Public Health Reporting and National Notification for Elevated Blood Lead Levels

Details

• Personal Author:
  Stanbury, Martha
• Description:
  Background: Inorganic lead is a bluish gray metal that has been used since ancient times because of its useful properties, such as low melting point, pliability, and resistance to corrosion. The ancient Romans and Greeks first discovered its toxic effects. Lead is ubiquitous in the U.S. environment because of the widespread use of lead compounds in industry, gasoline, and paints during the past century. Lead is not an essential element nor does it serve any useful purpose in the body. It adversely affects multiple organ systems and can cause permanent damage. Research shows that lead has adverse health effects, including neurotoxicity and adverse renal and reproductive effects at much lower levels than once believed safe. Human exposure to inorganic lead occurs when dust and fumes are inhaled and when lead from lead-contaminated hands, food, water, cigarettes, and clothing is ingested. Lead absorbed from the respiratory and digestive systems into the blood is distributed to tissues throughout the body. More than 90 percent of total body lead content eventually accumulates in the bones, where it has a half-life of years to decades. Lead stored in bones continues to be released, via the bloodstream, to tissues throughout the body long after the external environmental exposure has ceased. There are several biological measures of lead exposure. Elevation of protoporphyrin (free or zinc protorporphyrin) concentration in red blood cells can indicate inhibition of heme synthesis by lead, but it is an insensitive biomarker of lead exposures in individuals with blood lead concentrations below 25 ug/dL. Additionally, there are other causes (e.g., iron-deficiency anemia and inflammatory conditions) of elevated protoporphyrin levels. Lead concentrations in urine, teeth, and hair have been used as biological indicators of current or past lead exposure. Urine lead is less validated than blood lead as a biomarker of external lead exposure, while laboratory analysis for lead in hair is not standardized. For these reasons, there is rarely any value in measuring lead in urine or hair. Measurement of bone lead levels, via K-shell X-ray fluorescence (K-XRF), provides an accurate method for determining cumulative lead exposure and the total body burden of lead. Currently, K-XRF remains largely a research tool. At present, the best method for monitoring biological exposure to lead is measurement of the blood lead level (BLL) in whole blood. Blood lead levels provide a readily available, standardized, and relatively low cost method to assess lead exposure. The frequency and severity of symptoms associated with lead exposure generally increase as the BLL increases although there is much individual variability. No such relationship between symptoms and the other measures of lead exposure has been established. An elevated BLL has been defined by CSTE and CDC since 1998 as 10 ug/dL or greater for a child, and, since 1999, as 25 ug/dL or greater in an adult. Recent research has documented adverse health effects at BLLs well below these defined levels. There is now increasing concern over the toxicity of lead for adults at low doses and its association with hypertension, adverse effects on renal function, cognitive dysfunction, and adverse female reproductive outcome. Current recommendations are to maintain adult BLLs less than 10 ug/dL to avoid long-term health risks and less than 5 ug/dL to avoid spontaneous abortion. It should also be noted that, with decreases in environmental lead sources (e.g., gasoline and paint), the lead burden in the U.S. population has been steadily declining as evidenced by the NHANES Third National Report on Human Exposure to Environmental Chemicals, which estimated that the mean (geometric) blood lead concentration in 2001-2002 was 1.45 ug/dL for the U.S. population aged 1 year and older. Based on scientific research, public health concerns, and geometric mean BLLs in the U.S., this position statement recommends lowering the definition of elevated blood lead in adults from 25 to 10 ug/dL. The leading cause of elevated blood lead in children is exposure to lead-based paint in older houses. The leading cause in adults is occupational exposure to lead; employers are required to monitor blood lead levels of their employees when airborne lead is known to exceed certain levels. Other sources of lead exposure include hobbies such as sport shooting and stained glass making, use of lead-contaminated alternative medicines, and renovation of old homes. Some states require reporting of lead poisoning by health care providers. However, reporting of elevated BLLs by clinical laboratories to state childhood and adult/occupational lead surveillance systems has been shown to be the most complete and effective reporting source. Surveillance built on laboratory reporting of elevated BLL has led to a wide variety of public health prevention and intervention activities. Reporting of all BLL by laboratories, which is required in many states, is essential for determining true prevalence in the tested population. Justification: An elevated BLL meets the following criteria for a nationally and standard notifiable condition, as specified in CSTE position statement 08-EC-02: A majority of state and territorial jurisdictions-or jurisdictions comprising a majority of the U.S. population-have laws or regulations requiring standard reporting of elevated BLLs to public health authorities. CDC requests standard notification of elevated BLLs to federal authorities. CDC has condition-specific policies and practices concerning the agency's response to, and use of, notifications. [Description provided by NIOSH]
• Subjects:
  Environmental Exposure Epidemiology Lead Occupational Health Public Health Safety
• Keywords:
  Biological Monitoring Blood Lead Levels Environmental Exposure Health Effects Lead-based Paint Lead Dust Public Health Surveillance
• Publisher:
  Council of State and Territorial Epidemiologists
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Report
• Place as Subject:
  Georgia ; Michigan ; OSHA Region 4 ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-11
• NIOSHTIC Number:
  nn:20060342
• Citation:
  Atlanta, GA: Council of State and Territorial Epidemiologists, 2009 Jul; :1-11
• Contact Point Address:
  Martha Stanbury, Michigan Department of Community Health, Division of Environmental Health, PO Box 30195, Lansing MI 48909
• Email:
  stanburym@michigan.gov
• CAS Registry Number:
  Lead (CAS RN 7439-92-1)
• Federal Fiscal Year:
  2009
• Performing Organization:
  Council of State and Territorial Epidemiologists, Atlanta, Georgia
• Peer Reviewed:
  False
• Start Date:
  20060701
• Source Full Name:
  Public health reporting and national notification for elevated blood lead levels
• End Date:
  20111231
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:a105b5b6c99b84652cc6837fd587751605c7b58b2a5764201f178e23e98953e9a1b6fffa50018758555a5fa888deefe78f21920f3e254974d9139d9f56f50862
• Download URL:
  https://stacks.cdc.gov/view/cdc/224283/cdc_224283_DS1.pdf
• File Type:
  [PDF - 98.55 KB ]