Lead Toxicity: Prevention and Management Travis Hobart, MD, MPH CNY Lead Poisoning Resource Center Medical Director CNY Children’s Environmental Health Center
Objectives • Identify sources of lead exposure in the environment • Describe acute and chronic effects of lead exposure • Describe prevention and treatment of lead exposure • Describe the long term benefits of preventing exposure
20 month old child in Broome County • BLL of 45.9 mcg/dL (venous) • Prior BLL (fingerstick) was < 3.3 mcg/dL at age 10 months • Exterior trim of windows was chipping • They own the home and were certified lead safe to fix the issues by themselves
The Problem
https://www.cdc.gov/nceh/lead/
https://www.cdc.gov/nceh/lead/
https://www.cdc.gov/nceh/lead/
Progress Has Been Made Over Time Source: Prevention of Childhood Lead Toxicity, Pediatrics , 2017
Definition of “Elevated” Has Changed Over Time https://www.atsdr.cdc.gov/csem/csem.asp?csem=34&po=8
Challenges in in New York State Built before 1979: Norwich 91.4% Chenango County 68.2% (American Fact Finder, US Census Bureau, Selected Housing Characteristics:2013-2017 American Community Survey 5-Year Estimates)
Screening
NYS Lead Testing and Assessment • Test all children for lead poisoning at age 1 and again at age 2 • Assess all children age 6 months to 6 years at each well child check for risk of lead exposure using the Risk Assessment Questionnaire. Test children found to be at high risk. • Educate all families on lead poisoning prevention
March 11, 2020 15 Public Health Law Changes - 2019 • Requires health care providers to: • Confirm any capillary blood lead specimens ≥ 5 µg/dL with a venous blood sample and perform risk reduction and nutrition counseling (previously ≥ 10 µg/dL). • Provide comprehensive follow-up services for all children (<18yo) with confirmed venous blood lead levels ≥ 5 µg/dL (previously ≥ 15 µg/dL) • Requires local health departments to: • Provide care coordination and environmental management for all children with confirmed venous blood lead levels ≥ 5 µg/dL (previously ≥ 10 µg/dL and ≥ 15 µg/dL, respectively)
March 11, 2020 16 Risk Assessment Questions
Percent of NY children screened Screened by 17 months Screened by 35 months
Pathophysiology
Toxicokinetics Lead Half-life: • Blood: 28 to 36 days • Soft tissues: 40 days • Bone: >25 years O’Flaherty, E.J. 1993. Physiologically based models for bone -seeking elements. IV. Kinetics of lead disposition in humans. Toxicol. Appl. Pharmacol. 118(1):16-29.
Why are kids so vulnerable to lead exposure? • Hand to mouth behavior • Higher absorption from gut than adults • Higher levels in brain tissue than adults • Developing brain is particularly sensitive to the effects Theodore I. Lidsky, Jay S. Schneider; Lead neurotoxicity in children: basic mechanisms and clinical correlates, Brain , Volume 126, Issue 1, 1 January 2003, Pages 5 – 19, https://doi.org/10.1093/brain/awg014
Systems affected • Neurologic • Hematologic • Renal • Endocrine • GI Staudinger KC, Roth VS. Occupational Lead Exposure. Am Fam Physician. 1998 Feb 15;57(4):719-726.
Effect on Heme Synthesis aka ALA dehydratase aka free erythrocyte protoporphyrin (FEP) (ZnPP) FEP or ZnPP can be measured in the blood and indicate subacute or chronic lead levels approximately above 30 mcg/dL
3.5 year old boy presents to PCP • Significant autism spectrum disorder • History of pica noted at home, including eating paint chips • Family had just recently moved there, and were able to remediate indoor of home after chelation • Exterior hazards were not remediated right away but were done in spring of 2017.
64 mcg/dL
Pregnancy and Lactation
15 month old girl • Tested at WCC with BLL 70 mcg/dL • Brother, aged 3 years, also tested and found to have BLL 45 mcg/dL • Mom was pregnant in first trimester, so she was tested • BLL 30 mcg/dL • Family doing major home renovations with kids present • Sadly, mom had a spontaneous abortion shortly thereafter
Pathophysiology in pregnancy https://www.cdc.gov/nceh/lead/publications/leadandpregnancy2010.pdf
Pregnancy • ACOG and CDC recommend screening for risk factors • Blood testing of high risk women • Pica • Home renovations • Occupational exposure • Family member with high lead level • Refugee or immigrant status • Spices or cosmetics from abroad • Lead easily crosses placenta
Adverse effects • Maternal hypertension and maybe pre-eclampsia • Impaired fetal growth • Spontaneous abortion
Effects on the infant • Impaired infant growth • Impaired neurodevelopment • Effects appear to be independent of post-natal exposure • Some studies show the strongest postnatal effects are at low levels of exposure
Breastfeeding • Breastfeeding not recommended when maternal BLL over 40 mcg/dL • Or if infant has BLL over 5 mcg/dL • Recommended to pump and dump until below 40 or baby’s level goes down • Maternal calcium and vitamin C supplementation have been shown to decrease lead levels in milk.
Treatment
March 11, 2020 35 Confirmatory and Follow-up Testing (1)
March 11, 2020 36 Confirmatory and Follow-up Testing (2)
March 11, 2020 37 Clinical Lead Exposure Assessment
Chela lation • Chelating agent binds to lead in the blood forming the “chelate” • Allows body to excrete lead more readily • Expect decreased BLL to about 50% of prior level • Continue to monitor BLL closely • BLL will rebound as body burden re-equilibrates to the blood • Re-treat greater than 80% rebound or if above 45 mcg/dL
3 year old girl with BLL 68 mcg/dL • Developmentally delayed • Jan 2014 when initially admitted for chelation, child was in EI program and had severe pica behavior.
3 year old girl with BLL 68 mcg/dL • Developmentally delayed • Jan 2014 When initially admitted for chelation, child was in EI program and had severe pica behavior. • Home was remediated (2013) prior to initial chelation when she had lower BLL (around 20s), when reinspected there were no new exposures identified and paint was intact. Second chelation (2014) leads to reinspection, again. Furnace, ducts, and basement were targeted and lardlord responsible to hire someone to clean them. Family moves (2014). • Now spends time in grandfather’s apartment, and still at the old home while waiting for bus to pre-k. • Remains in new apartment, family says she is not going anywhere else (2016) • Level comes down slowly between 2016-2019, in Aug 2019 she is admitted to ER for abdominal pain, abd xray shows high density flecks, school also showed concern that she was ingesting non-food items.
2.5 year old boy with BLL 74 mcg/dL • Developmentally delayed, pica behavior • Home had lots of lead hazards, requiring significant amount of remediation. • Bedroom floor of child's room, dust wipe standards exceeded. • Mom also reported that she catches the child trying to play with parts of the window. • Home was worked on by a community funded program in order to remediate and replace windows. Old leaded windows were not properly removed and were stacked uncovered in the family's backyard (happened between May/June of 2018, where level increased again)
Prevention
Pri rimary Prevention • There is no “safe” blood lead level • Children living in poverty and children of color disproportionately affected • Education on lead poisoning prevention and available community resources • Abatement is the most effective strategy
Report From Pew Trusts in 2017 Intervention for kids born in 2018 Costs Future Benefits Removing lead paint from homes of low $2.5 Bil $3.5 Bil income children built before 1960 Ensuring lead safe renovation $1.4 Bil $4.5 Bil Removing lead pipes from homes $2 Bil $2.7 Bil
Conclusion • Children are uniquely vulnerable to environmental exposure • Lead is a potent neurotoxin with irreversible long-term effects • The most effective strategy is primary prevention • Investment in healthy housing makes a big difference
How long does it takes to return to “normal” depends on both amount and duration of exposure
12/31/2 … 10 20 30 40 50 60 70 80 90 0 1/31/2017 2/28/2017 3/31/2017 4/30/2017 5/31/2017 6/30/2017 7/31/2017 8/31/2017 9/30/2017 10/31/2 … DC Jefferson Co 2016-2019 11/30/2 … 12/31/2 … 1/31/2018 2/28/2018 3/31/2018 4/30/2018 5/31/2018 6/30/2018 7/31/2018 8/31/2018 9/30/2018 10/31/2 … 11/30/2 … 12/31/2 … 1/31/2019 0 100 200 300 400 500 600
10 20 30 40 50 60 70 80 0 3/1/2013 5/1/2013 7/1/2013 9/1/2013 11/1/2013 1/1/2014 3/1/2014 5/1/2014 7/1/2014 9/1/2014 11/1/2014 1/1/2015 3/1/2015 5/1/2015 7/1/2015 9/1/2015 11/1/2015 1/1/2016 LJ Cayuga Co 2013-2020 3/1/2016 5/1/2016 7/1/2016 9/1/2016 11/1/2016 1/1/2017 3/1/2017 5/1/2017 7/1/2017 9/1/2017 11/1/2017 1/1/2018 3/1/2018 5/1/2018 7/1/2018 9/1/2018 11/1/2018 1/1/2019 3/1/2019 5/1/2019 7/1/2019 9/1/2019 11/1/2019 1/1/2020 0 50 100 150 200 250 300 350 400 450
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