Medical surveillance in workplaces that use beryllium-containing materials can identify individuals with BeS and at-risk groups of workers, which can help prioritize efforts to reduce inhalational and dermal exposures.

The potential hazards from exposure to beryllium or beryllium compounds in the workplace were first reported in the 1930s. The tritiated thymidine beryllium lymphocyte proliferation test (BeLPT) is an in vitro blood test that is widely used to screen beryllium exposed workers in the nuclear industry for sensitivity to beryllium. The clinical significance of the BeLPT was described and a standard protocol was developed in the late 1980s. Cell proliferation is measured by the incorporation of tritiated thymidine into dividing cells on two culture dates and using three concentrations of beryllium sulfate. Results are expressed as a 'stimulation index' (SI) which is the ratio of the amount of tritiated thymidine (measured by beta counts) in the simulated cells divided by the counts for the unstimulated cells on the same culture day. Several statistical methods for use in the routine analysis of the BeLPT were proposed in the early 1990s. The least absolute values (LAV) method was recommended for routine analysis of the BeLPT. This report further evaluates the LAV method using new data, and proposes a new method for identification of an abnormal or borderline test. This new statistical Á/biological positive (SBP) method reflects the clinical judgment that: (i) at least two SIs show a 'positive' response to beryllium; and (ii) that the maximum of the six SIs must exceed a cut-point that is determined from a reference data set of normal individuals whose blood has been tested by the same method in the same serum. The new data is from the Y-12 National Security Complex in Oak Ridge (Y-12) and consists of 1080 workers and 33 nonexposed control BeLPTs (all tested in the same serum). Graphical results are presented to explain the statistical method, and the new SBP method is applied to the Y-12 group. The true positive rate and specificity of the new method were estimated to be 86% and 97%, respectively. An electronic notebook that is accessible via the Internet was used in this work and contains background information and details not included in the paper. #

Mercuric chloride has been used for control of insect and fungal infestations in herbarium collections for over two centuries. One of the lasting effects of this use is the long­term evolution of elemental mercury vapor from treated specimens. The vapor can contaminate untreated specimens sharing the same closed environment and can pose a human health hazard. By modifying the technique for use of a commercially available mercury indicating powder (Mallinckrodt Baker, Inc., J. T. Baker Mercury Indicator) it is possible to create an inexpensive and fairly rapid test for mercury vapor in herbarium cabinets. The indicator is mixed with deionized water and applied to glass microscope slides. One or more slides are placed inside a cabinet and any color change in the indicator is compared to unexposed controls. In the authors’ experiments, the indicator results were compared against readings taken using a Jerome 431­X Mercury Vapor Analyzer and a Lumex RA­915+ Multifunctional Mercury Analyzer and were found to be broadly related to the concentration of mercury vapor present in each cabinet. The method can be used to check for mercury contamination in incoming shipments of specimens and to identify cabinets that currently contain or formerly contained contaminated specimens. Practical safety guidelines have been developed for accessing cabinets that give a positive test for the vapor and for handling contaminated specimens.

Beryllium is the lightest chemically stable metallic element. Research and development in the 1930s led to its use in industrial applications beginning in the 1940s. Subsequently, reports of lung and skin disease surfaced leading to epidemiologic and toxicology studies of beryllium's health effects. These studies have identified a range of health effects with solubility of the chemical form of beryllium as a key determinant whether the effects are acute (short term) or chronic (long term).The development of lymphocyte proliferation testing (BeLPT) for beryllium sensitization (BeS) in the 1980s and its use in medical screening has led to increasing awareness that occupational chronic beryllium disease (CBD) has not been controlled to the extent once thought. The enforceable long-standing occupational exposure limits intended to prevent CBD are now considered to be obsolete. However, proposed new limits have yet to be adopted. The basis for existing and proposed occupational and public exposure limits and regulatory requirements are discussed here. The current ACGIH and OSHA adopted occupational exposure limit for workers is 2.0 mg/m 3 , based as an 8-hour time weighted average (TWA). An occupational exposure limit of 0.2 m/m 3 (8-Hr TWA) has been adopted by California as a regulatory limit and is being used by others as well. To protect the public from CBD, there is a long-standing EPA beryllium ambient air limit set of 0.01 mg/m 3 as a 30-day TWA.Unlike the acute health effects, CBD affects a few percent (0-4%) of those exposed to beryllium. The latency period between exposure and CBD can vary from months to decades. CBD is caused by the immune system's continuing reaction to the less soluble forms of beryllium retained in the body. An individual is considered to be sensitized to beryllium if BeLPT results show they are able to mount an immune response to beryllium. The morbidity and mortality associated with CBD are primarily due to lung damage caused by chronic inflammation. CBD is treatable but not curable.The existing ERPGs for Be are intended to prevent the acute health effects, primarily chemical pneumonitis caused by the more soluble forms of Be. Patients who survive acute beryllium disease will typically recover in less than 1 year. The need for an emergency response to prevent chronic effects is less obvious, and short-term exposure to the less soluble forms of Be could contribute to risk for CBD. Based on medical surveillance data from various DOE sites for current workers tested (13,270) and former workers (43,628), the number of sensitization and CBD cases at each site is a few percent (0-4%). Sensitization and CBD are due to an immune-system response, and they have not been found to be sensitive to the length of employment of a worker in a beryllium facility.

This article recommends an 8-hour occupational exposure limit (OEL) for beryllium. It responds to growing concerns about the continuing incidence of chronic beryllium disease despite the long-standing OEL for beryllium: 2 micrograms of beryllium per cubic meter of air (microgram/m3), 8-hour time-weighted average (TWA). Current 8-hour TWA beryllium OELs are not based on chronic beryllium disease toxicology and an increasing number of studies report incidence of chronic beryllium disease at exposure levels apparently below 2 micrograms/m3. The experience of the beryllium-exposed population of Lorain, Ohio, in the late 1940s, and the ambient air regulatory standards derived from that event provide evidence that establishing a protective level is possible. These levels are used as the basis for a new recommended beryllium exposure standard. A correspondingly protective 8-hour TWA level of 0.1 microgram/m3 has been derived, which, for commonly encountered workplace conditions (in terms of geometric standard deviation and percent-compliance), should provide long-term mean exposure protection comparable to that received by the unaffected Lorain subpopulation and provided by the Environmental Protection Agency (EPA) ambient standard. It is concluded that an exposure limit of 0.1 microgram/m3 combined with exposure monitoring to assure a high rate of day-to-day compliance would provide better control of both long-term mean exposure levels and short-term levels than do current occupational exposure limits. The health data available, while certainly not conclusive, support further reductions in exposure levels to help minimize the incidence of chronic beryllium disease.