ATSDR Presentation to the Washington, DC, Scientific Advisory Board

• Susan W. Metcalf, MD, MSPH

• Ketna Mistry, M.D., F.A.A.P
• Ken Orloff, Ph.D., DABT

The primary public health agency for addressing human health issues that might arise from exposure to hazardous substances

To better characterize past, current, and possible future human exposures to hazardous substances in the environment.

• Environmental samples
• Biomarkers
• Exposure-dose reconstruction

• Quantifies the absorbed Arsenic
• Clears within a few hours
• Not useful for low-level exposure

• Good marker of recent exposure
  • (3-4 days)
• Includes both inorganic and organic forms
• Reference range available

• Inorganic As (As+3, As+5)
• MMA (monomethylarsonic acid)
• DMA (dimethylarsenic acid)
• Trimethylated forms
  • Arsenobetaine
  • Arsenocholine

• Measures several months of exposure
• Collection is non-invasive

• Possibility of external contamination
• Paucity of reference range data for unexposed populations

• Soil arsenic levels
  • Average 57 ppm
  • Highest level 498 ppm
• Children immediately relocated to another area of the campus

• Covered with 2 inches of mulch or grass in some areas
• Playground is periodically remulched

• Daycare roster:
  • 28 children
  • 4 adult staff
• Length of time at daycare:
  • ~50% present: < 7 months
  • ~50% present: > 1 year

• Wood preservatives
• Pesticides
• Arsenic containing herbal medicines
• Parental occupational exposure
• Hobbies
• Consumption of seafood
• Pica (soil eating) behavior

• Hair samples for arsenic:
• 24/ 32 hair samples : not detected
• 8 / 32 hair samples: detected
• 8 Arsenic detected hair samples ranged from 0.10 ppm to 0.14 ppm

• Textbooks: < 1 ppm
• National Research Council: 0.2 ppm
• NCEH: 95th percentile: 0.28 ppm

• Hair arsenic levels were not elevated in the 32 participants of this exposure investigation
• Therefore, no unusual exposure to arsenic was found in the participants at the Child Daycare Center

• Measured speciated urinary As in 300 children near smelter site
• Average soil levels 121-236 ppm
• Average urinary arsenic levels 8.6 µg/L

• Mining site
• Soil levels up to 3500 ppm
• Urine samples tested for As
  • 20/23 below detection levels
  • 6-8 µg/g Cr As in samples where As detected

• Hair analysis
  • 26/36 below level of detection
  • 7 had elevated hair levels
• Urine levels not elevated
• All were remediation workers
• Likely due to external contamination

• At soil levels < 100 ppm, average urine arsenic is similar to background levels
• At soil levels > 100 ppm, urinary levels may show exposure but are below levels associated with health effects