, estimated airborneconcentrations of the particulates of the other metals are also below levels of public health concern.Past emissions of metal particulates from PGDP smelter operations in building C-746A posed "noapparent health hazard", which means that people may have been exposed to metal particulates butthat such exposure is not expected to cause any adverse health effects.
|Metal||Estimated Amount of Metal Smelted at PGDP (pounds) 1||Health Comparison Value |
|Aluminum||> 11,500,000 pounds over more than 21 years 2||8 hr TWA3- 5000 µg/m3|
|Cobalt||71,500 pounds over 4 years||14-365 day MRL4- 0.03 µg/m3 |
8 hr TWA- 50 µg/m3
|Gold||~5284 pounds over 21 years||Not Available|
|Lead||>1,258,990 pounds (no dates)||8 hr TWA- 50 µg/m3|
|Monel (copper-nickel alloy)||882,440 pounds over 4 years||see Nickel|
|Nickel||~37,000,000 pounds over |
6 ˝ years
|>365 day MRL- 0.2 µg/m3 |
8 hr TWA- 15 µg/m3
|Silver||~9,630 pounds over 8 years||8 hr TWA- 10 µg/m3|
|Steel||22,000 pounds (process terminated after test runs)||8 hr TWA- 5000 µg/m3 (as iron oxide dust/fumes)|
|1 Estimates of total amount of metals smelted are derived from DOE [1,2]. |
2 Internal DOE (or AEC) memos and letters indicate, but do not prove, that aluminum smelting at PGDP began in the 1950's, but that in early years was limited to laboratory and bench testing of methods and processes that were instituted in production scale operations in the 1960's.
3 TWA- is the 8 hour time weighted average occupational exposure limit established by the National Institute of Occupational Safety and Health .
4 MRL- is the minimal risk level for residential exposures established by ATSDR.
Comments and Responses to the Public Release Version of the Health Consultation(November 6, 2001)
The following comments were received by ATSDR in response to the public release version of thehealth consultation dated November 6, 2001, which has been included in the public healthassessment as this Appendix I. These comments elicited several modifications of the originalevaluation. Potential source contributions from the PGDP steam plant and TVA Shawnee Facilityhave been added to the dispersion model. Clarifying information and references have been added asindicated in each response. The comments are included verbatim and refer to the consultation,although names and personal identifiers have been redacted. ATSDR responses are in bold type todistinguish the community comments from ATSDR's responses.
I read the recently released Health Consultation titled Exposure Assessment of Airborne Nickel andother Metal Particulates from Historic Smelter Operations at the Paducah Gaseous Diffusion Plantand have the following observations and recommendations for your review.
- Item one: Page one paragraph 2--"Between 1952 and 1986 the PGDP operatedseveral smelters to recycle scrap materials"
Comment: During the referenced time frame the PGDP did operate smelters in theC-746A building for recycling materials but most of the scrap was processed todestroy or disguise the classified nature of the scrap. Another smelter operated in theC-340 complex to produce uranium alloys for use by the DOD and AEC. Though it ispresented as a total review of smelting operations at the PGDP I found no mention ofthe uranium smelter in the document. The processing of other materials is veryimportant since some materials handled in these units was far more dangerous (e.g.organics, beryllium components and uranium) and the cumulative problem presentedby all operations must be studied and quantified. Were conditions "beyond the fence"terribly bad? I don't know but I had hoped that those with the expertise to evaluatethe situation would be given all available information by the DOE.
- Item two: Page one paragraph 3--"The PGDP permit application…emissions occuras nickel oxides."
Comment: As this entire review appears to be based on the PGDP permit applicationand ingot samples (addressed under item 5) and since this report is apparently goingto be used by the DOE as the "there are no problems from smelting" banner, we mustmake sure that e