Document 1EggNz7KmQ4yKjzpoNe7LeRa

UNION CARBIDE CORPORATION CHEMICALS AND PLASTICS p. o. box 3370, brownsville. texas 78520 To (Name) A. L. Barefoot Company Location Brownsville Plant Copy to J. L. Wyatt (w/o att) Date June 25, 1982 Originating Dept. Answering letter date Subject Contractor Information Safety and Health Dear Ashton: Attached is the information you requested relating to contract workers and required medical surveillance. List of items included: *^"1. Summary of medical testing requirements. *-'-2'. Excerpts from OSHA on medical requirements on Asbestos, Lead and a summary by a medical testing company that will bring a unit into the plant and test the workers. 3. Corporation Occupational Health ^loivtractor policy. 4. The contractor guideline found in- the Safety>and Health^Informat ion Manual, CMD. V* Call if there are any questions. KGT:mfw Attachment K. 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M o 2 CO Crf M CJ H co tu 3 erf M CO a d M HI < W 4 5 Q ca CO o M O /> -4 k! H /--s <s g 2 o J W < - z CO 35 {*4 5 HAZARDS 31V830S A T0$ REFERENCE FILE Legend Notation BrMtUinc.. Asbestos-Duat- U point Gothic. .14*7 Kjuartsus - To Tortr. Health! . sura as soon as practicable.but not lateq than~6 days' of 4he finding. Thaemployee shall also be timely notified of the cor-, rective action being taken. Spacing between lines shall.be at least! (J) Medical examinations--(1) Gen equal to- the height of the upper of any eral. The employer shall provide or make two lines. available at his cost, medical examina (2) Caution labels--(1) Labeling. Cau tions relative to exposure to asbestos re tion labels shall be affixed to all raw quired by this paragraph. materials, mixtures, scrap, waste, debris, (2) Preplacement. The employer shall and other products containing asbestos provide or make available to each of his fibers, or to their containers, except that employees, within 30 calendar days fol no label Is required where asbestos fibers lowing his first employment in an have been-modified by a bonding agent, occupation exposed -to rlrbornc con coating, binder, or other material so that centrations of asbestos fibers, a compre during any reasonably foreseeable use, hensive medical examination, which shall handling, storage, disposal, processing, or include, as a minimum, a chest roent transportation, no. airborne- concentra genogram (posterior-anterior 14 x 17 tions- of asbestos fibers in excess , of the Inches), a history to elicit symptom exposure limits prescribed, in paragraph atology of respiratory - disease, .and <bl of this section will be released. . pulmonary function tests to include Ill) Label specifications. The caution forced vital capacity (FVC) and forced labels required by subdivision (1) of this expiratory volume at 1 second (FEVi..h subparagraph shall be printed In letters "(3)" Annual examinations. `On or be of' sufficient size and contrast as to be fore January 31, 1873, and at least an readily visible and legible. The label shall, nually thereafter,- every employer shall state: provide, or make available, comprehen Caution; sive medical examinations to each of his contains Asbestos Fibers Avoid Cresting- Dust Breathing Asbestos Dust May Cause Serious Bodily Harm Chi Housekeeping--(i) Cleaning. All external surfaces In any place of employ ment-shall be maintained free of accu mulations of asbestos fibers if,- with their dispersion, there would be an excessive concentration. employees engaged in occupations ex posed to airborne concentrations of as bestos fibers. Such annual examination shall Include,- as a minimum, a chest roentgenogram (posterior-anterior 14 x 17 Inches), a history to elicit symptom atology of respiratory disease, and pulmonary function tests to include forced vital capacity (FVC) and forced expiratory volume at 1 second (FEV,.,).. (2i Waste disposal. Asbestos 'waste, (4) Termination of employment. The scrap, debris, bags' containers, eqiiip- employer shall provide, or make avail nent, and 'asbestos-contaminated cloth able, within 30 calendar'days before or ing, consigned for disposal, which-may after the termination of employment of produce in any reasonably foreseeable' any employee engaged in an occupation use, - handling', storage, -processing, dis exposed'to airborne. concentrations of posal, or transportation airborne concen asbestos fibers.'a comprehensive medical, trations of asbestos fibers in excess of the examination which shall include, as a exposure limits prescribed in paragraph minimum, a chest roentgenogram (pos (b) of this section shall be collected and terior-anterior 14 x 17 inches), a history disposed' of In sealed imperr.ieable bags, to elicit symptomatology of respiratory or other closed,1 impermeable containers. disease, and pulmonary function tests (1) Recordkeeping--(1) Exposure rec ords. Every employer shall maintain rec ords .of any personal or environmental to Include forced vital capacity (FVC) and forced expiratory volume at 1 second (FEV,,.). monitoring required by this section. Rec ords shall be maintained for a period of at least 20 years and shall be made avail able upon request to the Assistant Sec retary of Labor for Occupational. Safety and Health, the Director of the National Institute for Occupational Safety and Health, and to authorized representa tives of either. (1910.1001(0(1) amended at 41 FR 11505, March 19, 19761 (5) ReCe'hYetaniinatioris. "No medldST examination -is required of any em ployee, If- adequate records show that the-' employee has been examined in ac cordance' with this paragraph within the past -1-year period. (6) Medical'. records--(1) Mainte nance. Employers of employees examined pursuant to this paragraph shall cause to be maintained complete and accurate; records of all such medical examina (2) Access. Employee exposure records tions. Records- shall be retained' '-by required by this paragraph shall be pro employers for at least 20 years. vided upon request to employees, designated representatives, and the Assistant Secre tary in accordance with 29 CFR 1910.20 (a)-(c) and (g)-(l). (Section 1910.1001 (i)(2) amended at 45 FR 35212, May 23, 1980, effective August 21, 1980] (ii) Access. Records of the medical examinations required by this paragraph shall be provided upon request to em ployees, designated representatives, and the Assistant Secretary in accordance with 29 CFR 1910.20(a)-(e) and (g)-(i). These records shall also be provided upon the XZ)XEmployee notification. Any. em ployee louitd to have been exposed htispy. iirne'to. airborne concentrations of nabes*' ios-:fibers lh- excess'-of the liralta- pros scribed In paragraph (b) of this section shall be notified in writing of the.cXpo- request to the Director of NIOSH. Any physician who conducts a medical exam ination required by this paragraph shall furnish to the employer of the examined employee all the information specifically required by this paragraph, and any other Occupational Safety 8. Hcolth Reporter medical information related to occupa tional exposure to asbestos fibers. ISection 1910.1001(j)(61(ii) amended at 45 FR 35212, May 23, 1980, effective August 21, 1980; corrected by 45 FR 54333, August 15. 1980) 1910.1002 Coal tar- pilch volatiles; intcrprelnlion of terra. As used in Sec. 1910.1000 (Table Z-l), coal tar pitch volatiles include the fused poly cyclic hydrocarbons which volatilize from the distillation residues of coal, petroleum, wood, and other organic mat-, ter. ^1910.1003 4-NitiobiphenyI. . (a) Scope and application. (1) This section applies to any area In which 4-NitrobiphenyJ, Chemical Abstracts Pervice Registry Number 92933 is manu factured, processed, repackaged, re leased, handled, or stored, but shall not apply to transshipment in sealed con tainers. except for the labeling require ments under paragraphs (e) (2), (3), and (4) of this section. (2) This section shall not apply to solid or liquid mixtures containing less than 0.1 percent by weight or volume of `4-Nitrobiphenyl. (b) Definitions. -For the purposes of .this section: (1) "Absolute filter" is one capable of retaining 99.97 percent of a jnono disperse aerosol of 0.3 nm. particles. (2) "Authorized employee" means an employee whose duties require him to be In the. regulated area and who has been Specifically assigned by the employer. (3) "Clean change room" means a room where employees put on clean' Clothing and/or protective equipment in Bn environment free of 4-Nitrobiphenyl. The clean change room shall be con tiguous to and have an entry from a shower room, when the shower room facilities are otherwise required in'thls5 section. (4) "Closed system" means an opera tion Involving 4-Nitrobiphenyl where containment prevents the release of 4Nitroblphenyl into regulated areas, nonregulated areas, or the external environ ment,, (5) "Decontamination" means the in activation of 4-Nitrobiphenyl or Its safd .disposal.. (6) "Director" means the Director, National "Institute for Occupational .Safety and Health, or any person di rected by him or the Secretary of Health, Education, and Welfare to act for the Director. (7) "Disposal" means the safe re moval of 4-Nitrobiphenyl from the work environment. (8) "Emsrgency" means an unforseen circumstance or set of circumstances re- .uultlng In the release of 4-NitTobl'phenyl which may result In exposure to or con tact with 4-Nitrobiphenyl. (9) "External environment" means any environment external to regulate*! and nonregulated areas. (10) "Isolated system" means a fully enclosed structure other than the vessel ci .containment of 4-Nitrobiphenyl, ISec. 1910.1003(b) (101) 60 31:8424 j 7 ujout-u /<_/ >o t / ^ 7/f^ k.EhO> PAtfiT - tfST REFERENCE FILE (2) Cleaning floors. (I) Floors and other surfaces where lead accumulates may not be cleaned by the use of com pressed air. (11) Shoveling, dry or wet sweeping and brushing may be used only where vacuuming or other equally effective methods have been tried and found not to be effective. (3) Vacuuming. Where vacuuming, methods are selected, the vacuums shall be used and emptied In a manner which minimizes the reentry of lead into the workplace. [Section 1910.1025(h)(2)(ii) corrected at 44 FR 5446, January 26, 1979, effective Feb ruary 24,1979] [Section 1910.1025(h) effective date was March 31.1979, to extent that employers must acquire vacuums to comply, according to action by U.S. Court of Appeals for District of Columbia Circuit (44 Fr 14554, March 13. 1979)] (1) Hygiene facilities and practices. ture `controlled, positive pressure, fil tered dir supply, and are readily acces sible to employees. (ili) The employer shall assure that employees who work in areas where their airborne exposure to lead is above the PEL without regard to the use of a respirator ivasn their hands and face prior ip eating, .drinking, smoking or applying cosmetics. liv) The employer shall assure that employees do not enter lunchroom fa cilities with protective work clothing or equipment unless surface lead dust has been removed by vacuuming, downdraft booth, or other cleaning method. (5) Lavatories. The employer shall provide an adequate number of lavar tory facilities which comply with M10.141(d) (1) and (2) of this Part. moved from exposure to lead due to an elevated blood lead level. (ii) Follow-up blood sampling tests. Whenever the results of a blood lead level test indicate t)i%l an employee's blood lead level exceeds the numerical criterion for medical removal under paragraph (k)ClXi). the employer shall provide a second (follow-up) blond sampling test within two weeks after the employer receives the results of the first blood sampling test. (iii) Accuracy of blood lead level sam pling and analysis. Blood lead level sampling and analysis provided pursu ant to this section shall have an accu racy (to a confidence level of '95 per cent) within plus or minus 15 percent or -6 pg/100ml. whichever is greater, and shall be conducted by a laboratory licensed by the Center for Disease Control, United States Department of Health, (1) The employer shall assure that in areas where employees are exposed to lead above the PEL, without regard to the use of respira tors, food or beverage is not present or consumed, tobacco products are not [Sections 1910.1025(i)(l), (i)(2), (i)(3) (i) and (ii), and (i}(4)(2) and (iii) amend ed, and (i)(6) deleted, at 44 FR 5446, Janu ary 26, 1979, effective February 24, 1979] Education and Welfare (CDC) or which has received a satisfactory grade in blood lead proficiency testing from CDC in the prior twelve months. present or used, and cosmetics are not (j) Medical surveillance. Cl) General! (iv) Employee notification. Within applied, except In change rooms, (i) The employer .shall institute a five working days after the receipt of lunchrooms, and showers reQuired medical surveillance program for all biological monitoring results, the em under paragraphs (i)(2)-<l)(4) of this .employees who are or may be exposed, ployer shall notify in writing each em section. (2) Change rooms. (1) The employer above the action level for more titan 30 days per year. ployee whose blood lead level exceed1; 40 ye/100 g: (A) of that employee's shall provide clean change rooms for blood lead level and (B) that -the employees who work in areas where their (ii) The employer shall assure' that standard requires temporary medical airborne exposure to lead is above the all medical examinations and proce removal with Medical Removal Protec PEL, without regard to the use of res dures are performed by or under the tion benefits when an employee's pirators. (ii) The employer shall assure that supervision of a licensed physician. (Hi) The employer shall provide the blood lead level exceeds the numerical criterion for medical removal under paragraph (kXlXi) of this section. change rooms are equipped with sepa rate storage facilities for protective work clothing and equipment and for street clothes which prevent cross-con tamination. (3) Showers. The.employer shall assure that employees who work in areas where their airborne exposure to lead required medical surveillance including mul tiple physician review under paragraph (j) (3)(iii) without cost to employees and at a reasonable time and place. t2) Biological monitoring. --(1) Blood lead and ZPP level sampling and analysis. The employer shall make available biological monitoring (3) Medical examinations and con sultations.--iliFreguency. The employ er shall make available medical .exami nations and consultations to each em ployee covered under paragraph. (jXl)Cl) of this section on the follow ing schedule: is above the PEL. without regard to in the form* of' blood sampling and (A) At least annually for each em the use of respirators, shower :at the analysis for lead and zinc protopor ployee for whom a blood sampling test end of the work shift. phyrin levels to each employee cov conducted at any time during the pre (ii) The employer shall provide ered, under paragraph (j)ClXl) of this ceding 12 months Indicated a blood shower facilities in accordance with section on the following schedule: lead level at or above 40 yg/100 g; 1910.141(d){3) of this Part (A> At least every 6 months to each (B) Prior to assignment for each em (iii) The employer shall assure that employee covered under paragraph ployee being assigned for the first employees who are required to shower (jXl)ti) of this section; time to an area in which airborne con pursuant to paragraph (i)(3)(i) do not leave the workplace wearing any cloth ing or equipment worn during the work shift. C4) Lunchrooms, (i) The employer shall provide lunchroom faciUti.es-for employees who work in areas where their airborne exposure to lead is above the PEL, without regard to the use of respira tors. (B) At least every two months for', each employee whose last blood sam centrations of lead are at or above the action level; - pling and analysis indicated a blood (C) As soon as possible, upon* notifi ]ead level at or above 40 ^g/100 g of Whole blood. This frequency shall con tinue until two consecutive blood sam ples and analyses indicate a blood lead level below 40 ^.g/100 g of whole bloocl and cation by an cmployee'elther that the employee has developed signs or symp toms commonly associated with lead intoxication, that the employee de sires medical advice concerning the ef fects of current or past exposure to lead on the employee's ability to pro (ii) The employer shall assure thal CC> At least monthly during the re-, create a healthy child, or that the em lunch'room facilities have a tempera moval period of each employee re ployee has demonstrated difficulty in Occupational Sofety & Health Reporter (Sec. 1910.1025(j)(3)(i)(C)l V 8 TOXIC SUBSTANCES S159 31:8425 breathing during a respirator fitting test or during use: and (D) As medically appropriate for each employee either removed from exposure to lead due to a risk of sus taining material impairment to health, or otherwise limited pursuant to a final medical determination. (ii) Content Medical examinations made available pursuant to paragraph (JX3)(i)(A)-(B) of this section shall in clude the following elements: (A) A detailed work history and a medical history, with particular atten tion to past lead exposure (occupation al and non-occupational), personal habits (smoking, hygiene}, and past gastrointestinal, hematologic, renal, cardiovascular, reproductive and neu rological problems; (B) A ..thorough physical examina tion. with particular attention to teeth, gums, hematologic, gastrointes tinal, renal, cardiovascular, and neuro logical systems. Pulmonary status should be evaluated if respiratory pro tection will be used; (C) A blood pressure measurement: (D) A blood sample and analysis which determines: (1) Blood lead level: (2) Hemoglobin and hematocrit de terminations. red cell Indices, and ex amination of peripheral smear mor phology; 13) Zinc protoporphyrin: 14) Blood urea nitrogen: and, (5) Serum creatinine: (E) A routine urinalysis with micro scopic examination: and (F) Any laboratory or other test which the examining physician deems necessary by sound medical practice. The content of medical examinations made available pursuant to paragraph (jK3)(lXC)-<D) of this section shall be determined by an examining physician and. if requested by an employee, shall include pregnancy testing or labora tory evaluations! male fertility. (iii> Multiple physieixn. rtvieio mech anism. (A) ff the employer selects the initial physician who conducts any medical examination or consultation provided to an employee under this-' section, the employee may-designate a second physician: ID To review any findings, determN nations or recommendations of the ini tial physician: and (2) To conduct such examinations, consultations, and laboratory tests as the second physician deems necessary to facilitate this review. (B) The employer shall promptly to any other toxic substance (if appli notify an employee of the right to cable); seek a second medical opinion after {4) A description, of any personal each occasion that an initial physician protective equipment used or to be conducts _a medical examination or used; consultation pursuant to this section. (5) Prior-blood lead determinations: The employer may condition its par and ticipation inland payment for. the (C) All prior written medical opin multiple physician review mechanism ions concerning the employee in the' upon the employee doing the follow employer's possession or control. ing within fifteen (15) days after re (B) The employer shall provide the- ceipt of the foregoing notification, or foregoing information to a second or receipt of the initial physician's writ third physician conducting a medical ten opinion, whichever is later:' examination or . consultation under 11) The employee informing Lhe cm-, this section upon request either by the ployer that he or she intends to seek a second or third'physician, or by lltt- second medical opinion, and cmployee. (2) The employee initiating steps to make an appointment with a second physician. (v) Written medical opinions. (A) The employer shall obtain and furnish the employee with a copy of a written medical opinion from each examining; (C) If the findings, determinations or consulting physician which contains or recommendations of the second the following information: physician differ from those of the Ini (f) The physician's opinion as to tial physician, then the employer and whether the employee has any detect the employee shall assure that efforts ed medical condition which would are made for the two physicians to re place the employee at increased risk of solve any disagreement. material impairment of the employee's (D) If the two physicians have been unable to quickly resolve their dis agreement, then the employer and the employee through their respective physicians shall designate a third phy sician: health from exposure to lead; (2) Any recommended special protcc-' tive measures to be provided to the employee, or limitations to be placed upon the employee's exposure to lead; (3) Any recommended limitation upon the employee's use of respira (f) To review any findings, determi tors, including a determination of nations or recommendations of the whether Lhe employee can wear 'a prior physicians; and powered air purifying respirator if a (2) .To conduct such examinations, physician determines that the employ consultations, laboratory tests and dis ee cannot wear a negative pressure res cussions with the prior physicians as pirator; and the third physician, deems necessary to 14) The results of the blood lead de resolve the disagreement of the prior terminations. physicians. (B> The employer shall instruct each (E) The employer shall act consist examining to: and consulting physician ent with the findings, determinations and recommendations of the third physician, unless the employer and the employee reach an agreement which is otherwise oonsistent with the recommendations of .at least, one of the three physicians. (f) Not reveal either in the written opinion, or in any other means of com munication with the employer, find ings. including laboratory results, or diagnoses unrelated to an employee's occupational exposure to lead; and 12) Advise the employee of any medi (iv) Information provided to examin cal condition, occupational or nonoc- ing and consulting physicians. (A) cupationa). which .dictates further The employer shall provide an initial medical examination or treatment. physician conducting a medical exami (vi) Alternate Physician Determina nation or consultation under this sec tion Mechanisms. The employer and tion with the following information: an employee or authorized employee (/) A copy of this regulation for lead includ representative may agree upon the use ing all Appendices; of any expeditious alternate physician determination mechanism in Hcu of (2) A description of the affected em the multiple physician review mecha ployee's duties as they relate to the nism provided by this paragraph so employee's exposure; long as the alternate mechanism oth (2) The employee's exposure level or erwise satisfies the requirements cojv anticipated exposure level to lead and tained. in this paragraph. 12-11-80 [See. 1010.10251j) (3) (vi)] Published by THE BUREAU OF NATIONAL AFFAIRS. INC.. WASHINGTON. D.C. 20037 69 TOXIC SUBSTANCES LEA IX (LoriT* ia#?-C&&7 fiA^t S-131 31:8437 Appendix C to Section 1910.1025-- Section 1 provides a detailed action level of 30 pg/m3TWA formore Medical Surveillance Guidelines Introduction The primary purpose of the Occupational Safety and Health Act of 1970 is to assure, so far as possible, safe and healthful working conditions for every worldng man and woman. The occupational health standard for inorganic lead was promulgated to protect workers exposed to inorganic lead including metallic lead, all inorganic lead compounds and organic lead soaps. Under this final standard in effect as of March 1,1979, occupational exposure to inorganic lead* is to be limited to 50 pg/m* (micrograms per cubic meter) based on an 8 hour time-weighted average (TWA). This level of exposure eventually must be achieved through a combination of engineering, work practice and other administrative controls. Periods of time ranging from 1 to 10 years are provided for different industries to implement these controls. The schedule which is based on individual industry considerations is given in Table 1. Until these controls are in place, respirators must be used to meet the 50 pg/m3 exposure limit. The standard also provides for a program of biological monitoring and medical surveillance for all employees exposed to levels of inorganic lead above the action level of 30pg/m* (TWA) for more than 30 days per year. The purpose of this document is to outline the medical surveillance provisions of the standard for inorganic lead, and to provide further information to the physician regarding the examination and evaluation of workers exposed to inorganic lead. (Section 1910.1025, Appendix C footnote added at 44 FR 68827, November 30, 1979) description of the monitoring procedure lhan 30 days each year. This program including the required frequency of blood testing for exposed workers, provisions for medical removal protection (MRP), the recommended right of the employee to a second consists of periodic blood sampling and medical evaluation to be performed on schedule which is defined by previous laboratory results, worker complaints c>r medical opinion, and notification and concerns, and the clinical assessment of recordkeeping requirements of the the examining physician. employer. A discussion of the requirements for respirator use and respirator monitoring and OSHA's position on prophylactic chelation therapy are also included in this section. Under this program, the blood lead level of all employees who are exposed to lead above the action level of 30 pg/rr is to be determined at least every six months. The frequency is increased lo Section 2 discusses the toxic effects .and clinical manifestations of lead every two months for employees whose last blood lead level was between 40 poisoning and.effects of lead fig/100 g whole blood and the level intoxication on enzymatic pathways in requiring employee medical removal to heme synthesis. The adverse effects on both male and female reproductive capacity and on the fetus are also be discussed below. For employees who are removed from exposure to lead due discussed. to an elevated blood lead, a new blood Section 3 outlines the recommended medical evaluation of the worker exposed to inorganic lead including lead level must be measured monthly. A zinc protoporphyrin (ZPP) measurement is strongly recommended on each details of the medical history, physical occasion that a blood lead level examination, and recommended measurement is made. ZPP monitoring is laboratory tests, which are based on the one of several requirements of the toxic effects of lead as discussed in standard that has been temporarily Section 2. . stayed by pending litigation over the Section 4 provides detailed information concerning the laboratory tests available for the monitoring of exposed workers. Included also is a discussion of the relative value of each lead standard. Unless otherwise noted In this document, all provisions of the standard pertaining to medical surveillance and medical removal protection are currently in effect. test and the limitations and precautions An annual medical examination and which are necessary in the consultation performed under the interpretation of the laboratory results. guidelines discussed in Section 3 is to be [Section 1910.1025, Appendix C corrected at 44 FR 68827, November 30, 1979) made available to each employee for whom a blood test conducted at any time during the preceding 12 months I. Medical surveillance and monitoring requirements for workers exposed to inorganic lead Under the occupational health * indicated a blood lead level at or above 40 pg/100 g. Also, an examination is to be'given to all employees prior to their assignment to an area in which airborne lead concentrations reach or exceed the standard for inorganic lead, a program action level. In addition, a medical `The term inorganic lead used throughout the medical surveillance appendices is meant to be synonymous with the definition of lead set forth in the standard. of biological monitoring and medical surveillance is to be made available to all employees exposed to lead above the Table t examination must be provided as soon as possible after notification by an employee that the employee has developed signs or symptoms commonly associated with lead intoxication, that Effective date the employee desires medical advice Permissible airborne lead levels by industry (pg/my Mar. 1. Mar. i, Mar. 1, Mar. 1, Mar. 1, Mar. 1. regarding lead exposure and the ability 1979 I960 1961 1962 1964 1989 to procreate a healthy child, or that the (final) employee has demonstrated difficulty in ,, 200 200 200 200 200 200 100 100 100 50 50 50 breathing during a respirator fitting test 200 200 100 100 200 100 100 too 200 200 200 100 50 50 50 50 or during respirator use. An examination 50 50 is also to be made available to each 6. All other industries..--........... -- _____________ 200 50 50 50 50 50 employee removed from exposure to Airborne levels to bo achieved without reliance or respirator protection through a combination oi engineering, work practice iead due to a risk of sustaining material end other administrative controls. While these controls ero boing implemented respirators must bo used to meet tho SO pgSm* impairment to health, or otherwise exposure limit 1-31-80 ISec. 1910.1025, Appendix C) Published by THE BUREAU OF NATIONAL AFFAIRS, INC., Washington, D.C. 20037 29 31:8438 REFERENCE FILE Table 2 EflKlivo do* Mar. 1,1978' Mar. 1.1860 Mar. 1,1981 Mar. 1,1982 Mar. 1.1983 (final) A. Blood lead level requiring employee medical removal (level must JsfiOpg/ioo g_ j>7r.ug/l00 g_ >60/rg/100 g.. _>60 pg/100 g. >60pgf100 g or average ot last llaee blood sam be confirmed with second follow-up blood lead level within two ples or al blood samples over previous 6 months weeks of first raporl) (whichever is over a longer lime period) b 50 pg/ 100 g or greater unless las* blood sample is 40 l-g/100 g or less. a Frequency which employees exposed to action level d lead (30 pg/m' TWA) must have blood lead level checked (ZPP is also strongly recommended In each occasion that a blood lead is ot> tairad); 1.1> blood lead level less than 40 jig/100 g................... Every 6 months Every 6 months. Every 6 months. Every 6 months. Every C months. 2. Last blood lead level between 40 pg/100 g and level Every 2 months. Every 2 months Every 2#nths. Every 2 months. Every 2 months. requiring medcal removal (see A above). 3. Employees removed from exposure to lead because ol an Every 1 month. Every 1 month- Every 1 month. Every 1 month. Every 1 month. elevated blood lead level & PwirissMe airborne exposm imit lor workers removed liom work <100pg/m*8' <50pg/m*8 <30pg/m`8 OOpg/m'B <30 pg/m>8 tv TWA. due to an elevated blood lead level (without regard to respirator hr TWA. hr TWA. hr TWA. hr TV/A. protection). a Blood lead level confirmed with a second blood analysis, at which _<60 pg/100 g__ <50 pg/100 g__ a40 pg/100 g--<40 pg/tOO g--cQ pg/100 J. employee may taken to wort. Permissible exposure without regvd to respirator protection Is fisted by industry In Table l Note.--When medical opinion Indicates that an employee is at risk o( material Impairment from exposure to lead, the physician can remove an employee from exposures exceeding the action level (or less) or recommend special protective measures as deemed appropriate and necessary. Medical monitonng during the medical removal period can be more stringent than noted fr> the table above if the physician so specifies. Return to work or removal of kmitalions and special protections is permitted when the physician indicatas tr^t the worker is no longer at risk of materialimpaxment {Section i91o.1025, Appendix C, Table 2 corrected at 44 FR 68827, November 30, 1979] limited or specially protected pursuant to medical recommendations. Results of biological monitoring or the recommendations of an examining physician may necessitate removal of an employee from further lead exposure pursuant to the standard's medical removal protection (MRP) program. The object of the MRP program is to provide temporary medical removal to workers either with substantially elevated blood lead levels or otherwise at risk of sustaining material health impairment from continued substantial exposure to lead. The following guidelines which are summarized in Table 2 were created under the standard for the temporary removal of an exposed employee end his or her subsequent return to work in an exposure area. Under the standard's ultimate worker removal criteria, a worker is to be removed from any work having any eight hour TWA exposure to lead of 30 pg/m3 or more whenever either of the following circumstances apply: (1) a blbod lead level of 60 pg/100 g or greater is obtained and confirmed by a second follow-up blood lead level performed within two weeks after the employer receives the results of the first blood sampling test, or (2) the average of the previous three blood lead determinations or the average of allblood lead determinations conducted during the previous six months, whichever encompasses the longest time employee whose blood lead level period, equals or exceeds 50 p.g/100 g, - exceeds 40 pg/100 g. In addition each unless the last blood sample indicates a such employee is to be informed that the blood lead level at or below 40 jig/100 g standard requires medical removal with in which case the employee need not be MRP benefits, discussed below, when an removed. Medical removal is to continue employee's blood lead level exceeds the until two consecutive blood lead levels above defined limits. are 40 pg/100 g or less. In addition to the above blood lead' During the first two years that the ultimate removal .criteria pre being phased in, the return criteria have been set to assure that a worker's blood lead level has substantially declined during the period of removal. From March 1, 1979 to March 1,1980, the blood lead level requiring employee medical removal is CO pg/100 g. Workers found to have a confirmed blood lead at this level or.greater need only be removed from work having a daily 8 hour TWA exposure to lead at or above 100 pg/m3. Workers so removed are to be returned to work when their blood lead levels are at or below 60 p.g/100 g of whole blood. From March 1,1980 to March 1,1981, the blood lead level requiring medical removal is 70 )tg/100 g. During this period workers need only be removed from jobs having a daily 8 hour TWA exposure to lead at or above 50 pg/m3 and are to be returned to work when a level criteria, temporary worker removal may also take place as a result of medical determinations and recommendations. Written medical opinions must be prepared after each examination pursuant to the standard. If the examining physician includes a medical finding, determination or opinion that the employee has a medical condition which places the employee at increased risk of material health impairment from exposure to lead, then the employee must be removed from exposure to lead at or above the action level! Alternatively, if the examining physician recommends special protective measures for an employee (e.g., use of a powered'air purifying respirator] or recommends limitations on an employee's exposure to lead, then the employer must implement these recommendations. Recommendations may be more stringent than the specific level of 50 pg/100 g is achieved. Beginning March l, 1981, return depends on a worker's blood lead level declining to 40 pg/100 g of whole blood provisions of the standard. The examining physician, therefore, is given broad flexibility to tailor special protective procedures to the needstif As part of the standard, the employer individual employees. This flexibility is required to notify in writing each extends to the evaluation and Occupational Safety & Health Reporter [Sec. 1910.1025, Appendix C] TOXIC SUBSTANCES V-,151 31:8439 management of pregnant workers and opinion concerning potential lead that an employee is at risk of material male and female workers who are poisoning or toxicity. If an employee health impairment. This is based on the planning to raise children. Based on the wishes a second opinion, he or she can numerous inadequacies of respirators history, physical examination, and make an appointment with a physician including skin rash where the facepiece laboratory studies, the physician might of his or her choice. This second makes contact with the skin, recommend special protective measures physician will review the findings, unacceptable stress to breathing in com. or medical removal for an employee recommendations or determinations of workers with underlying who is pregnant or who is planning to the first physician and conduct any cardiopulmonary impairment, difficulty conceive a child when, in the examinations, consultations or tests in providing adequate fit. the tendency physician's judgment, continued deemed necessary in an attempt to for respirators to create additional exposure to lead 8t the current job make a final medical determination. If hazards by interfering with vision, would pose a significant risk. The return the first and second physicians do not hearing, and mobility, and the of the employee to his or her former job agree in their assessment they must try difficulties of assuring the maximum status, or the removal of special to resolve their differences.. If they effectiveness of a complicated work* protections or limitations, depends upon cannot reach an agreement then they practice program involving respirators. the examining physician determining must designate a third physician to Respirators do, however, serve a useful that the employee is no longer at resolve the dispute. This multiple function where engineering and work increased risk of material impairment or physician review mechanism has been practice controls are inadequate by that special measures are no longer temporarily stayed during the pending providing supplementary, interim, or needed. litigation but OSHA recommends that it short-term protection, provided they are During the period of any form of special protection or removal, the employer must maintain the worker's earnings, seniority, and other employment rights and benefits (as though the worker had not been removed) for a period of up to 18 months. This economic protection will maximize meaningful worker participation in the medical surveillance program, and is appropriate as part of be used if disputes arise over medical determinations. The employer must provide examining and consulting physicians with the following specific information: u copy of the lead regulations and all appendices, a description of the employee's duties as related to exposure, the exposure level to lead and any other toxic substances (if applicable), a description of personal protective equipment used, blood lead levels, and all prior written medical properly selected for the environment in which the employee will be working, properly fitted to the employee, maintained and cleaned periodically^ and worn by the employee when required. In its final standard on occupational exposure to inorganic lead, OSHA has prohibited prophylactic chelation. Diagnostic and therapeutic chelation are permitted only under the supervision of the employer's overall obligation to provide a safe and healthful workplace. opinions regarding the employee in the employer's possession or control. The a licensed physician with appropriate medical monitoring in an acceptable The provisions of MRP benefits during the employee's removal period may, employer must also obtain from the physician and provide the employee clinical setting. The decision to initiate chelation therapy must be made on an however, be conditioned upon with a written medical opinion individual basis and take into account participation in medical surveillance. containing blood lead levels, the the severity of symptoms felt to be a On rare occasions, an employee's physicians's opinion as to whether the result of lead toxicity along with blood blood lead level may not acceptably employee is at risk of material lead levels, ZPP levels, and other decline within 18 months of removal. impairment to health, any recommended laboratory tests as appropriate. EDTA. This situation will arise only in unusual protective measures for the employee if and penicillamine which are the primary circumstances, thus the standard relies further exposure is permitted, as well as chelating agents used in the therapy of on an individual medical examination to any recommended limitations upon an occupational lead poisoning have determine how to protect such an employee's use of respirators. significant potential side effects and employee. This medical determination is Employers must instruct each their use must be justified on the basis to be based on both laboratory values, physician not to reveal to the employer of expected benefits to the worker. including lead levels, zinc in writing or in any other way his or her Unless frank and severe symptoms are protoporphyrin levels, blood counts, and findings, laboratory results, or diagnoses present, therapeutic chelation is not other tests felt to be warranted, as well which are felt to be.unrelated to recommended given the opportunity to as the physician's judgment that any occupational lead exposure. They must remove a worker from exposure and symptoms or findings on physical also instruct each physician to advise allow the body to naturally excrete examination are a result of lead toxicity. the employee of any occupationally or accumulated lead. As a diagnostic aid, The medical determination may be that non-occupationally related medical the chelation mobilization test using----- the employee is incapable of ever safely condition requiring further treatment or CA-EDTA has limited applicability. returning to his or her former job status. evaluation. According to some investigators, the test The medical determination may provide The standard provides for the use of can differentiate between lead-induced additional removal time'past 18 months respirators where engineering and other and other nephropathies. The test may for some employees or specify special primary controls have not been fully also provide an estimation of the mobile protective measures to be implemented. implemented. However, the use of fraction of the total body lead burden. The lead standard provides for a multiple physician review in cases respirator protection shall not be used in Employers are required to assure that lieu of temporary medical removal due accurate records are maintained on where the employee wishes a second to elevated blood lead levels or findings exposure monitoring, medical 1'31'80 ISec. 1910.1025, Appendix C] Published by THE BUREAU OF NATIONAL AFFAIRS, INC., Washington, D.C. 20037 31:8440 REFERENCE FILE surveillance, and medical removal for effects to the parents and developing to the later stages of clinical disease, each employee. Exposure monitoring fetus. The adverse effects of lead on disruption of these enzyme processes and medical surveillance records must reproduction are being actively over a working lifetime is considered to be kept for 40 years or the duration of researched and OSHA encourages the be a material impairment of health. employment plus 20 years, whichever is longer, while medical removal records must be maintained for the duration of employment All records required under the standard must be made available upon request to the Assistant Secretary of Labor for Occupational Safety and Health and the Director of the National Institute for Occupational Safety and Health. Employers must also make environmental and biological monitoring and medical removal records available to affected employees and to former employees or their authorized employee representatives. Employees or their specifically designated representatives have access to their entire medical surveillance records. In addition, the standard requires that the employer inform all workers exposed to lead at or above the action physician to remain abreast of recent developments in the area to best advise One of the eventual results of lead- pregnant workers or workers planning induced inhibition of enzymes in the to conceive children. heme synthesis pathway is anemia which can be asymptomatic if mild but The spectrum of health effects caused associated with a wide array of by lead exposure can be subdivided into symptoms including dizziness, fatigue, Eire developmental stages: normal, and tachycardia when more severe. physiological changes of uncertain Studies have indicated that lead levels significance, pathophysiological . as low as 50 pg/100 g can be associate.^ changes, overt symptoms (morbidity), with a definite decreased hemoglobin, " and mortality. Within this process there although most cases of lead-induced are no sharp distinctions, but rather a anemia, as well as shortened red-cell continuum of effects. Boundaries survival times, occur at lead levels between categories overlap due to the exceeding 80 pg/100 g-. Inhibited wide variation of individual responses hemoglobin synthesis is more common and exposures in the working in chronic cases whereas shortened population. OSHA's development of the .erythrocyte life span is more commonIn lead standard focused on acute cases. pathophysiological changes as well as later stages of disease. In lead-induced anemias, there is usually a reticulocytosis along with the level of the provisions of the standard 1. Heme Synthesis Inhibition. The presence of basophilic stippling, and and all its appendices, the purpose and earliest demonstrated effect of lead ringed sideroblasts, although none of the description of medical surveillance and involves its ability to inhibit at least two above are pathognomonic for lead- provisions for medical removal enzymes of the heme synthesis pathway induced anemia. protection if temporary removal is at very low blood levels. Inhibition of required. An understanding of the delta aminolevulinic acid dehydrase 2. Neurological Effects. Inorganic lead potential health effects of lead exposure (ALA-D) which catalyzes the has been found to have toxic effects on by all exposed employees along with conversion of delta-aminolevulinic acid both the central and peripheral nervous full understanding of their rights under (ALA) to protoporphyrin is observed at systems. The earliest stages of lead- the lead standard is essential for an a blood lead level below 20 pg/100 g induced central nervous system effects effective monitoring program. whole blood. At a blood lead level of 40 first manifest themselves in the form of [Section 1910.1025, Appendix C(I) cor rected at 44 FR 68827, November 30, ug/100 g, more than 20% of the population would have 70% inhibition of. behavioral disturbances and central nervous system symptoms including 1979] ALA-D. There is an exponential irritability, restlessness, insomnia and increase in ALA excretion at blood lead other sleep disturbances, fatigue, II. Adverse health effects ofinorganic levels greater than 40 pg/100 g. vertigo, headache, poor memory, tremor, lead Although the toxicity of lead has been known for 2,000 years, the knowledge of the complex relationship between lead exposure and human response is still being refined. Significant research into the toxic properties of lead continues throughout the world, and it should be anticipated that our understanding of thresholds of effects and margins of safety will be improved in future years. The provisions of the lead standard are founded on two prime medical judgments: first, the prevention of adverse health effects from exposure to lead throughout a working lifetime Another enzyme, ferrochelatase, is also inhibited at low blood lead levels. Inhibition of ferrochelatase leads to increased free erythrocyte protoporphyrin (FEP) in the blood which can then bind to zinc to yield zinc protoporphyrin. At a blood lead level of 50 pg/100 g or greater, nearly 100% of the population will have an increase in FEP. There is also an exponential relationship between blood lead levels greater than 40 pg/100 g and the associated ZPP level, which has led to the development of the'ZPP screening test for lead exposure. depression, and apathy. With more severe exposure, symptoms can progress to drowsiness, stupor, hallucinations, delerium. convulsions and coma. The most severe and acute form of lead poisoning which usually follows ingestion or inhalation oflarge amounts of lead is acute encephalopathy which may arise precipitously with the onset of intractable seizures, coma, cardiorespiratory-arrest, and death within 48 hours. While there is disagreement about what exposure levels are needed to produce the earliest symptoms, most requires that worker blood lead levels While the significance of these effects experts agree that symptoms definitely be maintained at or below 40 pg/100 g is subject to debate, it is OSHA's can occur at blood lead levels of 60 fig/ and second, the blood lead levels of position that these enzyme disturbances 100 g whole blood and therefore workers, male or female, who intend to are early stages of a disease process recommend a 40 pg/100 g maximum. parent in the near future should be which may eventually result in the The central nervous system effects maintained below 30 pg/100 g to clinical symptoms of lead poisoning. frequently are not reversible following minimize adverse reproductive health Whether or not the effects do progress discontinued exposure or chelation Occupational Safety & Health Reporter [Sec. 1910.1025, Appendix C] 32 TOXIC SUBSTANCES 151 31:6441 therapy and when improvement does glomeruli and dilated and atrophied blood are comparable to concentrations occur, it is almost always only partial. proximal tubules; all represent end stage of lead in the umbilical cord at birth. The peripheral neuropathy resulting kidney disease. Azotemia can be Transplacental passage becomes from lead exposure characteristically progressive, eventually resulting in frank detectable at 12-14 weeks of gestatior involves only motor function with uremia necessitating dialysis. There is and increases until birth. minimal sensory damage and has a occasionally associated hypertension There is little direct data on damage marked predilection for the extensor and hyperuricemia with or without gouL to the fetus from exposure to lead but it muscles of the most active extremity. Early kidney disease is difficult to is generally assumed that the fetus and The peripheral neuropathy can occur detect. The urinalysis is normal in early newborn would be at least as with varying degrees of severity. The lead neohropathy and the blood urea susceptible to neurological damage as earliest and mildest form which can be nitrogen and serum creatinine increase young children. Blood lead levels of 50- detected in workers with blood lead onlywhen two-thirds of kidney function 60 pg/100 g in children can cause levels as low as 50pg/l00 g is is lost. Measurement of creatinine significant neurobehavioral impairments manifested by slowing of motor nerve clearance can often detect earlier and there is evidence of hyperactivity at conduction velocity often without disease as can other methods of blood levels as'low as 25pg/l00 g. clinical symptoms. With progression of measurement of glomerular filtration Given the overall body of literature the neuropathy there is development of rate.'An abnormal Ca-EDTA concerning the adverse health effects of painless extensor muscle weakness mobilization test has been used to lead in children, OSHA feels that the usually involving the extensor muscles differentiate between lead-induced and blood lead level in children should be of the fingers and hand in the most other nephropathies, but this procedure maintained below 30 pg/100 g with a active upper extremity, followed in is not widely accepted. A form of population mean of 15pg/l00 g. Blood severe cases by wrist drop or, much less Fanconi syndrome with aminoaciduria, lead levels in the fetus and newborn commonly, foot drop. glycosuria, and hyperphosphaturia likewise should not exceed 30pg/100 g. In addition to slowing of nerve indicating severe injury to the proximal Because of lead's ability to pass conduction, electroriyographical studies renal tubules is occasionally seen in through the placental barrier and also in patients with blood lead levels children. because of the demonstrated adverse greater than 50 pg/100 g have 5. Reproductive effects. Exposure to effects oflead on reproductive function demonstrated a decrease in the number lead can have serious effects on in both the male and female as well as of acting motor unit potentials, an reproductive function in both males and the risk of genetic damage of lead on increase in the duration of motor unit females. In male workers exposed to both the ovum and sperm, OSHA potentials, and spontaneous lead there can be a decrease in sexual recommends a 30 pg/100 g maximum pathological activity including drive, impotence, decreased ability to permissible blood lead level in both fibrillations and fasciculations. Whether produce healthy sperm, and sterility. males and females who wish to bear these effects occur at levels of 40 pg/100 Malformed sperm (teratospermia), children.' g is undetermined. decreased number of sperm 6. Other toxic effects. Debate and While the peripheral neuropathies can (hypospermia), and sperm with research continue on the effects of Ir occasionally be reversed with therapy, decreased motility (asthenospermia) can on the human body. Hypertension h.- again such recovery is not assured all occur. Teratospermia has been noted frcqucnlly been noted in occupation;! Uy particularly in the more severe at mean blood lead levels of 53 pg/100 g exposed individuals although it is neuropathies and often improvement is and hypospermia and asthenospermia at difficult to assess whether this is due to only partial. The lack of reversibility is 41 pg/100 g. Furthermore, there appears lead's adverse effects on the kidney or if felt to be due in part to segmental demyelinalion. to be a dose-response relationship for some other mechanism is involved. teratospermia in lead exposed workers. Vascular and electrocardiogarphic 3. Gastrointestinal. Lead may also Women exposed to lead may changes have been detected but have affect the gastrointestinal system experience menstrual disturbances not been well characterized. Lend is producing abdominal colic or diffuse including dysmenorrhea, menorrhagia thought to impair thyroid function and abdominal pain, constipation, and amenorrhea. Following exposure to interfere with the pituitary-adrenal axis, obstipation, diarrhea, anorexia, nausea lead, women have a higher frequency of but again these effects have not been and vomiting. Lead colic rarely develops sterility, premature births, spontaneous well defined. at blood lead levels below 80 pg/100 g. miscarriages, and stillbirths. 4. Renal. Renal toxicity represents one Germ cells can be affected by lead - ILL Medical Evaluation of the most serious health effects of lead and cause genetic damage in the egg or The most important principle in poisoning. In the early stages of disease sperm cells before conception and result evaluating a worker for any nuclear inclusion bodies can frequently in failure to implant, miscarriage, occupational disease including lead be identified in proximal renal tubular stillbirth, or birth defects. poisoning is a high index of suspicion on ceils. Renal function remains normal Infants of mothers with lead poisoning the part of the examining physician. As and the changes in this stage are have a higher mortality during the first discussed in Section 2, lead can affect probably reversible. With more year and suffer from lowered birth numerous organ systems and produce a advanced disease there is progressive weights, slower growth, and nervous wide array of signs and symptoms, most interstitial fibrosis and impaired renal system disorders. of which are non-specific and subtle in function. Eventually extensive Lead can pass through the placental nature at least in the early stages of interstitial fibrosis ensues with sclerotic barrier and lead levels in the mother's disease. Unless serious concern for lead 1-31-BO I See. 1910.1025, Appendix C] Published by THE BUREAU OF NATIONAL AFFAIRS, INC., Washington, D.C. 20037 33 31:8442 REFERENCE FILE toxicity is present, many of the early exposures should be elicited. Any potential blood loss through the clues to diagnosis may easily be previous bistory.of hematological, gastrointestinal tract. overlooked. neurological, gastrointestinal, renal, A complete neurological examination The crucial initial step in the medical psychological, gynecological, genetic, ot should include an adequate mental evaluation is recognizing that a worker's reproductive problems should be status evaluation including a search for employment can result in exposure to specifically noted. behavioral and psychological lead. The worker will frequently be able A careful and complete review of disturbances, memory testing, to define exposures to lead and lead systems must-beperfonned to assess evaluation for irritability, insomnia, containing materials but often will not both recognized complaints and subtle hallucinations, and mental clouding. volunteer this information unless or slowly acquired symptoms which the Gait and Coordination should be specifically asked. In other situations worker might not.appreciate afe being examined along with close observation the worker may not know of any significant The review of symptoms for tremor. A detailed evaluation of exposures to lead but the suspicion should include the following: peripheral nerve function including might be raised on the part of the General--weight loss, fatigue, careful serisory and motor function physician because of the industry or decreased appetite. testing"is warranted. Strength testing occupation of the worker. Potential Head, Eyes, Ears,Nose, Throat occupational exposure to lead and its (HEENT)--headaches, visual particularly of extensor muscle groups of all Cxtremitiesis "of fundamental compounds occur in at least 120 disturbances or decreased visual acuity, importance. . occupations, Including lead smelting, the hearing deficits or tinnitus, pigmentation, Cramal'nerve evaluation should also manufacture of lead storage batteries, of the oral mucosa, or metallic taste in be included in the routine examination. the manufacture of lead pigments and mouth. products containing pigments, solder Cardiopulmonary--shortness of The abdominal examination should include auscultation for bowel sounds manufacture, shipbuilding and ship breath; cough, chest pains, palpitations, and abdominal bruit's and palpation for repair, auto manufacturing, construction, or orthopnea. and painting. Gastrointestinal--nausea, vomiting, Once the possibility for lead exposure heartburn, abdominal pain, constipation is raised, the focus can then be directed or diarrhea. toward eliciting information from the Neurologic--irritability, insomnia, medical history, physical exam, and weakness (fatigue), dizziness, loss of finally from laboratory data to evaluate memory, confusion, hallucinations, the worker for potential lead toxicity. incoordination, ataxia, decreased A complete and detailed work history strength in hands or feet, disturbances is important in the initial evaluation. A in gait, difficulty in climbing stairs, or listing of all previous employment with seizures. organomegaly, masses, and diffuse abdominal tenderness. Cardiovascular examination should evaluate possible early signs of congestive, heart failure.:Pulmonary status should be addressed particularly if respirator protection is contemplated. As part of the medical evaluation, the lead standard requires the following laboratory studies: information on work processes, Hematologic--pallor, easy fatigability, 1. Blood lead level exposure to fumes or dust, known abnormal blood loss, melena. 2. Hemoglobin and hematocrit exposures to lead or other toxic Reproductive (male and female and determinations, red cell indices, and substances, respiratory protection used, spouse where relevant)--history of examination of the peripheral blood and previous medical surveillance infertility, impotence, loss of libido, smear to evaluate red blood cell should all be Included in the worker's abnormal menstrual periods, history of morphology record. Where exposure to lead is miscarriages, stillbirths, or children with 3. Blood urea nitrogen suspected, information concerning on- birth defects. 4. Serum creatinine the-job personal hygiene, smoking or Musculo-skeletal--muscle and joint 5. Routine urinalysis with microscopic eating habits in work areas, laundry pains. examination. procedures, and use of any protective The physical examination should 6. A zinc protoporphyrin level (This clothing or respiratory protection emphasize the neurological, requirement is currently not in effect equipment should be noted. A complete gastrointestinal, and cardiovascular due to the pending litigation, but is work history is essential in the medical systems. The worker's weight and blood recommended nonetheless). evaluation of a worker with suspected pressure should be recorded and the In addition to the above, the physician lead toxicity, especially when long term oral mucosa checked for pigmentation is authorized to order any further effects such as neurotoxicity and characteristic of a possible Burtonian or laboratory or other tests which he or she nephrotoxicity are considered. lead line on the gingiva. It should be deems necessary in accordance with The medical history is also pf noted, however, that the lead line may sound medical practice. The evaluation fundamental importance and.should- not be present even in severe lead must also include pregnancy testing or include a listing of all past and current poisoning if good oral hygiene is laboratory evaluation of male fertility if medical conditions, current medications practiced. requested by the employee. including proprietary drug intake, The presence of pallor on skin Additional tests which are probably previous surgeries and hospitalizations, examination may indicate an anemia, not warranted on a routine basis but allergies, smoking history,-alcohol which if severe might also be associated may be appropriate when blood lead consumption, and also non-occupational with a tachycardia. If an anemia is and ZPP levels are equivocal include lead exposures such a3 hobbies suspected, an active search for blood delta aminolevulinic acid and (hunting, riflery). Also known childhood loss should be undertaken including coproporphyrin concentrations in the Occupational Safety & Health Reporter [Sec. 1910.1025, Appendix C] 34 TOXIC SUBSTANCES .<151 31:8443 . urine, and dark-Beld illumination for total lead is deposited there. A very toxicity than the level of blood lead detection of basophilic -stipplinfi in red important component of the total lead itself. The level of ZPP reflects lead blood cells. bodybuttfen is lead in soft tissue (liver, absorption over the preceding 3 to 4 If an anemia Is detected further kidney, and brain]. This fraction of the months, and therefore is a better studies including a oareful examihatlon lead body burden, the biologically active indicator of lead body burden. The ZP1 of the peripheral smear! reticulocyte" lead, is not entirely reflected by-blood requires more lime than the blood lead count,- 6tool for occult blood, serum iron, lead levels since it Is i function `of the to read significantly elevated levels; the total ironbinding capacity, bilirubin; dynamics of lead absorption, return to normal after discontinuing lead and, if appropriate, vitamin B12 and distribution, deposition in bone and exposure is also slower. Furthermore, folate may ba of valiie:iti attempting to identify the cause of the anemia. If a peripheral neuropathy is suspected, nerve conduction studies are warranted both for diagnosis and-as a basis to nronitorony therapy; ; If renal disease is questioned, a,24 hour urine collection for creatinine clearance^protein, and electrolytes may be indicated. Elevated uriaacid levelp may result from lead-induced renal disease and a.serum uric add level. might be performed. An electrocardiograni and chest.x-ray may be.obtained as deemed appropriate. Sophisticated and highly specialize/! testing should'not be done routinely and where indicated shouldpe under the direction of a specialist.' excretion. Following discontinuation of the ZPP test is simpler, faster, and less exposure to lead, the excess body expensive to perform and no burden is only slowly mobilized from contamination is possible. Many bone and other relatively stable body investigators believe it is the most stores and excreted. Consequently, a reliable means of monitoring chronic high blood lead level may only represent lead absorption. recent heavy exposure to lead without a Zinc protoporphyrin results from the significant total body excess and inhibition of the enzyme ferrochelatase likewise a low blood lead level does not which catalyzes the insertion of an iron exclude an elevated total body burden molecule into the protoporphyrin of lead. molecule, which then becomes heme. If Also due to its correlation with recent exposures, the blood lead level may vary considerably over short time intervals. iron is not inserted into the molecule then zinc, having a greater affinity for protoporphyrin, takes the place of the iron, forming ZPP. An elevation in the level of circulating To minimize laboratory error and ZPP may occur at blood lead levels as erroneous results due to contamination, low as 20-30 pg/100 g in stime workers. blood specimens must be carefully Once the blood lead level has reached [Section 1910.1025, Appendix C(II1) collected after thorough cleaning of the 40 pg/100 g there is more marked rise in corrected at 44 FR 68827, November 30, skin with appropriate methods using the ZPP value from its normal range of 1979] lead-free blood containers and analyzed less than 100 pg/100 ml Increases in IV. LaboratoryEvaluation The blood lead level present remains the single most important test to. monitor lead exposure ahd is the test used in themedical surveillance bya reliable laboratory. Under the standard, samples must be analyzed in laboratories which are approved by the Center for Disease Control (CDC) or which have received satisfactory grades blood lead levels beyond 40 pg/100 g are associated with exponential increases in ZPP. Whereas blood lead levels fluctuat.-. over short time spans, ZPP levels ren . relatively stable. ZPP is measured program under the }ead standard to in proficiency testing by the CDC in the directly in red blood cells and is presen, guide employee medicafremoval.The. previous year. Analysis is to be for the cell's entire 120 day life-span. ZPP which has several Advantages ovfer made using atomic absorption spectro Therefore, the ZPP level in blood the blood lead level is, due to the photometry, anodic stripping voltam reflects the average ZPP production over pending litigation, not required under metry, or any method which meets the the previous 3-4 months and the standard. Because of irrelatively accuracy requirements set forth by the consequently the average lead exposure recent development and the lack of standard. during that time interval. extensive data concerning its interpretation, the ZPP currently remains an ancillary test; This section will discuss the blood lead level and ZPP in detail and will outline their relative advantages and disadvantages. Other blood tests currently available to evaluate lead exposure will also be reviewed. The blood lead level is a good index of current or recent lead absorption when there is no anemia present and when the worker has not.taken any chelating agents. However, blood lead levels along with urinary lead levels do not necessarily indicate the total body The determination of lead in urine is generally considered a less reliable monitoring technique than analysis of., whole blood primarily due to individual variability in urinary excretion capacity as well as the technical difficulty of obtaining accurate 24 hour urine collections. In addition, workers with renal insufficiency, whether due to lead or some other cause, may have decreased lead clearance and consequently urine lend levels may underestimate the true lend burden. Therefore, urine lend levels should not be used as a routine test. It is recommended that a hematocrit be determined whenever a confirmed .ZPP of 50 pg/100 ml whole blood is obtained to rule out a significant underlying anemia. If the ZPP is In excess of 100 pg/100 ml and not associated with abnormal elevations in blood lead levels, the laboratory should be checked to be sure that blood leads were determined using atomic absorption spectrophotometry, anodic stripping voltametry, or any method which meets the accuracy requirements set forth by the standard by a CDC aproved laboratory which is experienced in lead level burden of lead and arc not adequate The zinc protoporphyrin test, unlike determinations. Repeat periodic blood measures of past exposure. One reason the blood lead determination, measures lead studies should be obtained in all for this is that lead has a high affinity an adverse metabolic effect of lead and individuals with elevated ZPP levels to for bone and up to 90% of the body's as such is a belter indicator of lead be certain that an associated elevated blood lead level has not been missed / ~ r* \ 1-31-80 [Sec. 1910.1025, Appendix C] Published by THE BUREAU OF NATIONAL AFFAIRS, INC., Washington, D.C. 20037 35 31:8444 REFERENCE FILE due to transient fluctuations in blood the disadvantages include variability in Even with adequate worker education leads. results, the necessity to collect a on the adverse health effects of lead and ZPP has a characteristic fluorescence complete 24 hour urine sample which appropriate training in work practices, spectrum with a peak at 594 nm which is has a specific gravity greater than 1.010, personal hygiene and other control detectable with a hematofluorimeter. and also the fact that ALA decomposes measures, the physician has a primary The hematofluorimeter is accurate and in the presence of light. responsibility for evaluating potential portable and can provide on-site, .The pattern of porphyrin excretion in lead toxicity in the worker. It is only instantaneous results for workers who the urine can also be helpful in through a careful and detailed medical can be frequently tested via a finger identifying lead intoxication. With lead and work history, a complete physical prick. poisoning, the urine concentrations of examination and appropriate laboratory However, careful attention must be coproporphyrins I and II, testing that an accurate assessment can given to calibration and quality control porphobilinogen and uroporphyrin I rise. be made. Many of the adverse health procedures. Limited data on blood The most important increase, however, effects of lead toxicity are either lead--ZPP correlations and the ZPP is that of coproporphyrin III; levels may irreversible or only partially reversible levels which are associated with the exceed 5.000 pg/l in the urine in lead and therefore early detection of disease adverse health effects discussed in poisoned individuals, but its correlation is very important Section 2 are the major limitations of the with blood lead levels and.ZPP are not test Also it is difficult to correlate ZPP as good as those of ALA. Increases in levels with environmental exposure and urinary porphyrins are not diagnostic of there is some variation of response with, lead toxicity and may be seen in age and sex. Nevertheless, the ZPP porphyria, some liver diseases, and in promises to be an important diagnostic patients with high reticulocyte counts. test for the early detection of lead toxicity and its value will increase as more data is collected regarding its fSection 1910.1025, Appendix C(IV) corrected at 44 FR 68827, November 30, 1979] This document outlines the medical monitoring program as defined by the occupational safety and health standard for inorganic lead. It reviews the adverse health effects of lead poisoning and describes the important elements of the history and physical examinations as they relate to these adverse effects. relationship to other manifestations of Summary. The Occupational Safety lead poisoning. and Health Administration's standard Finally, the appropriate laboratory testing for evaluating lead exposure and Levels of delta-aminolevulinic acid for inorganic lead places significant toxicity is presented. (ALA) in the urine are also used as a measure of lead exposure. Increasing emphasis on the medical surveillance of It is hoped that this review and all workers exposed to levels of discussion will give the physician a concentrations of ALA are believed to inorganic lead above the action level of better understanding of the OSHA result from the inhibition of the enzyme 30 pg/m* TWA. The physician has a standard with the ultimate goal of delta-aminolevulinic acid dehydrase fundamental role in this surveillance protecting the health and well-being of (ALA-D). Although the test is relatively program, and in the operation of the the worker exposed to lead under his or easy to perform, inexpensive, and rapid. medical removal protection program. her care. 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