DEPARTMENT OF HEALTH AND HUMAN SERVICES

Public Health Service

National Institute for Occupational
Safety and Health
Robert A. Taft Laboratories
4676 Columbia Parkway
Cincinnati OH 45226-1998

July 16, 2008
HETA 2008-0055
S. Randall Humm
Investigative Counsel
Oversight and Review Division
Office of the Inspector General
United States Department of Justice, Suite 13100
Washington D.C. 20530
Dear Mr. Humm:
On November 27, 2007, the National Institute for Occupational Safety and Health (NIOSH)
received your request for technical assistance in your health and safety investigation of the
Federal Prison Industries (UNICOR) electronics recycling program at Federal Bureau of Prisons
(BOP) institutions in Elkton, Ohio; Texarkana, Texas; and Atwater, California. You asked us to
assist the United States Department of Justice, Office of the Inspector General (USDOJ, OIG) in
assessing the existing medical surveillance program for inmates and staff exposed to lead and
cadmium during electronics recycling, and to make recommendations for future surveillance. In
addition, you asked us to assess past exposures to lead and cadmium, and to investigate the
potential for take home exposure. This interim letter summarizes our findings and provides
recommendations to improve the safety and health of the inmates and staff at the Federal
Correctional Institution (FCI) in Elkton, Ohio. These findings will be included in a final report
that will contain findings from the evaluations at all three institutions identified in your request.
Electronics recycling at FCI Elkton appears to have been performed from 1997 until May 2003
without adequate engineering controls, respiratory protection, medical surveillance, or industrial
hygiene monitoring. The current GBO is a significant improvement, but can be further enhanced
to limit exposure to those performing glass breaking, as well as limiting the migration of lead
and cadmium from the room into other areas.

Background
FCI Elkton opened in 1997, and began electronics recycling soon thereafter. The recycling of
electronic components is done in three separate buildings: 1) the main factory located within the
FCI main compound (which will be referred to as the factory in this report); 2) the Federal
Satellite Low (FSL); and 3) the warehouse.

Page 2 – S. Randall Humm
The glass breaking operation (GBO) is where cathode ray tubes (CRTs) from computer monitors
or televisions are processed. Disassembly and glass breaking occurred at the factory from 1997
until early 2003 and the warehouse until about 2003, although staff at Elkton were unsure when
glass breaking ended at the warehouse. Based upon our review of documents and interviews
with staff and inmates conducted by DOJ and by us, it appears that there was no respiratory
protection used or any type of engineering control in place to minimize exposures during the
GBO until about 2001. At this time a “sawdust collection system” was installed at the factory,
but not in the warehouse. It was also reported that some inmates began to use respiratory
protection at this time. The type of respiratory protection is unknown. In April of 2003,
construction of a glass breaking room was completed in the factory.
The glass breaking room is divided into four areas by vinyl strip curtains hanging from the
ceiling: an entry area, the GBO workstations, the ventilation discharge area, and the “clean area”
where inmates don and doff coveralls and other personal protective equipment (PPE). There is a
walk-off mat immediately outside the entrance to the room to reduce dust carryout on shoes.
A local exhaust ventilation (LEV) system adapted from a spray painting operation is installed in
the room. Two inmate glass breakers, who stand facing each other at the ends of a rectangular
grated work surface (table), are oriented at 90 degrees to the LEV airflow entering the prefilter.
Each workstation has two small rectangular hoods and fans mounted behind and just below the
work surface that are intended to capture airborne dust above the Gaylord boxes containing
broken CRT glass. The fans/hoods are not ducted, but discharge into the work area
approximately 2 ½ to 3 feet from the face of the retrofitted spray painting LEV system. The
discharge is directed toward the face of the LEV system.
An inmate receives large open-top wooden and cardboard boxes with CRTs for the GBO, and
stages the boxes outside the glass breaking room. Periodically, he uses a manual pallet jack to
roll the boxes through the strip curtain into the area where the operation actually occurs, and to
remove Gaylord boxes of broken glass from the room.
Inmates who perform the GBO (“glass breakers”) enter the clean area where they don cloth
coveralls, gloves, and a hooded powered air purifying respirator (PAPR), and then enter the glass
breaking area. CRTs are placed on the grate where they are manually shattered with hammers.
The glass breakers reach through a strip curtain at opposite ends of the grate to break funnel
glass at one work station, and panel glass at the other. Broken glass falls into Gaylord boxes
positioned below the grate. When inmates finish breaking glass, they return to the clean area in
their coveralls and PAPR, use a high-efficiency particulate air (HEPA) filtered vacuum on their
coveralls before removing them, then remove their PPE and leave the area. Staff enter the room
only when there is no glass breaking going on to put away tools and search the area, otherwise
they observe the inmates in the glass breaking room through the window or vinyl curtains.
While housekeeping is a routine component of all production processes, a weekly extensive
cleaning is conducted in the glass breaking area. During that operation no production takes place
and all workers in this area remove settled dust by vacuuming and wet mopping. All surfaces,
including walls, equipment, and floors are cleaned. The blanket pre-filter on the LEV system is
vacuumed using the HEPA vacuum cleaner.

Page 3 – S. Randall Humm
Additionally, at approximately monthly intervals, the filters in the LEV system are removed and
either cleaned or replaced. Prior to an evaluation by Federal Occupational Health (FOH) and the
NIOSH Division of Applied Research Technology (DART) in March 2007, filters were removed
and cleaned by vacuuming, shaking, or banging on the floor to shake dust out. This took most of
the work shift and reportedly created a thick cloud of dust within the enclosed glass breaking
room. This process was changed after the FOH-NIOSH/DART evaluation, and is reported to
now be a wet process where the filters are wetted, removed, and bagged for disposal and new
filters used as replacements.
A chip recovery program began at the FSL in October 2005, and ended in October 2006.
Computer chips were removed from the mother board by holding the mother board over either a
lead solder pot or a lead solder wave fountain. Although the solder temperature was supposed to
be maintained just above the melting point (reportedly 400 to 600 degrees F), staff reported that
the solder temperature was set subjectively (i.e., the temperature was not measured), which may
have resulted in overheating, producing lead fume. There was no LEV for the first several
months of this operation until what was described by staff as a “make-shift PVC system” was
installed. This LEV system was replaced the following year with a LEV system designed by a
consultant. Despite the use of LEV at chip recovery stations, staff described a visible haze in the
FSL, and expressed concern about exposure to lead fume from this operation.

Assessment
In response to your request we reviewed the following documents:
· Results of medical surveillance provided by your office;
· Results of biologic monitoring provided by the medical clinic at FCI Elkton;
· Work instructions for the GBO and maintenance;
· Rosters for inmates working in recycling that provided location and dates of work, provided by
the factory manager;
· Timelines for recycling operations provided by the American Federation of Government
Employees (AFGE) Local 607;
· DOJ interviews with staff and inmates;
· Industrial hygiene sampling performed by consultants to UNICOR;
· Findings and recommendations of industrial hygiene assessments performed by FOH; and
· Draft report of the industrial hygiene assessment performed by the NIOSH/DART
We conducted a site visit on February 21-22, 2008 with you and a representative of FOH .
During this site visit we held an opening conference with FCI and UNICOR management, AFGE
representatives, UNICOR recycling staff, and the health service administrators and regional
medical director. After the conference we toured the FCI, including the recycling factory, the
warehouse, and the FSL. We conducted informational meetings for FCI and UNICOR staff, and
inmates. We spoke to several UNICOR staff who approached us after the meetings about their
medical issues and how they might relate to exposures at the FCI. We also met with the safety
manager, factory manager, and health services administrator. We ended the site visit with a
closing conference where we presented our initial impressions and recommendations.

Page 4 – S. Randall Humm
We were told that BOP has had an industrial hygienist on staff for several years, and that
UNICOR recently hired one. Neither of these individuals was present during our visit, and it is
unclear what, if any role, they may have had in setting up or monitoring the electronic recycling
program.
On March 25, 2008, we conducted an industrial hygiene survey to determine if lead- and
cadmium-bearing dust had migrated from the glass breaking room to other FCI buildings and
work areas and if there was evidence of “take-home” contamination in inmate housing and
privately-owned staff vehicles. The purpose of this survey was to gather additional information
to complement the extensive body of industrial hygiene data collected by FOH and
NIOSH/DART.
The survey was preceded by a brief opening meeting with FCI and UNICOR management,
AFGE representatives, and UNICOR recycling staff to explain the purpose of the site visit.
Following the meeting, we were escorted to the factory and automated data processing (ADP),
where we set up area air sampling pumps to assess airborne concentrations of lead, cadmium,
and other elements (minerals and metals). Air samples were collected, digested, and analyzed
according to NIOSH Method 7303 [NIOSH 2003a] with modifications for digestion.
Wipe samples were collected from undisturbed dusty surfaces in ADP, as well as at air diffusers
in ADP, inside air handling units serving the laundry, visiting room, education, chapel, ADP
offices, and from the floor mat at the entrance to the glass breaking room. Wipe samples were
collected from the floor in three inmate cubicles where inmates place their boots, and from
combination locks on lockers in the cubicles. Wipe samples were collected from personal
vehicles used by UNICOR staff. Flat surfaces (e.g., ADP work stations) were sampled by wiping
a 100 square centimeter (cm2) area (10 cm2 x 10 cm2) according to the sampling procedure
outlined in NIOSH Method 9102 [NIOSH 2003b]. Surface area was not considered when
collecting wipe samples from non-flat surfaces such as padlocks and vehicle steering wheels.
Hand wipe samples were collected according to the dermal sampling procedure outlined in
NIOSH Method 9105 [NIOSH 2003c] Hand wipe samples were collected after workers had
washed their hands at the end of the workday. All wipe samples were collected using Ghost
Wipes, which were digested and analyzed for elements according to NIOSH Method 9102
[NIOSH 2003b] with modifications for digestion. Bulk samples of material were collected from
beneath the stone roof ballast on the factory roof at the exhaust fan of the sawdust collection
system that was in use from 2001 until May 2003. Bulk samples were digested and analyzed for
elements according to NIOSH Method 7303 [NIOSH 2003a] with modifications for digestion.

Page 5 – S. Randall Humm

Results and Discussion 1
Medical surveillance
Inmates
Medical surveillance began in March 2003, immediately prior to the installation of the glass
breaking room, for inmates in glass breaking and disassembly, and staff. It is performed annually
and consists of limited biological monitoring but no physical examinations. Biological
monitoring consists of blood lead levels (BLL), blood cadmium (CdB), urine cadmium (CdU),
and urine beta-2-microglobulin (B-2-M), although not all inmates involved in GBO and
disassembly received all of these tests. In addition, some inmates had urine lead, blood or urine
arsenic or mercury, and serum B-2-M, none of which seem to have been based upon work
exposures or indicated by work history. Paper copies of test results are maintained in both the
inmate’s personal medical record and with UNICOR management; however, the factory manager
has been unable to locate any medical surveillance results at this time. Each inmate’s medical
records are transferred with them; no medical records are retained at Elkton after an inmate is
either transferred or released. Inmates are only informed of the results of their biological
monitoring if the results are abnormal. Although start dates were not available to us for all
inmates working in the GBO, it does not appear that any inmate had biological monitoring
performed preplacement. Because smoking can increase cadmium and lead burdens in the body,
it is important to note that smoking has been banned throughout the FCI for inmates since 2004,
although staff may smoke in designated areas. The results of the available inmate biological
monitoring are summarized below by area. Because measurements on individual inmates and
staff were sporadic and the number tested small, no group analyses were performed.
Glass Breaking Operation
We received biological monitoring results for 26 inmates who performed glass breaking. Each
inmate was tested 1 to 5 times, for a total of 54 rounds of testing. Table 1 shows inmate BLLs by
year collected. The laboratory’s limit of detection (LOD) for blood lead was 1.0 microgram per
deciliter of whole blood (µg/dL). In general, BLLs declined over time. Five of the seven tests
done in early 2003 were done in March or April and may reflect exposures to lead prior to
installation of the glass breaking room, but do not reflect exposures prior to the installation of the
sawdust ventilation system in 2001 because the half-life of lead in blood is too short.
There were 50 CdB tests done on inmates from 2003-2007. The laboratory’s LOD for CdB was
0.5 microgram per liter (µg/L). Twenty-seven were below the LOD; the remainder ranged from
0.5-1.2 µg/L. The earliest CdB were done in June 2003. Six inmates were tested in June 2003,
and three were below the LOD; the remainder ranged from 0.5-1.1 µg/L. These six CdB may

1

See Occupational exposure limits and health effects in Appendix .

Page 6 – S. Randall Humm
reflect exposures to cadmium prior to installation of the glass breaking room, but do not reflect
exposures prior to the installation of the sawdust ventilation system in 2001 because the half-life
of cadmium in blood is too short.
There were 28 CdU measurements. More than one laboratory was used for this analysis. At the
lab most commonly used the LOD was 1 µg/L and 23 measurements were below this LOD.
Other labs had lower LODs. If the CdU was above the LOD, then it was adjusted to the urinary
concentration of creatinine to control for the variability in urine dilution. The five that were
above the LOD ranged from 0.5 micrograms per gram of creatinine (µg/g/Cr) to 1 µg/g/Cr.
These CdU measurements do integrate exposure over time because the half-life of cadmium in
the urine is years to decades. However, only one of these inmates worked in GBO prior to May
2001; his CdU was less than 1 µg/L. Six inmates had urinary B-2-M measured; these ranged
from less than 10 to 54 µg/g/Cr.
Glass Breaking Room Maintenance
One inmate who performed cleaning and filter change-outs in the GBO was monitored for lead
and cadmium exposure from April 2003 until 2007, prior to the change in the filter change-out
process. His annual BLLs ranged from 10-4 µg/dL, with a progressive decline over time. His
CdBs ranged from 0.5 to 0.8 µg/L, and his CdUs were less than the LOD of 1 µg/L. Another
inmate who performs maintenance in the room was monitored in 2007 and 2008. His BLL was 5
in 2007, and was not done in 2008. CdB was 0.6 µg/L in 2007, and less than the LOD of 0.5
µg/L in 2008. CdUs were less than 1 µg/L.
Chip Recovery
We reviewed biological monitoring for 14 inmates who worked in the chip recovery area; all
were tested on February 16, 2007, 4 months after the operation ceased. BLLs ranged from 1-5
µg/dL. CdB was below the LOD for four inmates, and the remainder ranged from 0.5-1.1 µg/dL.
All but one CdU were below the LOD, and the remaining one was 0.6 µg/g/Cr. No inmates had
urine B-2-M measured.
Factory (not GBO)
We reviewed the results of biological monitoring done in April 2007 for 14 inmates who worked
in the factory, but did not perform glass breaking. Two had BLLs less than the LOD, and the
others ranged from 1-3 µg/dL. A BLL of 8 µg/dL was found in one inmate monitored in 2003.
Seven had CdBs below the LOD, and the remainder ranged from 0.5-1.0 µg/L. Twelve had CdU
below the LOD of 1 µg/L, and the other two were 0.2 and 0.6 µg/g/Cr. None had urine B-2-M
performed.

Page 7 – S. Randall Humm
Warehouse
Fourteen inmates who worked in the warehouse, but did not perform glass breaking, had
biological monitoring done in February 2007, almost 4 years after the GBO ceased in the
warehouse. BLLs ranged from1-5 µg/dL. Seven had CdBs below the LOD, and the remainder
ranged from 0.5-0.8 µg/L. All 14 had CdU below the LOD, and none had urine B-2-M
performed.
Clerks
We reviewed biological monitoring results for 2 clerks, one from the factory and one from the
FSL. One had testing annually from 2003-2005, the other was tested in 2007. There were three
BLLs ranging from 1-2 µg/dL. Three of four CdBs were less than the LOD of 0.5 µg/L, and one
was 0.6 µg/L. Two CdUs were less than the LOD of 1 µg/L, and one B-2-M was 40 µg/g/Cr.
Results of other tests
We reviewed biological testing results for which we were unable to determine the reason the
testing was done on inmates. Two inmates had serum B-2-M above normal. This test is often
used to determine prognosis in hematologic malignancies and for dialysis patients. It is difficult
to interpret in this setting because no medical history is available. In addition, three inmates had
elevated urinary total arsenic, and one also had an elevated blood arsenic. The arsenic results
were speciated and found to be organic arsenic, the type of arsenic which is found in seafood and
is not considered toxic. All other tests (urine lead, blood or urine arsenic and mercury) were
within normal limits.
UNICOR Staff
UNICOR staff see their private physicians for medical surveillance so their exams are not
standardized. We reviewed available medical records and found that most staff members had
records for CdB, CdU, urine B-2-M, and zinc protoporphyrin (ZPP). Some had physical exams
documented, some had urinalysis, complete blood count, pulmonary function tests, or chest xrays.
We reviewed the biological monitoring and medical exams provided for 10 UNICOR staff,
including nine of 11 recycling technicians who had worked in electronics recycling. Each was
tested between 1 and 5 times between 2003 and 2007. Their testing was done by a number of
different laboratories, and thus, the LOD and range of normal for the tests varied. For example
the LOD for BLL was either 1 or 3 µg/dL. Eighteen BLLs were below the LOD, and seven
ranged from 1-2.5 µg/dL. One employee had a BLL of 10 µg/dL, however his BLLs the year
before and after were below the LOD. His urine B-2-M was elevated at 445 µg/g/Cr, but he had
normal B-2-M levels the year before and after this test result. Standard medical practice usually
dictates that a physician repeat a lone elevated test result to determine whether the result is
spurious (such as from lab error) or actually elevated. The tests were not repeated at the time, so
laboratory error cannot be ruled out. Twenty-five CdB were done; 12 were below an LOD of 0.5

Page 8 – S. Randall Humm
µg/L, 2 were reported as zero, and the remainder ranged from 0.2-2.1 µg/L. Twenty-one CdU
were done; 13 were below the LOD of 1 µg/L and the rest ranged from 0.1-0.7 µg/L. Eighteen
urine B-2-M were done between 2003 and 2007, and all were normal with the exception noted
above. Twenty-two ZPPs were done between 2003 and 2007, and all were normal.

Interviews with Staff
Five staff asked to speak with us after NIOSH’s public meeting with concerned Elkton staff on
February 21, two of the five worked in recycling. One of the recycling staff reported having been
diagnosed with iron deficiency anemia in the past year. This condition is not related to recycling
work or other occupational exposures at FCI Elkton. The other reported an increase in the blood
zinc level over the past year, however, when we reviewed this employee’s biological monitoring
results, we found that it was the ZPP that had risen, and that the levels were still well within
normal limits. ZPP is not related to blood zinc. Of note, both staff noted these reported
conditions in the recent past, well after construction of the glass breaking room. An employee
from an adjacent area reported bipolar disorder, and one from another building reported
transverse myelitis, neither of which can be related to this workplace. Finally, another employee
from the adjacent area reported seeing a private physician and being tested for lead and
cadmium, and that both were below the LOD.

Industrial Hygiene
Records Review
The OIG provided consultant reports, industrial hygiene sampling results, and laboratory
analysis results for 13 surveys conducted at FCI Elkton between summer 2001 and November
2007. Twelve surveys were conducted by consultants to UNICOR, and one was conducted by
FOH in conjunction with a NIOSH/DART evaluation. Five reports contained sampling data
indicating worker exposures to cadmium at levels exceeding the OSHA action level, and two
reports documented exposures above the OSHA permissible exposure limit (PEL) for cadmium.
One of the reports documented lead exposure above the PEL during a now-discontinued filter
change procedure.
No industrial hygiene reports, sampling data, or laboratory analysis reports were provided for the
period from 1998 until August 2001. According to information provided by the OIG, it appears
that there are no industrial hygiene reports for this period; thus, we have no information or data
to help us assess the potential for early exposures to lead, cadmium, and possible other agents
when glass breaking occurred in other locations without local exhaust ventilation. Assuming that
we received reports for all industrial hygiene evaluations and/or laboratory analyses conducted
from 2001 through 2007, we noted that only two evaluations were conducted prior to 2004. Two
surveys were performed in 2004; no industrial hygiene evaluations were conducted in 2005,
other than an OSHA inspection which resulted in a serious citation for exposure above the
cadmium PEL and inadequate engineering/work practice controls.

Page 9 – S. Randall Humm
Our review of the consultant reports found that two consultants hired by UNICOR measured
worker exposures exceeding the OSHA action level for cadmium, but did not discuss the
findings or the implications of exceeding the action level. This omission occurred during one of
two surveys conducted in 2004, and two of five surveys in 2006. The quality of the reports, i.e.,
observations, discussion, recommendations, was greatly improved in 2007 when the most recent
consultant and FOH independently evaluated the glass breaking process, ventilation, and work
practices.
2001
A laboratory report of sample analysis, dated August 20, 2001, was provided to us. This
analytical report contains no information regarding the type of sample (personal sample versus
area sample), sample volume, location, the work being performed, PPE, or exposure control
methods. Lead was measured in one of the two air samples that were analyzed for lead; cadmium
was not detected. Wipe samples indicated quantifiable amounts of lead and cadmium on
surfaces.
June 2003
A laboratory report of sample analysis, dated June 3, 2003, was provided to us. Although this
analytical report contains no information regarding sample type, work processes, PPE, or
exposure control methods, the report does contain a record of sample volume along with results
for cadmium and lead. Based on an average sample volume of 744 liters, and assuming that
sampling was conducted at the usual rate of two liters per minute, the nine samples from late
May 2003 provide an estimate of airborne concentrations throughout a 370 minute sampling
period. The analytical results indicate that the airborne lead concentrations were likely below the
OSHA action level; however, airborne cadmium concentrations may have exceeded the OSHA
PEL in five of the nine samples, and may have exceeded the action level in one other sample
(range: 3-37 micrograms per cubic meter of air [µg/m3]). It is important to note that, at best,
these samples only provide an estimate of airborne concentrations at unknown sampling
locations under unspecified conditions. If sampling flow rates were higher or lower than the
typical rate of two liters per minute, the concentration estimates could be higher or lower than
those noted here.
2004
Consultant reports were provided for two evaluations conducted during June 2004. On June 2,
personal breathing zone (PBZ) samples were collected for three glass breakers and one feeder;
four area samples were collected on June 2. All results were below the action level for lead and
cadmium. Wipe samples determined the presence of lead and cadmium on surfaces in the work
area. Sampling was repeated on June 18, and the consultant reported that samples collected on
this date revealed “no overexposure;” however, results in the sample summary sheet show that a
PBZ sample collected on one of three glass breakers indicated exposure to airborne cadmium at
the OSHA PEL of 5 µg/m3. Although this sample did not prove statistical exceedance of the
PEL, the report should have contained a recommendation for further evaluation, and guidance
regarding OSHA requirements for periodic air and medical monitoring where workers are
exposed above the action level. In addition, one of four area samples indicated an airborne
cadmium concentration of 5 µg/m3. Wipe samples collected on June 18 indicated that surface
contamination had been reduced in locations previously sampled on June 2. Wipe sampling was
repeated on July 9; results were similar to those for the June 18 wipe samples. The consultant

Page 10 – S. Randall Humm
measured air velocity at three locations on June 18 to assess the direction and velocity of air into
and through the GBO. The consultant’s report did not interpret these measurements with respect
to the effectiveness of the LEV system.
2005
No consultant reports were provided for 2005. On September 8, 2005, OSHA conducted air
monitoring for lead and cadmium that determined one of two glass breakers was exposed to
cadmium above the PEL, and lead above the action level. UNICOR was cited for the
overexposure and for inadequate engineering and work practice controls.
2006
A different environmental consulting firm was hired to conduct air sampling during glass
breaking during site visits in January, February, June, July and September 2006.
PBZ sampling results for two glass breakers and two workers outside the booth did not exceed
the action level for cadmium or lead on January 17. Several air velocity measurements were
obtained “to determine if sufficient general ventilation is provided within the glass breaking
area.” No authoritative industrial hygiene references or guidelines were used to support the
consultant’s conclusion that adequate ventilation was provided.
Sampling and air velocity measurements were repeated on February 17. Air sampling results for
this visit indicate that cadmium exposures exceeded the action level for one handler and one
glass breaker. As in one of the 2004 consultant reports, this report did not note that the action
level had been exceeded.
The consultant returned on June 26 and 27 to conduct air sampling and assess ventilation in the
GBO and chip recovery. Sample results indicate that a glass breaker was exposed to cadmium
above the PEL, and a handler was exposed above the action level. As in earlier consultant
reports, the report for June 26 did not mention or discuss the significance of exceeding the action
level, nor did it provide guidance regarding medical surveillance, a written compliance program,
and other OSHA requirements triggered when air sampling indicates worker exposure above the
PEL. Air sampling conducted on June 27 at chip recovery in the FSL did not detect lead or
cadmium above the analytical LODs. The consultant also collected air samples for ethylene
glycol and n-propanol at chip recovery. It is not clear why these chemicals were selected for
evaluation.
The OIG provided two laboratory reports of sample analyses (both reports are dated July 10,
2006) which appear to be for wipe samples collected in GBO and chip recovery during the June
evaluation. We did not find these laboratory results in the industrial hygiene reports that were
provided to us. One report indicates small quantities of cadmium in five samples collected from
surfaces in chip recovery (less than 4.8 µg/sample). The average quantity of lead in the five wipe
samples was much greater: 1600 µg/sample (range 190 to 6800 µg/sample). Small quantities of
cadmium and lead were measured in one sample collected from an inmate’s hands. The other
laboratory report indicates that the average quantities of cadmium and lead in six surface wipe
samples collected in the GBO was 35 µg/sample and 290 µg/sample respectively. The average
amount of cadmium and lead in three hand wipe samples was 40 µg/sample for both elements.

Page 11 – S. Randall Humm
A consultant report for a July 7 survey indicates concentrations of cadmium and lead to be well
below occupational exposure limits in five PBZ and five area air samples. A second report for
this survey notes that cadmium and lead were measured in five surface wipe samples and three
hand wipe samples. This report noted a need for more thorough cleaning of surfaces and hands.
On September 6, the consultant collected five PBZ and five area samples. All results were below
OELs. Hand wipe samples from three individuals (one staff, two inmates) measured 5.8, 340,
and 870 µg-cadmium on their hands. The corresponding quantities of lead in the hand wipes was
26, 250, and 710 µg-lead/sample. The average quantity of cadmium and lead in five surface wipe
samples was 240 µg (range 10 to 640 µg), and 19,000 µg (range 57 to 85,000 µg) respectively.
2007
On February 27 and 28, FOH collected air, wipe, bulk dust, and waste samples in the factory,
warehouse, and FSL where electronics recycling had been conducted in the past, or was currently
being conducted. Air sampling during two days of glass breaking indicated that worker
exposures were below applicable occupational exposure limits (OELs). The report noted that the
LEV system was adequately controlling exposure at the GBO during routine operations;
however, air sampling during LEV filter change-out, a maintenance function, found airborne
cadmium and lead concentrations well above the PELs. This overexposure, which exceeded the
respirator protection factor, resulted from poor change-out procedures that included banging the
dirty filters together to knock the dust off. The results of personal air monitoring in the
warehouse and FSL were well below OELs. (Note: chip removal in the FSL had been
discontinued in 2006.) Wipe samples in the factory, warehouse, and FSL found significant lead
and cadmium contamination on various surfaces. This report concluded that the surface
contamination does not pose an “imminent inhalation threat,” but could “be responded to in a
prompt but well-coordinated manner.” FOH noted that migration of lead- and cadmium-bearing
dust from the current GBO could be reduced by installing a three-stage decontamination room.
On September 7, the third industrial hygiene consultant, for which we received reports, evaluated
the GBO with PBZ sampling, surface wipe sampling, and assessment of the LEV system.
Airborne cadmium was above the action level. Ventilation measurements and observations
indicated apparent leakage in the LEV system. This report contained numerous recommendations
regarding ventilation system repair, testing, and maintenance, as well as recommendations for
improving work practices and use of PPE.
On November 6, the industrial hygiene consultant conducted a subsequent evaluation of the
GBO. Although all air sampling results were below the action levels for lead and cadmium, the
results for one glass breaker indicated that his exposure approached the action level for
cadmium. Wipe samples found various concentrations of lead and cadmium on surfaces in the
glass breaking area.

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HHE Sampling, March 25, 2008
Wipe sample results are presented in Table 2. Wipe samples collected from three ceiling heating,
ventilating and air-conditioning (HVAC) diffusers in ADP indicated concentrations of cadmium
and lead ranging from 11-14 µg/100 cm2 and 49-55 µg/100 cm2 respectively. Lead and cadmium
were found in a wipe sample of undisturbed dust on a ledge along the north wall of the ADP
mezzanine, and in the mixed air plenum of air handler AH-3, which serves the factory tool room
and ADP offices. These results indicate that undetermined concentrations of lead and cadmium
migrated from the factory to ADP, possibly via the HVAC system. Given the low concentrations
of airborne lead and cadmium determined by air sampling in 2007, it seems unlikely that
significant migration of contaminants is occurring at this time. It is our opinion that the wipe
sample results reflect much earlier workplace conditions, i.e., when glass breaking occurred in
the middle of the factory with only a roof exhaust fan to remove airborne dust.
Wipe samples, collected in three air handlers serving the laundry, education, visiting room, and
chapel found quantifiable concentrations of lead and cadmium. Concentrations inside these air
handlers were much lower than those inside AH-3 in the ADP. The route whereby these
contaminants migrated to these air handlers is not clear.
Two bulk samples of material beneath stone roof ballast on the factory roof at the exhaust fan of
the sawdust collection system that was in use from 2001 until May 2003 contained 1000 and
1400 parts per million (ppm) lead (by weight), and 5000 and 7400 ppm cadmium (by weight).
These samples provide evidence that glass breaking operations during the time the sawdust
collection system was in use generated cadmium- and lead-bearing dust that was exhausted to the
roof.
Cadmium and lead contamination was found on the return air damper of rooftop air handler
AHU-5HV1, which serves the factory. Given the low contaminant concentrations indicated by
air sampling conducted by FOH and the current industrial hygiene consultant, we believe
contamination inside this unit primarily reflects conditions prior to construction of the present
glass breaking room.
As shown in Table 2, quantifiable amounts of cadmium were present on the floor in three inmate
cubicles where shoes are kept. Some lead was present in one cubicle. The presence of these
metals on the floor indicates that some lead and cadmium is being tracked out of the glass
breaking room. This finding is consistent with sample results showing lead on the soles of inmate
and staff footwear (Table 2, samples W-27 and W-28).
Hand wipe samples following hand washing by inmate workers demonstrated lead contamination
on hands ranging from approximately 1.5 to 130 µg/wipe. This demonstrates that handwashing
needs to be improved.
Lead and cadmium contamination in two staff personal vehicles was generally below the limits
of detection and/or quantitation; however, 3.3 µg-lead/100 cm2 was present on the center of the
steering wheel in one vehicle. This indicates a potential for take-home contamination, but the
concentration is minimal.

Page 13 – S. Randall Humm
Area air sampling results are shown in Table 3. One air sample indicated a quantifiable airborne
concentration of lead and cadmium. This sample, which was collected within a few feet of the
glass breaking operation (behind the strip curtain separating the GBO from the entry and changeout areas), was well-below applicable OELs. The area sample collected at the window in the
GBO entry detected a trace concentration of lead and cadmium. The other six area air samples
collected in the glass breaking room, factory, and ADP did not detect lead or cadmium.

Conclusions
Electronics recycling at FCI Elkton appears to have been performed from 1997 until May 2003
without adequate engineering controls, respiratory protection, medical surveillance, or industrial
hygiene monitoring. Because of the lack of both biological monitoring and industrial hygiene
data, we cannot determine the extent of exposure to lead and cadmium that occurred during that
time frame, but descriptions of work tasks from staff and inmates indicate that exposures during
that time frame were likely higher than current exposures. The current GBO is a significant
improvement, but can be further enhanced to limit exposure to those performing glass breaking,
as well as limiting the migration of lead and cadmium from the room into other areas. While
some take-home contamination does occur, surface wipe sampling and biological monitoring
suggest that take-home contamination does not pose a health threat at this time. Take-home
contamination can be further reduced by changes to the GBO, work practices, and improved
personal hygiene as recommended below.
We cannot determine the extent of exposure to lead that occurred in the chip recovery process
because of the lack of data. Descriptions of work tasks from staff, and a BLL of 5 µg/dL in an
inmate 4 months after the process ended indicate that exposure to lead during this process did
occur. We found no evidence that actions were taken to prevent exposure to lead at the outset in
the chip recovery process and found that no medical surveillance was performed until after the
process ended.
Medical surveillance that has been carried out among inmates and staff has not complied with
OSHA standards. No medical exams (including physical examinations) are done on inmates;
staff receive inconsistent examinations and biological monitoring by their personal physicians;
biological monitoring for lead is not done at established standard intervals; and results are not
communicated to the inmates. Inappropriate biological monitoring tests have been done. Records
of medical surveillance are not maintained by the employer for the appropriate length of time.
At this time, after careful review of existing records and current operations, we conclude that the
only persons with current potential for exposure to either lead or cadmium over the action level
are the inmates who perform glass breaking or the monthly filter change-out. We believe that
medical surveillance can be discontinued for all other inmates and staff. Some former inmates
and/or staff may require surveillance under the OSHA cadmium standard.
Wipe and bulk sample results indicated that lead- and cadmium-containing dust migrated out of
the GBO in the past. Low levels of lead- and cadmium-containing dust on staff and inmate shoes
and the floor mat outside the glass breaking room suggest that this is still occurring, although in
small amounts. Contamination of inmate housing and staff vehicles is occurring, but is minimal;

Page 14 – S. Randall Humm
we have no data regarding the extent of past contamination in these locations. Hand washing is
less than optimal for some individuals, including both staff and inmates. There is legacy
contamination of the factory, FSL, and warehouse, which is scheduled to be remediated. We
concur with FOH that surface contamination does not present an imminent hazard at this time,
and should be remediated in a “prompt but well-coordinated manner.”

Recommendations
`
The following recommendations are provided to improve the safety and health of both the staff
and inmates involved with electronics recycling at the Elkton FCI.
1. Continue to work with the current industrial hygiene consultant to increase the effectiveness of
the LEV system. Improvements in the LEV system will not only reduce worker exposure to
airborne contaminants, but will capture dust that would otherwise contribute to surface
contamination, which could lead to an ingestion hazard (hand-to-mouth) or inhalation hazard if
re-entrained. Conduct an industrial hygiene assessment to determine inmate exposure to lead and
cadmium after the LEV is modified.
2. The change-out room should be reconfigured to ensure that GBO workers do not carry
cadmium or lead out of the glass breaking room. Separate storage should be provided for nonwork uniforms and GBO work apparel/PPE. All potentially-contaminated work clothing and PPE
should remain in the “dirty” chamber of the change-out room; non-work clothing should never
come in contact with work items. As a minimum requirement, workers should be required to
wash hands and all potentially exposed skin after doffing PPE, before putting on uniforms when
exiting the GBO. Work clothes and PPE should never be worn outside of the GBO to minimize
migration of cadmium- and lead-contaminated dust to other parts of the institution. Laundry
personnel should be made aware of the potential exposure to lead and cadmium from work
clothes and take action to minimize exposure to themselves.
3. Ensure full compliance with all applicable OSHA standards, including the General Industry
Lead standard [29 CFR 1910.1025], the Cadmium Standard [29 CFR 1910.1027], the Hazard
Communication Standard [29 CFR 1910.1200], and the Respiratory Protection Standard [29
CFR 1910.134]. This includes record keeping requirements, communication requirements,
compliance plans, and medical surveillance. In addition to the OSHA requirements, we
recommend that the preplacement examination for cadmium exposure be identical to the periodic
examinations so that baseline health status may be obtained prior to exposure.
4. Contract a board-certified, residency-trained occupational medicine physician who is familiar
with OSHA regulations on exposures at the FCI to oversee the medical surveillance program.
BOP may be able to find a local physician, or contract with Federal Occupational Health. This
contractor should also oversee medical clearance for respirators.
5. Carefully evaluate the qualifications and expertise of any consultant who may be hired to
assess occupational or environmental health and safety issues. Anyone can present him/herself as
an “industrial hygienist,” regardless of education, training, or expertise. One useful benchmark
for vetting individuals who provide industrial hygiene services is the designation of Certified

Page 15 – S. Randall Humm
Industrial Hygienist (CIH). Certification by the American Board of Industrial Hygiene (ABIH)
ensures that prospective consultants have met ABIH standards for education, ongoing training,
and experience, and have passed a rigorous ABIH certification examination. The UNICOR
and/or BOP industrial hygienists can assist in the selection of your consultants.
6. Perform a detailed job hazard analysis prior to beginning any new operation or before making
changes to existing operations. This will allow BOP to identify potential hazards prior to
exposing staff or inmates, and to identify appropriate controls and PPE. Involve the BOP and/or
UNICOR industrial hygienists in these job hazard analyses. If medical surveillance is needed
then BOP should perform pre-placement evaluations of exposed staff and inmates.
7. Appoint a union safety and health representative. This individual should be a regular
participant on the joint labor-management safety committee that meets quarterly. Since inmates
do not have a mechanism for representation on this committee, ensure that they are informed of
its proceedings and that they have a way to voice their concerns about and ideas for improving
workplace safety and health.
This interim letter will be included in a final report that will include visits to two other BOP
facilities. Please post a copy of this letter for 30 days at or near work areas of affected staff and
inmates. Thank you for your cooperation with this evaluation. If you have any questions, please
do not hesitate to contact us at 513-841-4382.
Sincerely yours,

Elena H. Page, M.D., M.P.H.
Medical Officer

David Sylvain, M.S., C.I.H.
Industrial Hygienist
Hazard Evaluations and Technical
Assistance Branch
Division of Surveillance, Hazard
Evaluations and Field Studies
cc:
J. T. Shartle, Warden, FCI Elkton
Bill Meek, Vice-President, AFGE Local 607
Paul Laird, Assistant Director, UNICOR

Page 16 – S. Randall Humm

Tables
Table 1. Blood lead levels of inmates doing glass breaking, by year
HETA 2008-0055, Federal Bureau of Prisons, FCI Elkton, Elkton, OH
Mean BLL

Median BLL

Range

Number

(µg/dL)

(µg/dL)

(µg/dL)

sampled

2003

5.6

4.5

3-9

7

2004

3.7

3.0

2-7

7

2005

3.7

3.9

2-10

12

2006

2.3

2.0

1-5

13

2007

1.7

1.5

1-4

10

Year

HETA 2008-0055
Federal Bureau of Prisons
FCI Elkton, Elkton, OH

Table 2.
Wipe sampling results, March 25, 2008
Sample
ID

Location

Surface

Approx.
Elevation
(feet)

Description

Area
Wiped
2

W-1

HVAC diffuser

~15

W-2

desktop

2½

HVAC diffuser

15

W-4

desktop

2½

W-5

HVAC diffuser

15

W-6

desktop

2½

W-3

ADP

row ADP4
above
workstation
C116
Workstation
C116
near center of
room; Row
ADP4 above
workstation
C025
workstation
C025
southwest
corner of ADP;
Row ADP1
above
workstation
C007
workstation
C007

Cadmium

Lead
2

2

cm

µg/wipe

µg/100 cm

µg/wipe

µg/100 cm

200

27

14

110

55

100

nd

--

nd

--

200

21

11

97

49

100

trace

--

nd

--

200

28

14

110

55

100

nd

--

nd

--

Page 17 – S. Randall Humm
HETA 2008-0055
Federal Bureau of Prisons
FCI Elkton, Elkton, OH

Table 2. (Continued)
Wipe sampling results, March 25, 2008
Sample
ID

Location

Surface

Approx.
Elevation
(feet)

Description

Area
Wiped
2

W-7

C-beam

8

Factory
Mezzanine
mixed air
plenum, AH-3

W-8

n/a

ledge along
north wall
serves offices
along north
wall from
factory tool
room to ADP

Lead
2

2

µg/wipe

µg/100 cm

µg/wipe

µg/100 cm

100

820

820

970

970

315

70

22

430

140

100

53

53

55

55

not
determined

1400

1200

32

ADP
Mezzanine

C-beam

W-10

Factory Roof

return air
damper
AHU-5HV1

n/a

W-11

Mechanical
Room laundry

filter brace return air
5-AH2

n/a

serves laundry

not
determined

4.9

W-12

Mechanical
Room laundry

Mixed air
plenum
5-AH2

n/a

serves laundry

315

2.1

0.67

19

6.0

W-13

Mechanical
Room

Outside air
plenum
5-AH4

n/a

serves
education

270

8.3

3.1

46

17

W-14

Mechanical
Room

mixed air
plenum
5-AH5

100

2.7

2.7

16

16

100

0.14

0.14

nd

--

not
determined

13

100

0.19

not
determined

0.19

100

0.23

not
determined

0.10

nd

28

130

7.2

41

0.23

trace

W-9

W-15

C/D Unit
D-A cube
51U

W-16
W-17

C/D Unit
D-A cube
29L

floor, inmate
cubicle
combination
lock on inmate
locker
floor, inmate
cubicle

W-18

combination
lock on inmate
locker

W-19

floor, inmate
cubicle

C/D Unit
D-B cube
005

8

n/a
0

ledge along
north wall

Cadmium

cm

serves visiting
room and
chapel
where shoes
are kept

1½
0

where shoes
are kept

1½
0

where shoes
are kept

nd
0.19

nd

nd
0.23

2.2

W-20

combination
lock on inmate
locker

1½

W-21

hands, inmate
#1

n/a

W-22

hands, inmate
#2

n/a

W-23

hands, inmate
#3

n/a

W-24

hands, inmate
#4

n/a

0.51

4.3

W-25

hands, inmate
#5

n/a

11

41

Factory

hand wipe after
washing hands
at end of
workday in
glass breaking

not
determined

--

2.2

Page 18 – S. Randall Humm
HETA 2008-0055
Federal Bureau of Prisons
FCI Elkton, Elkton, OH

Table 2. (Continued)
Wipe sampling results, March 25, 2008
Sample
ID

Location

Surface

Approx.
Elevation
(feet)

Description

Area
Wiped
2

cm
W-25

hands, inmate
#5

W-26

hands, inmate
#6

W-27

sole of right
shoe, staff

W-28

Factory
(continued)

sole of
sneaker,
inmate #4
exterior,
locker #2

W-29

µg/wipe

2

µg/100 cm

11

41

n/a

not
determined

2.2

3.1

n/a

worn in glass
breaking

not
determined

3.1

120

n/a

sneaker not
worn while
working

not
determined

4.3

200

6

locker door in
glass breaking
decon area

100

trace

--

nd

1½

glass breaking
decon area

100

0.30

0.30

9.8

100

3.9

3.9

490

490

100

7.2

7.2

1000

1000

trace

--

3.3

3.3

n/a

bench seat

W-31

floor mat

0

W-32

floor mat

0

personal
vehicle
(Jeep)

Lead
2

µg/100 cm

hand wipe after
washing hands
at end of
workday in
glass breaking

W-30

W-39

Cadmium
µg/wipe

entry to glass
breaking room
center of
steering wheel

9.8

steering wheel

n/a

steering wheel

n/a

100
not
determined

W-41

driver's seat

n/a

100

trace

--

nd

--

W-42

console-arm
rest

n/a

0.14

0.14

trace

--

steering wheel

n/a

100
not
determined

0.098

carpet

n/a

100

nd

W-40

W-43
W-44

personal
vehicle
(Mazda)

left side at foot
rest

trace

trace

2.3
--

trace

--

Page 19 – S. Randall Humm
Table 3. Area air sampling for lead and cadmium
HETA 2008-0055, Federal Bureau of Prisons, FCI Elkton, Elkton, OH

Location
HEPA discharge
area behind glass
breaking
At window in glass
breaking
Stanchion next to
glass breaking
Change-out area
near clock
Mezzanine rail
above glass
breaking
At vinyl strip curtain
in glass breaking
entry
ADP, east center
ADP, west center
NIOSH REL-TWA
OSHA PEL-TWA
ACGIH TLV

Sampling
Period
(minutes)

Sample
Volume
(liters)

Cadmium
Concentration
3
(µg/m )

Lead
Concentration
3
(µg/m )

407

810

nd

nd

408

816

trace

trace

376

753

0.31

4.6

406

808

nd

nd

403

802

nd

nd

387
380
381

774
760
762

nd
nd
nd
Ca
5
10

nd
nd
nd
50
50
50

“nd” (not detected) indicates that the sample result is below the analytical limit of detection. The limits of detection for
cadmium and lead are 0.02 ug/wipe and 0.6 ug/wipe, respectively.
“trace” indicates that the sample result is between the analytical limits of detection and quantitation. The limits of quantitation
for cadmium and lead are 0.077 ug/wipe and 1.9 ug/wipe, respectively.
See the Appendix for a discussion of NIOSH recommended exposure limits (RELs), OSHA permissible exposure limits
(PELs), and ACGIH Threshold Limit Values (TLVs).
“Ca” indicates that NIOSH regards cadmium as a potential occupational carcinogen and that exposures should be reduced
to the lowest feasible concentration.

References
NIOSH [2003a]. Elements by ICP: Method 7303. In: NIOSH Manual of Analytic Methods, 4th
ed, 3rd Suppl. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for
Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS
(NIOSH) Publication No. 03-127.
NIOSH [2003b]. Elements on wipes: Method 9102. In: NIOSH Manual of Analytic Methods, 4th
ed, 3rd Suppl. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for
Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS
(NIOSH) Publication No. 03-127.
NIOSH [2003c]. Lead in dust wipes by chemical spot test (colorimetric screening method):
Method 9105. In: NIOSH Manual of Analytic Methods, 4th ed, 3rd Suppl. Cincinnati, OH: U.S.
Department of Health and Human Services, Centers for Disease Control and Prevention,
National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 03-127.

Page 20 – S. Randall Humm

Appendix
Occupational exposure limits and health effects
In evaluating the hazards posed by workplace exposures, NIOSH investigators use both
mandatory (legally enforceable) and recommended occupational exposure limits (OELs) for
chemical, physical, and biological agents as a guide for making recommendations. OELs have
been developed by Federal agencies and safety and health organizations to prevent the
occurrence of adverse health effects from workplace exposures. Generally, OELs suggest levels
of exposure to which most workers may be exposed up to 10 hours per day, 40 hours per week
for a working lifetime without experiencing adverse health effects. However, not all workers will
be protected from adverse health effects even if their exposures are maintained below these
levels. A small percentage may experience adverse health effects because of individual
susceptibility, a pre-existing medical condition, and/or a hypersensitivity (allergy). In addition,
some hazardous substances may act in combination with other workplace exposures, the general
environment, or with medications or personal habits of the worker to produce health effects even
if the occupational exposures are controlled at the level set by the exposure limit. Also, some
substances can be absorbed by direct contact with the skin and mucous membranes in addition to
being inhaled, which contributes to the individual’s overall exposure.
Most OELs are expressed as a time-weighted average (TWA) exposure. A TWA refers to the
average exposure during a normal 8- to 10-hour workday. Some chemical substances and
physical agents have recommended short-term exposure limit (STEL) or ceiling values where
health effects are caused by exposures over a short-period. Unless otherwise noted, the STEL is a
15-minute TWA exposure that should not be exceeded at any time during a workday, and the
ceiling limit is an exposure that should not be exceeded at any time.
In the U.S., OELs have been established by Federal agencies, professional organizations, state
and local governments, and other entities. Some OELs are legally enforceable limits, while
others are recommendations. The U.S. Department of Labor Occupational Safety and Health
Administration’s (OSHA) permissible exposure limits (PELs) (29 CFR 2 1910 [general industry];
29 CFR 1926 [construction industry]; and 29 CFR 1917 [maritime industry]) are legal limits
enforceable in workplaces covered under the Occupational Safety and Health Act. NIOSH
recommended exposure levels (RELs) are recommendations based on a critical review of the
scientific and technical information available on a given hazard and the adequacy of methods to
identify and control the hazard. NIOSH RELs can be found in the NIOSH Pocket Guide to
Chemical Hazards [NIOSH 2005]. NIOSH also recommends different types of risk management
practices (e.g., engineering controls, safe work practices, worker education/training, personal
protective equipment, and exposure and medical monitoring) to minimize the risk of exposure
and adverse health effects from these hazards. Other OELs that are commonly used and cited in
the U.S. include the threshold limit values (TLVs) recommended by the American conference of
Governmental Industrial Hygienists (ACGIH), a professional organization, and the Workplace

2

Code of Federal Regulations. See CFR in references.

Page 21 – S. Randall Humm
environmental exposure limits (WEELs) recommended by the American Industrial Hygiene
Association, another professional organization. ACGIH TLVs are considered voluntary exposure
guidelines for use by industrial hygienists and others trained in this discipline “to assist in the
control of health hazards” [ACGIH 2007]. WEELs have been established for some chemicals
“when no other legal or authoritative limits exist” [AIHA 2007].
Outside the U.S., OELs have been established by various agencies and organizations and include
both legal and recommended limits. Since 2006, the Berufsgenossenschaftlichen Institut für
Arbeitsschutz (German Institute for Occupational Safety and Health) has maintained a database
of international OELs from European Union member states, Canada (Québec), Japan,
Switzerland, and the U.S. [http://www.hvbg.de/e/bia/gestis/limit_values/index.html]. The
database contains international limits for over 1250 hazardous substances and is updated
annually.
Employers should understand that not all hazardous chemicals have specific OSHA PELs, and
for some agents the legally enforceable and recommended limits may not reflect current healthbased information. However, an employer is still required by OSHA to protect its employees
from hazards even in the absence of a specific OSHA PEL. OSHA requires an employer to
furnish employees a place of employment free from recognized hazards that cause or are likely
to cause death or serious physical harm [Occupational Safety and Health Act of 1970 (Public
Law 91–596, sec. 5(a)(1))]. Thus, NIOSH investigators encourage employers to make use of
other OELs when making risk assessment and risk management decisions to best protect the
health of their employees. NIOSH investigators also encourage the use of the traditional
hierarchy of controls approach to eliminate or minimize identified workplace hazards. This
includes, in order of preference, the use of: (1) substitution or elimination of the hazardous agent,
(2) engineering controls (e.g., local exhaust ventilation, process enclosure, dilution ventilation),
(3) administrative controls (e.g., limiting time of exposure, employee training, work practice
changes, medical surveillance), and (4) personal protective equipment (e.g., respiratory
protection, gloves, eye protection, hearing protection). Control banding, a qualitative risk
assessment and risk management tool, is a complementary approach to protecting worker health
that focuses resources on exposure controls by describing how a risk needs to be managed
[http://www.cdc.gov/niosh/topics/ctrlbanding/]. This approach can be applied in situations where
OELs have not been established or can be used to supplement the OELs, when available.

Lead
Occupational exposure to lead occurs via inhalation of lead-containing dust and fume and
ingestion from contact with lead-contaminated surfaces. In cases where careful attention to
hygiene (for example, handwashing) is not practiced, smoking cigarettes or eating may represent
another source of exposure among workers who handle lead. Industrial settings associated with
exposure to lead and lead compounds include smelting and refining, scrap metal recovery,
automobile radiator repair, construction and demolition (including abrasive blasting), and firing
range operations [ACGIH 2001]. Occupational exposures also occur among workers who apply
and/or remove lead-based paint or among welders who burn or torch-cut metal structures.

Page 22 – S. Randall Humm
Acute lead poisoning, with blood lead levels (BLLs) usually over 70 micrograms per deciliter of
whole blood (µg/dL), presents with abdominal pain, hemolytic anemia, neuropathy, and has in
very rare cases progressed to encephalopathy and coma [Moline and Landrigan 2005].
Symptoms of chronic lead poisoning include headache, joint and muscle aches, weakness,
fatigue, irritability, depression, constipation, anorexia, and abdominal discomfort [Moline and
Landrigan 2005]. Overt symptoms usually do not develop until the BLL reaches 30-40 µg/dL
[Moline and Landrigan 2005]. Overexposure to lead may also result in damage to the kidneys,
anemia, high blood pressure, impotence, and infertility and reduced sex drive in both sexes.
Studies have shown subclinical effects on heme synthesis, renal function, and cognition at BLLs
<10 µg/dL [ATSDR 2007]. Inorganic lead is reasonably anticipated to cause cancer in humans
[ATSDR 2007].
In most cases, an individual's BLL is a good indication of recent exposure to lead, with a half-life
(the time interval it takes for the quantity in the body to be reduced by half its initial value) of 12 months [Lauwerys and Hoet 2001; Moline and Landrigan 2005; NCEH 2005;]. The majority of
lead in the body is stored in the bones, with a half-life of years to decades. Bone lead can be
measured using x-ray techniques, but these are primarily research based and are not widely
available. Elevated zinc protoporphyrin (ZPP) levels have also been used as an indicator of
chronic lead intoxication, however, other factors, such as iron deficiency, can cause an elevated
ZPP level, so the BLL is a more specific test for evaluating occupational lead exposure.
In 2000, NIOSH established an REL for inorganic lead of 50 micrograms per cubic meter of air
(μg/m3) as an 8-hour TWA. This REL is consistent with the OSHA PEL, which is intended to
maintain worker BLLs below 40 µg/dl; medical removal is required when an employee has a
BLL of 60 µg/dL, or the average of the last 3 tests at 50 µg/dL or higher [29 CFR 1910.1025; 29
CFR 1962.62]. NIOSH has conducted a literature review of the health effects data on inorganic
lead exposure and finds evidence that some of the adverse effects on the adult reproductive,
cardiovascular, and hematologic systems, and on the development of children of exposed
workers can occur at BLLs as low as 10 µg/dl [Sussell 1998]. At BLLs below 40 µg/dl, many of
the health effects would not necessarily be evident by routine physical examinations but
represent early stages in the development of lead toxicity. In recognition of this, voluntary
standards and public health goals have established lower exposure limits to protect workers and
their children. The ACGIH TLV for lead in air is 50 µg/m3 as an 8-hour TWA, with worker
BLLs to be controlled to ≤ 30 µg/dl. A national health goal is to eliminate all occupational
exposures that result in BLLs >25 µg/dl [DHHS 2000]. The Third National Report on Human
Exposure to Environmental Chemicals (TNRHEEC) found the geometric mean blood lead
among non-institutionalized, civilian males in 2001-2002 was 1.78 µg/dL [National Center for
Environmental Health 2005].
OSHA requires medical surveillance on any employee who is or may be exposed to an airborne
concentration of lead at or above the action level, which is 30 µg/m3 as an 8-hour TWA for more
than 30 days per year [29 CFR 1910.1025]. Blood lead and ZPP levels must be done at least
every 6 months, and more frequently for employees whose blood leads exceed certain levels. In

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addition, a medical examination must be done prior to assignment to the area, and should include
detailed history, blood pressure measurement, blood lead, ZPP, hemoglobin and hematocrit, red
cell indices, and peripheral smear, blood urea nitrogen (BUN), creatinine, and a urinalysis.
Additional medical exams and biological monitoring depend upon the circumstances, for
example, if the blood lead exceeds a certain level.

Cadmium
Cadmium is a metal that has many industrial uses, such as in batteries, pigments, plastic
stabilizers, metal coatings, and television phosphors [ACGIH 2001]. Workers may inhale
cadmium dust when sanding, grinding, or scraping cadmium-metal alloys or cadmiumcontaining paints [ACGIH 2001]. Exposure to cadmium fume may occur when materials
containing cadmium are heated to high temperatures, such as during welding and torching
operations; cadmium-containing solder and welding rods are also sources of cadmium fume. In
addition to inhalation, cadmium may be absorbed via ingestion; non-occupational sources of
cadmium exposure include cigarette smoke and dietary intake [ACGIH 2001]. Early symptoms
of cadmium exposure may include mild irritation of the upper respiratory tract, a sensation of
constriction of the throat, a metallic taste and/or cough. Short-term exposure effects of cadmium
inhalation include cough, chest pain, sweating, chills, shortness of breath, and weakness [Thun et
al. 1991]. Short-term exposure effects of ingestion may include nausea, vomiting, diarrhea, and
abdominal cramps [Thun et al. 1991]. Long-term exposure effects of cadmium may include loss
of the sense of smell, ulceration of the nose, emphysema, kidney damage, mild anemia, and an
increased risk of cancer of the lung, and possibly of the prostate [ATSDR 1999].
The OSHA PEL (29 CFR 1910.1027) for cadmium is 5 μg/m3 TWA [CFR 1993]. The ACGIH
has a TLV for total cadmium of 10 μg/m3 (8-hour TWA), with worker cadmium blood level to
be controlled at or below 5 μg/dL and urine level to be below 5 μg/g creatinine, and designation
of cadmium as a suspected animal carcinogen [ACGIH 2007]. NIOSH recommends that
cadmium be treated as a potential occupational carcinogen and that exposures be reduced to the
lowest feasible concentration [NIOSH 1984].
Blood cadmium levels measured while exposure is ongoing reflect fairly recent exposure (in the
past few months). The half-life is biphasic, with rapid elimination (half-life approximately 100
days) in the first phase, but much slower elimination in the second phase (half-life of several
years) [Lauwerys and Hoet 2001; Franzblau 2005]. Urinary cadmium levels are reflective of
body burden and have a very long half-life of 10-20 years [Lauwerys and Hoet 2001].
OSHA requires medical surveillance on any employee who is or may be exposed to an airborne
concentration of cadmium at or above the action level, which is 2.5 µg/m3 as an 8-hour TWA for
more than 30 days per year [29 CFR 1910.1027]. A preplacement examination must be provided,
and shall include a detailed history, and biological monitoring for urine cadmium (CdU) and
beta-2-microglobulin (B-2-M), both standardized to grams of creatinine (g/Cr), and blood
cadmium (CdB), standardized to liters of whole blood (lwb). OSHA defines acceptable CdB
levels as < 5 µg/L, CdU as < 3 µg/g/Cr, and B-2-M as < 300 µg/g/Cr. NHANES III found
geometric mean CdB of 0.4 µg/L among men in 1999-2000. The geometric mean CdU for men
in 2001-2002 was 0.2 µg/g/Cr. Smokers can have CdB levels double that of nonsmokers

Page 24 – S. Randall Humm
[Lauwerys and Hoet 2001]. Periodic surveillance is also required one year after the initial exam
and at least biennially after that. Periodic surveillance shall include the biological monitoring,
history and physical examination, a chest x-ray (frequency to be determined by the physician
after the initial x-ray), pulmonary function tests, blood tests for BUN, complete blood count
(CBC), and Cr, and a urinalysis. Men over 40 years of age require a prostate examination as
well. The frequency of periodic surveillance is determined by the results of biological monitoring
and medical examinations. Biological monitoring is required annually, either as part of the
periodic surveillance or on its own. We recommend that the preplacement examination be
identical to the periodic examinations so that baseline health status may be obtained prior to
exposure. Termination of employment examinations, identical to the periodic examinations, are
also required. The employer is required to provide the employee with a copy of the physician’s
written opinion from these exams and a copy of biological monitoring results within 2 weeks of
receipt.
Biological monitoring is also required for all employees who may have been exposed at or above
the action level unless the employer can demonstrate that the exposure totaled less than 60
months. In this case it must also be conducted one year after the initial testing. The need for
further monitoring for previously exposed employees is then determined by the results of the
biological monitoring.

Zinc
Zinc is a very common element in the earth’s crust, and is found in air, soil, water, and foods. It
has many industrial uses. For example, metallic zinc is used to galvanize other metals, and zinc
compounds are used in paints, ceramics, rubber products, and in many drug products, like
ointments, sunscreen, vitamins, and shampoos. Zinc is an essential element, which means it is
required for the body to function properly. Zinc is not well absorbed through the skin, but is
absorbed through the gastrointestinal system. Inhalational exposure to high levels of zinc oxide
fume (generally above 75 mg/m3) can cause metal fume fever. [ATSDR 2005]. Metal fume fever
is a syndrome of cough, shortness of breath, fever, aches, chills, and a high white blood cell
count that occurs within hours of exposure, and can last up to 4 days. Normal serum or plasma
zinc levels are about 1 mg/mL [ATSDR 2005]. The OSHA PEL and the NIOSH REL for zinc
oxide are 5 mg/m3. This is 100 times higher than the PEL for lead, and reflects the relatively low
toxicity of zinc. There is no mandated medical surveillance for workers exposed to zinc.

References
ACGIH [2001]. 2001 Documentation of the threshold limit values and biological exposure
indices. Cincinnati, OH: American Conference of Governmental Industrial
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ACGIH [2007]. 2007 TLVs® and BEIs®: threshold limit values for chemical substances and
physical agents and biological exposure indices. Cincinnati, OH: American Conference of
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AIHA [2007]. 2007 Emergency response planning guidelines (ERPG) & workplace
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NIOSH [1978]. Occupational exposure to inorganic lead. Cincinnati, OH: U.S.
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occupational exposure to inorganic lead: request for comments and information.

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