# Presentation: 129029

## AOEC Medical Management for Lead Exposed Adults

**Kathleen Fagan, MD, MPH**
**June 27, 2007**

## Diseases of Potters:  “First their hands become palsied, then they become paralytic, splenetic, lethargic, cachectic, and toothless, so that one rarely sees a potter whose face is not cadaverous and the color of lead.”

## In the early 1900’s, working first for the State of Illinois and later for the Federal government, Dr. Alice Hamilton investigated hundreds of cases of lead poisoning in the smelting, enameling and paint industries.

## MMWR, August 18, 2006

- “Despite improvements, exposure to lead remains a substantial (largely occupational) health problem in the United States.”

## Why do we need new guidelines for clinical management of lead exposed adults ? 

- NHANES:  adult lead levels in 1970’s – 15mcg/dl; now < 2 mcg/dl
- OSHA lead standard has not been updated since 1978 !
- Significant advances in medical research on lead health effects to not only children but also adults
- Urgent need for guidance to health care providers treating adults with lead exposure

## LEAD TOXICITY

- Routes of entry:  Lung, GI
- Add skin for organic lead
- Transport by RBCs throughout body
- Crosses BBB and placenta
- Target Organs:  CNS, PNS, Kidney, Reproductive, Cardiovascular, GI
- Storage:  Bone
- Elimination:  Kidney
- Multiple mechanisms of toxicity; genetic factors

## TABLE 3

**Health Effects to Lead Exposed Adults by Blood Lead Level**

| Blood Lead Level (μg/dL) (μmol/L) |  |  |  |  |
| --- | --- | --- | --- | --- |
| 5-9(0.24-0.43) | 10-19(0.48-0.92) | 20-39(0.97-1.88) | 40-79(1.93-3.81) | ≥ 80(≥ 3.86) |
| Possible adverse population effects suggested by epidemiological studies  | Possible spontaneous abortion
Reduced newborn birth weight
Possible blood pressure changes
Possible renal dysfunction | Spontaneous abortion
Reduced newborn birth weight
Possible blood pressure changes
Possible renal dysfunction
Possible non-specific symptoms
     -Headache
     -Fatigue
     -Sleep disturbance
     -Anorexia
     -Constipation
     -Diarrhea
     -Arthralgia
     -Myalgia
     -Decreased Libido
  -Mood Swings,      personality changes
Possible CNS effects
-Memory and attention deficits  | Spontaneous abortion
Reduced newborn birth weight
Non-specific symptoms
CNS effects
Sperm effects
   -lowered counts
   -abnormal sperm
Subclinical peripheral neuropathy
Possible hypertension
Possible anemia
Possible renal damage
Possible gout | Spontaneous abortion
Reduced newborn birth weight
Non-specific symptoms
CNS effects
Sperm effects
Peripheral Neuropathy
Hypertension
Anemia
Abdominal Colic
Nephropathy
Gout |

## Slide 8

## Slide 9

## Typical Scenario- Case # 1

- 23 year old woman whose job is packaging lead-tin solder comes in with her husband to discuss family planning.  You draw a blood lead level.  It is 10 mcg/dl.  What do you advise?

## Typical Scenario- Case #2

- You are the occupational consultant to a steel mill.  You are doing a medical surveillance exam on a 35 year old African American man who works in the blast furnace.  He has difficult to control hypertension and his lead levels have been running in the mid-30’s (mcg/dl).  What do you advise him and his employer?

## Typical Scenario- Case #3

- Mr. Smith is referred to you by his attorney.  He is depressed, irritable, and his wife says he is “not the same man I married”.  He has worked at a brass foundry for 15 years.  His lead level has been as high as 62 mcg/dl in the past but has been <30 for the past 2 years.  He wants to switch jobs from furnace operator to shipping and receiving.  His company doesn’t want to do this, and the company doc says his problems are due to alcohol.

## Little guidance for health care providers until now...

- AOEC Medical Management Guidelines for Lead-Exposed Adults _[http://www.aoec.org/documents/positions/MMG_FINAL.pdf](http://www.aoec.org/documents/positions/MMG_FINAL.pdf)_
- Kosnett MJ et al, “Recommendations for medical management of adult lead exposure”, 2007, EHP, 115:463-471.
- EPA review of lead research (10/06)  http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=158823

## AOEC Guidelines for Medical Management of Lead Exposed Adults

- 2003- AOEC convened a panel to review medical management of lead exposed adults.
- 2005- AOEC produced initial draft of guidelines, which were reviewed by membership and updated several times.
- 2007- Present guidelines have been approved by 58/60 member clinics.

## Clinical Assessment

- Detailed medical, occupational and environmental history
- Physical exam:  BP
- Blood Lead Level (BLL)
- Other labs:  CBC, BUN, Cr, U/A, EP
- Urine and hair lead levels usually not helpful

## Exposure Investigation

- Identify the source (exposure history)
- MSDSs
- Information from employer, such as air level testing, biologic monitoring (with worker permission)

## Health Based Medical Management

- Consider individual, health issues, risk factors, exposure factors, family and social context.
- Consider both BLL and estimate of cumulative dose.
- Seek advice (OM, Tox, AOEC)
- Removal from exposure – When?

## TABLE 4 Health Based Management Guidelines

| Blood Lead Level (μg/dL) (μmol/L) |  |  |  |
| --- | --- | --- | --- |
| 5-9(0.24-0.43) | 10-29(0.48-1.40) | 30-79**(1.45-3.81)** | ≥ 80(≥ 3.86) |
| Lead education
    -Occupational
    -Environmental
    -Reproductive
Follow-up blood
     lead levels (BLLs) | Consider clinical assessment
     -History:
        occupational
        environmental
        medical
    -Exam, labs
    -Identify risk  factors
    -Family BLLs
Exposure investigation
     -MSDSs
     -Air testing
     -Workplace   communication
Consider consultations
    -Occupational Medicine
     -Industrial Hygienist
     -Public Health     department
Lead hazard reduction
Consider removal from lead exposure if warranted
Lead education
Follow-up BLLs
    (See Medical   Surveillance recommendations) | Lead education
Clinical assessment
     -History
     -Exam, labs (BUN, Cr,   CBC) 
    -Identify risk  factors
     -Family BLLs
Exposure Assessment
Consultations as appropriate
Lead Hazard Reduction
Removal from lead exposure**
Possible chelation for BLL>50 with signs or symptoms of  toxicity
Medical Surveillance
    -Follow-up BLLs
-Follow-up clinical  assessments
**Note this is the recommendation by AOEC. Consult the OSHA Standard for the levels currently defined in regulation which provides workers’ protections. | Immediate removal from lead exposure
Refer for immediate/  
    urgent medical
    evaluation and
    consideration 
    of chelation therapy
Clinical assessment
Lead education
Exposure investigation
Consultations
Lead hazard reduction
Medical surveillance |
|  |  |  |  |

## Medical Surveillance

- OSHA standard _not_ protective
- Recommend surveillance for any worker with potential harmful exposure to lead
- More frequent early biologic monitoring (BLLs)
- More flexibility in surveillance that accounts for variability in jobs and exposures.

## Treatment 		(? Chelation)

- STEP #1:  Removal from exposure
- No evidence-based guidelines for chelation due to lack of good studies
- Decision to chelate based on lead level and acute symptoms, particularly CNS
- Oral chelation has largely supplanted parenteral chelation.

## Chelation Therapy

*recommended* for adults with BLLs 100 μg/dL (4.83 μmol/L) or greater,
*strongly considered* for BLLs 80 to 99 μg/dL (3.86-4.78 μmol/L)
*possibly considered* for BLLs between 50 and 79 μg/dL (2.41-3.81 μmol/L) in the presence of lead-related symptoms

## Pregnancy and Breast Feeding Concerns

- Fetal blood lead = 80% mother’s BLL
- Exposure to lead in utero may be the most devastating in a child’s development
- Recommend BLL < 5 mcg/dl for pregant women and women considering pregnancy
- Lead in breast milk is much _lower_ than in blood; thus benefits of breast feeding generally outweigh risks.

## Key Points of Guidelines

- The toxic effects of lead can occur without overt symptoms.
- Long term low dose can lead to progressively larger cumulative dose and long term health effects.
- Current occupational standards are not sufficiently protective and should be strengthened.
- Prevention of lead exposure should remain the primary goal of health care providers, public health professionals, and employers.

## Further Information	about AOEC

- Katherine Kirkland, MPH
- Association of Occupational & Environmental Clinics
- 1010 Vermont Ave., NW #513
- Washington, DC  20005
- (888) 347-AOEC (2632)
- kkirkland@aoec.org
- www.aoec.org