of the American Journal of Public Health, profiles the decade-long saga of mining industry coalition efforts to impede an epidemiological study undertaken by the National Institute for Occupational Safety and Health (NIOSH) and the National Cancer Institute (NCI), and to derail a health standard promulgated by the Mine Safety and Health Administration (MSHA). The paper highlights the industry coalition’s mastery of the legislative, judicial and executive branches of government and the reaction of policymakers. Some of the documents cited in this article appear below.

In August 2005, industry officials opposed to MSHA's DPM rule met with officials from the White House. Details of their meeting are not available to the public, but shortly thereafter, MSHA proposed delaying the 160 ug/m3 exposure limit for an additional five years (until 2011). Experts from the public health community, including Douglas Dockery, Kyle Steenland and Les Stayner, raised objections to MSHA's proposed delay. Ultimately, the agency decided on a 2008 effective date and responded favorably to a request from miners’ representatives to require medical evaluation (and transfer rights) to miners who are required to wear respirators in high DPM-concentration environments. (DPM Final Rule 2006)

Industry opponents of the rule to protect metal and non-metal miners continue their fight against MSHA’s health standard. In a  newsletter written by their lead attorney, they criticize NIOSH for failing to release its health effect study data, challenge MSHA’s risk assessment, and suggest that eventual judicial review “will not permit the flawed rules to escape.” The coalition’s lead attorney divulged his next line of attack, i.e., challenging citations issued by MSHA inspectors for violating the DPM rule and seeking reversal or reinterpretation of the rule by the Federal Mine Safety & Health Review Commission (MSHRC).

The mining industry opponents of MSHA's DPM health standard also challenged the rule in U.S. Court of Appeals.  In January 2007, before a three-judge panel, industry lawyers argued that MSHA's DPM rule was neither scientifically valid nor feasible.  Just 30-days later, on February 9, 2007, the court issued its ruling.  The judges found the industry's arguments to be without merit and they denied their petition to review the MSHA DPM rule.   

Update (May 2008):

A more protective exposure limit of 160 ug/m3 (8-hour TWA) (TC (total carbon)), which was included in MSHA's January 2001 final rule on diesel particulate matter, took affect on May 20, 2008.  In a Federal Register notice published on the same day, MSHA announced that it was withdrawing its plans to pursue rulemaking to develop a conversion factor to convert the 160 ug/m3 (TC) exposure limit to an elemental carbon (EC) exposure limit.  (MSHA's Fed Reg notice here)

As of May 22, 2008, results from the aforementioned NIOSH/NCI mortality study of underground miners exposed diesel exhaust have not yet been published.

Update (January 2010): In comments submitted by Burlington Northern Sante Fe Railraod (BNSF) to the Corps of Engineers concerning a proposed new intermodal rail facility near Kansas City, BNSF claims

"...under a current diesel exhaust study of the mining industry by NIOSH in conjunction with the National Cancer Institute and the Mining Safety and Health Administration, preliminary results are causing a reevaluation of the extent and severity of health effects from exposure to diesel exhaust. The National Research Council is currently evaluating the study." 

NIOSH Director John Howard, MD sets the record straight, saying there is no "reevaluation" of the study nor any involvement of the National Academies.  Dr. Howard replied in response to our inquiry.

Update (May-July 2011)

MARG's motion for civil contempt, April 9, 2010 (here)

MARG's supplemental motion for civil contempt, May 12, 2010 (here

HHS's opposition to MARG's motion for civil contempt, June 3, 2010 (here)

Judge's order, June 23, 2010 (here)

HHS's opposition to MARG's motion for injunctive relief, July 5, 2011 (here)

Letter from Cong. John Kline (R-MN) and Tim Wahlberg (R-MI) to NIOSH director John Howard requesting documents and data on behalf of MARG, July 8, 2011

Letter from Cong. George Miller (D-CA) to NIOSH Director John Howard, August 16, 2011 (here)

HHS opposition to MARG's motion for injunctive relief (July 7, 2011)

MARG motion for injunctive relief (June 10, 2011)

HHS motion to extend June 2010 order (May 31, 2011)

Judge Haik's decision/order August 19, 2011 (here)

Fifth Circuit Court of Appeals order for stay, Sept 2, 2011 (here)


Selected references

Kennecott Greens Creek Mining Company et al v. MSHA, U.S. Court of Appeals (DC Circuit), No 01-1046, Decided February 9, 2007.

Affidavit of William F. Goodling, Member of Congress, May 6, 1999 (Affidavit from Cass Ballenger, Member of Congress, dated May 4, 1999 is otherwise identical.) (AJPH page 29)

Order by Richard T. Haik, US District Judge, March 10, 2000. (AJPH page 29)

Letter from US Senators to Secretary of Labor Alexis Herman, June 2000.

Letter from Senator Enzi to Secretary of Labor Alexis Herman, June 2000.

Final Order by Richard T. Haik, US District Judge, June 5, 2001. (AJPH page 29)

Email from Henry Chajet, MARG Counsel to Asst. Secretary of Labor Lauriski, January 5, 2004. (AJPH page 31)

Chase G. Characterization of Lung Cancer in Cohort Studies and a NIOSH study on Health Effects of Diesel Exhaust in Miners, 2004. (Ref #46)

National Biodiesel Board Applauds Efforts to Improve Air Inside Salt Mine, December 2004. (AJPH page 31)

MARG Data Quality Act Petition, August 2005.

US Senate, Committee on Appropriations, Report No. 104-368 (1996). (Ref #26)

Jim Morris, "Is diesel exhaust hurting miners," USA Today, 2006 (here)

Silverman et al, Diesel exhaust in miners study: nested case control, JNCI, March 2012 (here)

Attfield et al, Diesel exhaust in miners study: cohort mortality study, JNCI, March 2012 (here)