The Beryllium Thread

[Simplex3]

I'm putting this in here so that it won't hang around the top of the lounge while I cut and paste information in to post after post.

This is part of my ongoing offseaon attempt to get us ranked on the first page of some search engine(s) when nerds search for "beryllium".

Before you PM me with "Why?", the answer is simply that I am sitting around reading log files at work and cutting and pasting into this thread requires absolutely NO mental stress.

[Simplex3]

Eisenbud, was the principle investigator of the Lorain Incident and through his work, it was decide that there should be some type of limits for beryllium exposure. What he decided was that there was a need for two separate limits based on the premise that the acute disease was a direct dose-response, and the chronic disease which appeared to be a selective response of the immune system. Essentially what was derived from his findings was that to prevent being afflicted with the acute disease, a single exposure ceiling level was needed and to keep from getting the chronic beryllium disease, a long term average exposure was need for those that constantly worked with beryllium.

[Simplex3]

This led to the 'Eisenbud levels' for beryllium exposure;

[Simplex3]

(1)to control acute disease, an in-plant maximum concentration of 25 ug beryllium/m3 of air measured,

[Simplex3]

(2) to control the chronic disease, an in-plant concentration of not to exceed 2 ug/m3 of air averaged over an eight hour day and third, in light of the Lorain incident, to protect the general public in the vicinity of a beryllium plant, a concentration not to exceed 0.01 ug/m3 of air as a monthly average concentration.

[Simplex3]

Eisenbud's level seemed so reasonable and valid for the time that, the first two, were adopted by the American Industrial Hygiene Association, the American Conference of governmental Industrial Hygienists and there American National Standards Institute. These profound levels were also, in 1972, used as a consensus standard by the Occupational Safety and Health Administration. Eisenbud's third level was adopted by the United States Environmental Protection Agency in 1974 as a National Emissions Standard for Hazardous Air Pollutants and in Section 112 of the Clean Air Act.

[Simplex3]

{As an aside, in recalling our lecture in class given by Dr. Gordon on respiratory toxicology, bearing in mind that beryllium is such a highly toxic material, should it's exposure levels be changed to an one hour time frame as opposed to theeight hour exposure limit enforced presently? I only bring this up due to Dr. Grodon's mention of the debate presently going I in California about changing the threshold limit values of ozone from it's present eight hour time frame to a one hour time frame. Although, the ozone has peak levels during the day and lower levels during the night and early morning prior to rush hour.}

[Simplex3]

Interestingly, up until 1984, the vast amount of research literature on the pulmonary effects of beryllium and its compounds, there was no specific article/report directly addressing the 'effectiveness' of the threshold limits whichwere adopted in 1949, based on Eisenbuds findings and recommendations. Otto P. Preuss states in a 1984 paper, A Contribution to the Epidemiology of Beryllium Disease that, " The validity of the TLV of 2ug/m3 of air and a thirty minute peak value of 25ug for the prevention of disease has generally been accepted on the basis of overall impressions. However, to date it has never been confirmed in a published study."

[Simplex3]

The conclusions made by Preuss through his own observations, retrospectively, are as follows:

[Simplex3]

1. Exposure to dusts or fumes from pure beryllium metal and beryllium alloys will not cause acute beryllium disease.

[Simplex3]

2. The high selectivity of CBD, and our knowledge that the lymph cells of diseased individuals show evidence of sensitization, justifies the assumption of immune mechanism as its cause.

[Simplex3]

3. Sensitized individuals still require minimum exposures for the development of disease.

[Simplex3]

4. No new cases of CBD have occurred whenever the adopted TLV of 2ug was maintain.

[Simplex3]

So even with out the 'validation' Preuss said Eisenbud's labels were lacking, they still were correct and effective in decreasing the number of CBD cases.

[Simplex3]

With all the new regulation and strict levels being established, a lot changes in the beryllium industry on a whole were taking place. Various plants were closing due to the increased awareness of the hazardous potential of beryllium and the search for alternatives to beryllium led to the decrease in the number of products using beryllium in its production. This was during the 1948-49 time period. In time, 1960-1980, the beryllium industry reemerged and overall, the Eisenbud level proofed to be effective in lowering the number of CBD reports, in light of the increase of beryllium production and the number of employees. This data was collected in 1983.(2) Still with the decrease in the number of beryllium disease cases, reports of the disease still continue to occur, despite the generalized adoption of current air standards. Granted the majority of these reports are due to accidental exposure to spills and/or unmaintained equipment.(4)

[Simplex3]

In 1975 OSHA tried to get the level for the average daily concentrations of beryllium from 2ug to 1ug and also to reduce the maximum concentration from25ug to 5ug. This was done in light of the finding that beryllium was also considered a cancer causing agent and needed further and stricter regulation but this was never passed, because of, once again the lack of sufficient evidence.