Lead exposure occurs through inhalation and ingestion.[4]Rabinowitz M. Historical perspective on lead biokinetic models. Environ Health Perspect. 1998;106(suppl 6):1461S-1465S.
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1533457&blobtype=pdf
http://www.ncbi.nlm.nih.gov/pubmed/9860905?tool=bestpractice.com
In the US, removal of lead from gasoline around 1980 dramatically decreased the population-wide exposure to lead from this source. Closure of lead smelters in the US has removed the major point-source exposure. Decreases in airborne lead in the US resulted in a decline in blood lead levels for people ages 1 to 74 years, from 12.8 micrograms/dL in 1976 to 1980 to 2.8 micrograms/dL in 1991.[5]Centers for Disease Control and Prevention (CDC). Blood lead levels: United States, 1988-1991. MMWR Morb Mortal Wkly Rep. 1994;43:545-548.
http://www.cdc.gov/mmwr/preview/mmwrhtml/00032080.htm
http://www.ncbi.nlm.nih.gov/pubmed/8035771?tool=bestpractice.com
Airborne lead continues to be a problem in the very few countries that still use leaded gasoline.
Lead is a cumulative toxicant with very prolonged residence in bone. Because multiple real and potential sources of lead exposure exist throughout life, evaluating sources of exposure requires evaluation of lifelong events, particularly in older adults. Patients living in poverty are more likely to live in old and poorly maintained housing with deteriorating paint surfaces, and therefore have an increased risk of lead exposure.[6]Harvey B, ed. Managing elevated blood lead levels among young children: recommendations from the Advisory Committee on Childhood Lead Poisoning Prevention. Atlanta, GA: CDC; 2002.
http://www.cdc.gov/nceh/lead/casemanagement/managingEBLLs.pdf
Lead exposure in children
In the US, the major risk to children is from lead-based paints and soil and dust contaminated with lead-based paint. Secondary sources include lead jewelry, toys, and other lead items. Lead levels in children usually increase during the period of hand-to-mouth activity (ages 9-36 months) due to the nature of these sources. Blood lead levels in children peak at age 18 to 24 months.[6]Harvey B, ed. Managing elevated blood lead levels among young children: recommendations from the Advisory Committee on Childhood Lead Poisoning Prevention. Atlanta, GA: CDC; 2002.
http://www.cdc.gov/nceh/lead/casemanagement/managingEBLLs.pdf
Blood lead surveillance is a useful tool.[7]Ettinger AS, Leonard ML, Mason J. CDC's lead poisoning prevention program: a long-standing responsibility and commitment to protect children from lead exposure. J Public Health Manag Pract. 2019 Jan-Feb;25(suppl 1):S5-S12.
http://www.ncbi.nlm.nih.gov/pubmed/30507764?tool=bestpractice.com
CDC: childhood lead poisoning prevention program
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Public Health England: lead exposure in children surveillance reports
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In England, 35 cases of lead exposure in children were notified in 2020.[8]UK Health Security Agency. Lead Exposure in Children Surveillance System (LEICSS) annual report 2021. Health Protection Report. 2021 Oct 26;15(17) [internet publication].
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1033890/HPR1721_LEICSS-2020_v2b.pdf
The number of cases detected was much lower than the expected incidence of lead exposure based on international population survey data. Cases were typically 1 to 4 years of age, male, and resident in more deprived areas; the median blood lead concentration of cases was 14.7 micrograms/dL.[8]UK Health Security Agency. Lead Exposure in Children Surveillance System (LEICSS) annual report 2021. Health Protection Report. 2021 Oct 26;15(17) [internet publication].
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1033890/HPR1721_LEICSS-2020_v2b.pdf
Lead exposure in adults
The primary source of lead exposure is occupational (such as scraping off old lead paint, smelters, battery manufacturing, and radiator repair), rather than oral ingestion of lead-contaminated materials. Occupational exposures have, however, declined significantly in the US.[9]Centers for Disease Control and Prevention (CDC). Adult blood lead epidemiology and surveillance - United States, 2008-2009. MMWR Morb Mortal Wkly Rep. 2011 Jul 1;60(25):841-5.
https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6025a2.htm
http://www.ncbi.nlm.nih.gov/pubmed/21716198?tool=bestpractice.com
Use of traditional folk medicines, such as Ayurvedic herbal remedies, has resulted in lead toxicity.[10]Breeher L, Mikulski MA, Czeczok T, et al. A cluster of lead poisoning among consumers of Ayurvedic medicine. Int J Occup Environ Health. 2015;21(4):303-7.
http://www.ncbi.nlm.nih.gov/pubmed/25843124?tool=bestpractice.com
[11]Breyre A, Green-McKenzie J. Case of acute lead toxicity associated with Ayurvedic supplements. BMJ Case Rep. 2016 Jun 30;2016:bcr2016215041.
http://www.ncbi.nlm.nih.gov/pubmed/27364782?tool=bestpractice.com