Shift Work and Sleep Disturbance in the Oil Industry.

BACKGROUND: Rotating shift work is common in high-hazard industries, despite documented associations with sleep disturbance and impairment. In the oil industry, where rotating and extended shift schedules are used to staff safety-sensitive positions, work intensification and increasing overtime rates have been broadly documented over the last few decades. Research on the impacts of these work schedules on sleep and health has been limited for this workforce. METHODS: We examined sleep duration and quality among rotating shift workers in the oil industry and explored associations between schedule characteristics, sleep, and health outcomes. We recruited hourly refinery workers from the West and Gulf Coast oil sector members of the United Steelworkers union. FINDINGS: Impaired sleep quality and short sleep durations were common and associated with health and mental health outcomes common among shift workers. Shortest sleep durations followed shift rotations. Early rise and start times were associated with shorter sleep duration and poorer sleep quality. Drowsiness and fatigue-related incidents were common. CONCLUSION/APPLICATION TO PRACTICE: We observed lower sleep duration and quality and increased overtime in 12-hour rotating shift schedules. These long workdays with early start times may reduce available hours for quality sleep; here they were associated with reduced exercise and leisure activity which correlated with good sleep. This safety-sensitive population appears severely impacted by poor sleep quality, which has broader implications for process safety management. Later start times, slower rotation, and a reconsideration of two-shift schedules are interventions to consider for improving sleep quality among rotating shift workers.

An analysis of prenatal exposure factors and offspring health outcomes in rodents from synthesized nanoparticles.

Over the past several decades the industry involving nanotechnology has developed at a rapid pace, increasing global human exposure to synthesized nanoparticles (NPs). A consensus within toxicology on the effect of synthesized NPs to human health has yet to be reached, and little is known about the NPs developmental toxicology to organisms exposed in utero. This review aimed to identify the current state of in vivo prenatal NP toxicology literature and to provide an overview of several influential factors on offspring exposure and health outcomes. Scientific peer-reviewed literature was identified through PubMed, Web of Science, and Google Scholar database searches using combinations of keywords relevant to prenatal NP exposure. The 220 articles yielded from the database search were screened for inclusion and exclusion criteria, and 37 articles were included in the final analysis. Across selected literature, eight NP materials and eight exposure routes were identified. Pregnant murine dams were exposed to NPs throughout the entire gestational period, and some studies expanded exposure durations into preconception or postnatal periods. The average particle size across all exposure routes was 27.03 nm, although aerosolized agglomerates and cellular uptake where not accounted for. Thirty-five studies reported significant adverse effects on offspring after birth, where abnormalities of the nervous system were most commonly reported. Although current literature suggests a biological plausibility for prenatal NP toxicity, the lack of standardized methodology and diverse endpoints contribute to the continued ambiguity as to the attributable risks of individual exposure factors on health outcomes and mechanisms of cellular toxicity.

Metal(loid)s in Cucurbita pepo in a Uranium Mining Impacted Area in Northwestern New Mexico, USA.

More than 500 unreclaimed mines and associated waste sites exist on the Navajo Nation reservation as a result of uranium (U) mining from the 1940s through the 1980s. For this study, the impact of U-mine waste on a common, locally grown crop food was examined. The goal of this site-specific study was to determine metal(loid) concentration levels of arsenic (As), cadmium (Cd), cesium (Cs), molybdenum (Mo), lead (Pb), thorium (Th), U, vanadium (V) and selenium (Se) in Cucurbita pepo Linnaeus (squash), irrigation water, and soil using inductively coupled plasma-mass spectrometry. The concentrations of metal(loid)s were greatest in roots > leaves > edible fruit (p < 0.05), respectively. There were significant differences between metal(loid)s in squash crop plot usage (<5 years versus >30 years) for V (p = 0.001), As (p < 0.001), U (p = 0.002), Cs (p = 0.012), Th (p = 0.040), Mo (p = 0.047), and Cd (p = 0.042). Lead and Cd crop irrigation water concentrations exceeded the United States Environmental Protection Agency (USEPA) Maximum Contaminant Levels for drinking water for those metals. Edible squash concentration levels were 0.116 mg/kg of As, 0.248 mg/kg of Pb, 0.020 mg/kg of Cd, and 0.006 mg/kg of U. Calculated human ingestion of edible squash did not exceed Provisional Tolerable Weekly Intake or Tolerable Upper Limit levels from intake based solely on squash consumption. There does not appear to be a food-ingestion risk from metal(loid)s solely from consumption of squash. Safer access and emphasis on consuming regulated water was highlighted. Food intake recommendations were provided. Continued monitoring, surveillance, and further research are recommended.

Understanding the Workplace Interactions of Young Adult Cancer Survivors With Occupational and Environmental Health Professionals.

Work provides satisfaction and stability to young adult cancer survivors. However, progressive health changes because of cancer may compromise safety and diminish functional ability. The purpose of this study was to describe long-term young adult cancer survivors' work experiences and describe their interactions with occupational and environmental health professionals (OEHPs) within the workplace. Cancer survivors were recruited from the Los Angeles County Cancer Surveillance Program. Professional organizations provided access to OEHPs. Constructivist grounded theory guided individual semi-structured interviews during data collection and analysis. Processes of interaction between cancer survivors and OEHPs found to influence work included revealing the survivor-self, sustaining work ability, gatekeeping (employment opportunities, return to work), and accessing support. OEHPs appeared to facilitate survivors' work ability in the long term if services were available, services were known to survivors, and survivors revealed needs. Educating workers about OEHP services throughout cancer experiences and survivorship could ultimately improve interactivity and provide supportive work environments.

Association of Spontaneous Preterm Delivery and Future Maternal Cardiovascular Disease.

Cardiovascular disease (CVD) risk factors are well established. However, little is known about a woman's cardiovascular response to pregnancy, which appears to be an early marker of future maternal CVD risk. Spontaneous preterm delivery (sPTD) has been associated with a ≤3-fold increased risk of maternal CVD death later in life compared with having a term delivery. This review focuses on 3 key areas to critically assess the association of sPTD and future maternal CVD risk: (1) CVD risk factors, (2) inflammatory biomarkers of interest, and (3) specific forms of vascular dysfunction, such as endothelial function and arterial stiffness, and mechanisms by which each may be linked to sPTD. The association of sPTD with subsequent future maternal CVD risk suggests that a woman's abnormal response to pregnancy may serve as her first physiological stress test. These findings suggest that future research is needed to understand why women with sPTD may be at risk for CVD to implement effective interventions earlier in a woman's life.

Uranium and Associated Heavy Metals in Ovis aries in a Mining Impacted Area in Northwestern New Mexico.

The objective of this study was to determine uranium (U) and other heavy metal (HM) concentrations (As, Cd, Pb, Mo, and Se) in tissue samples collected from sheep (Ovis aries), the primary meat staple on the Navajo reservation in northwestern New Mexico. The study setting was a prime target of U mining, where more than 1100 unreclaimed abandoned U mines and structures remain. The forage and water sources for the sheep in this study were located within 3.2 km of abandoned U mines and structures. Tissue samples from sheep (n = 3), their local forage grasses (n = 24), soil (n = 24), and drinking water (n = 14) sources were collected. The samples were analyzed using Inductively Coupled Plasma-Mass Spectrometry. Results: In general, HMs concentrated more in the roots of forage compared to the above ground parts. The sheep forage samples fell below the National Research Council maximum tolerable concentration (5 mg/kg). The bioaccumulation factor ratio was >1 in several forage samples, ranging from 1.12 to 16.86 for Mo, Cd, and Se. The study findings showed that the concentrations of HMs were greatest in the liver and kidneys. Of the calculated human intake, Se Reference Dietary Intake and Mo Recommended Dietary Allowance were exceeded, but the tolerable upper limits for both were not exceeded. Food intake recommendations informed by research are needed for individuals especially those that may be more sensitive to HMs. Further study with larger sample sizes is needed to explore other impacted communities across the reservation.

Young adult cancer survivors and work: a systematic review.

CONTEXT: Sixty-three percent of cancer survivors continue to work, or return to work after treatment. Among this population, work ability and challenges encountered in the workplace by young adult cancer survivors have not been well established. PURPOSE: The purposes of the study are to describe what is currently known about work-related issues for young adult cancer survivors diagnosed between ages 15 and 39, to identify gaps in the research literature, and to suggest interventions or improvements in work processes and occupational settings. METHODS: A narrative review of articles using PubMed, CINAHL, and PsychInfo was conducted without date limitations. Search phrases included young adult cancer survivors, long-term cancer survivors, young adults affected by cancer, further combined with key terms employment, work, and occupationally active. Inclusion criteria for publications were young adult cancer survivors initially diagnosed between the ages of 15 and 39, data about work or employment was presented, and articles written in English. RESULTS: Twenty-three publications met the inclusion criteria. Work-related issues included the potential for reduced work productivity from cancer-changed physical and cognitive functional ability that affected income, and resulted in distress. Coping style, support systems, and changing perspectives about work and life in general were also influential on career decisions among young adult cancer survivors. CONCLUSIONS: More research is needed to study interventions to better manage health changes in young adult cancer survivors within the context of the workplace. Since financial hardship has been shown to be especially high among young cancer survivors, employment is essential to ensure payment of cancer-associated costs and continued medical care. IMPLICATIONS FOR CANCER SURVIVORS: While young adult cancer survivors may initially grapple with cancer-related physical and psychosocial changes that impact work productivity or influence choice of occupation, employment appears to enhance overall quality of life.

Health Effects of Vanpooling to Work.

Shared commutes to work, such as vanpooling, benefit the environment and provide economic gain for riders in terms of fuel costs, parking fees, and personal vehicle wear and tear. Although ride sharing is commonly believed to promote health through stress reduction, published evidence on this topic is limited, and findings vary. This study explored the perceived health and well-being of vanpoolers using a qualitative, descriptive design. Five focus groups of vanpoolers and two individual interviews with drivers were conducted (N=40 participants). Stress, change in sleep patterns, and interpersonal relationships emerged as major themes. Employee insights about the impact of vanpooling on work productivity and how employer commitment to the vanpool program influences the vanpool experience also were important findings.

Environmental hexachlorobenzene exposure and human male reproductive function.

Hexachlorobenzene (HCB) is a persistent environmental fungicide that may disrupt androgen regulation. The aim of this study was to investigate associations between HCB levels and biomarkers of male reproductive function. 589 Spouses of pregnant women from Greenland, Poland and Ukraine were enrolled between 2002 and 2004. The men provided semen and blood samples and were interviewed. HCB was measured in serum by gas chromatography. The mean serum concentrations of HCB were higher in Ukraine (182.3ng/g lipid) and Greenland (79.0ng/g lipid) compared to Poland (14.2ng/g lipid). Sex hormone binding globulin (SHBG) and free androgen index (FAI) were associated with HCB in men from Ukraine and Poland. This study spanning large differences in environmental HCB exposure levels shows a positive association for SHBG and negative association for FAI with high serum levels of HCB in fertile men, but without major consequences for semen quality and the Inuit study population.

Harnessing genomics to identify environmental determinants of heritable disease.

Next-generation sequencing technologies can now be used to directly measure heritable de novo DNA sequence mutations in humans. However, these techniques have not been used to examine environmental factors that induce such mutations and their associated diseases. To address this issue, a working group on environmentally induced germline mutation analysis (ENIGMA) met in October 2011 to propose the necessary foundational studies, which include sequencing of parent-offspring trios from highly exposed human populations, and controlled dose-response experiments in animals. These studies will establish background levels of variability in germline mutation rates and identify environmental agents that influence these rates and heritable disease. Guidance for the types of exposures to examine come from rodent studies that have identified agents such as cancer chemotherapeutic drugs, ionizing radiation, cigarette smoke, and air pollution as germ-cell mutagens. Research is urgently needed to establish the health consequences of parental exposures on subsequent generations.

Walnuts improve semen quality in men consuming a Western-style diet: randomized control dietary intervention trial.

We tested the hypothesis that 75 g of whole-shelled walnuts/day added to the Western-style diet of healthy young men would beneficially affect semen quality. A randomized, parallel two-group dietary intervention trial with single-blind masking of outcome assessors was conducted with 117 healthy men, age 21-35 yr old, who routinely consumed a Western-style diet. The primary outcome was improvement in conventional semen parameters and sperm aneuploidy from baseline to 12 wk. Secondary endpoints included blood serum and sperm fatty acid (FA) profiles, sex hormones, and serum folate. The group consuming walnuts (n = 59) experienced improvement in sperm vitality, motility, and morphology, but no change was seen in the group continuing their usual diet but avoiding tree nuts (n = 58). Comparing differences between the groups from baseline, significance was found for vitality (P = 0.003), motility (P = 0.009), and morphology (normal forms; P = 0.04). Serum FA profiles improved in the walnut group with increases in omega-6 (P = 0.0004) and omega-3 (P = 0.0007) but not in the control group. The plant source of omega-3, alpha-linolenic acid (ALA) increased (P = 0.0001). Sperm aneuploidy was inversely correlated with sperm ALA, particularly sex chromosome nullisomy (Spearman correlation, -0.41, P = 0.002). Findings demonstrated that walnuts added to a Western-style diet improved sperm vitality, motility, and morphology.

Reproductive hormones and interleukin-6 in serious leisure male athletes.

Lifestyles associated with different types and intensities of exercise result in improved health including positive changes in chronic low-grade inflammatory biomarkers. Alternatively, some forms of exercise adversely affect reproductive health of men, including changes in circulating reproductive hormones. To explore the associations between exercise intensity and circulating levels of reproductive hormones, and inflammatory analytes in serious leisure athletes (triathletes and cyclists) and recreational athletes. Male athletes 18-60 years old, 16 triathletes, 46 cyclists and 45 recreational athletes, were recruited to provide plasma for the measurement of total testosterone, estradiol, follicular stimulating hormone, luteinizing hormone (LH), sex hormone-binding globulin (SHBG), cortisol, interleukin-6 (IL-6), and interleukin-1ß (IL-1ß) levels, and calculation of free androgen index (FAI) and the estradiol:SHBG ratio (ESR). Plasma estradiol concentrations were more than two times higher in cyclists than in triathletes and recreational athletes (p < 0.01). Testosterone levels were also higher in cyclists than recreational athletes (p < 0.01), but not significantly different from triathletes. SHBG levels were higher in triathletes and cyclists than in recreational athletes (p < 0.01). LH levels were lower in cyclists than in recreational athletes (p < 0.05). IL-6 and IL-1ß levels were each two times lower in triathletes than in cyclists (p < 0.05) and IL-6 levels were lower in cyclists than in recreational athletes (p < 0.01). IL-1ß levels were two times lower in triathletes than in cyclists (p < 0.05). Circulating estradiol and testosterone levels were elevated in serious leisure male cyclists. This effect is discussed in light in the absence of a substantial concomitant change in gonadotropin levels and other variables.

A hierarchical zero-inflated log-normal model for skewed responses.

Although considerable attention has been given to zero-inflated count data, research on zero-inflated lognormal data is limited. In this article, we consider a study to examine human sperm cell DNA damage obtained from single-cell electrophoresis (COMET assay) experiment in which the outcome measures present a typical example of log-normal data with excess zeros. The problem is further complicated by the fact that each study subject has multiple outcomes at each of up to three visits separated by six-week intervals. Previous methods for zero-inflated log-normal data are based on either simple experimental designs, where comparison of means of zero-inflated log-normal data across different experiment groups is of primary interest, or longitudinal measurements, where only one observation is available for each subject at each visit. Their methods cannot be applied when multiple observations per visit are possible and both inter- and intra-subject variations are present. Our zero-inflated model extends the previous methods by incorporating a hierarchical structure using latent random variables to take into account both inter- and intra-subject variations in zero-inflated log-normal data. An EM algorithm has been developed to obtain the Maximum likelihood estimates of the parameters and their standard errors can be estimated by parametric bootstrap. The model is illustrated using the COMET assay data.

Chronic boron exposure and human semen parameters.

Boron found as borates in soil, food, and water has important industrial and medical applications. A panel reviewing NTP reproductive toxicants identified boric acid as high priority for occupational studies to determine safe versus adverse reproductive effects. To address this, we collected boron exposure/dose measures in workplace inhalable dust, dietary food/fluids, blood, semen, and urine from boron workers and two comparison worker groups (n=192) over three months and determined correlations between boron and semen parameters (total sperm count, sperm concentration, motility, morphology, DNA breakage, apoptosis and aneuploidy). Blood boron averaged 499.2 ppb for boron workers, 96.1 and 47.9 ppb for workers from high and low environmental boron areas (p<0.0001). Boron concentrated in seminal fluid. No significant correlations were found between blood or urine boron and adverse semen parameters. Exposures did not reach those causing adverse effects published in animal toxicology work but exceeded those previously published for boron occupational groups.

Y:X sperm ratio in boron-exposed men.

Several epidemiologic investigations have shown shifts in sex ratios at birth toward females in populations with relatively high boron exposure. To investigate the paternal origin of these shifts, we assayed sperm Y:X ratio in men exposed to a range of environmental and workplace boron. Participants included 63 workers in boron industry: 39 men living in an area of high environmental boron but not employed in boron industry, and 44 controls living in an area of low environmental boron. Total daily boron exposure was calculated as the sum of boron in 24-hour duplicate food and fluid intakes plus personal air sampling for workplace inhalable dust. Internal dose was measured in blood, urine, and semen. Sperm were analyzed by fluorescence in situ hybridization for Y- versus X-bearing cells. Potential confounders were identified using a questionnaire. Total exposure was correlated with internal dose (Pearson correlation for total exposure and boron in blood = 0.63, P < .0001; semen = 0.80, P < .001; and urine = 0.79, P < .0001). Linear regression of logged boron in biologic fluids on Y:X ratio was significant for blood P = .02, semen P = .0003, and urine P = .005. Additionally, when subjects were categorized by exposure group, decreased Y:X sperm ratio was found for boron workers compared with men in a high boron environment and controls (P < .0001). Exogenous environmental or workplace boron exposures were associated with decreases in Y- versus X-bearing sperm. This may explain earlier findings from us and others showing changes in offspring sex ratios at birth for men exposed to boron.

Boron workers in China: exploring work and lifestyle factors related to boron exposure.

This article describes the lifestyle patterns of boron mining and processing workers (N=936) and a comparison group (N=251) in northeast China, and explores relationships between boron exposure and reproductive health. An English version of an interview guide addressing areas of work and lifestyle relevant to boron exposure and metabolism was developed by an occupational health research team, translated to Chinese, and translated back, for clarity. Modifications incorporated suggestions from a local community advisory board and boron industry workers; the translation-back translation process was reapplied, and cultural and semantic equivalence was attained. Results from the interviews showed more than 64% of workers and comparison group participants smoked tobacco and more than 92% reported exposure to environmental tobacco smoke. Boron workers and the comparison group varied in their food intake and alcohol consumption, but not in their smoking habits. Thirty-four percent of boron workers reported eating in the contaminated work area. Nearly all boron workers (99%) showered or bathed after work, although approximately 10% redressed in their contaminated clothes. Reproductive health outcomes were explored, including delayed pregnancy, multiple births, spontaneous miscarriages, induced abortions, stillbirths, and an unusual ratio of male to female offspring. Implications for occupational health nurses and recommendations for future research are provided.

Workgroup report: Implementing a national occupational reproductive research agenda--decade one and beyond.

The initial goal of occupational reproductive health research is to effectively study the many toxicants, physical agents, and biomechanical and psychosocial stressors that may constitute reproductive hazards in the workplace. Although the main objective of occupational reproductive researchers and clinicians is to prevent recognized adverse reproductive outcomes, research has expanded to include a broader spectrum of chronic health outcomes potentially affected by reproductive toxicants. To aid in achieving these goals, the National Institute for Occupational Safety and Health, along with its university, federal, industry, and labor colleagues, formed the National Occupational Research Agenda (NORA) in 1996. NORA resulted in 21 research teams, including the Reproductive Health Research Team (RHRT). In this report, we describe progress made in the last decade by the RHRT and by others in this field, including prioritizing reproductive toxicants for further study; facilitating collaboration among epidemiologists, biologists, and toxicologists; promoting quality exposure assessment in field studies and surveillance; and encouraging the design and conduct of priority occupational reproductive studies. We also describe new tools for screening reproductive toxicants and for analyzing mode of action. We recommend considering outcomes such as menopause and latent adverse effects for further study, as well as including exposures such as shift work and nanomaterials. We describe a broad domain of scholarship activities where a cohesive system of organized and aligned work activities integrates 10 years of team efforts and provides guidance for future research.

Episodic air pollution is associated with increased DNA fragmentation in human sperm without other changes in semen quality.

BACKGROUND: This study examined potential associations between exposure to episodes of air pollution and alterations in semen quality. The air pollution, resulting from combustion of coal for industry and home heating in the Teplice district of the Czech Republic, was much higher during the winter than at other times of year with peaks exceeding US air quality standards. METHODS: Young men from Teplice were sampled up to seven times over 2 years allowing evaluation of semen quality after periods of exposure to both low and high air pollution. Routine semen analysis (sperm concentration, motility and morphology) and tests for sperm aneuploidy and chromatin integrity were performed, comparing measurements within each subject. Exposure was classified as high or low based on data from ambient air pollution monitoring. RESULTS: Using repeated measures analysis, a significant association was found between exposure to periods of high air pollution (at or above the upper limit of US air quality standards) and the percentage of sperm with DNA fragmentation according to sperm chromatin structure assay (SCSA). Other semen measures were not associated with air pollution. CONCLUSION: Exposure to intermittent air pollution may result in sperm DNA damage and thereby increase the rates of male-mediated infertility, miscarriage, and other adverse reproductive outcomes.

Off to a good start: the influence of pre- and periconceptional exposures, parental fertility, and nutrition on children's health.

The scientific community is developing a compelling body of evidence that shows the importance of the in utero environment (including chemical and hormonal levels) to the ultimate health of the child and even of the aging adult. This article summarizes the evidence that shows this impact begins with conception. Only a full life-cycle evaluation will help us understand these impacts, and only such an understanding will produce logically prioritized mitigation strategies to address the greatest threats first. Clearly, the time for analysis begins when the next generation is but a twinkle in the eye.

Use of versant TMA and bDNA 3.0 assays to detect and quantify hepatitis C virus in semen.

Previous findings of hepatitis C virus (HCV) in human semen have been inconsistent. This study attempted to elucidate the presence of HCV in semen from 80 HCV RNA blood plasma positive homeless men using two novel non-PCR based techniques. Semen was frozen immediately upon ejaculation in order to preserve virus quantity. This study demonstrated that 36% of the study population had HCV in semen. Bayer's Versant HCV RNA Qualitative Assay (Bayer Diagnostics, Emeryville, CA) based on transcription mediated amplification (TMA) assay detected 29 positive semen samples and Versant HCV RNA 3.0 Assay (bDNA) (Bayer Diagnostics, Emeryville, CA) detected only six. This demonstrated that TMA was more sensitive than the bDNA in detecting HCV in semen (P<0.002). HCV blood plasma viral load was positively correlated with the presence of HCV in semen (Spearman's Rho=0.40, P<0.0002), while the presence of leukocytes in semen was not (Spearman's Rho=0.19, P<0.12). This supports the hypothesis that HCV is "leaked out" from the peripheral circulation into semen. Three semen samples had a viral load of >5000 IU/mL. The presence of a high viral load in semen in certain men suggests that sexual transmission of the virus is possible. Laboratory capability to accurately detect HCV positive semen is an important step in establishing the risk of sexual transmission and in identifying strategies for protecting uninfected partners.