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Hanford: workplace beryllium exposure risk assessment. Wint Su Wai and Thanh-Hien Ngo. Hanford. History. Hanford is the most contaminated nuclear site in the western hemisphere Established in 1943 as part of the Manhattan Project to develop nuclear weapons for WWII - PowerPoint PPT Presentation
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HANFORD: WORKPLACE BERYLLIUM EXPOSURE RISK ASSESSMENT
Wint Su Wai and Thanh-Hien Ngo
HANFORD
History
Hanford is the most contaminated nuclear site in the western hemisphere
Established in 1943 as part of the Manhattan Project to develop nuclear weapons for WWII
Home to the B reactor, the first full-scale plutonium production reactor in the world
Focus of the nation's largest environmental cleanup
Stakeholders Hanford Tri-Party Agreement - USDOE, USEPA, ECY-WA Hanford Advisory Board Indian Nations Program Hanford Natural Resource Trustee Council Local Advocacy Groups -Columbia Riverkeeper, Heart of America
Northwest, Hanford Watch, Hanford Challenge, Physicians for Social Responsibility
Nuclear Safety Division of the Oregon Office of Energy
Washington State Department of Health
Present Threats
Water Contamination 450 billion gallons of contaminated
waste have been dumped into unlined soil trenches
53 million gallons of waste in 177 underground storage tanks , 60 have leaked; contamination of groundwater near Columbia River
Atmospheric Contamination
Who is at risk? Workers 1 million people living in the 42 cities or
towns located below Hanford on the Columbia
Draw water from Columbia for municipal, commercial & industrial uses.
Tribal members (Yakima, Utmilla, Nez Perce)
hunting, fishing, social gathering
Radioactive and Chemical Contamination
Hazard Identification
Beryllium
Grayish, lightweight but strong alkaline earth metal
Mining, refining, and in the manufacture of ceramics, electronic, and aerospace equipment.
Used at Hanford from 1960 until 1986 in the production of nuclear fuel rods
“When certain sensitive individuals are exposed to even minute amounts of inhaled beryllium, they are at considerable risk of becoming beryllium sensitized and contracting a potentially fatal granulomatous lung disease called chronic
beryllium disease (CBD) and an increased risk of lung cancer...
...from a worker health and safety perspective based on the number of affected workers,
beryllium currently rates as a greater hazard than radiation.”
- The Hanford Advisory Board
Routes of Exposure
Inhalation (Direct) airborne particles of beryllium metal, alloys,
oxides, and ceramics
Ingestion (Indirect) Hand-to-mouth
Dermal (Indirect) ultrafine particles
Adverse Health Affects
Beryllium Sensitization (BeS) to clinically apparent pulmonary disease
Acute disease: inflammation of lungs and acute pneumonitis
Chronic beryllium disease (CBD) or berylliosis
Dermal and carcinogenic effects Group B1: probable human carcinogen (EPA) Group 1: human carcinogen (IARC)
Takaro et al. study:Screening for Beryllium Sensitization among Former Hanford Workers
Beryllium workers respondent to date, May 1998:
AGE: 21-86 years old Average: 62 years old
SEX: 108 males (87.1%) 16 females (12.9%)
Precautionary Assessment
Parameter Score
Community/Social IssuesGoal 3
Need 3
Future Generations 2
Democratic community based process
2
Alternatives 3
Total 13/15
Unsupportive of health and community
Exposure Issues
Exposure 2
Multiple Exposures 3
Children Exposed 0
Consumer Products 0
Occupational Exposure 3
Food Exposure 0
Total 8/20
Relatively medium risk of exposure
Hazard/Toxicity
Hazard 10
Individual Sensitivity 2
Ecological hazard 2
Volume 5
Persistent 3
Bioaccumulate 3
Uncertainty 2
Total 27/30
Extremely hazardous
Standards and RegulationsAgency Focus Level Comments
American Conference of Government al Industrial Hygienists
ACGIH
Air: workplace 2 ug/m3
0.05 ug/m3
0.2 ug/m3
Advisory: TLV-TWA
Notice of intended change, 2007; TLV-TWA
Notice of Intended Change, 2007; STEL
National Institute for Occupational Safety and Health(NIOSH)
Air: workplace 0.5 ug/m3 Advisory, 10-hour TWA, REL
Occupational Safety and Health Administration (OSHA)
Air: workplace 2 ug/m3
5 ug/m3
25 ug/m3
Regulation, PEL as TWA
Regulation, Ceiling
Regulation, STEL, 30 minute maximum peak
Environmental Protection Agency(EPA)
Air emissions to atmosphere (Clean Air Act)
10 g/24 hours Regulation
Uncertainty FactorsChildren N/A
Subchronic to chronic extrapolation
8
Human Variability 10
Database uncertainty 10
Uncertainty Factor: 8 x 10 x 10 = 800
RfC (Reference Concentration) (ug/m3) =
NOAEL (ug/m3) / Uncertainty Factors
RfC for EPA : 0.02 µg/m3
NOAEL from Eisenbud et al. 1949 : 0.01-0.1 ug/m3
NOAEL from EPA: 0.1 ug/m3
RfC for Eisenbud: 0.005 ug/m3 /800 = 0.00000625 ug/m3
RfC for EPA: 0.1 ug/m3 / 800 = 0.000125ug/m3
Conclusions
The maximum concentration of beryllium via inhalation should be 0.000125 ug/m3 to prevent adverse health affects from workplace exposure. (EPA=0.02 ug/m3)
The OSHA occupational exposure limit for 8-hr workshift 2 ug/m3 is not protective. Should use ACGIH: 0.5 ug/m3
More stringent regulations and guidelines at state, national, and international level.
Risk Management
More studies for workplace inhalation exposure
data for possible chemical transformation of Beryllium and its half-life in air
limited information on reproductive or developmental effects
More adequate exposure monitoring
Dose
Exposure concentrati
on, duration, frequency
Occupational health standard, PPE,
Engineering and Administration
control
Adverse Health Risk: CBD, Lung
Cancer
Genetic Susceptibility
Age, gender, nutrition, behavior
Screening Wellness Program
Surveillance
Hazard
Healthy Worker
Subclinical Disease (BeS)Repair
Progression
Pathways from exposure to disease showing modifying factors and opportunities for interventions.
Risk Communication
Monitoring ambient concentrations Promote awareness towards Beryllium
exposure Preventive Focused Education for workers :
safety, PPE, changing clothes AdvanceMed Hanford’s Beryllium Monitoring
Program BeLPT (Beryllium Lymphocyte proliferation test) Chest radiographs Pulmonary Function Tests Carbon monoxide diffusion Regular follow-up visits
Media Coverage
Do not always get it right
Loss of interest
Disaster or loss of funding newsworthy
Questions?