ADVANCEMENT OF THE SCIENCE
TABLE 3
Case 3: 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
19.9770 0.0003 15.7713 0.0003 0.78947 0.00001 1.96219 0.00002 1.090 µg/L 19.7307 0.0004 15.7469 0.0004 0.79810 0.00001 1.98160 0.00003 9.008 µg/L 19.2338 0.0005 15.6970 0.0004 0.81612 0.00001 2.00743 0.00003 60 µg/ft 2
2 Kitchen first draw Tap water
3 Child’s bedroom floor carpet 4 Living room windowsill 5 Kitchen floor
Wipe
Wipe
19.2135 0.0007 15.6936 0.0006 0.81680 0.00001 2.00960 0.00003 443 µg/ft 2
Wipe Wipe
19.2393 0.0005 15.6952 0.0005 0.81578 0.00001 2.01453 0.00002 37 µg/ft 2 18.9651 0.0006 15.6662 0.0006 0.82606 0.00001 2.03770 0.00003 313 µg/ft 2
6 Front porch entry floor
7 Living room floor
Wipe
19.0367 0.0007 15.6786 0.0006 0.82361 0.00001 2.02807 0.00003 250 µg/ft 2
8 Backyard
Soil 19.3163 0.0004 15.7040 0.0004 0.81300 0.00001 2.01272 0.00003 3,261 µg/g
9 Service lateral 10 Back stairwell windowsill 11 Kitchen window trough 12 Living room window jamb 13 Front porch door 14 Window sash by bed 15 Subject initial blood draw
Pipe
20.6057 0.0005 15.8491 0.0004 0.76915 0.00001 1.91982 0.00003 19,483 µg/g 18.9586 0.0005 15.6716 0.0005 0.82662 0.00001 2.02849 0.00003 3,116 µg/g
Paint
Paint
19.4228 0.0004 15.7114 0.0004 0.80892 0.00001 2.00226 0.00003 63,318 µg/g
Paint
19.8662 0.0004 15.7560 0.0005 0.79311 0.00001 1.97517 0.00003 36,975 µg/g
Paint Paint
19.4478 0.0004 15.7190 0.0004 0.80827 0.00001 1.99512 0.00002 34,821 µg/g 18.3150 0.0007 15.6114 0.0006 0.85239 0.00001 2.07881 0.00003 14,675 µg/g
Whole blood
19.0458 0.0008 15.6809 0.0007 0.82333 0.00001 2.02366 0.00003 16.8 µg/dl
Note. The report unit for the lead isotope ratio is the atom ratio.
Case 5 Case 5 involved a female at 16 months with a BLL of 23 µg/dl. The risk assessment did not identify potential lead hazards in the walls, floors, or points of entry of the home. Based on the HUD questionnaire, suspected hazards included items manu- factured in India, such as pressure cookers, spices, and kajal. The sample closest to the blood (sample 20) isotope composition was kajal (sample 19) and red chili (sample 15; Table 5). Even though the kajal material was insoluble, a sig- nificant amount of lead (approximately 500 ng) was present in the leachate, suggesting this material was rich in lead (Supplemental Table). The kajal isotope ratios were con- sistent with the blood isotopic composition by both major and minor ratios. The wipes
sent for isotopic analysis along with other environmental samples. LIA did not indicate lead-contaminated dust (samples 3–10) or tap water (samples 1 and 2) as potential sources of lead exposure by both the major and minor ratios (Table 4). Samples closest to the blood isotope composition (sample 22) were black pepper (sample 11), cilantro powder (sample 16), and turmeric (sample 13; Figure 1, Case 4). Although black pepper was the closest in isotopic composition to the child’s blood, tur- meric and asafetida had the highest levels of lead concentration out of the spice samples (Supplemental Table). The family stopped using the spices and pressure cookers and were advised to buy locally sourced food items and cookware. After 7 months, the child’s BLL decreased to 4 µg/dl.
(samples 3–11), tap water (samples 1 and 2), and spices (samples 12–18) except red chili (sample 15) had isotope ratios that were not consistent with the blood composition (Fig- ure 1, Case 5). Intervention included use of alternative and locally sourced eyeliners, spices, and pressure cookers. Over the next 6 months, five additional blood lead measurements demonstrated a slow decrease in BLLs: 16, 15, 15, 14 (isotope-analyzed result for sample 20), and 13 µg/dl, respectively. Case 6 Case 6 involved a male at 10 months with a BLL of 14 µg/dl. The child was 16 months at the first isotope-analyzed blood draw (8 µg/dl). The risk assessment found one lead hazard: a bell with a lead concentration of 93 µg/ft 2 . The
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Volume 85 • Number 9
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