Air Quality Criteria for Lead Volume II of II - (NEPIS)(EPA) - US ...

Table AX7-2.2.5. Comparison of NCBP and NAWQA Ambient Lead Levels
in Whole Organism Tissues
Whole Organism Lead Concentration (µg/g dry weight)
Statistic NCBP 1 NAWQA
Geometric Mean 0.55 0.54
Maximum 24.40 22.60
85th Percentile 1.10 1.60
1 To convert between wet and dry weight, wet weight values were multiplied by a factor of five.
southeastern states (Figure AX7-2.2.12 and Figure AX7-2.2.13). As expected, the majority of
the samples with elevated Pb concentrations were taken from sites classified as urban,
commercial/industrial, or mining.
Input and Distribution of Lead in Other Aquatic Systems
Because the NAWQA database does not cover lakes or the sea where atmospheric
deposition of Pb is highly likely, the primary literature was searched for studies using ultra-clean
sampling/analytical techniques to characterize Pb concentrations in these environments. Lead
concentrations in lakes and oceans were generally found to be much lower than those measured
in the lotic waters assessed by NAWQA. Surface water concentrations of dissolved Pb measured
in Hall Lake, Washington in 1990 ranged from 2.1 – 1015.3 ng/L (Balistrieri et al., 1994).
Nriagu et al. (1996) found that the average surface water dissolved Pb concentrations measured
in the Great Lakes (Superior, Erie, and Ontario) between 1991 and 1993 were 3.2, 6.0, and
9.9 ng/L, respectively. Lead concentrations ranged from 3.2 – 11 ng/L across all three lakes.
Similarly, 101 surface water total Pb concentrations measured at the HOT station ALOHA
between 1998 and 2002 ranged from 25 – 57 pmol/kg (5 – 11 ng/kg; (Boyle et al., 2005). Based
on the fact that Pb is predominately found in the dissolved form in the open ocean (