Respiratory Health Associated with Systemic Metal Exposure in Post 9/11 Veterans in the Department of Veterans Affairs Toxic Embedded Fragment Registry

OBJECTIVE

Adverse respiratory outcomes in post-9/11 Veterans with elevated urinary metal measures and enrolled in the VA's Toxic Embedded Fragment registry were compared to those without elevated urinary metals.

METHODS

Veterans completed questionnaires, pulmonary physiology tests (pulmonary function and oscillometry) and provided urine samples for analysis of 13 metals. Respiratory symptoms, diagnoses and physiology measures were compared in Veterans with ≥1 urine metal elevation to those without metal elevations, adjusted for covariates, including smoking.

RESULTS

Among 402 study participants, 24% had elevated urine metals, often just exceeding upper limits of reference values. Compared to Veterans without elevated metals, those with elevated metals had had higher FEV1 values but similar frequencies of respiratory symptoms and diagnoses and abnormalities on pulmonary physiology tests.

CONCLUSIONS

Mild systemic metal elevations in post 9/11 Veterans are not associated with adverse respiratory health outcomes.

Succimer chelation does not produce lasting reductions of blood lead levels in a rodent model of retained lead fragments

Retained lead fragments from nonfatal firearm injuries pose a risk of lead poisoning. While chelation is well-established as a lead poisoning treatment, it remains unclear whether chelation mobilizes lead from embedded lead fragments. Here, we tested whether 1) DMSA/succimer or CaNa2EDTA increases mobilization of lead from fragments in vitro, and 2) succimer is efficacious in chelating fragment lead in vivo, using stable lead isotope tracer methods in a rodent model of embedded fragments. DMSA was > 10-times more effective than CaNa2EDTA in mobilizing fragment lead in vitro. In the rodent model, succimer chelation on day 1 produced the greatest blood lead reductions, and fragment lead was not mobilized into blood. However, with continued chelation and over 3-weeks post-chelation, blood lead levels rebounded with mobilization of lead from the fragments. These findings suggest prolonged chelation will increase fragment lead mobilization post-chelation, supporting the need for long-term surveillance in patients with retained fragments.

The Department of Veterans' Affairs Depleted Uranium Cohort in the Time of COVID-19: Translating a Traditional Surveillance Protocol to a Telehealth Platform

OBJECTIVE

In 2021, 37 members of a cohort of depleted uranium-exposed Gulf War I veterans were evaluated using a protocol tailored to accommodate COVID-19 safety practices on a telehealth platform.

METHODS

Individual elements of the legacy protocol were reviewed for urgency and feasibility of inclusion in a modified, telehealth platform.

RESULTS

The redesigned protocol included a participant readiness for telehealth assessment, nurse and physician telehealth visits, collection of usual health questionnaires, and urine collections for exposure monitoring for uranium and other fragment-related metal measures.

CONCLUSIONS

Despite some limitations in scope, the telehealth platform permitted a visual "visit" with surveillance participants who expressed a high comfort level with the format. The telehealth platform has apparent utility for occupational surveillance and should be explored as a standard approach for surveillance outside of public health emergencies.

Laying the Foundation for a Mesothelioma Patient Registry: Development of Data Collection Tools

Mesothelioma, a cancer of mesothelial cells that line the chest, lungs, heart, and abdomen, is a relatively rare disease. In the United States, approximately 3000 individuals are diagnosed with mesothelioma annually. The primary risk factor for mesothelioma is occupational asbestos exposure which can occur decades prior to disease development, though in approximately 20% of cases, known asbestos exposure is lacking. While several other countries have developed mesothelioma registries to collect key clinical and exposure data elements to allow better estimation of incidence, prevalence, and risk factors associated with disease development, no national mesothelioma registry exists in the U.S. Therefore, as part of a larger feasibility study, a patient exposure questionnaire and a clinical data collection tool were created using a series of key informant interviews. Findings suggest that risk factor and clinical data collection via an on-line questionnaire is feasible, but specific concerns related to confidentiality, in the context of employer responsibility for exposure in the unique U.S. legal environment, and timing of enrollment must be addressed. Lessons learned from piloting these tools will inform the design and implementation of a mesothelioma registry of national scope.

Characteristics Associated With Health Care Worker Knowledge and Confidence in Elastomeric Half-Mask Respirator Use

OBJECTIVE

This study evaluated health care workers' (HCWs') knowledge and confidence in using elastomeric half-mask respirator (EHMR) attributes known to influence usage.

METHODS

Health care workers were surveyed regarding their EHMR donning and doffing experience. Respondents were categorized into competency categories based on their scores. Category differences were analyzed using χ 2 and multiple logistic regression.

RESULTS

Seventy-two percent showed high levels of EHMR donning and doffing knowledge and confidence (mastery); however, 21% had greater confidence than knowledge (misinformed). Respiratory therapists had greater odds of mastery than other HCWs ( P < 0.05), whereas those working in medical/surgical and pediatric units had greater odds of doubt than other HCWs ( P < 0.01).

CONCLUSIONS

Although most HCWs show high knowledge and confidence with EHMR use, strategies to confirm respirator use competency may ensure greater HCWs protection.

Respiratory Protection Perceptions among Malian Health Workers: Insights from the Health Belief Model

Reusable respiratory protective devices called elastomeric respirators have demonstrated their effectiveness and acceptability in well-resourced healthcare settings. Using standard qualitative research methods, we explored the feasibility of elastomeric respirator use in low- and middle-income countries (LMIC). We conducted interviews and focus groups with a convenience sample of health workers at one clinical center in Mali. Participants were users of elastomeric and/or traditional N95 respirators, their supervisors, and program leaders. Interview transcripts of participants were analyzed using a priori constructs from the Health Belief Model (HBM) and a previous study about healthcare respirator use. In addition to HBM constructs, the team identified two additional constructs impacting uptake of respirator use (system-level factors and cultural factors). Together, these framed the perceptions of Malian health workers and highlighted both facilitators of and barriers to respirator use uptake. As needs for respiratory protection from airborne infectious hazards become more commonly recognized, elastomeric respirators may be a sustainable and economic solution for health worker protection in LMIC.

Physiological Impacts of Surgical Mask Coverage of Elastomeric Half-mask Respirator Exhalation Valves in Healthcare Workers

OBJECTIVES

Elastomeric half-mask respirator (EHMR) use in healthcare increased significantly during the COVID-19 pandemic. Concern for potential release of infectious aerosols from EHMR exhalation valves prompted recommendations to cover them with surgical masks (SMs), thereby improving source control. The physiological and subjective effects of wearing a SM over the exhalation valve of an EHMR, however, are unknown.

METHODS

Twelve healthy healthcare worker volunteers completed a 30-min series of simulated healthcare-related tasks, including resting, talking, walking, and bending, proning and supinating a weighted manikin, and performing cardiopulmonary resuscitation. This series recurred three times with different mask configurations-SM only, EHMR only, or EHMR with SM covering the exhalation valve. A transcutaneous sensor continuously measured carbon dioxide (tcPCO2), oxygen saturation (SpO2), and heart rate (HR) from each subject. Subjects scored their rates of perceived exertion (RPE) and levels of discomfort after each round. Physiological parameters and subjective scores were analyzed using mixed linear models with a fixed effect for mask type, activity, age, body mass index (BMI), and gender. Analysis also tested for interaction between mask type and activity.

RESULTS

Physiological parameters remained within normal ranges for all mask configurations but varied by task. Statistically significant but small decreases in mean tcPCO2 (37.17 versus 37.88 mmHg, P < 0.001) and SpO2 (97.74 versus 97.94%, P < 0.001) were associated with wearing EHMR with SM over the exhalation valve compared with EHMR alone. Mean HR did not differ between these mask configurations. Wearing SM only was associated with lower RPE and level of discomfort compared with EHMR, but these subjective scores did not differ when comparing EHMR with SM to EHMR only. Age, BMI, and gender had no significant effect on any outcomes.

CONCLUSIONS

Wearing a SM over an EHMR did not produce clinically significant changes in tcPCO2, SpO2, or HR compared with uncovered EHMR during healthcare-related tasks. Covered EHMR use also did not affect perceived exertion or discomfort compared with uncovered EHMR use. Covering the exhalation valve of an EHMR with a SM for source control purposes can be done safely.

Urine miRNAs as potential biomarkers for systemic reactions induced by exposure to embedded metal

Aim: Explore the potential of urine microRNAs as biomarkers that may reflect the biological responses to pure metals embedded in skeletal muscle over time. Materials & methods: We tested a panel of military-relevant metals embedded in the gastrocnemius muscles of 3-month-old, male, Sprague-Dawley rats (n = 8/group) for a duration of 1, 3, 6 and 12 months, and performed small RNA-sequencing on the urine samples. Results: Results provide potential tissue targets affected by metal exposure and a list of unique or common urine microRNA biomarkers indicative of exposure to various metals, highlighting a complex systemic response. Conclusion: We have identified a panel of miRNAs as potential urine biomarkers to reflect the complex systemic response to embedded metal exposure.

Surveillance of Depleted Uranium-exposed Gulf War Veterans: More Evidence for Bone Effects

ABSTRACT

Gulf War I veterans who were victims of depleted uranium (DU) "friendly-fire" incidents have undergone longitudinal health surveillance since 1994. During the spring of 2019, 36 members of the cohort were evaluated with a monitoring protocol including exposure assessment for total and isotopic uranium concentrations in urine and a comprehensive review of health outcomes, including measures of bone metabolism and bone mineral density (BMD) determination. Elevated urine U concentrations were observed in cohort members with retained depleted uranium (DU) shrapnel fragments. In addition, a measure of bone resorption, N-telopeptide, showed a statistically significant increase in those in the high DU subgroup, a finding consistent with a statistically significant decrease in bone mass also observed in this high DU subgroup compared to the low DU subgroup. After more than 25 y since first exposure to DU, an aging cohort of military veterans continues to show few U-related health effects in known target organs of U toxicity. The new finding of impaired BMD in the high DU subgroup has now been detected in two consecutive surveillance visits. While this is a biologically plausible uranium effect, it is not reflected in other measures of bone metabolism in the full cohort, which have largely been within normal limits. However, ongoing accrual of the U burden from fragment absorption over time and the effect of aging further impairing BMD suggest the need for future surveillance assessments of this cohort.

The Utility of Spot vs 24-Hour Urine Samples for Metal Determination in Veterans With Retained Fragments

OBJECTIVES

The objective of this investigation is to explore the utility of using a spot urine sample in lieu of a 24-hour collection in assessing fragment-related metal exposure in war-injured veterans.

METHODS

Twenty-four veterans collected each urine void over a 24-hour period in separate containers. Concentrations of 13 metals were measured in each void and in a pooled 24-hour sample using inductively coupled plasma mass spectrometry. To assess the reliability of spot sample measures over time, intraclass correlations (ICCs) were calculated across all spot samples. Lin's concordance correlation coefficient was used to assess agreement between a randomly selected spot urine sample and each corresponding 24-hour sample.

RESULTS

In total, 149 spot urine samples were collected. Ten of the 13 metals measured had ICCs more than 0.4, suggesting "fair to good" reliability. Concordance coefficients were more than 0.4 for all metals, suggesting "moderate" agreement between spot and 24-hour concentrations, and more than 0.6 for seven of the 13 metals, suggesting "good" agreement.

CONCLUSIONS

Our fair to good reliability findings, for most metals investigated, and moderate to good agreement findings for all metals, across the range of concentrations observed here, suggest the utility of spot urine samples to obtain valid estimates of exposure in the longitudinal surveillance of metal-exposed populations.

The management of embedded metal fragment patients and the role of chelation Therapy: A workshop of the Department of Veterans Affairs-Walter Reed National Medical Center

Exposure to retained metal fragments from war-related injuries can result in increased systemic metal concentrations, thereby posing potential health risks to target organs far from the site of injury. Given the large number of veterans who have retained fragments and the lack of clear guidance on how to medically manage these individuals, the Department of Veterans Affairs (VA) convened a meeting of chelation experts and clinicians who care for embedded fragment patients to discuss current practices and provide medical management guidance. Based on this group's clinical expertise and review of published literature, the evidence presented suggests that, at least in the case of lead fragments, short-term chelation therapy may be beneficial for embedded fragment patients experiencing acute symptoms associated with metal toxicity; however, in the absence of clinical symptoms or significantly elevated blood lead concentrations (greater than 80 µg/dL), chelation therapy may offer little to no benefit for individuals with retained fragments and pose greater risks due to remobilization of metals stored in bone and other soft tissues. The combination of periodic biomonitoring to assess metal body burden, longitudinal fragment imaging, and selective fragment removal when metal concentrations approach critical injury thresholds offers a more conservative management approach to caring for patients with embedded fragments.

Semen Uranium Concentrations in Depleted Uranium Exposed Gulf War Veterans: Correlations with Other Body Fluid Matrices

Environmental metal exposure, as well as dietary metals, may adversely affect semen quality even as others play an essential role in normal spermatogenesis and fertility. Measures of seminal fluid metals have therefore been of high interest in the last several decades but have shown inconsistent results in correlations with some semen quality parameters. As well, environmental metal measures across various body fluid matrices have not been consistently correlated contrary to what one might hypothesize based on a systemic body burden of metal. This may be due to the body fluid matrices assessed and to other differences in laboratory methods and sample preparation. Measures of uranium, a potentially toxic metal in humans, have not previously been reported in the semen of environmentally metal-exposed populations. We report here uranium seminal fluid results and the high correlation of uranium concentrations across several body fluid matrices in a cohort of military veterans exposed to depleted uranium in combat events during the Iraqi Gulf War. These results inform the risk communication conversation for exposed populations and broaden the public health assessments from various exposure scenarios.

Surveillance results and bone effects in the Gulf War depleted uranium-exposed cohort

A small group of Gulf War I veterans wounded in depleted uranium (DU) friendly-fire incidents have been monitored in a clinical surveillance program since 1993. During the spring of 2017, 42 members of the cohort were evaluated with a protocol which includes exposure monitoring for total and isotopic uranium concentrations in urine and a comprehensive assessment of health outcomes including measures of bone metabolism, and for participants >50 years, bone mineral density (BMD) determination. Elevated urine U concentrations were observed in cohort members with retained DU shrapnel fragments. Only the mean serum estradiol concentration, a marker of bone metabolism, was found to be significantly different for lower-vs- higher urine U (uU) cohort sub-groups. For the first time, a significant deficit in BMD was observed in the over age 50, high uU sub-group. After more than 25 years since first exposure to DU, an aging cohort of military veterans continues to exhibit few U-related adverse health effects in known target organs of U toxicity. The new finding of reduced BMD in older cohort members, while biologically plausible, was not suggested by other measures of bone metabolism in the full (all ages) cohort, as these were predominantly within normal limits over time. Only estradiol was recently found to display a difference as a function of uU grouping. As BMD is further impacted by aging and the U-burden from fragment absorption accrues in this cohort, a U effect may be clarified in future surveillance visits.

Mobilization of Metal From Retained Embedded Fragments in a Blast-Injured Iraq War Veteran

A frequent comorbidity of traumatic injury due to a blast or explosion, commonly reported in Iraq and Afghanistan veterans, is that of retained embedded fragments typically of unknown content. Because of concerns over both local and systemic health effects related to both the physical presence of and mobilization of materials from embedded fragments, the Department of Veterans Affairs established a surveillance program for this group of veterans. We present here the case of a surveillance-enrolled veteran who submitted: (1) three surgically removed fragments for content analyses, (2) tissue adhered to the fragments for histology and metal concentration evaluation, and (3) pre- and postfragment removal urine samples to assess concentrations of various metals often found in fragments. Results indicate that removed fragments were aluminum-copper alloys. Surrounding tissue analyses revealed elevated concentrations of these metals and evidence of chronic inflammation, but no neoplastic changes. Urine aluminum concentrations, initially elevated compared to normal population values, decreased significantly after fragment removal, illustrating the utility of urine biomonitoring to provide insight into fragment composition. A medical surveillance program integrating fragment composition data, tissue analyses, and repeat urine biomonitoring can help inform the patient-specific medical management of both the local and systemic effects of retained metal fragments.

The U.S. Department of Veterans' Affairs depleted uranium exposed cohort at 25 Years: Longitudinal surveillance results

BACKGROUND

A small group of Gulf War I veterans wounded in depleted uranium (DU) friendly-fire incidents have been monitored for health changes in a clinical surveillance program at the Veterans Affairs Medical Center, Baltimore since 1994.

METHODS

During the spring of 2015, an in-patient clinical surveillance protocol was performed on 36 members of the cohort, including exposure monitoring for total and isotopic uranium concentrations in urine and a comprehensive assessment of health outcomes.

RESULTS

On-going mobilization of U from embedded fragments is evidenced by elevated urine U concentrations. The DU isotopic signature is observed principally in participants possessing embedded fragments. Those with only an inhalation exposure have lower urine U concentration and a natural isotopic signature.

CONCLUSIONS

At 25 years since first exposure to DU, an aging cohort of military veterans continues to show no U-related health effects in known target organs of U toxicity. As U body burden continues to accrue from in-situ mobilization from metal fragment depots, and increases with exposure duration, critical tissue-specific U concentration thresholds may be reached, thus recommending on-going surveillance of this veteran cohort.

Mutagenicity monitoring following battlefield exposures: Longitudinal study of HPRT mutations in Gulf War I veterans exposed to depleted uranium

A total of 70 military Veterans have been monitored for HPRT T-cell mutations in five separate studies at 2-year intervals over an 8-year period. Systemic depleted uranium (DU) levels were measured at the time of each study by determining urinary uranium (uU) excretion. Each HPRT study included 30-40 Veterans, several with retained DU-containing shrapnel. Forty-nine Veterans were evaluated in multiple studies, including 14 who were in all five studies. This permitted a characterization of the HPRT mutation assay over time to assess the effects of age, smoking and non-selected cloning efficiencies, as well as the inter- and intra-individual variability across time points. Molecular analyses identified the HPRT mutation and T-cell receptor (TCR) gene rearrangement in 1,377 mutant isolates. An unexpected finding was that in vivo clones of HPRT mutant T-cells were present in some Veterans, and could persist over several years of the study. The calculated HPRT mutant frequencies (MFs) were repeatedly elevated in replicate studies in three outlier Veterans with elevated urinary uranium excretion levels. However, these three outlier Veterans also harbored large and persistent in vivo HPRT mutant T-cell clones, each of which was represented by a single founder mutation. Correction for in vivo clonality allowed calculation of HPRT T-cell mutation frequencies (MutFs). Despite earlier reports of DU associated increases in HPRT MFs in some Veterans, the results presented here demonstrate that HPRT mutations are not increased by systemic DU exposure. Additional battlefield exposures were also evaluated for associations with HPRT mutations and none were found.

Mutagenicity monitoring following battlefield exposures: Molecular analysis of HPRT mutations in Gulf War I veterans exposed to depleted uranium

Molecular studies that involved cDNA and genomic DNA sequencing as well as multiplex PCR of the HPRT gene were performed to determine the molecular mutational spectrum for 1,377 HPRT mutant isolates obtained from 61 Veterans of the 1991 Gulf War, most of whom were exposed to depleted uranium (DU). Mutant colonies were isolated from one to four times from each Veteran (in 2003, 2005, 2007, and/or 2009). The relative frequencies of the various types of mutations (point mutations, deletions, insertions, etc.) were compared between high versus low DU exposed groups, (based on their urine U concentration levels), with HPRT mutant frequency (as determined in the companion paper) and with a database of historic controls. The mutational spectrum includes all classes of gene mutations with no significant differences observed in Veterans related to their DU exposures.

Occupational safety and health protections against Ebola virus disease

Even as the Ebola epidemic is finally showing signs of remitting, controversy continues regarding the modes of disease transmission, the understanding of which necessarily dictates methods of prevention. The initial public health response to the epidemic was based on assumptions formed during previous outbreaks, and in the belief that transmission was restricted to direct "contact" with other infected patients. However, the current Ebola outbreak differed from previous experiences in its intensity of transmission, speed of spread, and fatality rate and was also particularly unforgiving on health workers occupationally infected. Even with these differences, however, other modes of transmission were not considered by public health authorities, thus denying both the hard-hit health worker populations and the wider public more protective guidance. International Labor Conventions require employers to provide a comprehensive safety program that anticipates work-related risks and specifies strategies for protection against them. Such a precautionary approach is recommended in future epidemic planning, especially where evidence regarding transmission is incomplete.

Biologic monitoring and surveillance results for the department of veterans affairs' depleted uranium cohort: Lessons learned from sustained exposure over two decades

BACKGROUND

A small group of Gulf War I veterans wounded in depleted uranium (DU) friendly fire incidents have been monitored in a clinical surveillance program at the Veterans Affairs Medical Center, Baltimore since 1994.

METHODS

An in-patient clinical surveillance protocol was performed on 35 members of the cohort, including exposure monitoring for total and isotopic uranium concentrations in urine and a comprehensive assessment of health outcomes.

RESULTS

Although urine U concentrations continue to be elevated in this group, illustrating on-going in situ mobilization of U from embedded fragments, no consistent U-related health effects have been observed.

CONCLUSIONS

Now more than 20 years since first exposure to DU, an aging cohort of military veterans continues to show no U-related health effects in known target organs of U toxicity. As tissue concentrations continue to accrue with exposure duration, critical tissue-specific U concentration thresholds may be reached, thus recommending on-going surveillance of this veteran cohort.

Children's health in Latin America: the influence of environmental exposures

BACKGROUND

Chronic diseases are increasing among children in Latin America.

OBJECTIVE AND METHODS

To examine environmental risk factors for chronic disease in Latin American children and to develop a strategic initiative for control of these exposures, the World Health Organization (WHO) including the Pan American Health Organization (PAHO), the Collegium Ramazzini, and Latin American scientists reviewed regional and relevant global data.

RESULTS

Industrial development and urbanization are proceeding rapidly in Latin America, and environmental pollution has become widespread. Environmental threats to children's health include traditional hazards such as indoor air pollution and drinking-water contamination; the newer hazards of urban air pollution; toxic chemicals such as lead, asbestos, mercury, arsenic, and pesticides; hazardous and electronic waste; and climate change. The mix of traditional and modern hazards varies greatly across and within countries reflecting industrialization, urbanization, and socioeconomic forces.

CONCLUSIONS

To control environmental threats to children's health in Latin America, WHO, including PAHO, will focus on the most highly prevalent and serious hazards-indoor and outdoor air pollution, water pollution, and toxic chemicals. Strategies for controlling these hazards include developing tracking data on regional trends in children's environmental health (CEH), building a network of Collaborating Centres, promoting biomedical research in CEH, building regional capacity, supporting development of evidence-based prevention policies, studying the economic costs of chronic diseases in children, and developing platforms for dialogue with relevant stakeholders.

Hazards of the health care sector: looking beyond infectious disease

BACKGROUND

Possessing every hazard class, the health care sector poses significant health threats to its workforce in both high-resource settings and low- and middle-income countries (LMICs).

OBJECTIVES

The aim of this paper was to examine the applicability of the classical hierarchy of hazard control technologies in resource-constrained health care settings.

METHODS

Using a biologic and chemical hazard example, the hazard control hierarchy was applied for risk mitigation.

FINDINGS

Even when resource constraints force a reordered selection of hazard control elements, risk reduction can be achieved across a variety of hazard classes.

CONCLUSION

For LMICs with limited resources, the hazard control hierarchy can be effectively employed, although the selection of methods may be reordered, to achieve significant hazard control. Such prevention strategies can thereby strengthen and sustain a critical pillar of the health system, its workforce.

Chromosomal effects of non-alkylating drug exposure in oncology personnel

Therapy-related leukemia has been a recognized sequela of cancer treatment for decades with "signature" abnormalities of chromosomes 5, 7, and 11 observed in treated patients. Risk to oncology personnel handling anti-cancer agents has also been documented by non-specific measures of genotoxicity in blood and urine. Using chromosomal markers applied in clinical practice, we previously demonstrated in oncology workers, a dose-related increase in abnormalities of chromosomes 5 and 7, known to be targets of alkylating agent exposure. In the analysis presented here, we extended that work to also assess damage resulting from non-alkylating drug exposure. Peripheral blood lymphocytes from oncology personnel (N = 63) and non-exposed controls (N = 46) was collected and examined using the fluorescent in situ hybridization technique with probes for targets on chromosomes 5, 7, and 11. Participants recorded drug handling events over a 6 week period. Important co-variates were considered. Examining chromosomal outcomes as a function of drug handling frequency, we employed Poisson Regression to obtain incident rate ratios (IRRs) for selected drug handling frequencies. We found a dose-related increase in the IRR for aberrations in all three chromosomes 5, 7, and 11, reaching statistical significance for chromosome 5, as a function of non-alkylating drug handling. This suggests that the targeting of chromosome 5 is not limited to alkylating agent exposure, as some recent evidence in treated patients has also shown. Thus, the pattern of insult observed in treated patients appears to extend to oncology personnel exposed in the workplace.

Chapter 4 embedded metal fragments

The continued evolution of military munitions and armor on the battlefield, as well as the insurgent use of improvised explosive devices, has led to embedded fragment wounds containing metal and metal mixtures whose long-term toxicologic and carcinogenic properties are not as yet known. Advances in medical care have greatly increased the survival from these types of injuries. Standard surgical guidelines suggest leaving embedded fragments in place, thus individuals may carry these retained metal fragments for the rest of their lives. Nursing professionals will be at the forefront in caring for these wounded individuals, both immediately after the trauma and during the healing and rehabilitation process. Therefore, an understanding of the potential health effects of embedded metal fragment wounds is essential. This review will explore the history of embedded fragment wounds, current research in the field, and Department of Defense and Department of Veterans Affairs guidelines for the identification and long-term monitoring of individuals with embedded fragments.

The Gulf War depleted uranium cohort at 20 years: bioassay results and novel approaches to fragment surveillance

During the 1991 GulfWar, U.S. service members were exposed to depleted uranium (DU) through friendly-fire incidents involving DU munitions and vehicles protected by DU armor. Routes of exposure to DU involved inhalation of soluble and insoluble DU oxide particles, wound contamination, and retained embedded DU metal fragments that continue to oxidize in situ and release DU to the systemic circulation. A biennial health surveillance program established for this group of Veterans by the U.S. Department of Veterans Affairs has shown continuously elevated urine DU concentrations in the subset of veterans with embedded fragments for over 20 years. While the 2011 assessment was comprehensive, few clinically significant U-related health effects were observed. This report is focused on health outcomes associated with two primary target organs of concern for long term effects of this combat-related exposure to DU. Renal biomarkers showed minimal DU-related effects on proximal tubule function and cytotoxicity, but significant biomarker results were observed when urine concentrations of multiple metals also found in fragments were examined together. Pulmonary tests and questionnaire results indicate that pulmonary function after 20 y remains within the clinical normal range. Imaging of DU embedded fragment-associated tissue for signs of inflammatory or proliferative reactions possibly associated with foreign body transformation or with local alpha emissions from DU was also conducted using PET-CT and ultrasound. These imaging tools may be helpful in guiding decisions regarding removal of fragments.

Uranium quantification in semen by inductively coupled plasma mass spectrometry

In this study we report uranium analysis for human semen samples. Uranium quantification was performed by inductively coupled plasma mass spectrometry. No additives, such as chymotrypsin or bovine serum albumin, were used for semen liquefaction, as they showed significant uranium content. For method validation we spiked 2g aliquots of pooled control semen at three different levels of uranium: low at 5 pg/g, medium at 50 pg/g, and high at 1000 pg/g. The detection limit was determined to be 0.8 pg/g uranium in human semen. The data reproduced within 1.4-7% RSD and spike recoveries were 97-100%. The uranium level of the unspiked, pooled control semen was 2.9 pg/g of semen (n=10). In addition six semen samples from a cohort of Veterans exposed to depleted uranium (DU) in the 1991 Gulf War were analyzed with no knowledge of their exposure history. Uranium levels in the Veterans' semen samples ranged from undetectable (<0.8 pg/g) to 3350 pg/g. This wide concentration range for uranium in semen is consistent with known differences in current DU body burdens in these individuals, some of whom have retained embedded DU fragments.

Measures of genotoxicity in Gulf war I veterans exposed to depleted uranium

Exposure to depleted uranium (DU), an alpha-emitting heavy metal, has prompted the inclusion of markers of genotoxicity in the long-term medical surveillance of a cohort of DU-exposed Gulf War veterans followed since 1994. Using urine U (uU) concentration as the measure of U body burden, the cohort has been stratified into low-u (<0.10 μg U/g creatinine) and high-u groups (≥ 0.10 μg U/g creatinine). Surveillance outcomes for this cohort have historically included markers of mutagenicity and clastogenicity, with past results showing generally nonsignificant differences between low- vs. high-U groups. However, mean hypoxanthine-guanine phosphoribosyl transferase (HPRT) mutant frequencies (MFs) have been almost 50% higher in the high-U group. We report here results of a more comprehensive protocol performed in a 2009 evaluation of a subgroup (N = 35) of this cohort. Four biomarkers of genotoxicity [micronuclei (MN), chromosome aberrations, and MFs of HPRT and PIGA] were examined. There were no statistically significant differences in any outcome measure when results were compared between the low- vs. high-U groups. However, modeling of the HPRT MF results suggests a possible threshold effect for MFs occurring in the highest U exposed cohort members. Mutational spectral analysis of HPRT mutations is underway to clarify a potential clonal vs. a threshold uU effect to explain this observation. This study provides a comprehensive evaluation of a human population chronically exposed to DU and demonstrates a relatively weak genotoxic effect of the DU exposure. These results may explain the lack of clear epidemiologic evidence for U carcinogenicity in humans. Environ. Mol. Mutagen., 2011. © 2011 Wiley-Liss, Inc.

Patch testing with uranyl acetate in veterans exposed to depleted uranium during the 1991 Gulf war and the Iraqi conflict

BACKGROUND

The Depleted Uranium Follow-Up Program is a clinical surveillance program run by the Baltimore Veterans Affairs Medical Center since 1993 for veterans of the Gulf and Iraqi wars who were exposed to depleted uranium (DU) as a result of "friendly-fire" incidents.

OBJECTIVES AND METHODS

In 2009, 40 veterans from this cohort were screened for skin reactivity to metals by patch-testing with extended metal series and uranyl acetate (0.25%, 2.5%, and 25%). A control arm comprised 46 patients without any known occupational exposures to DU who were seen at the University of Maryland Dermatology Clinic for evaluation of allergic contact dermatitis.

RESULTS

Excluding irritant reactions, no patch-test reactions to uranyl acetate were observed in the participants. Irritant reactions to DU were more common in the clinic cohort, likely reflective of the demographic differences between the two arms of the study. Biologic monitoring of urine uranium concentrations in the DU program participants with 24-hour urine samples showed evidence of percutaneous uranium absorption from the skin patches.

CONCLUSION

We conclude that dermatitis observed in a subset of the veterans was unrelated to their military DU exposure. Our data suggest that future studies of skin testing with uranyl acetate should utilize 0.25%, the least irritating concentration.

Longitudinal health surveillance in a cohort of Gulf War veterans 18 years after first exposure to depleted uranium

As part of a longitudinal surveillance program, 35 members of a larger dynamic cohort of 79 Gulf War I veterans exposed to depleted uranium (DU) during combat underwent clinical evaluation at the Baltimore Veterans Administration Medical Center. Health outcomes and biomonitoring results were obtained to assess effects of DU exposure and determine the need for additional medical intervention. Clinical evaluation included medical and exposure histories, physical examination, and laboratory studies including biomarkers of uranium (U) exposure. Urine collections were obtained for U analysis and to measure renal function parameters. Other laboratory measures included basic hematology and chemistry parameters, blood and plasma U concentrations, and markers of bone metabolism. Urine U (uU) excretion remained above normal in participants with embedded DU fragments, with urine U concentrations ranging from 0.006 to 1.88 μg U/g creatinine. Biomarkers of renal effects showed no apparent evidence of renal functional changes or cellular toxicity related to U body burden. No marked differences in markers of bone formation or bone resorption were observed; however, a statistically significant decrease in levels of serum intact parathyroid hormone and significant increases in urinary calcium and sodium excretion were seen in the high versus the low uU groups. Eighteen years after first exposure, members of this cohort with DU fragments continue to excrete elevated concentrations of uU. No significant evidence of clinically important changes was observed in kidney or bone, the two principal target organs of U. Continued surveillance is prudent, however, due to the ongoing mobilization of uranium from fragment depots.

Biological monitoring for depleted uranium exposure in U.S. Veterans

BACKGROUND

As part of an ongoing medical surveillance program for U.S. veterans exposed to depleted uranium (DU), biological monitoring of urine uranium (U) concentrations is offered to any veteran of the Gulf War and those serving in more recent conflicts (post-Gulf War veterans).

OBJECTIVES

Since a previous report of surveillance findings in 2004, an improved methodology for determination of the isotopic ratio of U in urine ((235)U:(238)U) has been developed and allows for more definitive evaluation of DU exposure. This report updates previous findings.

METHODS

Veterans provide a 24-hr urine specimen and complete a DU exposure questionnaire. Specimens are sent to the Baltimore Veterans Affairs Medical Center for processing. Uranium concentration and isotopic ratio are measured using ICP-MS at the Armed Forces Institute of Pathology.

RESULTS

Between January 2003 and June 2008, we received 1,769 urine specimens for U analysis. The mean urine U measure was 0.009 microg U/g creatinine. Mean urine U concentrations for Gulf War and post-Gulf War veterans were 0.008 and 0.009 microg U/g creatinine, respectively. Only 3 of the 1,700 (0.01%) specimens for which we completed isotopic determination showed evidence of DU. Exposure histories confirmed that these three individuals had been involved in "friendly fire" incidents involving DU munitions or armored vehicles.

CONCLUSIONS

No urine U measure with a "depleted" isotopic signature has been detected in U.S. veterans without a history of retained DU embedded fragments from previous injury. These findings suggest that future DU-related health harm is unlikely in veterans without DU fragments.

Surveillance results of depleted uranium-exposed Gulf War I veterans: sixteen years of follow-up

As part of a longitudinal surveillance program, 35 members of a larger cohort of 77 Gulf War I veterans who were victims of depleted uranium (DU) "friendly fire" during combat underwent a 3-day clinical assessment at the Baltimore Veterans Administration Medical Center (VAMC). The assessment included a detailed medical history, exposure history, physical examination, and laboratory studies. Spot and 24-h urine collections were obtained for renal function parameters and for urine uranium (U) measures. Blood U measures were also performed. Urine U excretion was significantly associated with DU retained shrapnel burden (8.821 mug U/g creatinine [creat.] vs. 0.005 mug U/g creat., p = .04). Blood as a U sampling matrix revealed satisfactory results for measures of total U with a high correlation with urine U results (r = .84) when urine U concentrations were >/=0.1 mug/g creatinine. However, isotopic results in blood detected DU in only half of the subcohort who had isotopic signatures for DU detectable in urine. After stratifying the cohort based on urine U concentration, the high-U group showed a trend toward higher concentrations of urine beta(2) microglobulin compared to the low-U group (81.7 v. 69.0 mug/g creat.; p = .11 respectively) and retinol binding protein (48.1 vs. 31.0 mug/g creat.; p = .07 respectively). Bone metabolism parameters showed only subtle differences between groups. Sixteen years after first exposure, this cohort continues to excrete elevated concentrations of urine U as a function of DU shrapnel burden. Although subtle trends emerge in renal proximal tubular function and bone formation, the cohort exhibits few clinically significant U-related health effects.

The clinical content of preconception care: the use of medications and supplements among women of reproductive age

The use of prescription and over-the-counter medications and dietary supplements are common among women of reproductive age. For medications, little information about the teratogenic risks or safety is available, as pregnant women are traditionally excluded from clinical trials, and premarketing animal studies do not necessarily predict the effects of treatment in human pregnancy. Even less is typically known about the effects of dietary supplements on pregnancy outcomes, as they are not held to the same rigorous safety and efficacy standards as prescription medications. Congenital anomalies associated with medication use are potentially preventable, because they are linked with modifiable maternal exposures during the period of organogenesis. However, as women of reproductive age experience acute and chronic conditions that can result in adverse outcomes for the woman and her offspring, the benefits of use of a particular medication before or early in pregnancy may outweigh the risks. Resources and principles outlined in this article will aid healthcare providers in selecting appropriate medication regimens for women of reproductive age, particularly those with chronic health conditions, those who are planning a pregnancy, and those who may become pregnant.

The clinical content of preconception care: environmental exposures

Environmental origins of disease risk and harm to health have been increasingly acknowledged for numerous outcomes, in both adult and pediatric populations. Adverse reproductive and developmental effects have also been linked to environmental exposures. In addition to the current queries about a patient's alcohol and smoking history, key determinants of a future pregnancy outcome should also be elicited during the preconception visit. These determinants include: (1) mercury intake via fish consumption; (2) nitrate exposure from well water sources; (3) exposure to chemical, physical, or biologic hazards on the job; and (4) lead and other toxic exposures--possibly from hobbies or the use of lead-glazed dinnerware in the home. Eliciting a detailed environmental history permits tailored recommendations to optimize the woman's health and that of her future pregnancy.

Health surveillance of Gulf War I veterans exposed to depleted uranium: updating the cohort

A cohort of seventy-four 1991 Gulf War soldiers with known exposure to depleted uranium (DU) resulting from their involvement in friendly-fire incidents with DU munitions is being followed by the Baltimore Veterans Affairs Medical Center. Biennial medical surveillance visits designed to identify uranium-related changes in health have been conducted since 1993. On-going systemic exposure to DU in veterans with embedded metal fragments is indicated by elevated urine uranium (U) excretion at concentrations up to 1,000-fold higher than that seen in the normal population. Health outcome results from the subcohort of this group of veterans attending the 2005 surveillance visit were examined based on two measures of U exposure. As in previous years, current U exposure is measured by determining urine U concentration at the time of their surveillance visit. A cumulative measure of U exposure was also calculated based on each veteran's past urine U concentrations since first exposure in 1991. Using either exposure metric, results continued to show no evidence of clinically significant DU-related health effects. Urine concentrations of retinol binding protein (RBP), a biomarker of renal proximal tubule function, were not significantly different between the low vs. high U groups based on either the current or cumulative exposure metric. Continued evidence of a weak genotoxic effect from the on-going DU exposure as measured at the HPRT (hypoxanthine-guanine phosphoribosyl transferase) locus and suggested by the fluorescent in-situ hybridization (FISH) results in peripheral blood recommends the need for continued surveillance of this population.

Preventing occupational exposures to antineoplastic drugs in health care settings

The toxicity of antineoplastic drugs has been well known since they were introduced in the 1940s. Because most antineoplastic drugs are nonselective in their mechanism of action, they affect noncancerous as well as cancerous cells, resulting in well-documented side effects. During the 1970s, evidence came to light indicating health care workers may be at risk of harmful effects from antineoplastic drugs as a result of occupational exposure. Since that time, reports from several countries have documented drug contamination of the workplace, identified drugs in the urine of health care workers, and measured genotoxic responses in workers. Evidence also exists of teratogenic and adverse reproductive outcomes and increased cancers in health care workers. During the past 30 years, professional organizations and government agencies have developed guidelines to protect health care workers from adverse effects from occupational exposure to antineoplastic drugs. Although many safety provisions were advanced to reduce worker exposure in the 1980s, recent studies have shown that workers continue to be exposed to these drugs despite safety policy improvements. In 2004, the National Institute for Occupational Safety and Health (NIOSH) published an alert reviewing the most recent information available and promoting a program of safe handling during their use.

Chemical Hazards in Health Care: High Hazard, High Risk, but Low Protection

It is counter-intuitive that the healthcare industry, whose mission is the care of the sick, is itself a "high-hazard" industry for the workers it employs. Possessing every hazard class, with chemical agents in the form of pharmaceuticals, sterilants, and germicidals in frequent use, this industry sector consistently demonstrates poor injury and illness statistics, among the highest in the United States, and in the European Union (EU), 34% higher than the average work-related accident rate. In both the United States and the EU, about 10% of all workers are employed in the healthcare sector, and in developing countries as well, forecasts for the increasing need of healthcare workers (HCW) suggests a large population at potential risk of health harm. The explosion of technology growth in the healthcare sector, most obvious in pharmaceutical applications, has not been accompanied by a stepped up safety program in hospitals. Where there is hazard recognition, the remedies are often voluntary, and often poorly enforced. The wrong assumption that this industry would police itself, given its presumed knowledge base, has also been found wanting. The healthcare industry is also a significant waste generator threatening the natural environment with chemical and infectious waste and products of incineration. The ILO has recommended that occupational health goals for industrial nations focus on the hazards of new technology of which pharma and biopharma products are the leaders. This unchecked growth cannot continue without a parallel commitment to the health and safety of workers encountering these "high tech" hazards. Simple strategies to improve the present state include: (a) recognizing healthcare as a "high-hazard" employment sector; (b) fortifying voluntary safety guidelines to the level of enforceable regulation; (c) "potent" inspections; (d) treating hazardous pharmaceuticals like the chemical toxicants they are; and (e) protecting HCWs at least as well as workers in other high-hazard sectors.

Preconception brief: occupational/environmental exposures

In the last decade, more than half of U.S. children were born to working mothers and 65% of working men and women were of reproductive age. In 2004 more than 28 million women age 18–44 were employed full time. This implies the need for clinicians to possess an awareness about the impact of work on the health of their patients and their future offspring. Most chemicals in the workplace have not been evaluated for reproductive toxicity, and where exposure limits do exist, they were generally not designed to mitigate reproductive risk. Therefore, many toxicants with unambiguous reproductive and developmental effects are still in regular commercial or therapeutic use and thus present exposure potential to workers. Examples of these include heavy metals, (lead, cadmium), organic solvents (glycol ethers, percholoroethylene), pesticides and herbicides (ethylene dibromide) and sterilants, anesthetic gases and anti-cancer drugs used in healthcare. Surprisingly, many of these reproductive toxicants are well represented in traditional employment sectors of women, such as healthcare and cosmetology. Environmental exposures also figure prominently in evaluating a woman’s health risk and that to a pregnancy. Food and water quality and pesticide and solvent usage are increasingly topics raised by women and men contemplating pregnancy. The microenvironment of a woman, such as her choices of hobbies and leisure time activities also come into play. Caregivers must be aware of their patients’ potential environmental and workplace exposures and weigh any risk of exposure in the context of the time-dependent window of reproductive susceptibility. This will allow informed decision-making about the need for changes in behavior, diet, hobbies or the need for added protections on the job or alternative duty assignment. Examples of such environmental and occupational history elements will be presented together with counseling strategies for the clinician.

Depleted uranium exposure and health effects in Gulf War veterans

Health effects stemming from depleted uranium (DU) exposure in a cohort of Gulf War veterans who were in or on US Army vehicles hit by friendly fire involving DU munitions are being carefully monitored through the Baltimore Veterans Affairs (VA) DU Follow-Up Program initiated in 1993. DU exposure in this cohort has been directly measured using inductively coupled plasma-mass spectrometer (ICP-MS) isotopic analysis for DU in urine specimens. Soldiers with embedded DU fragments continue to excrete elevated concentrations of U in their urine, documenting ongoing systemic exposure to U released from their fragments. Biennial surveillance visits provide a detailed health assessment that includes basic clinical measures and surveillance for early changes in kidney function, an expected target organ for U. Tests also include measurements of genotoxicity and neuroendocrine, neurocognitive and reproductive function. With the exception of the elevated urine U excretion, no clinically significant expected U-related health effects have been identified to date. Subtle changes in renal function and genotoxicity markers in veterans with urine U concentrations greater than 0.1 microg(-1) creatinine, however, indicate the need for continued surveillance of these DU-exposed veterans.