JOURNAL OF fifteen dollars Environmental Health Published by the National Environmental Health Association www.neha.org Dedicated to the advancement of the environmental health professional Volume 85, No. 9 May 2023
eXact iDip GET IT ON Analyze 11 important pool parameters (Direct Read) (Total Alkalinity, Calcium Hardness, Chloride (Salt), Free/Total Chlorine, Total Bromine, Combined Chlorine, Copper, Cyanuric Acid, PH, and Phosphate) Poolside testing with lab-quality accuracy & reliability NEW! Connects with the eXact iDip® app using Bluetooth™ Time, Date & GPS location stamp (When used with eXact iDip® app) Economical solution for testing multiple pools 800-861-9712 SENSAFE.COM SENSAFE ITSSENSAFE SENSAFE_ITS DIGITAL ACCURACY FOR BETTER POOL CARE eXact iDip® is a registered trademark of Industrial Test Systems, Inc. Rock Hill, SC 29730 USA ©2023 Bluetooth® is a registered trademark. App Store is a service mark of Apple, Inc. Android and Google Play are service marks of Google, Inc. NEHA0423 Pool Certified to NSF/ANSI Standard 50 Safe, Simple, Certified™ NEW NOW WITH BLUETOOTH®
May 2023 • our4'l o, 4</ro4me4:'l e'l:. 3 ADVANCEMENT OF THE SCIENCE Lead Source Attribution by Stable Isotope Analysis in Child Risk Assessment Investigations ........................................................................................................... 8 Guest Commentary: A Call for Action to Increase the Scrutiny of Surface Cleaning and Cleaning Agents in Retail Food Establishments ..................................................................... 20 Special Report: Federal Meat and Poultry Inspection Duties and Requirements—Part 1: History and Current Responsibilities ........................................................................................... 22 ADVANCEMENT OF THE PRACTICE Special Report: Increasing Diversity in Environmental Health Graduate Programs ...................... 26 Direct From AAS: Strategic Professional Development ................................................................ 30 Direct From CDC/Environmental Health Services: Here Come the Surf Venues and Artificial Swimming Lagoons ................................................................................................ 32 Direct From U.S. EPA/O ce of Research and Development: Stimulating Innovation Through the Challenges and Prizes Program From the U.S. Environmental Protection Agency...... 34 Environmental Health Across the Globe: Artificial Intelligence and Environmental Health Teaching: Impacts for the Wider Profession ...................................................................... 38 Programs Accredited by the National Environmental Health Science and Protection Accreditation Council....................................................................................... 40 ADVANCEMENT OF THE PRACTITIONER Environmental Health Calendar ...............................................................................................42 Resource Corner........................................................................................................................ 43 JEH Quiz #6............................................................................................................................... 44 YOUR ASSOCIATION President’s Message: We Are Your Strongest Advocate ............................................................................. 6 Special Listing ........................................................................................................................... 46 NEHA 2023 AEC....................................................................................................................... 48 NEHA News .............................................................................................................................. 50 NEHA Member Spotlight .......................................................................................................... 54 JOURNAL OF Environmental Health Dedicated to the advancement of the environmental health professional Volume 85 No 9 '? ABOUT THE COVER Multiple organizations and agencies have called for a more diverse environmental health workforce. In environmental health practice—taking into consideration the importance of community engagement—diversity in the workforce is crucial to ensuring a wealth of cultural knowledge that facilitates community relations and builds trust. In this month’s cover article, “Increasing Diversity in Environmental Health Graduate Programs,” the study aimed to determine what motivates and deters students from historically marginalized populations from pursuing degrees in environmental health and to develop recommendations that programs can implement to diversify their student body and, subsequently, the workforce. See page 26. Cover image © iStockphoto: Pekic, Ridofranz, ferrantraite, eyecrave productions, FG Trade, Sabrina Bracher ADVERTISERS INDEX Custom Data Processing......................................... 7 Environmental Health and Land Reuse Certificate Program .............................................. 19 Hedgerow Software, US, Inc. ................................ 55 HS GovTech.......................................................... 56 Industrial Test Systems, Inc.................................... 2 JEH Advertising ....................................................41 NEHA Awards ..................................................5, 37 NEHA Credentials .......................................... 31, 45 NEHA Endowment and Scholarship Funds ..25, 29 NEHA Membership .......................................... 4, 41
4 Volume 85 • Number 9 in the next Journal of Environmental Health don’t miss Official Publication Journal of Environmental Health (ISSN 0022-0892) Kristen Ruby-Cisneros, Managing Editor Ellen Kuwana, MS, Copy Editor Hughes design|communications, Design/Production Cognition Studio, Cover Artwork Soni Fink, Advertising For advertising call (303) 802-2139 Technical Editors William A. Adler, MPH, RS Retired (Minnesota Department of Health), Rochester, MN Gary Erbeck, MPH Retired (County of San Diego Department of Environmental Health), San Diego, CA Thomas H. Hatfield, DrPH, REHS, DAAS California State University, Northridge, CA Dhitinut Ratnapradipa, PhD, MCHES Creighton University, Omaha, NE Published monthly (except bimonthly in January/February and July/ August) by the National Environmental Health Association, 720 S. Colorado Blvd., Suite 105A, Denver, CO 80246-1910. Phone: (303) 8022200; Fax: (303) 691-9490; Internet: www.neha.org. E-mail: kruby@ neha.org. Volume 85, Number 9. Yearly subscription rates in U.S.: $150 (electronic), $160 (print), and $185 (electronic and print). Yearly international subscription rates: $150 (electronic), $200 (print), and $225 (electronic and print). Single copies: $15, if available. Reprint and advertising rates available at www.neha.org/jeh. Claims must be filed within 30 days domestic, 90 days foreign, © Copyright 2023, National Environmental Health Association (no refunds). All rights reserved. Contents may be reproduced only with permission of the managing editor. Opinions and conclusions expressed in articles, columns, and other contributions are those of the authors only and do not reflect the policies or views of NEHA. NEHA and the Journal of Environmental Health are not liable or responsible for the accuracy of, or actions taken on the basis of, any information stated herein. NEHA and theJournal of Environmental Health reserve the right to reject any advertising copy. Advertisers and their agencies will assume liability for the content of all advertisements printed and also assume responsibility for any claims arising therefrom against the publisher. The Journal of Environmental Health is indexed by Clarivate, EBSCO (Applied Science & Technology Index), Elsevier (Current Awareness in Biological Sciences), Gale Cengage, and ProQuest. The Journal of Environmental Health is archived by JSTOR (www.jstor.org/journal/ jenviheal). All technical manuscripts submitted for publication are subject to peer review. Contact the managing editor for Instructions for Authors, or visit www.neha.org/jeh. To submit a manuscript, visit http://jeh.msubmit.net. Direct all questions to Kristen Ruby-Cisneros, managing editor, kruby@neha.org. Periodicals postage paid at Denver, Colorado, and additional mailing offices. POSTMASTER: Send address changes to Journal of Environmental Health, 720 S. Colorado Blvd., Suite 105A, Denver, CO 80246-1910. Printed on recycled paper. Coronavirus Surrogate Persistence and Cross-Contamination on Food Service Operation Fomites Federal Meat and Poultry Inspection Duties and Requirements—Part 2: The Public Health Inspection System, Marks of Inspection, and Slaughter Inspections Unfolding Outbreak Scenarios Can Be a Bite-Size Treat and Other Lessons From New Zealand’s First Online Environmental Health Conference Join our environmental health community. It is the only community of people who truly understand what it means to do what you do every day to protect the health of our communities. Join us today. Your people are waiting. neha.org/membership Find Your People. Find Your Training. Find Your Resources.
May 2023 • our4'l o, 4</ro4me4:'l e'l:. 5 Recognize your colleague! Do you work with someone who is always coming up with creative ways to educate the public or colleagues? Is there someone on your team who has created tools or a practice that has really made a difference in improving environmental health? Nominate them for the Joe Beck Educational Contribution Award and show them how much you value their contribution. Nomination Deadline: May 15, 2023 neha.org/awards Joe Beck Educational Contribution Award Do you know someone who is walking the walk? When your colleague or team steps up to create a more just, diverse, equitable, and inclusive environment, it matters! Let them know by nominating them today for the Dr. Bailus Walker, Jr. Diversity and Inclusion Awareness Award. Nomination Deadline: May 15, 2023 neha.org/awards Dr. Bailus Walker, Jr. Diversity and Inclusion Awareness Award
6 Volume 85 • Number 9 YOUR ASSOCIATION D. Gary Brown, DrPH, CIH, RS, DAAS We Are Your Strongest Advocate PRESIDENT’S MESSAGE Dr. Martin Luther King, Jr. said, “Courage is an inner resolution to go forward despite obstacles.” My fellow environmental health professionals, every day you show tremendous courage, fortitude, and empathy toward protecting the public. You constantly amaze me by coming up with novel solutions to problems people never realized they had. In our profession, people never speak about being bored. Speaking with environmental health professionals throughout the land, everyone loves our field. Please share your passion for environmental health with everyone you meet just like the individuals on Sesame Street. As Dr. David Dyjack, executive director of the National Environmental Health Association (NEHA), states, “Environmental health is a contact sport.” As such, contact is necessary to get our message out. We share the message of environmental health with our elected ocials and policy makers to improve the profession and provide our members with the tools they need. The NEHA Board of Directors, along with several of our members, spoke with elected ocials and policy makers during our sixth annual Hill Day on February 23, 2023, to educate, enlighten, and hopefully, even entertain. Darwin D. Martin stated, “A teacher’s job is to take a bunch of live wires and see that they are well-grounded.” Doug Farquhar, our director of Government Aairs, does an unbelievable job in preparing us for Hill Day and ensuring we are well-grounded. He even provides a Hawaiian shirt and sneaker wearing fashionista such as myself with professional dress tips such as wearing socks and a tie. We are the profession’s strongest advocate for excellence in the practice of environmental health as we deliver on our mission to build, sustain, and empower an eective environmental health workforce. Our message is to speak about the importance of a robust and well-resourced environmental health workforce. Many people might not know that we represent almost 7,000 government and private sector environmental health professionals in the U.S. The messages we shared during Hill Day included: • Environmental health professionals assure healthy, safe, and prosperous communities. • Environmental health professionals often work outside traditional health departments and might be omitted from the benefits of legislation if not specifically called out. • Environmental health professionals are allies in environmental justice eorts. • Environmental health professionals are on the front lines in climate and health issues. Environmental health services are not a luxury. They are essential to providing the public basic needs, such as safe drinking water, clean air, safe food, healthy housing, climate change adaptation, emergency preparedness, and more. Environmental health has long been recognized as being a crucial service of government at state, local, tribal, territorial, and federal levels. Environmental health professionals are scientifically trained and certified to identify and mitigate environmental dangers as well as promote alternatives. We are handling threats on the front lines of public health. Environmental health professionals form a critical component of the public health delivery system, providing services to curb environmental health threats and prevent adverse health outcomes. We assist communities to prepare for, respond to, and recover from disease outbreaks and natural and anthropogenic disasters. We are on the front lines of public health handling threats such as environmental inequities (e.g., lead exposure), climate change (e.g., drought), food safety (e.g., baby food), safe drinking water (e.g., perfluorooctanesulfonic acid [PFOS]), and clean air (e.g., ozone). Our message is to speak about the importance of a robust and well-resourced environmental health workforce.
May 2023 • Journal of Environmental Health 7 Environmental health professionals are strategically positioned to identify and intervene to prevent public health and environmental health threats from a ecting local populations. As a nation, the U.S. spends over $3 trillion annually on healthcare but lags behind other developed countries in practically every health metric. The lack of investment into the environmental health system is costly for this nation. The top four messages we wanted the congressional sta we met with during Hill Day to remember were to: 1. Fund the National Center for Environmental Health within the Centers for Disease Control and Prevention at $300 million and to fund the Agency for Toxic Substances and Disease Registry at $95 million. 2. Fund the Federal and State Initiative of the Food and Drug Administration— which supports food safety inspections— at $140 million and provide $35 million for states to purchase equipment to serve healthier meals and improve food safety. 3. Encourage the Health Resources and Services Administration to include environmental health within the Public Health Workforce Loan Repayment Program. 4. Share with the congressional oces the importance of environmental health to state and local public health agencies. The author J.K. Rowling said, “No story lives unless someone wants to listen. The stories we love best do live in us forever.” Please share your environmental health stories with your elected ocials and policy makers to improve the profession. Even if you are not comfortable speaking with these individuals, remember what Elmo said, “If you keep practicing, you can do anything.” The more we share our stories with elected ocials, policy makers, fellow scientists, and the public, the greater the impact. When people think of how public health improves their lives, what comes to mind is what environmental health ensures— clean air, food, and water along with a safe and healthy place to live, work, and play. Environmental health provides the biggest bang for the buck of all of the health fields. As Warren Bu ett stated, “Someone’s sitting in the shade today because someone planted a tree a long time ago.” Environmental health professionals have planted forests to protect the public. I look forward to seeing you at our 2023 Annual Educational Conference & Exhibition in New Orleans, Louisiana, on July 31– August 3. Thank you for all of your hard work to protect the public every day. Please continue helping me spread the word that environmental health is public health. As Yoda sagely stated, “Try not. Do or do not. There is no try.” gary.brown@eku.edu Environmental health solutions since 1983 CUSTOMIZE. REDUCE COSTS. IMPROVE ACCURACY. www.cdpehs.com (800) 888-6035 Inspections | Permits | Reporting | Scheduling | Online Bill Pay | On/Offline Mobility
8 Volume 85 • Number 9 ADVANCEMENT OF THE SCIENCE Introduction Lead exposure early in life can lead to irreversible harm; even low levels of lead exposure can a ect the developing central nervous system and result in impaired cognitive function (Hou et al., 2013; Reuben et al., 2017). The primary intervention for a child with a case of lead poisoning is to remove the sources of lead from the child’s environment. Finding the sources, however, can be a significant challenge because lead is pervasive and is present in many materials. Environmental health specialists use screening questionnaires to identify likely exposure routes and X-ray fluorescence instruments to determine lead concentrations of materials in the home. Confirming the cause of lead exposure requires removing the source and observing a reduction in the child’s blood lead level (BLL), the latter of which might take months to years depending on peak BLLs and chronicity of exposure. Standard risk assessment methods can fail to identify the primary cause and result in continued lead exposure. Lead isotope analysis (LIA) holds promise for improving the accuracy of childhood lead investigations. LIA is based on the four stable, naturally occurring isotopes of lead (204Pb, 206Pb, 207Pb, and 208Pb), which all have relative abundances in the Earth’s crust. Isotopes 208Pb, 207Pb, and 206Pb are products of radioactive decay over geologic time. The abundances of isotopes vary given the age of the lead ore due to this radioactive decay. Isotope abundances are analyzed as Pb isotope ratios (PbIR), which are distinct and commonly called isotopic fingerprints. Advancements in technology used to measure isotopic fingerprints have increased discrimination due to higher sensitivity and precision compared with earlier applications (Gulson et al., 1995; Gwiazda et al., 2005; Millen et al., 1995; Oulhote et al., 2011; Ya e et al., 1983). Given the potential of LIA for lead risk assessment, the Wisconsin Department of Health Services piloted a case series to demonstrate the use of high-precision LIA in identifying the primary source and secondary contributors of lead exposure among Wisconsin children with lead poisoning. Methods Investigation Protocol To be eligible for this case series, a child with a case of lead poisoning must have met the following criteria: 1) peak venous BLL ≥10 µg/dl, 2) age ≤6 years, and 3) resided in southern Wisconsin. Public health o¥cials identified and conducted data collection among six cases during May 2019–November 2021. Local health departments obtained consent from the child’s legal guardian. b9:r'): Lead isotope analysis (LIA) is a promising technique for identifying potential sources of lead exposure among children with lead poisoning that are not revealed via traditional lead risk assessment methods. A total of six Wisconsin children with blood lead levels (BLLs) ≥10 µg/dl were included in this case series. Lead isotope ratios from blood and environmental samples were analyzed using a multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS) to determine exposure source. LIA identified likely sources of lead poisoning: lead-based paint, dust, imported spices, ceremonial objects, or mixtures of these sources. LIA both corroborated findings from standard lead risk assessment and identified novel sources. LIA using high-precision MC-ICP-MS can identify and exclude sources of exposure when interpreted alongside traditional lead risk assessment approaches. Furthermore, LIA can serve as a useful tool in identifying and eliminating lead exposures in poisoning cases, particularly when traditional methods fail to identify the likely cause. Summer Shaw, MPH Bureau of Environmental and Occupational Health, Wisconsin Department of Health Services Sean Scott, PhD Wisconsin State Laboratory of Hygiene Maeve Pell, MPH Bureau of Environmental and Occupational Health, Wisconsin Department of Health Services University of Wisconsin Madison School of Medicine and Public Health Jeff Raiche-Gill Bureau of Environmental and Occupational Health, Wisconsin Department of Health Services University of Wisconsin Madison School of Medicine and Public Health Carrie Tomasallo, MPH, PhD Bureau of Environmental and Occupational Health, Wisconsin Department of Health Services Jonathan Meiman, MD Bureau of Environmental and Occupational Health, Wisconsin Department of Health Services Lead Source Attribution by Stable Isotope Analysis in Child Risk Assessment Investigations
May 2023 • our4'l o, 4</ro4me4:'l e'l:. 9 Certified risk assessors conducted a leadbased paint risk assessment and administered the Resident Questionnaire for Investigation of Children With Elevated Blood Lead Levels from the U.S. Department of Housing and Urban Development (HUD, Form 16.1). An environmental health specialist from the Wisconsin Department of Health Services obtained environmental samples for LIA. This case series was deemed by the Wisconsin Department of Health Services to constitute public health surveillance and practice, thus review by an institutional review board was not required. Lead-Based Paint Risk Assessment Lead in surface coatings was identified using an X-ray fluorescence instrument to determine lead loading in mg/cm2. Leadbased paint was defined as ≥0.7 mg/cm2 and a lead dust hazard as ≥40 µg/ft2 on a floor, 200 µg/ft2 on a windowsill, and 1,200 ppm in soil (Supplemental Text, www.neha.org/ jeh-supplementals). Isotope Sample Preparation and Analysis All acid reagents used for laboratory procedures were Optima grade purchased from Fisher Scientific. Different sample types required slight modifications to digestion and preparation procedures prior to purification. Tap water samples (first draw and 5-min flush) were collected in clean 2-L fluorinated ethylene propylene bottles and dried in 1-L polytetrafluoroethylene (PFA) jars. Dust wipes, paint samples, pipes and solder, spices, cosmetics, and whole blood were digested in PFA jars on a hotplate using combinations of concentrated nitric and hydrochloric acids. Soil samples were digested using a combination of nitric and hydrofluoric acids. Lead was purified from samples using the standard anion exchange technique (Strelow & Toerien, 1966). Lead isotopic analysis was performed using Tl-doping on a NeptunePlus multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS). Total lead concentrations of the analyzed materials were estimated using the dilution factors and standard concentrations used for the isotopic analysis. Full sample preparation and analytical details are provided in the Supplemental Text. Results from LIA were used to calculate major (ratios not including Pb204) and minor (ratios including Pb204) isotopic ratios. These ratios were qualitatively compared with isotopic ratios from blood samples to identify the likely source of exposure. Case 1: Lead Isotope Ratios With Standard Error and Concentration for Whole Blood and Environmental Sources Sampled for Lead Isotope Analysis Sample # Sample Sample Type 206Pb/204Pb 2σ/√n 207Pb/204Pb 2σ/√n 207Pb/206Pb 2σ/√n 208Pb/206Pb 2σ/√n Lead (Pb) Concentration 1 5-min flush Tap water 19.1288 0.0007 15.6850 0.0006 0.81997 0.00001 2.02814 0.00003 0.501 µg/L 2 Kitchen first draw Tap water 19.2560 0.0006 15.7004 0.0005 0.81535 0.00001 2.01897 0.00003 0.514 µg/L 3 Living room carpet floor Wipe 18.6609 0.0007 15.6362 0.0007 0.83792 0.00001 2.05779 0.00004 1.43 µg/ft2 4 Child’s bedroom trough Wipe 20.8818 0.0006 15.8365 0.0005 0.75839 0.00001 1.92719 0.00003 193 µg/ft2 5 Living room front trough Wipe 20.4126 0.0007 15.7959 0.0006 0.77383 0.00001 1.95307 0.00003 10.9 µg/ft2 6 Kitchen floor Wipe 19.0898 0.0006 15.6850 0.0005 0.82165 0.00001 2.03461 0.00003 0.458 µg/ft2 7 Child’s carpet floor Wipe 18.9164 0.0007 15.6667 0.0007 0.82821 0.00001 2.04463 0.00003 0.421 µg/ft2 8 Solder Solder (metal) 18.8035 0.0006 15.6916 0.0006 0.83452 0.00001 2.08079 0.00004 36.206 µg/g 9 Soil (side D) Soil 19.1292 0.0007 15.6883 0.0007 0.82014 0.00001 2.03425 0.00003 136 µg/g 10 Child’s window jamb Paint 20.6180 0.0008 15.8147 0.0006 0.76703 0.00001 1.94195 0.00003 8,696 µg/g 11 Living room window jamb Paint 21.5600 0.0008 15.8954 0.0006 0.73727 0.00001 1.89251 0.00003 7,766 µg/g 12 Subject initial blood draw Whole blood 20.4675 0.0012 15.8006 0.0009 0.77199 0.00001 1.95093 0.00004 11.1 µg/dl 13 Subject second blood draw Whole blood 20.7182 0.0006 15.8223 0.0005 0.76369 0.00001 1.93683 0.00003 15.4 µg/dl Note. The report unit for the lead isotope ratio is the atom ratio. TABLE 1
10 Volume 85 • Number 9 ADVANCEMENT OF THE SCIENCE Results Case 1 Case 1 involved a female at 24 months with a BLL of 12 µg/dl. The risk assessment found lead-based paint on the windows, doors, walls, and trim of the home. The highest lead concentrations were from the doorstop in the living room (20 mg/cm2) and the kitchen window (220 µg/ft2). The HUD questionnaire determined that the child played at her bedroom window and on the living room floor and ate in the living room. LIA indicated that the PbIR of the water (samples 1 and 2), soil (sample 9), solder (sample 8), and floors (samples 3, 6, and 7) did not match those of blood specimens (Table 1). The sample closest to the initial blood isotope (sample 12) was the wipe from the living room front window trough (sample 5; Figure 1, Case 1). The sample closest to the second blood isotope (sample 13) was the wipe from the child’s window jamb paint (sample 10), with the wipe from the child’s bedroom window trough (sample 4) as a close second match. Samples 5 and 10 remained the best matches to the Two-Dimensional Isotope Ratio Plots for Whole Blood and Environmental Lead Sources Sampled for Lead Isotope Analysis for Cases 1–6 A B Child' s Bedroom Trou g h Livi ng R oom F ront Trou g h Child' s Window Ja mb Blood Initial Blood Second 18.50 19.00 19.50 20.00 20.50 21.00 21.50 22.00 15.60 15.65 15.70 15.75 15.80 15.85 15.90 15.95 Child' s Bedroom Trou g h Livi ng R oom F ront Trou g h Child' s Window Ja mb Blood Initial Blood Second 1.85 1.90 1.95 2.00 2.05 2.10 0.72 0.74 0.76 0.78 0.80 0.82 0.84 0.86 Blood Second Blood Initial Paint Soil Solder Wipes Tap Water Blood Second Blood Initial Paint Soil Solder Wipes Tap Water 208Pb/206Pb 206Pb/204Pb Case 1 207Pb/206Pb 207Pb/204Pb A B Child' s Bedroom Carpet D ining R oom Window Sill R ear Stairwell F loor Street Lateral F ront Porch Blood 1.96 1.98 2.00 2.02 2.04 2.06 2.08 2.10 2.12 0.79 0.80 0.81 0.82 0.83 0.84 0.85 0.86 0.87 0.88 Child' s Bedroom Carpet D ining R oom Window Sill R ear Stairwell F loor Street Lateral F ront Porch Blood 17.50 18.00 18.50 19.00 19.50 20.00 15.55 15.60 15.65 15.70 15.75 15.80 Blood Paint Soil Pipes Wipes Tap Water Blood Paint Soil Pipes Wipes Tap Water 208Pb/206Pb 207Pb/206Pb 207Pb/204Pb 206Pb/204Pb Case 2 FIGURE 1 continued
May 2023 • Journal of Environmental Health 11 blood isotopes when all ratios were considered. These items (samples 5, 10, and 4) were also identified as the play areas from the questionnaire. LIA suggested the child ingested deteriorating lead-based paint via hand-to-mouth behavior while playing at the windows. After 6 months, the child’s BLL was 15 µg/dl, and 9 months after the initial BLL, the family’s home was remediated and passed clearance. Furthermore, 1.5 years after the initial BLL, the child’s venous BLL decreased to 4 µg/dl. Case 2 Case 2 involved a male at 24 months with a venous BLL of 14 µg/dl. The risk assessment found lead-based paint above acceptable limits on the windows, doors, walls, and trim of the home. The dust wipes with the highest concentrations were from the living room windowsill (10,000 µg/ft2) and back entry floor (10,000 µg/ft2). Questionnaire responses indicated that the child ate in the dining room and played in the living room. Blood PbIR were similar to the street lateral water pipe (sample 9) but dissimilar to tap water (samples 1 and 2) and the floor lateral Two-Dimensional Isotope Ratio Plots for Whole Blood and Environmental Lead Sources Sampled for Lead Isotope Analysis for Cases 1–6 A B F ront Porch E ntry F loor Livi ng R oom F loor Back Stairwell Windowsill Blood 1.90 1.92 1.94 1.96 1.98 2.00 2.02 2.04 2.06 2.08 2.10 0.76 0.77 0.78 0.79 0.80 0.81 0.82 0.83 0.84 0.85 0.86 F ront Porch E ntry F loor Livi ng R oom F loor Back Stairwell Windowsill Blood 18.00 18.50 19.00 19.50 20.00 20.50 21.00 15.55 15.60 15.65 15.70 15.75 15.80 15.85 15.90 Blood Paint Soil Pipes Wipes Tap Water Blood Paint Soil Pipes Wipes Tap Water 208Pb/206Pb 206Pb/204Pb 207Pb/206Pb 207Pb/204Pb Case 3 A B Black Pepper Tu rmeric Chili Powder Cilantro Powder A saf etida Mang o Powder Blood 2.04 2.06 2.08 2.10 2.12 2.14 2.16 0.82 0.83 0.84 0.85 0.86 0.87 0.88 0.89 0.90 0.91 Black Pepper Tu rmeric Chili Powder Cilantro Powder A saf etida Mang o Powder Blood 17.20 17.40 17.60 17.80 18.00 18.20 18.40 18.60 18.80 19.00 19.20 15.3 5 15.40 15.45 15.50 15.55 15.60 15.65 15.70 15.75 15.80 Blood Spices Wipes Tap Water Blood Spices Wipes Tap Water 208Pb/206Pb 206Pb/204Pb 207Pb/206Pb 207Pb/204Pb Case 4 FIGURE 1 continued continued on page 12
12 Volume 85 • Number 9 ADVANCEMENT OF THE SCIENCE pipe (sample 10; Table 2). Other samples closest to the blood PbIR were dust from the child’s bedroom carpet (sample 4), dust from the rear stairwell floor (sample 7), dust from the dining room windowsill (sample 6), and front porch paint (sample 11) by all ratios (Figure 1, Case 2). The dust wipe sample ratios fell within the upper and lower ratio limits of suspected paint contributors. This pattern was consistent with the deterioration of chipping paint from the walls and windowsills, which accumulated as lead-contaminated dust inhaled or ingested by the child (Figure 1, Case 2). LIA supported the exposure pathway of hand-to-mouth behavior in play areas identified by the questionnaire and lead concentration measurements from the risk assessment. Although there was no remediation completed, increased cleaning was recommended. After 5 months, the child’s second BLL decreased by one half to 7 µg/dl. Case 3 Case 3 involved a female at 19 months with a venous BLL of 18 µg/dl. The risk assessment found lead-based paint on the windows, Two-Dimensional Isotope Ratio Plots for Whole Blood and Environmental Lead Sources Sampled for Lead Isotope Analysis for Cases 1–6 Note. A = 208Pb/206Pb versus 207Pb/206Pb; B = 206Pb/204Pb versus 207Pb/204Pb. A B K aj al Blood 2.02 2.04 2.06 2.08 2.10 2.12 2.14 2.16 0.82 0.83 0.84 0.85 0.86 0.87 0.88 0.89 0.90 0.91 R ed Chili K aj al Blood 17.20 17.40 17.60 17.80 18.00 18.20 18.40 18.60 18.80 19.00 19.20 15.55 15.60 15.65 15.70 15.75 15.80 208Pb/206Pb 206Pb/204Pb 207Pb/206Pb 207Pb/204Pb Blood R ed Chili Spices K aj al ( Cosmetic) Wipes Tap Water Blood R ed Chili Spices K aj al ( Cosmetic) Wipes Tap Water R ed Chili Case 5 A B Masala Powder Ceremonial Bell Small Lamp Incense Holder Blood 1.90 1.95 2.00 2.05 2.10 2.15 2.20 0.78 0.80 0.82 0.84 0.86 0.88 0.90 Masala Powder Ceremonial Bell Small Lamp Incense Holder Blood 17.00 17.50 18.00 18.50 19.00 19.50 20.00 20.50 15.55 15.60 15.65 15.70 15.75 15.80 15.85 15.90 15.95 208Pb/206Pb 206Pb/204Pb 207Pb/206Pb 207Pb/204Pb Blood Wipes Powders Toothpaste Spices Blood Wipes Powders Toothpaste Spices Case 6 FIGURE 1 continued from page 11
May 2023 • our4'l o, 4</ro4me4:'l e'l:. 13 doors, walls, and trim of the home. The highest lead concentrations were the interior windowsills (mean of 1,158 µg/ft2), the porch entry floor (54 µg/ft2), 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 samples from paint (samples 10–14) and soil (sample 8), which suggested that the dust samples were likely a result of paint deterioration 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, cleaning 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 concentrations 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 Case 2: Lead Isotope Ratios With Standard Error and Concentration for Whole Blood and Environmental Sources Sampled for Lead Isotope Analysis Sample # Sample Sample Type 206Pb/204Pb 2σ/√n 207Pb/204Pb 2σ/√n 207Pb/206Pb 2σ/√n 208Pb/206Pb 2σ/√n Lead (Pb) Concentration 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 2 Kitchen first draw Tap water 19.0985 0.0004 15.6843 0.0004 0.82123 0.00001 2.01598 0.00003 0.798 µg/L 3 Child’s bedroom windowsill Wipe 18.3052 0.0005 15.6115 0.0004 0.85284 0.00001 2.07685 0.00002 57.6 µg/ft2 4 Child’s bedroom carpet Wipe 18.4668 0.0004 15.6265 0.0005 0.84619 0.00001 2.06621 0.00004 11.5 µg/ft2 5 Master bedroom floor Wipe 18.6236 0.0005 15.6444 0.0005 0.84004 0.00001 2.05522 0.00003 9.0 µg/ft2 6 Dining room windowsill Wipe 18.5622 0.0004 15.6333 0.0004 0.84221 0.00001 2.06086 0.00003 1,272 µg/ft2 7 Rear stairwell floor Wipe 18.4468 0.0006 15.6291 0.0005 0.84726 0.00001 2.06730 0.00003 181 µg/ft2 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 Pipe 18.5256 0.0003 15.6284 0.0004 0.84361 0.00001 2.06981 0.00003 128,683 µg/g 10 Floor lateral Pipe 19.7667 0.0005 15.7650 0.0004 0.79756 0.00001 1.98448 0.00002 32,438 µg/g 11 Front porch Paint 18.4497 0.0005 15.6255 0.0005 0.84692 0.00001 2.06890 0.00004 2,659 µg/g 12 Living room wall (side A) Paint 18.2564 0.0004 15.5862 0.0004 0.85374 0.00001 2.08100 0.00003 38,033 µg/g 13 Living room window jamb Paint 18.0086 0.0004 15.5817 0.0004 0.86524 0.00001 2.09786 0.00003 37,011 µg/g 14 Child’s bedroom window jamb Paint 17.8365 0.0004 15.5680 0.0005 0.87282 0.00001 2.10845 0.00003 53,193 µg/g 15 Rear stairwell Paint 19.1132 0.0004 15.6884 0.0004 0.82081 0.00001 2.01580 0.00003 25,993 µg/g 16 Subject initial blood draw Whole blood 18.4896 0.0005 15.6273 0.0005 0.84520 0.00001 2.06345 0.00003 13.2 µg/dl Note. The report unit for the lead isotope ratio is the atom ratio. TABLE 2
14 Volume 85 • Number 9 ADVANCEMENT OF THE SCIENCE 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, turmeric 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. 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 manufactured 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 significant 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 consistent with the blood isotopic composition by both major and minor ratios. The wipes (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 (Figure 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/ft2. The Case 3: Lead Isotope Ratios With Standard Error and Concentration for Whole Blood and Environmental Sources Sampled for Lead Isotope Analysis Sample # Sample Sample Type 206Pb/204Pb 2σ/√n 207Pb/204Pb 2σ/√n 207Pb/206Pb 2σ/√n 208Pb/206Pb 2σ/√n Lead (Pb) Concentration 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 2 Kitchen first draw Tap water 19.7307 0.0004 15.7469 0.0004 0.79810 0.00001 1.98160 0.00003 9.008 µg/L 3 Child’s bedroom floor carpet Wipe 19.2338 0.0005 15.6970 0.0004 0.81612 0.00001 2.00743 0.00003 60 µg/ft2 4 Living room windowsill Wipe 19.2135 0.0007 15.6936 0.0006 0.81680 0.00001 2.00960 0.00003 443 µg/ft2 5 Kitchen floor Wipe 19.2393 0.0005 15.6952 0.0005 0.81578 0.00001 2.01453 0.00002 37 µg/ft2 6 Front porch entry floor Wipe 18.9651 0.0006 15.6662 0.0006 0.82606 0.00001 2.03770 0.00003 313 µg/ft2 7 Living room floor Wipe 19.0367 0.0007 15.6786 0.0006 0.82361 0.00001 2.02807 0.00003 250 µg/ft2 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 Pipe 20.6057 0.0005 15.8491 0.0004 0.76915 0.00001 1.91982 0.00003 19,483 µg/g 10 Back stairwell windowsill Paint 18.9586 0.0005 15.6716 0.0005 0.82662 0.00001 2.02849 0.00003 3,116 µg/g 11 Kitchen window trough Paint 19.4228 0.0004 15.7114 0.0004 0.80892 0.00001 2.00226 0.00003 63,318 µg/g 12 Living room window jamb Paint 19.8662 0.0004 15.7560 0.0005 0.79311 0.00001 1.97517 0.00003 36,975 µg/g 13 Front porch door Paint 19.4478 0.0004 15.7190 0.0004 0.80827 0.00001 1.99512 0.00002 34,821 µg/g 14 Window sash by bed Paint 18.3150 0.0007 15.6114 0.0006 0.85239 0.00001 2.07881 0.00003 14,675 µg/g 15 Subject initial blood draw 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. TABLE 3
May 2023 • our4'l o, 4</ro4me4:'l e'l:. 15 HUD questionnaire identified imported powders and spices as main suspected hazards. LIA demonstrated that not only the bell (sample 3) but also other objects (samples 12 and 13) located on a religious altar where the family burned incense were similar to the blood in isotope concentration, suggesting lead exposure near the altar contributed to the child’s BLL. LIA indicated that the powders (samples 1 and 2) were not the primary suspected hazards because their isotopic compositions were dissimilar to the blood PbIR. The samples closest to the blood isotope composition were dust wipes from the small lamp (sample 12), incense holder (sample 13), and masala powder (sample 9; Table 6). These samples were also most similar to the blood isotope composition by minor isotope ratios (Figure 1, Case 6). After getting the LIA results, the family was advised to buy locally sourced spices and restrict access to the entire altar area. The child’s BLLs at 7, 8, 9, and 22 months decreased after the initial BLL and were 8, 7, 6, and 5 µg/dl, respectively. Discussion Our study demonstrates the application of LIA for source attribution among leadpoisoned children. In the six homes investigated, LIA identified lead-based paint, leadcontaminated dust, kajal, foreign ceremonial objects, and imported spices such as turmeric and black pepper as likely sources of lead poisoning. This technique was useful in ruling out exposures when interpreted alongside measurements of lead concentration and questionnaires about behavioral risk factors. Case 4: Lead Isotope Ratios With Standard Error and Concentration for Whole Blood and Environmental Sources Sampled for Lead Isotope Analysis Sample # Sample Sample Type 206Pb/204Pb 2σ/√n 207Pb/204Pb 2σ/√n 207Pb/206Pb 2σ/√n 208Pb/206Pb 2σ/√n Lead (Pb) Concentration 1 Kitchen first draw Tap water 18.3581 0.0006 15.6356 0.0005 0.85170 0.00001 2.07985 0.00003 3.388 µg/L 2 5-min flush (kitchen) Tap water 18.4378 0.0009 15.6373 0.0008 0.84810 0.00001 2.07245 0.00003 0.105 µg/L 3 Living room rug Wipe 17.8841 0.0006 15.6131 0.0006 0.87301 0.00001 2.11131 0.00003 0.1 µg/ft2 4 Bedroom carpet Wipe 17.7869 0.0004 15.6057 0.0005 0.87737 0.00001 2.11856 0.00003 0.2 µg/ft2 5 Large pressure cooker Wipe 17.3334 0.0005 15.5811 0.0005 0.89890 0.00001 2.14941 0.00003 43.7 µg/ft2 6 Small pressure cooker Wipe 18.2844 0.0025 15.6383 0.0022 0.85528 0.00003 2.08393 0.00008 0 µg/ft2 7 Bathtub Wipe 17.9773 0.0003 15.5985 0.0003 0.86768 0.00001 2.10208 0.00003 1.6 µg/ft2 8 Bedroom windowsill Wipe 18.6121 0.0005 15.6562 0.0005 0.84119 0.00001 2.05947 0.00003 1.3 µg/ft2 9 Halloween pumpkin Wipe 18.2618 0.0008 15.6385 0.0006 0.85634 0.00001 2.08272 0.00003 0.1 µg/ft2 10 Entry carpet Wipe 18.4166 0.0006 15.6520 0.0005 0.84988 0.00001 2.07266 0.00003 0.2 µg/ft2 11 Black pepper Kitchen spice 17.5736 0.0029 15.5855 0.0029 0.88686 0.00004 2.13096 0.00018 0.2 µg/g 12 Pink salt Kitchen spice 19.0658 0.0006 15.7676 0.0005 0.82702 0.00001 2.06173 0.00004 0.4 µg/g 13 Turmeric Kitchen spice 17.5815 0.0005 15.6032 0.0005 0.88748 0.00001 2.13628 0.00003 2.3 µg/g 14 Chili powder Kitchen spice 17.4722 0.0006 15.5942 0.0007 0.89252 0.00001 2.13718 0.00003 0.7 µg/g 15 White salt Kitchen spice 18.9118 0.0033 15.7701 0.0031 0.83387 0.00003 2.05695 0.00015 0.1 µg/g 16 Cilantro powder Kitchen spice 17.7199 0.0028 15.6279 0.0028 0.88199 0.00003 2.12744 0.00015 0.1 µg/g 17 Cumin seeds Kitchen spice 18.0285 0.0039 15.6482 0.0036 0.86804 0.00004 2.11106 0.00015 0.1 µg/g 18 Asafetida Kitchen spice 17.4226 0.0005 15.5828 0.0005 0.89440 0.00001 2.14508 0.00003 1.7 µg/g 19 Rai Kitchen spice 18.4908 0.0075 15.6962 0.0068 0.84886 0.00007 2.09457 0.00028 0.1 µg/g 20 Mango powder Kitchen spice 17.5334 0.0018 15.6214 0.0018 0.89095 0.00003 2.13850 0.00011 0.3 µg/g 21 Wheat flour Kitchen spice 17.5323 0.0424 15.4015 0.0374 0.87845 0.00020 2.12633 0.00053 0 µg/g 22 Subject initial blood draw Whole blood 17.6207 0.0008 15.5910 0.0008 0.88482 0.00001 2.13053 0.00004 10.3 µg/dl Note. The report unit for the lead isotope ratio is the atom ratio. TABLE 4
16 Volume 85 • Number 9 ADVANCEMENT OF THE SCIENCE Case 5: Lead Isotope Ratios With Standard Error and Concentration for Whole Blood and Environmental Sources Sampled for Lead Isotope Analysis Sample # Sample Sample Type 206Pb/204Pb 2σ/√n 207Pb/204Pb 2σ/√n 207Pb/206Pb 2σ/√n 208Pb/206Pb 2σ/√n Lead (Pb) Concentration 1 First draw Tap water 18.5807 0.0034 15.6494 0.0011 0.84225 0.00013 2.06144 0.00021 0.022 µg/L 2 5-min flush Tap water 18.5219 0.0174 15.6737 0.0150 0.84625 0.00008 2.07268 0.00014 0.002 µg/L 3 Elephant wipe Wipe 18.7607 0.0007 15.6776 0.0006 0.83566 0.00001 2.05194 0.00003 0.1 µg/ft2 4 Bracelet wipe Wipe 17.6595 0.0004 15.6009 0.0004 0.88342 0.00001 2.12768 0.00003 0.9 µg/ft2 5 Gold charm wipe Wipe 18.7060 0.0006 15.6671 0.0006 0.83754 0.00001 2.05626 0.00003 0 µg/ft2 6 Living room sill wipe Wipe 18.9088 0.0005 15.6826 0.0004 0.82939 0.00001 2.04150 0.00003 0.4 µg/ft2 7 Floor dust wipe Wipe 18.9274 0.0005 15.6892 0.0004 0.82892 0.00001 2.03924 0.00002 0.9 µg/ft2 8 Metal cart wipe Wipe 18.6116 0.0004 15.6625 0.0004 0.84154 0.00001 2.05890 0.00002 0.2 µg/ft2 9 Bathtub wipe Wipe 18.5758 0.0005 15.6337 0.0005 0.84162 0.00001 2.06975 0.00003 1.8 µg/ft2 10 Old cooker wipe Wipe 17.9282 0.0005 15.6125 0.0004 0.87083 0.00001 2.11286 0.00002 4.1 µg/ft2 11 New cooker wipe Wipe 17.7830 0.0004 15.6074 0.0005 0.87765 0.00001 2.11914 0.00003 2.6 µg/ft2 12 Chunky chat masala Kitchen spice 18.8568 0.0005 15.7673 0.0005 0.83617 0.00001 2.07926 0.00003 0.08 µg/g 13 Dal makhani masala Kitchen spice 18.0354 0.0006 15.6493 0.0006 0.86769 0.00001 2.11559 0.00003 0.09 µg/g 14 Sabzi masala Kitchen spice 18.3446 0.0004 15.6885 0.0004 0.85521 0.00001 2.09903 0.00003 0.15 µg/g 15 Red chili Kitchen spice 17.3785 0.0004 15.5843 0.0005 0.89675 0.00001 2.14614 0.00003 22.8 µg/g 16 Black pepper Kitchen spice 18.3640 0.0025 15.6853 0.0024 0.85412 0.00003 2.10746 0.00012 0.01 µg/g 17 Turmeric Kitchen spice 17.7062 0.0007 15.5994 0.0006 0.88102 0.00001 2.12986 0.00004 0.01 µg/g 18 Coriander Kitchen spice 17.7070 0.0005 15.6178 0.0006 0.88201 0.00001 2.12803 0.00003 0.05 µg/g 19 Kajal Cosmetic 17.4047 0.0010 15.5811 0.0005 0.89522 0.00004 2.14390 0.00006 – 20 Subject initial blood draw Whole blood 17.4400 0.0006 15.5834 0.0006 0.89355 0.00001 2.14124 0.00003 10.1 µg/dl Note. The report unit for the lead isotope ratio is the atom ratio. TABLE 5 Similar to previous studies, cases 1–3 demonstrated that LIA was able to identify the most common household exposure: legacy lead-based paint exposure via hand-to-mouth behavior (Becker et al., 2022; Gulson et al., 1995; Manton et al., 2000). BLLs decreased among these cases after intervention on sources identified by LIA. Cases 4–6 involved nonpaint-related sources more commonly identified in recent years (Forsyth et al., 2019; Gorospe & Gerstenberger, 2008; Mohta, 2010; Smith et al., 2017) and demonstrate at-risk groups for lead poisoning among immigrant populations (Angelon-Gaetz et al., 2018; Centers for Disease Control and Prevention, 2012; Shakya & Bhatta, 2019). A questionnaire can identify a foreign spice as a potential hazard, but LIA can provide additional evidence that the spice contributed to blood lead through matched PbIRs. Unlike other recent isotopic analyses, water was also investigated in our case series due to the historical use of lead pipes in the U.S. (Triantafyllidou et al., 2009). Contaminated water might be a significant contributor to overall lead exposure among young children even at low concentrations (Zartarian et al., 2017). Environmental health specialists extensively sampled water sources by testing tap water, pipes, and solder for five out of six cases. Water was not observed as the dominant or likely source in our cases. The PbIRs of the tap water samples for cases 1–5 were dissimilar to the children’s blood samples (Figure 1). For case 2, the PbIRs between street lateral pipe (sample 9) and child’s blood (sample 16) appeared similar but could be due to the lead street lateral pipe
May 2023 • our4'l o, 4</ro4me4:'l e'l:. 17 being from the same geological deposit as the dominant lead exposure source(s) or the same ratio as the sum of multiple lead exposure sources (Supplemental Table). The differences in environmental and blood PbIR between cases 4–6 and cases 1–3 demonstrate how abundances of isotopes vary given the age of the source lead ore. Cases 1–3 possessed a 208Pb/206Pb isotopic composition range of 1.93–2.06, which is consistent with Midwestern ore deposits (Doe & Delevaux, 1972; Field et al., 2018; Millen et al., 1995; Potra et al., 2018) or Great Lakes precipitation that reflects industrial pollution and coal burning (Sherman et al., 2015). In contrast, cases 4–6 possessed a 208Pb/206Pb isotopic composition range of 2.13–2.14, which is consistent with anthropogenic lead sources in India (Sen et al., 2016). The high precision aorded by MC-ICPMS methods is a major strength of our study. Previous LIA case series used sector field/ magnetic sector ICP (Gwiazda et al., 2005; Oulhote et al., 2011) or solid source MS (Gulson et al., 1995; Millen et al., 1995; Yae et al., 1983) for lead isotopes. The uncertainties around PbIR in those studies typically are between 0.1–1% (Gulson et al., 1995; Gwiazda et al., 2005; Millen et al., 1995; Oulhote et al., 2011; Yae et al., 1983). In contrast, our case-series method using MC-ICP-MS obtained precisions of approximately 0.02– 0.03% in whole blood (Supplemental Table) based on repeat analyses of whole blood standards, although there are still no isotopic reference materials for this purpose. Another strength of our study is our inclusion of a wide array of samples, even those with low lead concentrations. Moreover, our study was unique in that case follow-up of BLLs has not been reported routinely in past LIA studies and thus contributes data to the impact of LIA in remediation eorts. There are at least three limitations to our case series. Blood lead isotopic analysis represents all sources of lead—both endogenous or exogenous—which was supplemented by our diverse array of samples but could not account for lead from the mother during gestation or bone storage of lead. Also, mixtures of lead sources are challenging to interpret and not fully explored. Given that this study is a pilot project and case-series analysis, our sample size limits the generalizability of our results. A further limitation to conducting LIA is the cost and availability of mass spectrometers. Conclusion Overall, our findings suggest that high-precision isotopic analysis with MC-ICP-MS methods could be used as a supplemental tool during lead risk assessment. Our cases demonstrate that LIA can identify recontamination from legacy lead and imported items such as spices and cosmetics. All sources of lead exposure are important to consider because lead poisoning aects individuals with infinitely variable behaviors and environments. Future work should assess the use of LIA on a larger scale and the cost-eectiveness of this technique. Acknowledgements: This study and article were supported in part by an appointment to the Applied Epidemiology Fellowship ProCase 6: Lead Isotope Ratios With Standard Error and Concentration for Whole Blood and Environmental Sources Sampled for Lead Isotope Analysis Sample # Sample Sample Type 206Pb/204Pb 2σ/√n 207Pb/204Pb 2σ/√n 207Pb/206Pb 2σ/√n 208Pb/206Pb 2σ/√n Lead (Pb) Concentration 1 Lavender powder Cosmetic 19.8394 0.0004 15.8828 0.0004 0.80056 0.00001 1.96837 0.00002 0.18 µg/g 2 Baby powder Cosmetic – – – – – – – – – 3 Hindu powder Cosmetic 19.9784 0.0005 15.8952 0.0004 0.79561 0.00001 1.93069 0.00003 3.41 µg/g 4 Spicy masala powder Kitchen spice 17.7920 0.0005 15.6231 0.0005 0.87809 0.00001 2.11261 0.00004 0.07 µg/g 5 Turmeric Kitchen spice 17.8115 0.0004 15.6218 0.0004 0.87706 0.00001 2.11514 0.00002 0.63 µg/g 6 Masala powder Kitchen spice 17.5293 0.0007 15.6026 0.0007 0.89008 0.00001 2.14296 0.00004 0.04 µg/g 7 Chili powder Kitchen spice 17.8629 0.0007 15.6304 0.0006 0.87502 0.00001 2.10647 0.00003 0.05 µg/g 8 Coriander powder Kitchen spice 17.6877 0.0006 15.6154 0.0005 0.88284 0.00001 2.11941 0.00004 0.06 µg/g 9 Health mix powder Kitchen spice 17.9669 0.0019 15.6335 0.0017 0.87016 0.00002 2.11616 0.00005 0.01 µg/g 10 Toothpaste Cosmetic 18.1945 0.0005 15.7265 0.0005 0.86436 0.00001 2.11029 0.00004 0.03 µg/g 11 Subject initial blood draw Whole blood 17.5476 0.0007 15.5884 0.0006 0.88834 0.00001 2.13368 0.00004 5.3 µg/dl 12 Ceremonial bell Wipe 17.7146 0.0006 15.6011 0.0005 0.88068 0.00001 2.12352 0.00002 14.6 µg/ft2 13 Small lamp Wipe 17.5312 0.0006 15.5966 0.0005 0.88965 0.00001 2.13170 0.00003 0.8 µg/ft2 14 Incense holder Wipe 17.4571 0.0004 15.5907 0.0004 0.89309 0.00001 2.13964 0.00003 4.0 µg/ft2 15 Ceremonial vase Wipe 17.7920 0.0009 15.6135 0.0007 0.87758 0.00001 2.11546 0.00003 0.1 µg/ft2 Note. The report unit for the lead isotope ratio is the atom ratio. TABLE 6
www.neha.orgRkJQdWJsaXNoZXIy NTU5MTM=