Elevated Blood Lead Levels Among Adults

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The majority of cases of elevated blood lead levels (BLL) among adults are related to a workplace or hobby exposure.  Elevated blood lead may cause damage to the nervous, hematologic, reproductive, renal, cardiovascular, or gastrointestinal systems.  Some early symptoms of lead poisoning may include: fatigue, upset stomach or stomach cramps, poor appetite, irritability, nervousness or depression, headache, sleeplessness, metallic taste in the mouth, reproductive problems, high blood pressure, lack of concentration, and muscle and/or joint pain.  Because of these detrimental health effects, the Federal and Minnesota Occupational Safety and Health Administration (OSHA) lead standards (1910.1025) require, among many other items, monitoring of blood lead levels in adults who are exposed to airborne lead concentrations that exceed certain thresholds.

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The National Institute for Occupational Safety and Health (NIOSH) supports surveillance of adult blood levels through the Adult Blood Lead Epidemiology and Surveillance (ABLES) program.  CDC/NIOSH funds 40 states—including Minnesota—to collect blood lead level reports from laboratories to promote interventions and prevention of lead over-exposure.

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This indicator utilizes data collected by the MDH Lead Program and provided to the MDH Center for Occupational Health and Safety.  Minnesota Statute 144.9502 requires all health care providers and laboratories to report blood lead levels for both adults and children to the Minnesota Department of Health (MDH).  The Lead Program collects the Minnesota blood lead test results and other reportable data.  The childhood lead program addresses concerns related to elevated blood lead levels in children, and the MDH adult lead ABLES program address concerns for individuals over the age of 18 who have elevated blood lead levels. 

Occupational lead exposure is of concern both for the worker and the worker’s family living in the same household.  Similar to other occupational exposures, lead dust can be carried home on clothes, shoes, skin, and hair which can then be ingested by other members of the family.  Lead poisoning in young children or a developing fetus may cause learning, behavior, and health problems; or possibly miscarriages, premature births, and stillbirths in pregnant women. Information on how to prevent bringing lead home can be found at the MDH Environmental Health Division’s lead webpage:
http://www.health.state.mn.us/divs/eh/lead/fs/takehome.html

basement clean upThe lead indicator is based on a number of different blood lead levels reflecting various levels of concern and/or regulatory standards.  As adverse health effects are believed to occur at very low levels, the lowest level of concern identified by the indicator is at 10 µg/dL   The U.S. Department of Health and Human Services recommends that adult blood levels be less than 25 µg/dL, which is the second level for this indicator.  The third and highest threshold level is 40 µg/dL, which represents the highest blood lead level allowable by OSHA standards.

The national rate of prevalent cases of elevated blood leads ≥ 25 µg/dL in the year 2009 was 6.1/100,000 employed persons at least 16 years of age.  The national rate of prevalent cases of elevated blood leads ≥ 40 µg/dL in the year 2009 was 0.9/100,000 employed persons at least 16 years of age.  The rates in Minnesota are lower than the national average, but still represent a public health concern as they demonstrate that a large number of individuals are still being exposed to lead through work activities.   

Adult Cases of Blood Lead Levels ≥ 10µg/dL in Minnesota, 2005-2012

Year Prevalent Cases Incident Cases Prevalence Rate* Incidence Rate*
2005 607 282 21.6 10.0
2006 616 283 21.9 10.1
2007 593 271 21.4 9.8
2008 563 242 20.6 8.9
2009 509 191 18.8 7.1
2010 572 240 21.0 8.8
2011 428 181 15.7 6.7
2012 493 265 17.8 9.6
US 2008 22,861 -- -- --

*The rate is per 100,000 employed persons.

Adult Cases of Blood Lead Levels ≥ 25µg/dL in Minnesota, 2005-2012

Year Prevalent Cases Incident Cases Prevalence Rate* Incidence Rate*
2005 131 60 4.7 1.5
2006 134 63 4.8 1.4
2007 156 78 5.6 2.0
2008 125 52 4.6 1.9
2009 96 39 3.6 0.8
2010 113 60 4.2 1.5
2011 88 41 3.2 1.5
2012 123 66 4.4 2.4
US 2008 9,325 4,470 7.1 3.4

*The rate is per 100,000 employed persons.

Adult Cases of Blood Lead Levels ≥ 40µg/dL in Minnesota, 2005-2012

Year Prevalent Cases Incident Cases Prevalence Rate* Incidence Rate*
2005 11 8 0.4 0.2
2006 18 14 0.6 0.3
2007 29 23 1.1 0.6
2008 17 12 0.6 0.4
2009 5 3 0.2 0.1
2010 7 6 0.3 0.2
2011 7 6 0.3 0.2
2012 12 11 0.4 0.4
US 2008 1,486 693 1.1 0.5

*The rate is per 100,000 employed persons.

Number of Adults with an Elevated BLL in Minnesota, 2005-2012

The number of elevated blood lead cases in Minnesota between 2005 and 2012, data in tables above

Prevalence Rate of Adults with an Elevated BLL in Minnesota, 2005-2012

The prevalence rates of elevated lead cases in Minnesota between 2005 and 2012, data in tables above

Incidence Rate of Adults with an Elevated BLL in Minnesota, 2005-2012

Incidence rates of elevated blood lead levels between 2005 and 2012 in Minnesota, data in tables above

Blood lead levels have remained fairly consistent over the past eight years. Since the 1970’s there have been a number of regulatory actions, such as the banning of lead from paint, gasoline, and other products, that have greatly reduced exposures to lead in the United States population.  The reduction between levels measured in the 1970’s and current levels are dramatic; however, the decline has slowed over the last decade and there is little change seen over the past 5 years.   Trend analysis of the indicator finds there is no significant difference in the number of blood lead measures at 10, 25, and 40 µg/dL over the past 6 years.  This indicator may not be representative as it only captures information on individuals who have been referred for, or sought out, testing and assumes that all laboratories and clinics are compliant with the statute requiring reporting to the MDH.  It is believed that the possible undercount from non-compliant laboratories would be small as it is a requirement for a number of certifications that laboratories procure.  Even with this potential undercount, this indicator clearly demonstrates that potentially harmful occupational exposures to lead are continuing to occur each year.

Adult exposure to lead primarily occurs in the workplace.  Occupations with continued risk for lead exposure include battery manufacturing and recycling operations, smelting operations, and other manufacturing that utilizes lead based components.  As industries have begun to remove lead from the manufacturing process, re-engineered the manufacturing process to reduce exposure, and provided employees with personal protective equipment, levels have come down over time.  However, further efforts are warranted to prevent and reduce workplace exposures to lead.

For more information on the national ABLES program and blood lead levels from other states please visit http://www.cdc.gov/niosh/topics/ABLES/ables.html

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Updated Monday, April 07, 2014 at 09:13AM