Identifying Lead-poisoned Adults

The 1,050 State public health experts who make up the Council of State and Territorial Epidemiologists (CSTE) is urging the States and CDC to adopt a new case definition for adults of elevated blood-lead levels (BLL) and to require laboratories to report ALL blood lead test results to NIOSH's Adult Blood Lead and Epidemiology (ABLES) Program.  CSTE recommends the definition of  an "elevated BLL" change from 25 ug/dl and greater, to 10 ug/dl and greater. 

The CSTE's policy statement is grounded on the growing body of evidence linking "low" levels of lead in adults with decreased kidney function, cardiovascular disease and cognitive impairment.  A mini-monograph published in 2007 in Environmental Health Perspectives provides some of the most recent evidence cited by CSTE to support its recommendation.  The group identified a number of occupations for which workers are at particular risk of lead poisoning such as construction involving paint removal; demolition and maintenance of outdoor metal structures (e.g., bridges, water towers); and battery manufacturing and recycling.  (I've written previously about mine workers with lead poisoning.)  

 In CSTE's news release announcing the policy recommendation, the group noted:

"...only a fraction of known occupational cases are included in national health statistics, which currently only include counts of individuals with blood lead levels 25 ug/dl and greater.   ...The result is a significant underestimation of the health impact of elevated blood lead levels in the population of the United States.   ...With more complete reporting, we will have a clearer picture of the true scope of the problem to guide our efforts to prevent lead poisoning."

The CSTE's policy recommendation for an improved evidence-based definition of an elevated blood-lead level compelled me to look at a few of OSHA's requirements related to lead exposure, surveillance and prevention. 

OSHA's lead standard for general industry workers took effect (mostly) in 1981, and in 1993 for construction workers.  Both health standards include provisions for medical removal protection for lead-exposed workers (at no loss of pay) when 

1. their blood-lead level (BLL) is at or exceed 50 ug/dL, or
2. there is a medical determination that "the employee has a detected medical condition which places the employee at increased risk of material impairment to health from exposure to lead." [Section (k)(1) in 1910.1025 and 1926.62]

Under OSHA's standards, a worker may return to work when their BLL is at or below 40 ug/dL, and an employer is required to record cases that the medical removal criteria on the worksite's log of injuries and illnesses.  The disparity between OSHA's definition of a case of adult lead poisoning (i.e., 40 ug/dL) and the CSTE's recommended new definition of an elevated BLL in an adult (i.e., 10 ug/dL) raises interesting issues for public health policy:

• CSTE notes the importance of maintaining "adult BLLs less than 10 μg/dL to avoid long-term health risks," but OSHA's standard implies that a BLL of 40 ug/dL or less is not harmful. 
• CSTE's recommendation for laboratory reporting to the CDC/ABLES system of BLL's at 10 ug/dL or greater, but OSHA's requirements for recording a poisoning-injury is trigger only at the medical removal stage (typically a 40 ug/dL BLL).
• Should CSTE's recommendation and other calls for a more protective lead standard prompt OSHA to change its recording requirements for elevated BLLs?  Or would OSHA be able to ascertain easily using ABLES which employers' work conditions are responsible for elevated BLLs?
• Should MSHA (which has NO standard to protect workers from exposure to lead) adopt a policy requiring mine operators to report cases BLLs above 10 ug/dL as part of the agency's Part 50 reporting system.  Currently, mine operators' responsibility to report to MSHA hinges on their  knowledge of an illness case or an award of compensation.

My curiosity about how CSTE's recommendation jives with OSHA's lead standard and recordkeeping requirements, led me to several OSHA policy interpretations.  On the one hand, OSHA suggests that its recordkeeping rule, among other things, is supposed to help employers (and the agency) recognize trends and implement preventative measures.  With respect to an elevated BLL, this precautionary interpretative statement by OSHA seems to apply:

"A 'diagnosis of substantial impairment of a bodily function' is not required for a case to meet OSHA recordkeeping criteria, nor is it a limitation to recordability under the OSH Act.  Many injuries and illnesses meet the recording criteria of the Act but lack diagnosis of a substantial impairment of a bodily function.   ....The workers are being removed not only to prevent illness, but to prevent further damage beyond what has already been done." [emphasis added.]

On the other hand, and in the same document, OSHA explains the recording requirements in terms of medical removal provisions: 

"...The medical removal provisions of each standard were set using scientific evidence established in the record devoted to that rulemaking.  OSHA takes care when setting the medical removal provisions of standards to ensure that these provision reflect a material harm, i.e., the existence of an abnormal condition that is non-minor and thus worthy of entry in the OSHA injury and illness records."

"OSHA finds that cases involving a mandatory medical removal are cases that involve serious, significant, disabling illnesses resulting in restriction of work and transfer to another job, or both. These medical restrictions result either in days away from work or days when the worker can work but is restricted from performing his or her customary duties..."  [emphasis added]

Neither the CSTE document nor the published literature suggest that a BLL of 10 ug/dL constitute a "disabling illness."   Rather the evidence indicates that adults with elevated BLL are at risk of kidney, cognitive and cardiovascular impairment.  If OSHA wanted to amend its recordkeeping rule (1904) to require employers to record BLLs of 10 ug/dL, what would the resource demand be to make that simple change?   Would OSHA have to calculate the "paperwork" burden, prepare a regulatory flexibility analysis? determine special burdens for small businesses?  Egads! all that and probably more to simply make OSHA's recording requirement consistent with any new CDC case definition? 

I'm not sure a rulemaking change would be worth the effort.  The CSTE's recommendation, however, should invigorate between discussion at NIOSH, State-ABLE staff and OSHA of how BLLs at 10 ug/dL and above can be referred promptly for a workplace investigation and public disclosure of the employer(s) identity.