Medical surveillance lead workers

Source 1. Occupational Safety and Health Administration (OSHA) Lead Standard (29CFR1910.1025 and 29CFR1926.62.) K.L. Hipkins, B.L. Matema, MJ. Kosnett, J.W. Rogge, and J.E. Cone, Medical surveillance of the lead exposed worker, AAOHN Journal, 46(7) 330-339, 1998 2. D. Rempel, The lead-exposed worker, JAMA 262(4) 532-534, 1989 3. U.S. Department of Labor, OSHA, Lead in Construction, OSHA 3142, 1993. 

In general, all work involving possible exposure to lead has to be assessed, and the level of exposure has to be determined, either in the air or in the blood. The maximum allowed concentration of lead in the air is set at 150 pg m , calculated as a time-weighted average over 40 h per week. For blood, the maximum allowed lead level is 70 pg/100 mL blood of an individual worker. If one of these occupational exposure levels is exceeded, immediate protective measures are necessary to remedy the situation, including intensive medical surveillance. 

At the time, the OSHA proposal was for an action level of 50 pg/m, which NIOSH endorsed in its criteria document as a future goal to provide greater assurances of safety (NIOSH 1978, p. XII-19). That air level would keep BLLs at about 40 pg/dL or lower in virtually all workers, protecting against subclinical effects of lead. NIOSH also endorsed a vigorous medical surveillance program for workers exposed above the action level but below the proposed maximum air lead concentration of 100 pg/m. NIOSH estimated that even at the proposed air standard of 100 pg/m less than half of the workers will have blood lead levels above 40 [pg/dL] (NIOSH 1978, p. XII-19). 

Medical surveillance Provide initial and annual surveillance. For exposure more than 30 days annually and blood levels above pg/dl, full medical surveillance required. If blood lead level is 50 pg/deciliter, temporarily remove worker. 

The purpose of this document is to outline the medical surveillance provisions of the interim standard for inorganic lead in construction, and to provide further information to the physician regarding the examination and evaluation of workers exposed to inorganic lead. 

MEDICAL SURVEILLANCE AND MONITORING REQUIREMENTS FOR WORKERS EXPOSED TO INORGANIC LEAD... 

In addition, the standard requires that the employer inform all workers exposed to lead at or above 30 [ig/m of the provisions of the standard and all its appendices, the purpose and description of medical surveillance and provisions for medical removal protection if temporary removal is required. An understanding of the potential health effects of lead exposure by all exposed employees along with full understanding of their rights under the lead standard is essential for an effective monitoring program. 

A complete and detailed work history is important in the initial evaluation. A listing of all previous employment with information on job description, exposure to fumes or dust, known exposures to lead or other toxic substances, a description of any personal protective equipment used, and previous medical surveillance should all be included in the worker s record. Where exposure to lead is suspected, information concerning on-the-job personal hygiene, smoking or eating habits in work areas, laundry procedures, and use of any protective clothing or respiratory protection equipment should be noted. A complete work history is essential in the medical evaluation of a worker with suspected lead toxicity, especially when long term effects such as neurotoxicity and nephrotoxicity are considered. 

Summary. The Occupational Safety and Health Administration s interim standard for inorganic lead in the construction industry places significant emphasis on the medical surveillance of all workers exposed to levels of inorganic lead above 30 pg/m TWA. The physician has a fundamental role in this surveillance program, and in the operation of the medical removal protection program. 

Medical surveillance of exposed workers differs according to whether exposure is to inorganic lead or lead alkyls. In the case of inorganic lead the appropriate measure of recent exposure is the blood lead level (see Chapter 7). This is normally determined every three months and any worker whose blood lead exceeds 80 jUg (100 ml)" of whole blood is removed from lead exposure at work. Determinations of haemoglobin concentrations and clinical assessments are also used to evaluate the health of lead workers. For workers exposed to concentrated lead alkyls a measure of lead in urine is made at 6 weekly or more frequent intervals, and blood leads are measured annually. Any worker with a urinary lead value in excess of 0.8 iimol dm is suspended from lead work until considered medically fit to return. 

For plumbers and roofers who use lead in their work, medical surveillance by a doctor will be required if exposure is significarrt and the surveillance will include blood lead tests. Similarly workers who come into contact with asbestos will require medical surveillance as described later in this chapter. 

The OSHA Lead Standard (29 CFR 1910.1025, 1987) established two exposure limits, both applicable over an 8-hour time-weighted average, an action level of 30 pg/m= and a permissible exposure limit (PEL) of 50 pg/mf If an employee s exposure is at or above the action level, the standard requires the employer to perform exposure monitoring, medical surveillance, training, and remove workers with blood lead concentrations at or above 50 pg/dl of blood. If exposure exceeds the PEL, the employer must do the following. 

Responsibility for complying with the medical surveillance, recordkeeping, and blood lead proficiency testing requirements of the Lead standard belongs to the employer whose workers are exposed to lead. 

In any work situation there will be some people who are more vulnerable to certain risks than others, e.g. where such workers may be exposed to toxic substances, to small levels of radiation, or to dangerous metals, such as lead. T)qjical examples of vulnerable groups are young persons who, through their lack of experience, may be unaware of hazards pregnant women, where there may be a specific risk to the unborn child and disabled persons, whose capacity to xmdertake certain tasks may be limited. In a number of cases there may be a need for continuing medical and/or health surveillance of such persons. 

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