revised final - Agency for Toxic Substances and Disease Registry ...

MERCURY 415
5. POTENTIAL FOR HUMAN EXPOSURE
Granato et al. (1995) reported that municipal solid waste sludge mercury concentrations from the
Metropolitan Water Reclamation District of Greater Chicago ranged from 1.1 to 8.5 mg/kg (ppm), with a
mean concentration of 3.31 mg/kg (ppm). Sludge applications to a sludge utilization site in Fulton
County, Illinois, from 1971 to 1995 significantly increased extractable soil mercury concentrations. In
addition, 80–100% of the mercury applied to the soils in sewage sludge since 1971 still resided in the top
15 cm of soil.
Facemire et al. (1995) reported industrial contamination of soils and sediment in several states in the
southeastern United States. The authors reported soil concentrations up to 141,000 ppm associated with
contamination in northeastern Louisiana from mercury-charged manometers used to measure pressure and
delivery from natural gas wells. In Tennessee, a maximum mercury concentration of 1,100 ppm
(associated with previous operations of the Oak Ridge nuclear facility) was found in wetland soils
adjacent to the East Fork Poplar Creek. A pharmaceutical company’s effluents enriched sediments in a
localized area of Puerto Rico to 88 ppm mercury (Facemire et al. 1995). Rule and Iwashchenko (1998)
reported that mean soil mercury concentrations of 1.06 ppm were collected within 2 km of a former chloralkali
plant in Saltsville, Virginia, and that these concentrations were 17 times higher than regional
background soil samples (0.063 ppm). These authors further reported that soil organic content,
topographic factors, wind patterns, and elevation were variables significantly related to mercury
concentration as determined by regression analysis. Soil mercury levels decreasing with distance from
the former plant were indicative of a point source distribution pattern. A made land soil type (Udorthent),
which appears to be a by-product of the chlor-alkali manufacturing process, was found proximal to the
former plant site and contained about 68 times (4.31 ppm) the regional background concentration.
The top 15 cm of sediments in Wisconsin lakes contained higher levels of mercury (0.09–0.24 µg/g
[ppm]) than sediments at lower sediment levels (0.04–0.07 µg/g [ppm]). Because the lakes are not known
to receive any direct deposition of mercury, it was postulated that the primary mercury source was
atmospheric deposition (Rada et al. 1989). Mercury levels in surface sediments of the St. Louis River
ranged from 18 to 500 ng/L (ppt) (Glass et al. 1990). Mercury was detected in sediment samples from
Crab Orchard Lake in Illinois at concentrations greater than 60 µg/L (ppb) (Kohler et al. 1990). Surficial
sediment samples from several sites along the Upper Connecting Channels of the Great Lakes in 1985 had
mercury concentrations ranging from below the detection limit to 55.80 µg/g (ppm) (mean concentrations
ranged from 0.05 to 1.61 µg/g [ppm] at four sites) (Nichols et al. 1991). Mercury concentrations were
correlated with particle size fractions and organic matter content (Mudroch and Hill 1989). Surface