Occupational Benzene Exposure and Lung Cancer Risk: A Pooled Analysis of 14 Case-Control Studies.

Rationale: Benzene has been classified as carcinogenic to humans, but there is limited evidence linking benzene exposure to lung cancer. Objectives: We aimed to examine the relationship between occupational benzene exposure and lung cancer. Methods: Subjects from 14 case-control studies across Europe and Canada were pooled. We used a quantitative job-exposure matrix to estimate benzene exposure. Logistic regression models assessed lung cancer risk across different exposure indices. We adjusted for smoking and five main occupational lung carcinogens and stratified analyses by smoking status and lung cancer subtypes. Measurements and Main Results: Analyses included 28,048 subjects (12,329 cases, 15,719 control subjects). Lung cancer odds ratios ranged from 1.12 (95% confidence interval, 1.03-1.22) to 1.32 (95% confidence interval, 1.18-1.48) (Ptrend = 0.002) for groups with the lowest and highest cumulative occupational exposures, respectively, compared with unexposed subjects. We observed an increasing trend of lung cancer with longer duration of exposure (Ptrend < 0.001) and a decreasing trend with longer time since last exposure (Ptrend = 0.02). These effects were seen for all lung cancer subtypes, regardless of smoking status, and were not influenced by specific occupational groups, exposures, or studies. Conclusions: We found consistent and robust associations between different dimensions of occupational benzene exposure and lung cancer after adjusting for smoking and main occupational lung carcinogens. These associations were observed across different subgroups, including nonsmokers. Our findings support the hypothesis that occupational benzene exposure increases the risk of developing lung cancer. Consequently, there is a need to revisit published epidemiological and molecular data on the pulmonary carcinogenicity of benzene.

Occupational asbestos exposure and risk of esophageal cancer: A systematic review and meta-analysis.

Esophageal cancer (EC), which includes squamous cell carcinoma (ESCC) and adenocarcinoma (EAC), is an important cancer with poor prognosis and high mortality rate. Several occupational exposures have been associated with EC. We aim to investigate the association between occupational asbestos exposure and EC risk, considering types of asbestos and histology of the disease. We included studies mentioned in the list of references in previous reviews and pooled analyses, and we conducted an independent search in PubMed and Scopus. Forest plots of relative risks (RR) were constructed based on the association between occupational asbestos and EC risk. Random-effects models were used to address heterogeneity between 48 independent cohort and case-control studies. We found an association between occupational asbestos exposure and EC (meta-relative risk [RR] = 1.20, 95% confidence interval [CI] = 1.09-1.32; I2 = 58.8%, p-heterogeneity [het] <.001). The results of stratification by job (p-het = .20) indicate an increased RR among asbestos product workers (RR = 1.39, 95% CI = 1.07-1.81), asbestos applicators (RR = 1.41, 95% CI = 1.20-1.67), and construction workers (RR = 1.12, 95% CI = 1.02-1.24). There was no heterogeneity in meta-RR according to outcome (p = .29), geographic region (p = .69), year of publication (p = .59), quality score (p = .73), asbestos type (p = .93), study design (p = .87), and gender (p = .88), control for potential confounders (p = .20), year of first employment (p = .94) and exposure level (p = .43). The stratification analysis by histology type found an increased RR for both ESCC 1.33(1.03-1.71) and EAC 1.45(1.03-2.04) (p-het = .68). We didn't find evidence of publication bias (p = .07). The results of our study suggest that occupational asbestos exposure is associated with an increased risk of EC in both histology types.

Cohort Studies Versus Case-Control Studies on Night-Shift Work and Cancer Risk: The Importance of Exposure Assessment.

It is a general assumption that the prospective cohort study design is the gold standard approach and is superior to the case-control study design in epidemiology. However, there may be exceptions if the exposure is complex and requires collection of detailed information on many different aspects. Night-shift work, which impairs circadian rhythms, is an example of such a complex occupational exposure and may increase the risks of breast, prostate, and colorectal cancer. So far, for logistical reasons, investigators in cohort studies have assessed shift work rather crudely, lacking information on full occupational history and relevant shift-work metrics, and have presented mostly null findings. On the other hand, most cancer case-control studies have assessed the lifetime occupational histories of participants, including collection of detailed night-shift work metrics (e.g., type, duration, intensity), and tend to show positive associations. In this commentary, we debate why cohort studies with weak exposure assessment and other limitations might not necessarily be the preferred or less biased approach in assessing the carcinogenicity of night-shift work. Furthermore, we propose that risk-of-bias assessment and comparison of associations between studies with low versus high risks of bias be considered in future synthesis of the evidence.

Immunomodulation of susceptibility to pneumococcal pneumonia infection in mouse lungs exposed to carbon nanoparticles via dysregulation of innate and adaptive immune responses.

Carbon nanotubes (CNTs) are emerging pollutants of occupational and environmental health concern. While toxicological mechanisms of CNTs are emerging, there is paucity of information on their modulatory effects on susceptibility to infections. Here, we investigated cellular and molecular events underlying the effect of multi-walled CNT (MWCNT) exposure on susceptibility to Streptococcus pneumoniae infection in our 28-day sub-chronic exposure mouse model. Data indicated reduced phagocytic function in alveolar macrophages (AMs) from MWCNT-exposed lungs evidenced by lower pathogen uptake in 1-h infection assay. At 24-h post-infection, intracellular pathogen count in exposed AMs showed 2.5 times higher net increase (2-fold in vehicle- versus 5-fold in MWCNT-treated), indicating a greater rate of intracellular multiplication and/or survival due to MWCNT exposure. AMs from MWCNT-exposed lungs exhibited downregulation of pathogen-uptake receptors CD163, Phosphatidyl-serine receptor (Ptdsr), and Macrophage scavenger receptors class A type 1 (Msr1) and type 2 (MSr2). In whole lung, MWCNT exposure shifted the macrophage polarization state towards the immunosuppressive phenotype M2b and increased the CD11c+ dendritic cell population required to activate the adaptive immune response. Notably, the MWCNT pre-exposure dysregulated T-cell immunity, evidenced by diminished CD4 and Th17 response, and exacerbated Th1 and Treg responses (skewed Th17/Treg ratio), thereby favoring the pneumococcal infection. Overall, these findings indicated that MWCNT exposure compromises both innate and adaptive immunity leading to diminished host lung defense against pneumonia infection. To our knowledge, this is the first report on an immunomodulatory role of CNT pre-exposure on pneumococcal infection susceptibility due to dysregulation of both innate and adaptive immunity targets.

Systemic Sclerosis in Individuals With Exposure to World Trade Center Ground Zero Rescue and Recovery Efforts: A Case Series.

OBJECTIVE: The World Trade Center (WTC) attack in New York resulted in a dust plume containing silica, hydrocarbons, and asbestos. Autoimmune disorders have been reported among those with WTC site exposure. The characteristics of individuals developing systemic sclerosis (SSc) have not been previously described. The purpose of this study was to describe the features of patients with SSc with WTC exposure. METHODS: Data were collected from 11 patients with SSc or SSc spectrum conditions who reported exposure to the WTC site. Seven patients completed an exposure assessment. RESULTS: Of the 11 patients, the majority (n = 8) were female. The median (range) for age at diagnosis was 46 (36-75) years, time between exposure and first non-Raynaud phenomenon SSc symptom was 8 (1-19) years, and time between exposure and diagnosis was 11 (2-18) years. Fifty-five percent had SSc onset > 5 years from WTC exposure. Five patients had limited cutaneous SSc, 3 patients had diffuse cutaneous SSc, 1 patient with SSc features met criteria for mixed connective tissue disease (CTD), and 2 patients had undifferentiated CTD with features of SSc. Four patients had overlapping features with other CTDs. Interstitial lung disease (ILD) was present in 10 patients. Five of 11 patients had a history of tobacco use. Seven of 7 patients who completed the questionnaire reported other hazardous exposures outside of WTC. Of these, only 2 patients reported personal protective equipment use. CONCLUSION: A high frequency of ILD and overlap features were observed among patients with SSc with WTC exposure. Future studies are needed to characterize this association.

Occupational exposure to endotoxins and small cell lung cancer: a systematic review with meta-analysis.

The relationship of occupational exposure to endotoxins with different histologic subtypes of lung cancer has not been established. Our objective was to conduct a systematic review with meta-analysis to assess the effect of exposure to endotoxins on the development of small cell lung cancer (SCLC). A bibliographic search was conducted using MEDLINE, Embase, CENTRAL, and Web of Science databases until December 2022, including all cohort and/or case-control studies that examined occupational exposure to endotoxins and SCLC. Risk of bias was assessed using the U.S. Office of Health Assessment and Translation tool. A random effects model was applied, publication bias were assessed, and a sensitivity analysis was conducted. Four papers were selected for meta-analysis purposes. A total of 144 incident cases of SCLC and 897 population or hospital controls were included. Occupational exposure to endotoxins was considered for textile/leather industry and agricultural sector workers exposed to endotoxins originating from wool, cotton, or leather dust. Except for one study, all investigations were classified as having a low probability of risk of biases. The results of the meta-analysis were not statistically significant (pooled OR: 0.86; 95% CI:0.69-1.08). In addition, neither between-study heterogeneity (I2=0%;p=0.92) nor publication bias was observed (p=0.49). The results of the sensitivity analysis, after including five studies that assessed the risk of SCLC among textile industry and crop/livestock farm workers (not specifically exposed to endotoxins), showed a negative statistically non-significant association and low between-study heterogeneity (pooled OR: 0.90; 95% CI:0.79-1.02; I2=22%;p=0.23). Subjects exposed to occupational exposure to endotoxins seem to exhibit a negative association with the development of SCLC, although the results are not conclusive.

Longitudinal Mapping of Personal Biotic and Abiotic Exposomes and Transcriptome in Underwater Confined Space Using Wearable Passive Samplers.

Silicone-based passive samplers, commonly paired with gas chromatography-mass spectrometry (GC-MS) analysis, are increasingly utilized for personal exposure assessments. However, its compatibility with the biotic exposome remains underexplored. In this study, we introduce the wearable silicone-based AirPie passive sampler, coupled with nontargeted liquid chromatography with high-resolution tandem mass spectrometry (LC-HRMS/MS), GC-HRMS, and metagenomic shotgun sequencing methods, offering a comprehensive view of personalized airborne biotic and abiotic exposomes. We applied the AirPie samplers to 19 participants in a unique deep underwater confined environment, annotating 4,390 chemical and 2,955 microbial exposures, integrated with corresponding transcriptomic data. We observed significant shifts in environmental exposure and gene expression upon entering this unique environment. We noted increased exposure to pollutants, such as benzenoids, polycyclic aromatic hydrocarbons (PAHs), opportunistic pathogens, and associated antibiotic-resistance genes (ARGs). Transcriptomic analyses revealed the activation of neurodegenerative disease-related pathways, mostly related to chemical exposure, and the repression of immune-related pathways, linked to both biological and chemical exposures. In summary, we provided a comprehensive, longitudinal exposome map of the unique environment and underscored the intricate linkages between external exposures and human health. We believe that the AirPie sampler and associated analytical methods will have broad applications in exposome and precision medicine.

Quantifying 209 Polychlorinated Biphenyl Congeners in Silicone Wristbands to Evaluate Differences in Exposure among Demolition Workers.

A social housing estate in Denmark was designated for demolition due to exceedance of guidance values for polychlorinated biphenyls (PCBs) in indoor air. Here, we deployed precleaned silicone wristbands (n = 46) among demolition workers of these contaminated buildings during single workdays while conducting various work tasks. We established a method to analyze all 209 PCBs in wristbands to identify prominent congeners of exposure and evaluate differences between tasks. Wristbands were extracted using microwave-assisted extraction and then concentrated for gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis. Twenty-nine chromatographic peaks representing 37 congeners were detected in every wristband, and tetra-CBs were the dominant homologue group. PCB-66, -44, and -70 were the most abundant congeners measured in worker wristbands, none of which are included within the typical seven indicator or WHO 12 PCBs. Workers who cut PCB-containing sealants had wristbands with the highest PCB concentrations (geometric mean ∑209PCBs = 1963 ng/g wristband), which were followed by those handling concrete elements on the building roof. Additionally, wristbands captured a broader range of PCBs than has been previously measured in air and serum samples. Taken together, our results highlight the importance of total congener analysis in assessing current PCB exposure in demolition work and the utility of wristbands for assessing these exposures.

Analysis of characteristic and postexposure practices of occupational blood and body fluid exposures among health care workers in Chinese tertiary hospitals: a retrospective ten-year study.

BACKGROUND: Occupational blood and body fluid exposure (OBEs) is a highly concerning global health problem in health facilities. Improper or inadequate post-exposure practices increase the risk of infection with bloodborne pathogens. Understanding risk factors for OBEs and evaluating the post-exposure practices will contribute to healthcare workers' (HCWs) well-being. METHODS: This study retrospectively synthesized and reviewed the 10-year data (from 2010 to 2020) on OBEs in a tertiary teaching hospital. RESULTS: A total of 519 HCWs have reported OBEs, increasing yearly from 2010 to 2020. Of these, most were nurses (247 [47.2%]), female (390 [75.1%]), at 23-27 years old (207 [39.9%]). The hepatitis B was the primary bloodborne pathogen exposed to HCWs, with 285 (54.9%) cases, internal medicine was the main exposure site (161 [31.0%]), and sharp injury was the main exposure route (439 [84.6%]). Data analysis shows that there are significant differences between exposure route, exposed pathogens, and exposure site among the different occupational categories (X2 = 14.5, 43.7, 94.3, all P < 0.001). 3.3% of HCWs did not take any post-exposure practices. For percutaneous exposure, 4.7% did not rinse the wound, 3.3% did not squeeze out the wound, and 2.3% did not disinfect the wound. In the case of mucosal exposure, 90.4% clean the exposure area immediately. CONCLUSIONS: The data from the past decade underscores the seriousness of current situation of OBEs in Chinese tertiary hospital, particularly among young HCWs, and with hepatitis B as the predominant blood-borne pathogen. This study also identifies HCWs may take incorrect post-exposure practices. It's crucial in the future to discuss the effectiveness of main groups targeted for focused specialty-specific guidance for the prevention of such accidents, meanwhile, to include blood-borne disease immunity testing in mandatory health check-ups. Additionally, focus on optimizing post-exposure practices, offering significant steps toward prevention of such incidents and reducing infection risks should also be considered in future studies.

Occupational solar exposure and basal cell carcinoma. A review of the epidemiologic literature with meta-analysis focusing on particular methodological aspects.

BACKGROUND: Numerous epidemiologic studies and a few systematic reviews have investigated the association between occupational solar exposure and basal cell carcinoma (BCC). However, previous reviews have several deficits with regard to included and excluded studies/risk estimates and the assessment of risk of selection bias (RoSB). Our aim was to review epidemiologic studies with a focus on these deficits and to use meta-(regression) analyses to summarize risk estimates. METHODS: We systematically searched PubMed (including MEDLINE) and Embase for epidemiologic studies. Study evaluation considered four main aspects of risk of bias assessments, i.e. Selection of subjects (selection bias); Exposure variables; Outcome variables; Data analysis. RESULTS: Of 56 identified references, 32 were used for meta-(regression) analyses. The overall pooled risk estimate for BCC comparing high/present vs. low/absent occupational solar exposure was 1.20 (95% CI 1.02-1.43); among studies without major deficits regarding data analysis, it was 1.10 (95% CI 0.91-1.33). Studies with low and high RoSB had pooled risk estimates of 0.83 (95% CI 0.73-0.93) and 1.95 (95% CI 1.42-2.67), respectively. The definitions of exposure and outcome variables were not correlated with study risk estimates. Studies with low RoSB in populations with the same latitude or lower than Germany had a pooled risk estimate of 1.01 (95% CI 0.88-1.15). CONCLUSION: Due to the different associations between occupational solar exposure and BCC among studies with low and high RoSB, we reason that the current epidemiologic evidence base does not permit the conclusion that regular outdoor workers have an increased risk of BCC.

Multivariate analysis and data mining help predict asthma exacerbations.

BACKGROUND: Work-related asthma has become a highly prevalent occupational lung disorder. OBJECTIVE: Our study aims to evaluate occupational exposure as a predictor for asthma exacerbation. METHOD: We performed a retrospective evaluation of 584 consecutive patients diagnosed and treated for asthma between October 2017 and December 2019 in four clinics from Western Romania. We evaluated the enrolled patients for their asthma control level by employing the Asthma Control Test (ACT < 20 represents uncontrolled asthma), the medical record of asthma exacerbations, occupational exposure, and lung function (i.e. spirometry). Then, we used statistical and data mining methods to explore the most important predictors for asthma exacerbations. RESULTS: We identified essential predictors by calculating the odds ratios (OR) for the exacerbation in a logistic regression model. The average age was 45.42 ± 11.74 years (19-85 years), and 422 (72.26%) participants were females. 42.97% of participants had exacerbations in the past year, and 31.16% had a history of occupational exposure. In a multivariate model analysis adjusted for age and gender, the most important predictors for exacerbation were uncontrolled asthma (OR 4.79, p < .001), occupational exposure (OR 4.65, p < .001), and lung function impairment (FEV1 < 80%) (OR 1.15, p = .011). The ensemble machine learning experiments on combined patient features harnessed by our data mining approach reveal that the best predictor is professional exposure, followed by ACT. CONCLUSIONS: Machine learning ensemble methods and statistical analysis concordantly indicate that occupational exposure and ACT < 20 are strong predictors for asthma exacerbation.

Maternal occupational exposure to carbonaceous nanoscale particles and neurodevelopmental outcomes in early childhood: Analysis of the French Longitudinal Study of Children - Elfe study.

OBJECTIVE: To investigate the association between occupational exposures to carbonaceous unintentionally emitted nanoscale particles (UNPs) during pregnancy and the child's language development and behaviour at two years old. METHODS: Using data from the French Longitudinal Study of Childhood - ELFE, we selected mothers who worked during pregnancy and their children. Exposure to carbonaceous UNPs was assessed by the MatPUF (job-exposure matrix for ultrafine particles). Children's lexical development was analysed using 'the Mac Arthur - Bates communicative development inventories-words and sentences-short form' (MB-CDI) in a multivariate binary logistic regression. Their risk for autism spectrum disorders was studied using 'the Modified-CHecklist for Autism in Toddler' (M-CHAT) according to the recommended thresholds (low risk = 0-2; intermediate risk = 3-6 and high risk = 7-23) in unordered multinomial logistic regression models. RESULTS: Maternal occupational exposure to carbonaceous UNPs was associated with delayed child language development (ORadj: 1.34; 95 % CI: 1.00, 1.80) but not with behavioural disorders (autism spectrum disorders) at two years old. CONCLUSION: This is the first epidemiological study to show a significant association between maternal occupational exposure to carbonaceous nanoscale particles and child language development at 2 years old.

HBM4EU E-waste study: Assessing persistent organic pollutants in blood, silicone wristbands, and settled dust among E-waste recycling workers in Europe.

E-waste recycling is an increasingly important activity that contributes to reducing the burden of end-of-life electronic and electrical apparatus and allows for the EU's transition to a circular economy. This study investigated the exposure levels of selected persistent organic pollutants (POPs) in workers from e-waste recycling facilities across Europe. The concentrations of seven polychlorinated biphenyls (PCBs) and eight polybrominated diphenyl ethers (PBDEs) congeners were measured by GC-MS. Workers were categorized into five groups based on the type of e-waste handled and two control groups. Generalized linear models were used to assess the determinants of exposure levels among workers. POPs levels were also assessed in dust and silicone wristbands (SWB) and compared with serum. Four PCB congeners (CB 118, 138, 153, and 180) were frequently detected in serum regardless of worker's category. With the exception of CB 118, all tested PCBs were significantly higher in workers compared to the control group. Controls working in the same company as occupationally exposed (Within control group), also displayed higher levels of serum CB 180 than non-industrial controls with no known exposures to these chemicals (Outwith controls) (p < 0.05). BDE 209 was the most prevalent POP in settled dust (16 µg/g) and SWB (220 ng/WB). Spearman correlation revealed moderate to strong positive correlations between SWB and dust. Increased age and the number of years smoked cigarettes were key determinants for workers exposure. Estimated daily intake through dust ingestion revealed that ΣPCB was higher for both the 50th (0.03 ng/kg bw/day) and 95th (0.09 ng/kg bw/day) percentile exposure scenarios compared to values reported for the general population. This study is one of the first to address the occupational exposure to PCBs and PBDEs in Europe among e-waste workers through biomonitoring combined with analysis of settled dust and SWB. Our findings suggest that e-waste workers may face elevated PCB exposure and that appropriate exposure assessments are needed to establish effective mitigation strategies.

Cancer mortality and premature deaths among hairdressers in Brazil.

Hairdresser is an occupation classified by the International Agency for Research on Cancer as probably carcinogenic (Group 2A) for lung and bladder cancer, but evidence is accumulating on its association with other cancer types. To our knowledge, this is the first study aimed to compare the cancer mortality and premature mortality between hairdressers and other workers in Brazil. METHODS: In this exploratory study, information on deaths by selected cancers that occurred in Brazil, from 1996 to 2020, among workers aged 20-70y, with identified occupation was gathered from the Brazilian Mortality Information System. Sociodemographic characteristics, sex-specific mortality ratio, and Years of Potential Life Lost (YPLL) were compared between hairdressers, service workers, and general workers. We used logistic regression models to estimate crude (ORC) and adjusted (ORADJ) odds ratios. Models were adjusted by age, educational level, and ethnicity. We also used Poisson regression models to compare the YPLL rates across the occupational groups. RESULTS: From 1996 to 2020, 23 557 deaths occurred among hairdressers, 576 428 among service workers, and 13 332 996 among general workers in Brazil. Higher mortality ORs and YPLL were observed for several types of cancer among hairdressers, compared to service and general workers, especially for women. Hairdressers' mortality was significantly higher among whites, women, younger workers, and those who completed high school. Female hairdressers had significantly higher odds of dying from cancer of the digestive, respiratory, reproductive, urinary, and hematological systems, both in crude and adjusted models. For male hairdressers, higher odds were found only for urinary tract and bladder cancer, while other significant associations indicated lower mortality than the comparison groups. YPLL analyses revealed significant premature deaths among Brazilian hairdressers. In women, this was more evident among those who died of neoplasms of salivary glands, bones and articular cartilages, and acute lymphoid leukemia; in men, tongue, pharynx, and thyroid. CONCLUSIONS: Our results suggest that Brazilian female hairdressers are more likely to die from several cancers, with potential consequences on premature deaths. Causal associations to occupational risks, such as exposure to chemicals, should be investigated by observational epidemiologic studies. Meanwhile, it is important to promote public policies, regulations, and Occupational Safety and Health (OSH) strategies to protect hairdressers' health, mitigate occupational risks, and ensure safe workplaces.

The Western Australian Mesothelioma Registry: Analysis of 60 years of cases.

BACKGROUND AND OBJECTIVE: Australia introduced a partial ban on asbestos consumption in 1984. There is continuing concern about exposure to asbestos in the built environment and non-occupational exposures. The aim of this study was to describe epidemiological trends of mesothelioma in Western Australia (WA) over the 60 years since the first case was recorded. METHODS: Every case of mesothelioma notified to the WA Cancer Registry is reviewed by an expert panel. Data include demographic and clinical variables including principal mode of asbestos exposure and age at first exposure. Trends over time for survival, latency and pathological subtype of mesothelioma where analysed. Incidence rates for cases exposed during home renovation where calculated. RESULTS: Two thousand seven hundred ninety-six cases of mesothelioma were identified with males comprising the majority (n = 2368, 84.7%). The median (IQR) age at diagnosis was 70 (62-78) years, and median latency of 47 (38-55) years. Pleural mesothelioma was recorded in 2620 (93.7%) cases with the epithelioid subtype most prevalent (n = 1730, 61.9%). Overall, median survival was 298 (128-585) days and latency 46 (37-54) years, both effectively doubling over the study period. Non-occupational exposures were proportionally higher in females (52.6%), compared with males (9.5%). Home renovation was the primary exposure in 227 (8.1%) cases, with number of cases and incidence rate ratio peaking in 2005/09 but subsequently decreasing. CONCLUSION: The annual number of cases of mesothelioma in WA may have hit a plateau. The majority of females have non-occupational exposures and incidence rates from home renovation exposure may have peaked, suggesting the ban on asbestos has been effective.

Review on novel toxicological effects and personalized health hazard in workers exposed to low doses of benzene.

Several recent reports indicate health hazards for workers with below occupational limit exposure to benzene (BZ). Our updated review indicates that such low exposures induced traditional as well as novel toxicity/genotoxicity, e.g., increased mitochondria copy numbers, prolongation of telomeres, impairment of DNA damage repair response (DDRR), perturbations of expression in non-coding RNAs, and epigenetic changes. These abnormalities were associated with alterations of gene expression and cellular signaling pathways which affected hematopoietic cell development, expression of apoptosis, autophagy, etc. The overarching mechanisms for induction of health risk are impaired DDRR, inhibition of tumor suppressor genes, and changes of MDM2-p53 axis activities that contribute to perturbed control for cancer pathways. Evaluation of the unusual dose-responses to BZ exposure indicates cellular over-compensation and reprogramming to overcome toxicity and to promote survival. However, these abnormal mechanisms also promote the induction of leukemia. Further investigations indicate that the current exposure limits for workers to BZ are unacceptable. Based on these studies, the new exposure limits should be less than 0.07 ppm rather than the current 1 ppm. This review also emphasizes the need to conduct appropriate bioassays, and to provide more reliable decisions on health hazards as well as on exposure limits for workers. In addition, it is important to use scientific data to provide significantly improved risk assessment, i.e., shifting from a population- to an individual-based risk assessment.

Reproductive outcomes among female health care workers.

OBJECTIVE: Occupational exposures may be associated with reproductive health and pregnancy outcomes. This study investigated the association between occupational exposures and reproductive health, pregnancy outcomes, and the lactation period among hospital staff. MATERIALS AND METHODS: Seven hundred thirty-three female healthcare workers from hospitals affiliated with the Tehran University of Medical Sciences were invited to participate in this cross-sectional study. The measurement method for fertility consequences was self-report. Demographic characteristics, occupational data, medical history, and reproductive history were collected via data collection form. Finally, reproductive outcomes were evaluated in different occupational hazard categories. RESULT: Chemical exposures (solvents) were a risk factor for stillbirth. Prolonged working hours were associated with spontaneous abortion and breastfeeding periods. Shift workers did not have a higher frequency of reproductive and pregnancy outcomes, but the breastfeeding period was significantly decreased in shift workers. Psychiatric disorders were associated with preterm labour, low birth weight, and stillbirth in sequence with nervousness, depression, and mood disturbance. Furthermore, depression affects the breastfeeding period. Moreover, we found a link between job titles and infertility. In addition, socioeconomic status was related to stillbirth and infertility. CONCLUSION: The study revealed that chemical and ergonomic exposures have associations with some reproductive outcomes. We also conclude that shift work could adversely affect the breastfeeding period. So, implementing some organizational strategies to control adverse health effects of occupational hazards and modifying shift work and working hours for nursing mothers is recommended.

Impact of the Endonaut® angio-navigation system on radiation exposure in endovascular aortic repair performed with mobile C-arms.

OBJECTIVE: Fusion imaging systems have proved to reduce radiation exposure mostly in hybrid rooms but reports with mobile C-arms are few. The aim of this study was to analyse the impact of the Endonaut® navigation system on radiation exposure in endovascular aneurysm repair (EVAR) performed with mobile C-arms. METHODS: All patients undergoing EVAR and/or iliac branched devices implantation between January 2016 and August 2022 were included. All procedures were performed with a mobile C-arm (Siemens Avantic® or GE Elite® until March 2018, Siemens Cios Alpha® thereafter). The Endonaut® navigation system has been used since January 2021. Two groups were therefore compared : before (control group) and after the use of Endonaut®. Radiation data including Dose Area Product (DAP) values, Air Kerma (AK) and fluoroscopy time (FT) were collected retrospectively. RESULTS: Overall, 153 patients were included: control group (CGr), n = 121; Endonaut® group (EnGr), n = 32. No significant difference was found between the two groups regarding demographic data. DAP values were significantly lower in the EnGr (38 Gy.cm2 ± 24) vs. the CGr (76 Gy.cm2 ± 51) (p<.05) despite a significantly higher number of complex procedures such as iliac branched devices (p<.05). AK values were not significantly different between the EnGr and the CGr (196 mGy ± 114 vs. 209 mGy ± 138) as well as FT (33 minutes ± 18 vs. 33 minutes ± 16). Technical success was 97% (31/32) in the EnGr vs. 96% (116/121) in the CGr (p=.79). The volume of contrast media was significantly lower in the EnGr (94 cc ± 41) vs. the CGr (143 cc ± 66) (p<.05). CONCLUSION: In this study, the use of the Endonaut® angio-navigation system when performing EVAR with mobile C-arms led to a radiation dose reduction without compromising technical success or procedural time.

Establishing short-term occupational exposure limits (STELs) for sensory irritants using predictive and in silico respiratory rate depression (RD50) models.

Sensory irritation is a health endpoint that serves as the critical effect basis for many occupational exposure limits (OELs). Schaper 1993 described a significant relationship with high correlation between the measured exposure concentration producing a 50% respiratory rate decrease (RD50) in a standard rodent assay and the American Conference of Governmental Industrial Hygienists (ACGIH®) Threshold Limit Values (TLVs®) as time-weighted averages (TWAs) for airborne chemical irritants. The results demonstrated the potential use of the RD50 values for deriving full-shift TWA OELs protective of irritant responses. However, there remains a need to develop a similar predictive model for deriving workplace short-term exposure limits (STELs) for sensory irritants. The aim of our study was to establish a model capable of correlating the relationship between RD50 values and published STELs to prospectively derive short-term exposure OELs for sensory irritants. A National Toxicology Program (NTP) database that included chemicals with both an RD50 and established STELs was used to fit several linear regression models. A strong correlation between RD50s and STELs was identified, with a predictive equation of ln (STEL) (ppm) = 0.86 * ln (RD50) (ppm) - 2.42 and an R2 value of 0.75. This model supports the use of RD50s to derive STELs for chemicals without existing exposure recommendations. Further, for data-poor sensory irritants, predicted RD50 values from in silico quantitative structure activity relationship (QSAR) models can be used to derive STELs. Hence, in silico methods and statistical modeling can present a path forward for establishing reliable OELs and improving worker safety and health.

Exposure assessment and cytogenetic biomonitoring study of workers occupationally exposed to extremely low-frequency magnetic fields.

Human cytogenetic biomonitoring (HCB) has long been used to evaluate the potential effects of work environments on the DNA integrity of workers. However, HCB studies on the genotoxic effects of occupational exposure to extremely low-frequency electromagnetic fields (ELF-MFs) were limited by the quality of the exposure assessment. More specifically, concerns were raised regarding the method of exposure assessment, the selection of exposure metrics, and the definition of exposure group. In this study, genotoxic effects of occupational exposure to ELF-MFs were assessed on peripheral blood lymphocytes of 88 workers from the electrical sector using the comet and cytokinesis-block micronucleus assay, considering workers' actual exposure over three consecutive days. Different methods were applied to define exposure groups. Overall, the summarized ELF-MF data indicated a low exposure level in the whole study population. It also showed that relying solely on job titles might misclassify 12 workers into exposure groups. We proposed combining hierarchical agglomerative clustering on personal exposure data and job titles to define exposure groups. The final results showed that occupational MF exposure did not significantly induce more genetic damage. Other factors such as age or past smoking rather than ELF-MF exposure could affect the cytogenetic test outcomes.