Blood lead level standards

Bactericide A pesticide used to control or destroy bacteria Basal diet Ration for adults and starter ration for the young, appropriate to the species it should meet the standard nutritional requirement Base pair mutagens Chemicals or agents that produce a base change in the DNA BEA 2-Bromoethalamine BEI Biological exposure index BLL Blood lead level BEN Balkan endemic nephropathy... 

While the acceptable blood lead level set by the US Occupational Safety and Health Agency (OSHA) remained 50 //g/dL in 2007, that for children had been progressively lowered by the Center for Disease Control and Prevention (CDC) to 10 /(g/ dL by 1991. The disparity between acceptable blood lead levels in adults and children can be explained in part by the paucity of studies of lead toxicity in adults, and the increased sensitivity of the developing brain in children to toxins. The efforts of the lead industry to thwart public health regulation in the workplace contributed to the disparity in standards for children and adults. OSHA is reluctant to revise the occupational lead standard because of the risk of litigation. The mounting evidence of the impact of lower and lower lead levels on blood pressure and the kidneys in industry and the general public is reviewed in this chapter. 

Vi. Dosage and method of administration for lead poisoning (adults and children). Note Administration of EDTA should never be a substitute for removal from lead exposure. In adults, the federal OSHA lead standard requires removal from occupational lead exposure of any worker with a single blood lead concentration in excess of 60 mcg/dL or an average of three successive values in excess of 50 mog/dL. (However, recent declines in background lead levels and concern over adverse health effects of lower-level exposure support removal at even lower levels). Prophylactic chelation, defined as the routine use of chelation to prevent elevated blood lead concentrations or to lower blood lead levels below the standard In asymptomatic workers, is not permitted. Consult the local or state health department or OSHA (see Table IV-3, p 525) for more detailed information. 

In contrast, lead is a non-essential element that can be toxic. Limits have been recommended for maximum exposme via the diet. Similarly, limits for blood lead levels in the general population have been suggested and health based standards exist for lead in drinking water and for exposure in the occupational setting (2). 

After attributing a blood lead level of 12 /tg/dl to nonairbome ingested sources (i.e., food, water, soil, paint), this leaves 3 /tg as the maximum safe contribution from inhaled air. Assuming airborne lead (/tg Pb/m air) as 0.5 blood lead, this yields a safe air quality level of 1.5 /tg Pb//tg air, which was promulgated as the U.S. national ambient air quality standard for lead, as the maximum arithmetic mean averaged over a calendar quarter. 

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). 

As noted in Chapters 1 and 2, the committee specifically sought health-effects data on blood lead levels (BLLs) under 40 pg/dL because the current standard of the Occupational Safety and Health Administration (OSHA) aims to maintain BLLs below that concentration. Evidence on health effects at a corresponding estimated cumulative blood lead index (CBLl) of 1,600 pg-years/dL (that is, 40 years at 40 pg/dL) and tibia lead levels of 40-80 pg/g were also specifically sought. 

Abbreviations BLL, blood lead level Cl, confidence interval IRR, incidence rate ratio IVF, in vitro fertilization OR, odds ratio RR, relative risk SD, standard deviation UCSF, University of Califomia, San Francisco. 

Note. Inhabitants from two villages situated 0.5 and 4.0 km from the copper mill in Glogow. Blood lead levels in Lddf (textile industry) was selected as reference. Geometric mean standard deviatioh of geometric mean (GSD) 122]. 

In Massachusetts, where the problem is one of the worst in the country, the attitude is more aggressive than the standard CDC recommended protocol. At Children s Hospital in Boston, for example, chelation is often used if environmental and nutritional intervention have failed to reduce the blood lead level below 20 p.g/dl. Chelation can be unnecessary, once the other steps are taken. Where the exposure has been short term and the blood lead level is in the low 20s, or even in the 30s, if you just remove the lead source and WAIT, you may well see the blood lead go down to an acceptable level on its own over the course of a month. ... 

The standard way to measure the effectiveness of chelation is to conduct repeated tests of the level of lead in the child s blood. As a general rule, blood lead levels go down when a child is chelated. It can be confusing to determine exactly how much lead is being eliminated... 

B) The employer shall notify each employee whose blood lead level is at or above 40 pg/dl that the standard requires temporary medical removal with Medical Removal Protection benefits when an employee s blood lead level is at or above the numerical criterion for medical removal under paragraph (k)(1)(i) of this section. 

Health protection goals of the standard. Prevention of adverse health effects for most workers from exposure to lead throughout a working lifetime requires that a worker s blood lead level (BLL, also expressed as PbB) be... 

Biological monitoring under the standard must be provided at least every 2 months for the first 6 months and every 6 months thereafter until your blood lead level is below 40 ng/dl. A zinc protoporphyrin (ZPP) test is a very useful blood test which measures an adverse metabolic effect of lead on your body and is therefore an indicator of lead toxicity. 

If your BLL exceeds 40 xg/dl the monitoring frequency must be inaeased from every 6 months to at least every 2 months and not reduced until two consecutive BLLs indicate a blood lead level below 40 xg/dl. Each time your BLL is determined to be over 40 ig/dl, your employer must notify you of this in writing within five working days of his or her receipt of the test results. The employer must also inform you that the standard requires temporary medical removal with economic protection when your BLL exceeds 50 xg/dl. (See Discussion of Medical Removal... 

The standard requires your employer to provide oer-tain information to a physioian to aid in his or her examination of you. This information inoludes (1) the standard and its appendioes, (2) a desoription of your duties as they relate to oooupational lead exposure, (3) your exposure level or antioipated exposure level, (4) a desoription of any personal protective equipment you wear, (5) prior blood lead level results, and (6) prior written medioal opinions oonoerning you that the employer has. After a medioal examination or oonsultation the physioian must prepare a written report whioh must contain (1) the physioian s opinion as to whether you have any medioal oondition whioh plaoes you at inoreased risk of material impairment to health from exposure to lead, (2) any reoommended spe-oial proteotive measures to be provided to you, (3) any blood lead level determinations, and (4) any reoommended limitation on your use of respirators. This last element must inolude a determination of whether you oan wear a powered air purifying respirator (PAPR) if you are found unable to wear a negative pressure respirator. 

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