TABLE 2
Case 2: Lead Isotope Ratios With Standard Error and Concentration for Whole Blood and Environmental Sources Sampled for Lead Isotope Analysis
206 Pb/ 204 Pb 2 σ /√n
207 Pb/ 204 Pb 2 σ /√n
207 Pb/ 206 Pb 2 σ /√n
208 Pb/ 206 Pb 2 σ /√n Lead (Pb) Concentration
Sample #
Sample
Sample Type
1 5-min flush
Tap water
19.8351 0.0006 15.7582 0.0006 0.79446 0.00001 1.97195 0.00003 0.361 µg/L 19.0985 0.0004 15.6843 0.0004 0.82123 0.00001 2.01598 0.00003 0.798 µg/L 18.3052 0.0005 15.6115 0.0004 0.85284 0.00001 2.07685 0.00002 57.6 µg/ft 2
2 Kitchen first draw Tap water
3 Child’s bedroom windowsill 4 Child’s bedroom carpet 5 Master bedroom floor 6 Dining room windowsill 7 Rear stairwell floor
Wipe
Wipe
18.4668 0.0004 15.6265 0.0005 0.84619 0.00001 2.06621 0.00004 11.5 µg/ft 2
Wipe
18.6236 0.0005 15.6444 0.0005 0.84004 0.00001 2.05522 0.00003
9.0 µg/ft 2
Wipe
18.5622 0.0004 15.6333 0.0004 0.84221 0.00001 2.06086 0.00003 1,272 µg/ft 2
Wipe
18.4468 0.0006 15.6291 0.0005 0.84726 0.00001 2.06730 0.00003 181 µg/ft 2
8 Backyard
Soil
18.8866 0.0006 15.6614 0.0005 0.82924 0.00001 2.04108 0.00003
248 µg/g
9 Street lateral 10 Floor lateral 11 Front porch 12 Living room wall (side A) 13 Living room window jamb 14 Child’s bedroom window jamb 15 Rear stairwell 16 Subject initial blood draw
Pipe 18.5256 0.0003 15.6284 0.0004 0.84361 0.00001 2.06981 0.00003 128,683 µg/g Pipe 19.7667 0.0005 15.7650 0.0004 0.79756 0.00001 1.98448 0.00002 32,438 µg/g
Paint Paint
18.4497 0.0005 15.6255 0.0005 0.84692 0.00001 2.06890 0.00004 2,659 µg/g 18.2564 0.0004 15.5862 0.0004 0.85374 0.00001 2.08100 0.00003 38,033 µg/g
Paint
18.0086 0.0004 15.5817 0.0004 0.86524 0.00001 2.09786 0.00003 37,011 µg/g
Paint
17.8365 0.0004 15.5680 0.0005 0.87282 0.00001 2.10845 0.00003 53,193 µg/g
Paint
19.1132 0.0004 15.6884 0.0004 0.82081 0.00001 2.01580 0.00003 25,993 µg/g 18.4896 0.0005 15.6273 0.0005 0.84520 0.00001 2.06345 0.00003 13.2 µg/dl
Whole blood
Note. The report unit for the lead isotope ratio is the atom ratio.
doors, walls, and trim of the home. The high- est lead concentrations were the interior win- dowsills (mean of 1,158 µg/ft 2 ), the porch entry floor (54 µg/ft 2 ), and the backyard play area (4,874 ppm). The HUD questionnaire indicated that the child ate and played in the living room and at the windowsills. The main suspected sources of exposure were interior windowsills and floors with soil tracked from the backyard. LIA excluded tap water (samples 1 and 2) and the lateral service line (sample 9) as the primary source of exposure given the poor match with blood PbIR (sample 15; Table 3). Samples closest to the blood PbIR were the paint in the back stairwell windowsill (sample 10), wipe from the living room
floor (sample 7), and wipe from the front porch entry floor (sample 6) by both major and minor ratios. Dust sample (samples 3–7) isotope compositions were similar to each other and plotted within the upper and lower limits of the isotope ratios of the sam- ples from paint (samples 10–14) and soil (sample 8), which suggested that the dust samples were likely a result of paint dete- rioration and soil tracked inside the home (Figure 1, Case 3). LIA excluded potential sources so that priority could be given to the floors and points of entry to the home. Even though remediation work was not performed, clean- ing was increased. Overall, 2 months after the initial BLL, the second BLL decreased
to 9 µg/dl. The child’s family moved 15 months after first blood draw and 2 months after the move, the child’s BLL decreased further to 4 µg/dl. Case 4 Case 4 involved a male at 15 months with a venous BLL of 10 µg/dl. The risk assessment did not find any lead hazards in the walls, floors, or points of entry of the home. Based on the questionnaire, the main suspected sources of exposure were spices and pressure cookers purchased in India. Lead concentra- tions in turmeric, asafetida, teething powder, and kajal with aela (a cultural eye cometic) were 99, 180, 97, and 98 ppm, respectively. The spices turmeric and asafetida were then
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May 2023 • our4'l o, 4</ro4me4:'l e'l:.
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