Knowing Endangerment - Hanford Challenge

The PNNL report examined emissions from Tank C-103 and found that 221 gases released from C-
103 were identified from the Hanford Tank Waste Information Network System (TWINS). The goal
of the study was to determine the health risks from inhalation of the vapors exhausted from two
exhauster tank stack configurations (one bent at the top and one straight stack) and whether worker
exposures to the tank‟s chemical vapors were within OSHA guidelines. 14
The PNNL study identified major uncertainties in knowledge pertaining to
toxicity effects of many of the chemicals detected in the tank. The report
emphasizes the synergistic effects of the chemicals upon each other,
asserting that “many of the vapor-phase chemicals are in a volatile, reactive
state” and that “the potential for synergism increases exponentially with the
number of compounds making up the exposure.” 15 According to the report,
tank farm workers
may be at potentially greater risk than is commonly held for the
Hanford Site. The scenario becomes more realistic as the
maintenance of tank chemicals shifts to remediation. It is further
unclear whether cancer is induced after chronic exposure or
perhaps after a single release. In any case, because the latent
period for manifesting most forms of cancer is approximately 20
years, it will be unlikely that the etiology will be traced to any
given event. 16
The PNNL scientists
concluded that the risk
of contracting cancer
from exposure to the
chemical vapors from
tank C-103 could be as
high as 1.6 in 10, and
that even this estimate
“may not represent the
highest potential risks.”
They further asserted
that if other nearby
tanks were to vent to the
outside, which all
Hanford tanks do, then
“the risks would be
increased.”
The report went on to state that while a tank worker may not receive a chemical vapor dose in excess
of OSHA regulations (because of OHSA‟s methodology for determining exposures to mixtures of
chemicals), “the worker would be at risk of developing cancer, or other chronic disease, from the
exposure.” 17
C. Historical Exposures and Responses
The 1992 DOE Type B Investigation
In the 55 months between July 1987 and January 1992, there were 16 incidents where tank farm
workers were exposed to chemical vapors and required medical attention (see Appendix A). This
series of events triggered investigations by the U.S. Senate Committee on Governmental Affairs, the
DOE‟s Office of Environment, Safety and Health, DOE‟s Office of Inspector General, and, upon
invitation, the Occupational Safety and Health Administration (OSHA). 18 These investigations found
that DOE contractors were failing to provide adequate worker protection after repeated internal
14 Id.
15 Id. at 7.2.
16 Id. (emphasis added).
17 Id. at 8.1.
18 Robert Alvarez, Professional Staff, U.S. Senate Committee on Governmental Affairs, Memorandum to Files,
Environmental, Safety and Health Issues at the U.S. Department of Energy’s Hanford Site, April 10, 1993.
7