Autoimmune diseases, autoantibody status and silicosis in a cohort of 1238 workers from the artificial stone benchtop industry.

OBJECTIVES: Autoimmune disorders are multifactorial but occupational exposures have long been implicated, including respirable crystalline silica (RCS). A modern epidemic of silicosis is emerging internationally, associated with dry processing of engineered stone with high (>90%) RCS content. We aimed to investigate the prevalence of clinical autoimmune disease and common autoantibodies in exposed workers. METHODS: Stone benchtop industry workers in Victoria, Australia were offered free screening for silicosis and related disorders. Symptoms or diagnoses of autoimmune disease were evaluated by questionnaire and blood tests taken for rheumatoid factor (RF), antinuclear antibodies (ANAs) and extractable nuclear antigens (ENAs). RESULTS: Among 1238 workers (93.3% male) screened from 2019 to 2021, 0.9% were confirmed with autoimmune disease. Among those without clinical disease, 24.6% had detectable ANAs (93.5% male), 4.6% detectable ENAs and 2.6% were positive for RF. Silicosis was diagnosed in 253 workers (24.3% of those with diagnostic information available). Of those with ANA readings, 54 (6.6%) had ANA titre >1:320. The likelihood of positive autoantibodies increased with age; smoking; higher exposure to RCS and silicosis diagnosis. CONCLUSION: The proportion of workers with detectable ANAs or ENAs was considerably higher than the 5%-9% expected in the general population. Some of the antibodies detected (eg, Scl-70, CENPB) have high sensitivity and specificity for systemic sclerosis. Long-term follow-up will be needed to estimate incidence. Rheumatologists should explore occupational history in new cases of autoimmune disease. Screening for autoimmune disease is indicated in workers exposed to RCS as these individuals need specialised management and may be entitled to compensation.

Neurological and neurobehavioral effects of welders in Egypt exposed to manganese containing welding fumes.

PURPOSE: Welders are more likely to develop neurobehavioral disorders because of their exposure to neurotoxic metals such as manganese. This study aimed to measure the neurobehavioral performance of welders occupationally exposed to manganese at welding enterprises and its relationship with the workplace environment. METHODS: It is a comparative cross-sectional study carried out on 130 welders working at 50 welding enterprises in Menoufia governorate, Egypt, compared to 130 non-occupationally exposed controls. RESULTS: It was found that the environments of the studied welding enterprises had levels of respirable dust, manganese, and total welding fumes that exceeded internationally permissible limits. In addition, the mean blood manganese levels were significantly higher among welders (4.16 ± 0.61) than the controls (1.72 ± 0.41). Welders had a significantly higher prevalence of neurological manifestations and lower performance of neurobehavioral tests. Lower neurobehavioral performance among welders was significantly correlated with increased work duration and blood levels in some tests. CONCLUSION: To lessen the fumes in the breathing zone of workers, it is therefore strongly recommended to regularly wear high-quality personal protective equipment, especially masks, and to ensure proper ventilation.

Longitudinal changes in cardiovascular disease-related proteins in welders.

OBJECTIVE: Occupational exposure to welding fumes is linked to a higher risk of cardiovascular disease; however, the threshold exposure level is unknown. Here, we aimed to identify changes in proteins associated with cardiovascular disease in relation to exposure to welding fumes. METHODS: Data were obtained from two timepoints six years apart for 338 non-smoking men (171 welders, 167 controls); of these, 174 (78 welders, 96 controls) had measurements available at both timepoints. Exposure was measured as personal respirable dust (adjusted for personal protective equipment), welding years, and cumulative exposure. Proximity extension assays were used to measure a panel of 92 proteins involved in cardiovascular processes in serum samples. Linear mixed models were used for longitudinal analysis. The biological functions and diseases related to the identified proteins were explored using the Ingenuity Pathway Analysis software. RESULTS: At both timepoints, the median respirable dust exposure was 0.7 mg/m3 for the welders. Seven proteins were differentially abundant between the welders and controls and increased incrementally with respirable dust: FGF23, CEACAM8, CD40L, PGF, CXCL1, CD84, and HO1. CD84 was significant after adjusting for multiple comparisons. These proteins have been linked to disorders of blood pressure, damage related to clogged blood vessels, and chronic inflammatory disorders. CONCLUSION: Exposure to mild steel welding fumes below current occupational exposure limits for respirable particles and welding fumes in Europe and the US (1-5 mg/m3) was associated with changes in the abundance of proteins related to cardiovascular disease. Further research should evaluate the utility of these proteins as prospective biomarkers of occupational cardiovascular disease.

Assessment of ventilatory functions and associated inflammatory markers among workers in slaughterhouses.

OBJECTIVE: Meat processing is among the most extensive industries globally. However, data on the effects of occupational exposure on the pulmonary health of slaughterhouse workers is limited. Ascertaining the impact of the slaughterhouse atmosphere on the breathing habits of laborers exposed to it and the inflammatory markers associated with it was the aim of the current investigation. METHODS: A cross-sectional study was performed on 82 non-smoker subjects of 41 male workers working in one of the major slaughterhouses in Cairo, Egypt, matched to 41 controls of administrative personnel. An elaborate questionnaire encompassing medical and occupational history was administered to each participant in the research. General and local systemic examinations and ventilatory function tests were carried out, and serum levels of interleukin 6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) were measured. RESULTS: Respiratory symptoms were more prevalent with a statistically significant decline in ventilatory function parameters (FVC%, FEV1%, FEV1/FVC, FEF 25%, FEF 50%, FEF 75%, and PEF%) among the exposed group compared to those of control. In addition, there was a significantly higher serum level of inflammatory markers (IL-6 and hsCRP) among the exposed group compared to the control group, with a negative correlation with ventilatory functions. Moreover, there was a positive association between levels of serum IL-6 and hsCRP and the age and duration of employment of workers. CONCLUSION: There was a notable increase in the prevalence of respiratory disorders and inflammatory markers among slaughterhouse workers. Additionally, there was a substantial decrease in ventilatory function parameters, which could be attributed to the bioaerosols they encountered in the workplace.

Click evoked otoacoustic emissions in occupational exposure to lead, concentrations of selected essential elements and markers of oxidative stress.

PURPOSE: This study focused on the selected markers of oxidative stress, impact of elevated lead levels on long-term hearing quality. We investigated whether the presence of certain essential minerals might provide protection to the auditory system against the effects of lead (and cadmium) compounds. METHODS: The research group included 280 male employees of the zinc and lead smelter, which was divided into: L-Pb-low blood lead concentration (PbB) subgroup, H-Pb-high PbB subgroup. Hearing tests were performed using the click evoked otoacoustic emission (CEOAE). RESULTS: Zinc protoporphyrin level was significantly higher in the H-Pb subgroup by 68%. Cd concentration was significantly higher in H-Pb by 33%. The Ca concentration was significantly lower in the H-Pb by - 2%. Selected oxidative stress markers concentration were significantly higher in the H-Pb group: malondialdehyde (MDA) by 4%, and lipofuscin (LPS) by 9%. In the CEOAE results showed statistically significant differences between the L-Pb and H-Pb subgroups. Larger negative changes in otoemission amplitude were observed in H-Pb subgroup. All otoemission results showed a statistically significant negative correlation with age, time of work, MDA concentration, and with PbB. Selected CEOAE parameters showed a significant negative correlation with cadmium blood concentration (CdB), and a positive correlation with Ca and Zn. CONCLUSION: Elevated blood lead content in occupational exposure is associated with an increase in MDA and LPS concentration, which negatively correlates with CEOAE parameters. This suggests an important role of oxidative stress in the long-term deterioration of hearing.

[Study on the risk factors of coal workers' pneumoconiosis and the mechanism of pyroptosis in peripheral blood].

Objective: To explore the risk factors of coal workers' pneumoconiosis, reveal the molecular mechanism of pyroptosis in peripheral blood of coal workers' pneumoconiosis patients, and provide new strategies and potential diagnostic biomarkers for the treatment of the disease. Methods: From January 1, 2020 to December 31, 2022, workers with suspected occupational diseases who were diagnosed with coal workers' pneumoconiosis in the Third People's Hospital of Xinjiang Uygur Autonomous Region were included in the study, including 77 patients with coal workers' pneumoconiosis stage Ⅰ, 10 patients with stage Ⅱ, 6 patients with stage Ⅲ, and 49 workers with dust-free lung disease as the control group. General information of the subjects was collected, blood samples were collected for routine blood and blood biochemical results, and plasma levels of interleukin (IL) -1ß and IL-18 were measured. Combined with the results of clinical examination, multi-factor ordered logistic regression analysis was carried out to evaluate the influencing factors of coal workers' pneumoconiosis. At the same time, the expression of pyroptosis related proteins in blood cells was detected to reveal the molecular mechanism of coal workers' pneumoconiosis. Results: All 142 subjects were male, with an average age of (51.65±6.31) years old and an average working age of (15.94±9.38) years. There were significant differences in smoking age (F=4.95, P=0.003) and lunch break distribution (H=8.84, P=0.031) among all groups. The hemoglobin content of stage Ⅰ patients was higher than that of stage Ⅱ patients, and the neutrophil percentage of stage Ⅲ patients was higher than that of the other 3 groups (P<0.05). The levels of total bilirubin and indirect bilirubin in stage Ⅰ patients were higher than those in control group, while the erythrocyte sedimentation rate in stage Ⅱ patients was higher than that in the other 3 groups (P<0.05). The levels of IL-18 and IL-1ß in stage Ⅲ of coal workers' pneumoconiosis were higher than those in the other 3 groups (P<0.05). Multiple logistic regression analysis showed that smoking age (OR=1.03, 95%CI: 1.00-1.06) and IL-1ß level (OR=4.61, 95%CI: 1.59-13.32) were independent risk factors for coal workers' pneumoconiosis (P<0.05). Compared with the control group, the expression levels of nucleotide-binding of oligomeric domain-like receptor protein 3 (NLRP3), Caspase-1, GSDMD, Caspase-4 and other proteins in stage Ⅲ of coal workers' pneumoconiosis were significantly increased (P<0.05) . Conclusion: Smoking age is a risk factor for coal workers' pneumoconiosis, IL-1ß may be a potential biomarker for the diagnosis of coal workers' pneumoconiosis, and pyroptosis may play a role in the development of peripheral inflammation of coal workers' pneumoconiosis.

PEDF, a pleiotropic WTC-LI biomarker: Machine learning biomarker identification and validation.

Biomarkers predict World Trade Center-Lung Injury (WTC-LI); however, there remains unaddressed multicollinearity in our serum cytokines, chemokines, and high-throughput platform datasets used to phenotype WTC-disease. To address this concern, we used automated, machine-learning, high-dimensional data pruning, and validated identified biomarkers. The parent cohort consisted of male, never-smoking firefighters with WTC-LI (FEV1, %Pred< lower limit of normal (LLN); n = 100) and controls (n = 127) and had their biomarkers assessed. Cases and controls (n = 15/group) underwent untargeted metabolomics, then feature selection performed on metabolites, cytokines, chemokines, and clinical data. Cytokines, chemokines, and clinical biomarkers were validated in the non-overlapping parent-cohort via binary logistic regression with 5-fold cross validation. Random forests of metabolites (n = 580), clinical biomarkers (n = 5), and previously assayed cytokines, chemokines (n = 106) identified that the top 5% of biomarkers important to class separation included pigment epithelium-derived factor (PEDF), macrophage derived chemokine (MDC), systolic blood pressure, macrophage inflammatory protein-4 (MIP-4), growth-regulated oncogene protein (GRO), monocyte chemoattractant protein-1 (MCP-1), apolipoprotein-AII (Apo-AII), cell membrane metabolites (sphingolipids, phospholipids), and branched-chain amino acids. Validated models via confounder-adjusted (age on 9/11, BMI, exposure, and pre-9/11 FEV1, %Pred) binary logistic regression had AUCROC [0.90(0.84-0.96)]. Decreased PEDF and MIP-4, and increased Apo-AII were associated with increased odds of WTC-LI. Increased GRO, MCP-1, and simultaneously decreased MDC were associated with decreased odds of WTC-LI. In conclusion, automated data pruning identified novel WTC-LI biomarkers; performance was validated in an independent cohort. One biomarker-PEDF, an antiangiogenic agent-is a novel, predictive biomarker of particulate-matter-related lung disease. Other biomarkers-GRO, MCP-1, MDC, MIP-4-reveal immune cell involvement in WTC-LI pathogenesis. Findings of our automated biomarker identification warrant further investigation into these potential pharmacotherapy targets.

White Blood Cell Count and Serum Cytokine Profile in Tropical Hardwood Workers in Kumasi.

Background: Occupational exposure to wood dust particles has long been reported of its associated varying degrees of negative health effects due to different extractive chemicals present in the various timber species. However, tropical hardwood is also reported to have higher levels of extractive chemicals of antihistamine, antioxidant, and anti-inflammatory properties. In Ghana, woodworkers have for years been exposed to wood dust from mixed tropical hardwood species, with little or no protective equipment such as nose masks, yet with less significant respiratory conditions. This study seeks to investigate the serum cytokine profile in tropical hardwood workers in Kumasi to provide a better understanding of the immunoregulatory pattern activated in the woodworkers. Method: The study was carried out among woodworkers, teachers, and security men located in Kumasi. A cross-sectional sampling of adult male workers was selected to participate in the study (86 woodworkers and 89 nonwoodworkers). Participants donated blood collected by venepuncture into EDTA tubes and spun to separate serum for cytokine assay. Cytokines including IFN-gamma, IL-1ß, IL-2, IL-4, IL-6, IL-10, IL-12, IL-13, and IL-17 were assayed using the Human Premixed Multianalyte Kit (R&D System, Inc., Minneapolis, USA) following the manufacturer's procedure. The cytokine levels were quantified using the Luminex∗200 analyser. Results: The mean concentration levels for the various cytokines were significantly different (p < 0.05) between woodworkers and nonwoodworkers except IL-2. There were significantly increased levels of Th1 and Th2 cytokines expressed in the woodworkers more than the nonwoodworkers. Conclusions: The results from this study reveal that exposed woodworkers of mixed tropical hardwood species show a high level of Th1 and Th2 cytokines in their serum than nonwoodworkers.

Assessment of serum CK-MM level as a bioindicator for work-related musculoskeletal injuries among Emergency hospital workers.

Musculoskeletal disorders (MSDs) are considered a growing problem among healthcare personnel, especially service workers. The emergency room (ER) service workers are highly exposed to work-related risk factors which predispose them to MSDs. A cross-sectional study was performed on 78 ER workers. Full medical and occupational histories were taken. The Standardized Nordic Questionnaire (SNQ) was used for the assessment of musculoskeletal symptoms. Clinical examination was done with special emphasis on the locomotors system, and serum levels of muscle enzymes, including creatine kinase (CK) and creatine kinase isoenzyme (CK-MM), were measured. The study aims to detect the prevalence of occupational musculoskeletal disorders (MSDs) among ER workers at University hospitals, and assessment of CK-MM as a biomarker used in the early detection of MSDs. We found that 71.8% of the participants were complaining of musculoskeletal disorder in the last 7 days before the study, while only 34.6% were complaining of musculoskeletal disorder in the last 12 months before the study. The knee joint was the most commonly affected site in the past 7 days, by 39.7%. On the other hand, the highest prevalent disorder in the last 12 months was for the ankle joint (17.9%) with significantly high levels of serum CK-MM. In conclusion, musculoskeletal injuries are a common complaint among healthcare occupations, especially among ER service workers that need regular health education and ergonomic training programs. Monitoring of serum CK-MM level with cut-off value 90 ng\ml could be used as a novel approach for the early detection of work-related musculoskeletal disorders.

SARS-CoV-2 seroprevalence in health care workers from 10 hospitals in Quebec, Canada: a cross-sectional study.

BACKGROUND: The COVID-19 pandemic has disproportionately affected health care workers. We sought to estimate SARS-CoV-2 seroprevalence among hospital health care workers in Quebec, Canada, after the first wave of the pandemic and to explore factors associated with SARS-CoV-2 seropositivity. METHODS: Between July 6 and Sept. 24, 2020, we enrolled health care workers from 10 hospitals, including 8 from a region with a high incidence of COVID-19 (the Montréal area) and 2 from low-incidence regions of Quebec. Eligible health care workers were physicians, nurses, orderlies and cleaning staff working in 4 types of care units (emergency department, intensive care unit, COVID-19 inpatient unit and non-COVID-19 inpatient unit). Participants completed a questionnaire and underwent SARS-CoV-2 serology testing. We identified factors independently associated with higher seroprevalence. RESULTS: Among 2056 enrolled health care workers, 241 (11.7%) had positive SARS-CoV-2 serology. Of these, 171 (71.0%) had been previously diagnosed with COVID-19. Seroprevalence varied among hospitals, from 2.4% to 3.7% in low-incidence regions to 17.9% to 32.0% in hospitals with outbreaks involving 5 or more health care workers. Higher seroprevalence was associated with working in a hospital where outbreaks occurred (adjusted prevalence ratio 4.16, 95% confidence interval [CI] 2.63-6.57), being a nurse or nursing assistant (adjusted prevalence ratio 1.34, 95% CI 1.03-1.74) or an orderly (adjusted prevalence ratio 1.49, 95% CI 1.12-1.97), and Black or Hispanic ethnicity (adjusted prevalence ratio 1.41, 95% CI 1.13-1.76). Lower seroprevalence was associated with working in the intensive care unit (adjusted prevalence ratio 0.47, 95% CI 0.30-0.71) or the emergency department (adjusted prevalence ratio 0.61, 95% CI 0.39-0.98). INTERPRETATION: Health care workers in Quebec hospitals were at high risk of SARS-CoV-2 infection, particularly in outbreak settings. More work is needed to better understand SARS-CoV-2 transmission dynamics in health care settings.

Serotonin variations and sleep disorders among shift workers. A cross-sectional study.

Sleep disorders are prevalent occupational health problems among shift workers, especially healthcare workers with long shifts. Serotonin is a neurotransmitter related to circadian variations accompanied by shift work. A cross-sectional study was performed on 73 nurses at a tertiary hospital in Cairo, Egypt, to assess sleep quality among shift work nurses (SWNs), to determine blood serotonin level, and its relation to shift work and sleep quality. A demographic and occupational history questionnaire, Pittsburgh Sleep Quality Index (PSQI) questionnaire, and measurement of blood serotonin were carried out to the studied group. The data were analyzed using SPSS 25, and descriptive statistics, unpaired t-test, ANOVA, Kruskal-Wallis Test, Chi-square, Spearman correlation, and multivariate regression analysis were utilized. The results showed that the mean PSQI global score was significantly higher among SWNs than non-shift work nurses (NSWNs) and was the highest (10.32 ± 3.56 and 10.22 ± 2.4, respectively) among rotatory and fixed night shift nurses. Blood serotonin showed highly significant differences between SWNs over NSWNs (p = 0.001), and mostly reduced among rotatory and fixed night shift nurses (66.7% and 65%, respectively). Moreover, there were highly significant differences in serotonin levels between poor and good sleep quality nurses (p < 0.001), and most of the poor sleep quality nurses (62.7%) had low serotonin levels. Abnormal serotonin level (odds = 246.5) and working years (odds = 1.2) were statistically significant predictors of poor sleep quality. In conclusion, SWNs, especially rotating and night shift nurses, suffer from poor sleep quality associated with abnormal levels of blood serotonin.

Prevalence of work-related musculoskeletal disorders among Egyptian printing workers evidenced by using serum biomarkers of inflammation, oxidative stress, muscle injury, and collagen type I turnover.

OBJECTIVE: Printing workers experience a high rate of musculoskeletal disorders (MSDs). This study aims to determine the prevalence of MSDs, estimate serum biomarkers denoting musculoskeletal tissue changes, and determine some individual risk factors for MSDs among Egyptian printing workers. METHODS: Eighty-five male printing workers and 90 male administrative employees (control group) were recruited from a printing press in Giza. A validated version of the standardized Nordic questionnaire was used. Serum biomarkers of inflammation (interleukin (IL)-1α, IL-1ß, IL-6, tumor necrosis factor (TNF)-α, and C-reactive protein (CRP)), cell stress or injury (malondialdehyde (MDA) and creatine kinase skeletal muscle (CK-MM)), and collagen metabolism (collagen-I carboxy-terminal propeptide (PICP) and type-I collagen cross-linked C-telopeptide (CTx)) were measured for all participants. RESULTS: This study showed a significant (p < 0.001) prevalence of the musculoskeletal symptoms (76.5%) and significant (p < 0.001) elevation in the levels of all measured biomarkers among the printing workers (means ± SD: IL-1α = 1.55 ± 0.9, IL-1ß = 1.53 ± 0.87, IL-6 = 1.55 ± 0.85, TNF-α = 4.9 ± 2.25, CRP = 6.78 ± 3.07, MDA = 3.41 ± 1.29, CK-MM = 132.47 ± 69.01, PICP = 103.48 ± 36.44, and CTx = 0.47 ± 0.16) when compared with their controls (prevalence: 34.4%; means ± SD: IL-1α = 0.88 ± 0.61, IL-1ß = 0.96 ± 0.72, IL-6 = 1.03 ± 0.75, TNF-α = 2.56 ± 1.99, CRP = 2.36 ± 1.1, MDA = 0.85 ± 0.21, CK-MM = 53.48 ± 33.05, PICP = 56.49 ± 9.05, and CTx = 0.31 ± 0.06). Also, significant (p < 0.001) positive strong associations were observed between age, body mass index (BMI), and the duration of employment with all measured biomarkers, where all correlation coefficients were >0.7. CONCLUSION: Printing workers suffer a high prevalence of work-related MSDs that might be related to some individual factors (age, BMI, and duration of employment). Consequently, preventive ergonomic interventions should be applied. Further studies should be done to elucidate the link between tissue changes and detected biomarkers to follow the initiation and progression of MSDs and study the effectiveness of curative interventions.

Plasma Metabolomics Analysis of Polyvinyl Chloride Workers Identifies Altered Processes and Candidate Biomarkers for Hepatic Hemangiosarcoma and Its Development.

BACKGROUND: High-level occupational vinyl chloride (VC) exposures have been associated with hepatic hemangiosarcoma, which typically develops following a long latency period. Although VC is genotoxic, a more comprehensive mode of action has not been determined and diagnostic biomarkers have not been established. The purpose of this study is to address these knowledge gaps through plasma metabolomics. METHODS: Plasma samples from polyvinyl chloride polymerization workers who developed hemangiosarcoma (cases, n = 15) and VC exposure-matched controls (n = 17) underwent metabolomic analysis. Random forest and bioinformatic analyses were performed. RESULTS: Cases and controls had similar demographics and routine liver biochemistries. Mass spectroscopy identified 606 known metabolites. Random forest analysis had an 82% predictive accuracy for group classification. 60 metabolites were significantly increased and 44 were decreased vs. controls. Taurocholate, bradykinin and fibrin degradation product 2 were up-regulated by greater than 80-fold. The naturally occurring anti-angiogenic phenol, 4-hydroxybenzyl alcohol, was down-regulated 5-fold. Top affected ontologies involved: (i) metabolism of bile acids, taurine, cholesterol, fatty acids and amino acids; (ii) inflammation and oxidative stress; and (iii) nicotinic cholinergic signaling. CONCLUSIONS: The plasma metabolome was differentially regulated in polyvinyl chloride workers who developed hepatic hemangiosarcoma. Ontologies potentially involved in hemangiosarcoma pathogenesis and candidate biomarkers were identified.

Agricultural work and reduced circulating uric acid are both associated with initial hospital admission for Parkinson's disease.

Monoamine oxidase type B inhibitors act in Parkinson's disease (PD) via potentiation of dopamine, but may also have neuroprotective effects by reducing oxidative damage. Oxidative damage is also a feature of environmental toxins, including pesticides, that are an established risk factor for PD. Another risk factor is low circulating uric acid (UA), which may relate to UA being the major endogenous antioxidant in the human body. We have undertaken a study of 192 initial admissions for PD in a general hospital neurology department in a partly rural region of Southern China to determine if there is an increased rate of PD in agricultural workers who have a high risk of exposure to pesticides, and how it may relate to deficits in UA. We found a disproportionately high number of agricultural workers admitted with PD (66.7% vs. 54.3% of all neurology admissions) and that PD subjects have a substantial reduction in UA. This is further reduced in agricultural workers and thus may contribute to the increased vulnerability of this group to PD.

Acute kidney injury and workload in a sample of California agricultural workers.

BACKGROUND: Kidney damage is associated with an increased workload in high ambient temperatures and may represent a pathway to chronic kidney disease of unknown origin in agricultural workers. We tested the associations of workload and heat with acute kidney dysfunction in California agricultural workers. METHODS: We recruited a convenience sample of 471 agricultural workers from 29 farms in California during two summer harvest seasons. The sustained 3-minute maximum workload was estimated using accelerometer data collected from Actical monitors and individual heat load through elevations in core body temperature. Acute kidney injury (AKI) was defined by a change in serum creatinine of ≥0.3 mg/dL or ≥1.5 times the preshift creatinine over the course of the work shift. Associations between AKI and workload were modeled using logistic regression, controlling for demographic, physiologic, and occupational variables. RESULTS: Of the total, 357 workers (75.8%) had accelerometer readings in the moderate workload category, 93 (19.7%) had readings in the vigorous category. 177 (36%) had elevations of core body temperature ≥1°C; 72 workers (14.9%) demonstrated evidence of AKI after a single day of agricultural work. The workload category was associated with an increased adjusted odds of AKI (1.92; 95% confidence interval, 1.05-3.51). Piece-rate work was also associated with increased adjusted odds of AKI (3.02; 95% CI, 1.44-6.34). CONCLUSIONS: Heavy occupational workload and piece-rate work were associated with acute effects on the renal health of agricultural workers. This indicates that occupations requiring high physical effort put workers at risk for AKI, possibly independent of ambient and core body temperature. Changes to agricultural practices may reduce the risk of renal disorders for these workers.

Night shift work and cardiovascular disease biomarkers in female nurses.

BACKGROUND: Night shift work is associated with cardiovascular disease, but its associations with cardiovascular disease biomarkers are unclear. We investigated these associations in a study of female nurses. METHODS: We used data from the Nurses' Health Study II for total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, C-reactive protein (CRP), and fibrinogen. The sample sizes for our analysis ranged from 458 (fibrinogen) to 3574 (total cholesterol). From questionnaires, we determined the number of night shifts worked in the 2 weeks before blood collection and total years of rotating night shift work. We used quantile regression to estimate differences in biomarker levels by shift work history, adjusting for potential confounders. RESULTS: Nurses working 1 to 4 recent night shifts had median HDL cholesterol levels 4.4 mg/dL (95% confidence interval [CI]: 0.3, 7.5) lower than nurses without recent night shifts. However, working ≥5 recent night shifts and years of rotating night shift work were not associated with HDL cholesterol. There was no association between recent night shifts and CRP, but median CRP levels were 0.1 (95% CI: 0.0, 0.2), 0.2 (95% CI: 0.1, 0.4), and 0.2 (95% CI: 0.0, 0.4) mg/L higher among nurses working rotating night shifts for 1 to 5, 6 to 9, and ≥10 years compared with nurses never working rotating night shifts. These associations were attenuated when excluding postmenopausal women and women taking statins. We observed no associations between night shift work and other biomarkers. CONCLUSIONS: We found suggestive evidence of adverse short-term and long-term effects of night shift work on select cardiovascular disease biomarkers.

The effect of heat stress on hematological parameters and oxidative stress among bakery workers.

Heat stress causes physiological changes, and changes in hematological parameters and hormonal levels in the human body, known as thermal strain. This study was conducted to determine the effect of exposure to heat stress on hematological parameters and oxidative stress in the bakers of Shahroud City, Iran. A total of 163 bakery workers (exposed group) and 135 office workers (unexposed group) with a minimum of 1-year working experience were selected. Exposure to heat stress was measured using ISO-7243 criteria on the hottest days of the year (late July and August). Wet-bulb globe temperature (WBGT) was calculated based on indoor environments. Oxidative stress indices including malondialdehyde (MDA), nitric oxide (NO), total antioxidant capacity (TAC) in the bakers' and office workers' serum and hematological parameters were measured. Statistical analysis was done through independent t-test, and multivariate linear regression using SPSS v24. Analysis of hematological parameters showed that about 70% and 68% of the bakers had abnormal mean cell volume (MCV) and white blood cell (WBC) count, respectively, while only around 12% of them had abnormal mean cell hemoglobin concentration (MCHC). The counts of red blood cells (RBC), WBC, lymphocytes (LYM), and MCV showed significant differences in different occupational groups (p < 0.05). The levels of MDA and NO were significantly higher in bakers with WBGT more than the threshold value (p < 0.05). The WBGT index for assessing heat stress can be used as a predictor variable for MDA and NO levels. In addition, heat stress exposure could be a risk factor for abnormal WBC, RBC, LYM, and MCV.

Prediction of lung cancer risk using circulating pro-surfactant protein B and high-sensitivity C-reactive protein among Egyptian workers in the rubber industry.

OBJECTIVE: For several decades, there has been increasing evidence for excess incidence of lung cancer among workers in the rubber industry. The purpose of this study was to assess the risk of lung cancer occurrence among Egyptian workers involved in the rubber industry using two circulating protein biomarkers. METHODS: This study was performed in a rubber manufacturing factory in Shubra El-Kheima region in Greater Cairo, Egypt. Environmental assessment for the suspended particulate matter of size 10 µm (PM10) concentrations was done. Levels of plasma pro-surfactant protein B (pro-SFTPB) and serum high-sensitivity C-reactive protein (HsCRP) were measured among the studied population (n = 155) who were divided into two groups. The first group included 75 workers exposed to rubber manufacturing process while the control group involved 80 administrative subjects. RESULTS: The levels of PM10 neither exceeded the Egyptian nor the international permissible limits where the highest levels were observed in the mixing department. However, through medical history and clinical examination, it was observed that some general and respiratory manifestations were more prevalent among the exposed group when compared with their controls. Laboratory investigations revealed that the mean values of pro-SFTPB and HsCRP levels among exposed workers were significantly higher than those of the control group. These increased circulating proteins levels were strongly and positively correlated with each other and with the duration of employment of exposed workers. CONCLUSION: The study results support the conclusion that prolonged occupational exposure to rubber manufacturing process is associated with an elevated risk of lung cancer.

CYP3A Polymorphism and Chronic Mercury Intoxication.

We analyzed the relationship between polymorphic loci of CYP3A genes (CYP3A4 (rs2740574), CYP3A5 (rs776746) and CYP3A7 (rs2257401)) with the development of chronic mercury intoxication. Of 170 men examined, 120 were workers chronically exposed to mercury vapors and 50 were carriers of GG-HSPA1B (+1267A/G) genotype associated with chronic mercury intoxication. Urinary content of 4-hydroxyantipyrine (4-HAP) generated in the reaction predominantly catalyzed by CYP3A4/CYP3A5 was studied in workers without chronic mercury intoxication (group 1, N=46) and patients in the delayed period of chronic mercury intoxication (group 2, N=74) depending on the genotypes of CYP3A4 and CYP3A5. For polymorphic loci CYP3A5 and CYP3A7, a tendency to an increase in the frequency of genotypes with rare alleles was found (p=0.071 and p=0.078) in the combined group (group 2 together with GGHSPA1B genotype carriers) relative to group 1. The high level of linkage disequilibrium was noted, especially for the pair rs776746 and rs2257401 (LD (r)=0.89). In group 2, a trend to 4-HAP decrease compared to group 1 (p=0.056 and p=0.065) was revealed for carriers of AA-CYP3A4 and GG-CYP3A5 genotypes. The involvement of CYP3A in the development of mercury neurotoxic effect remains unclear.

Serum 25-hydroxyvitamin D fluctuations in military personnel during 6-month summer operational deployments in Afghanistan.

Soldier operational performance is determined by their fitness, nutritional status, quality of rest/recovery, and remaining injury/illness free. Understanding large fluctuations in nutritional status during operations is critical to safeguarding health and well-being. There are limited data world-wide describing the effect of extreme climate change on nutrient profiles. This study investigated the effect of hot-dry deployments on vitamin D status (assessed from 25-hydroxyvitamin D (25(OH)D) concentration) of young, male, military volunteers. Two data sets are presented (pilot study, n 37; main study, n 98), examining serum 25(OH)D concentrations before and during 6-month summer operational deployments to Afghanistan (March to October/November). Body mass, percentage of body fat, dietary intake and serum 25(OH)D concentrations were measured. In addition, parathyroid hormone (PTH), adjusted Ca and albumin concentrations were measured in the main study to better understand 25(OH)D fluctuations. Body mass and fat mass (FM) losses were greater for early (pre- to mid-) deployment compared with late (mid- to post-) deployment (P<0·05). Dietary intake was well-maintained despite high rates of energy expenditure. A pronounced increase in 25(OH)D was observed between pre- (March) and mid-deployment (June) (pilot study: 51 (sd 20) v. 212 (sd 85) nmol/l, P<0·05; main study: 55 (sd 22) v. 167 (sd 71) nmol/l, P<0·05) and remained elevated post-deployment (October/November). In contrast, PTH was highest pre-deployment, decreasing thereafter (main study: 4·45 (sd 2·20) v. 3·79 (sd 1·50) pmol/l, P<0·05). The typical seasonal cycling of vitamin D appeared exaggerated in this active male population undertaking an arduous summer deployment. Further research is warranted, where such large seasonal vitamin D fluctuations may be detrimental to bone health in the longer-term.