July/August 2003
We commend Scrap for continuing to provide a forum to discuss the important topic of safe handling of beryllium and beryllium-containing materials in the scrap industry. We agree and support many of the comments and cautionary statements made by the National Jewish Medical and Research Center [see the March/April 2003 issue], including the fact that beryllium can be managed in “practical and cost-effective ways,” chronic beryllium disease (CBD) “is preventable,” and “efforts must be made to reduce exposures in the industry as low as possible.” However, the center’s comment that Brush Wellman Inc. mischaracterized the current state of medical and scientific knowledge on the hazards of beryllium is incorrect.
Beryllium is one of many toxic metals found in the scrap processing industry. Aluminum, antimony, arsenic, barium, bismuth, boron, cadmium, chromium, cobalt, copper, iron, lead, magnesium, manganese, mercury, molybdenum, nickel, platinum, rhodium, selenium, silver, tantalum, tellurium, thallium, tin, titanium, tungsten, vanadium, zinc, and zirconium are also considered toxic metals and may be present in materials processed by the scrap industry. Though the relative toxicity of each may vary, overexposure to any of these metals can cause serious adverse health effects to scrap industry workers. Occupational exposure limits have been set for all of these metals and various types of engineering controls, work-practice controls, and personal protective equipment may be required to control employee exposure during the processing of scrap materials.
Recent research by the National Institute for Occupational Safety and Health (NIOSH), in partnership with Brush Wellman, has provided insight into the potential pathways for exposure and cause of CBD. Research findings have shown that a high level of compliance with the current OSHA standard can be protective at preventing clinical CBD, but not necessarily protective at preventing sensitization or subclinical CBD. Research findings also indicate that chemical form, particle size and number, and specific processes can affect work-related risk. These findings raise questions as to which outcome (sensitivity to beryllium, subclinical CBD, or clinical CBD) should be used to establish worker-protection levels and whether the current methods used to measure compliance with the occupational standard are the best way for measuring potential risk to the worker. Recently, an independent association of health scientists—the American Conference of Governmental Industrial Hygienists (ACGIH)—concluded that CBD is the critical endpoint for setting an occupational exposure limit for beryllium.
Brush Wellman used the National Jewish Center’s services in its early workplace studies of the beryllium blood lymphocyte proliferation test (BeBLPT/BeLPT/BLPT) for sensitization. The center is one of only four commercial laboratories in the United States that have invested in equipment and personnel to conduct the test. Conducting screening with the BeBLPT costs about $250 per test, and at least two tests are required to confirm sensitivity. Published scientific studies of BeBLPT results from the National Jewish Center and the three other laboratories revealed substantial disagreement in results among the laboratories. Brush Wellman believes that the National Jewish Center is overstating the value of the BeBLPT as a routine medical screening tool.
In its September 2002 feasibility assessment for beryllium, ACGIH’s biological exposure indices (BEI) committee addresses the value of the BeBLPT by stating, “…criteria for use in screening have not been met at present. The BEI Committee does not recommend BLPT as an effective indicator.”
Independent reviews of the value of the BeBLPT by the U.S. Army, Navy, and Air Force also found the BeBLPT inappropriate for use as a screening test. As an example, the Air Force position states, “Due to the difficulties of questionable sensitivity, specificity and predictive value, the BeLPT is not recommended for screening or surveillance in the Air Force.”
Brush Wellman agrees with the independent scientific positions of the ACGIH and Department of Defense and opposes the National Jewish Center’s efforts to expand the use of the BeBLPT as a screening test. Brush Wellman remains committed to preventing beryllium-related health effects and encourages anyone interested in learning more about beryllium and health to contact us at 800/862-4118 or visit our Web site at www.brushwellman.com.
Theodore Knudson, CIH, Manager, Product Stewardship, Brush Wellman Inc. (Cleveland)
Editor’s Note: To help close this dialog on beryllium, Scrap gave the National Jewish Medical and Research Center the opportunity to respond to two statements in the above letter about the center and its positions.
First, regarding the claim that the National Jewish Center is “overstating the value of the BeBLPT as a routine medical screening tool,” the center replies:
- “The BeLPT is the only currently available clinical test to identify early adverse health effects related to beryllium exposure. Other clinical tests, including chest radiography and pulmonary function tests, are less sensitive, not detecting CBD until late clinical manifestations of the disease are apparent. Chest X-ray and pulmonary function tests are nonspecific and are unable to differentiate CBD from other pulmonary disorders. Furthermore, these tests can’t detect beryllium sensitization (BeS), the allergic condition that precedes the development of CBD. As a clinical test, the BeLPT has very good sensitivity, with estimates ranging from 80 to 90 percent and specificity estimates of 95 percent and greater. We can’t determine the positive predictive value for the BeLPT in detecting CBD because the BeLPT identifies BeS and isn’t diagnostic of CBD. A bronchoscopy or other clinical tests are needed to determine if an individual with a positive blood test has CBD.”
And second, regarding the statement that the National Jewish Center is seeking to “expand the use of the BeBLPT as a screening test,” the center responds:
- “National Jewish supports the use of the BeLPT as part of a multipronged medical surveillance program for workers exposed to beryllium. The BeLPT, used in conjunction with industrial hygiene measures, can identify areas in the plant that pose a risk for the development of BeS and disease. Using a medical surveillance program to screen for BeS allows industries to control exposures with more precision.
“Individual workers who test positive in medical surveillance can be evaluated and, if necessary, treated for CBD prior to the development of irreversible symptoms. Additionally, positive tests can inform the workplace of potentially unsafe exposures related to task-specific work processes.
“National Jewish does not support the position of any industry or institution that advocates withholding the BeLPT from beryllium workers until they present with symptoms. These workers, if they test positive, almost certainly have progressed from BeS to CBD. It’s unlikely that their clinical symptoms can be completely reversed with treatment. Quality of life for a worker diagnosed at this stage of disease will be worse than that of a worker diagnosed with BeS and followed closely for the earliest signs of disease.” •