Occupational risk of COVID-19 in foreign-born employees in Denmark.

BACKGROUND: Foreign-born workers in high-income countries experience higher rates of COVID-19 but the causes are only partially known. AIMS: To examine if the occupational risk of COVID-19 in foreign-born workers deviates from the risk in native-born employees in Denmark. METHODS: Within a registry-based cohort of all residents employed in Denmark (n = 2 451 542), we identified four-digit DISCO-08 occupations associated with an increased incidence of COVID-19-related hospital admission during 2020-21 (at-risk occupations). The sex-specific prevalence of at-risk employment in foreign born was compared with the prevalence in native born. Moreover, we examined if the country of birth modified the risk of a positive SARS-CoV-2 polymerase chain reaction (PCR) test and COVID-19-related hospital admission in at-risk occupations. RESULTS: Workers born in low-income countries and male workers from Eastern Europe more often worked in at-risk occupations (relative risks between 1.16 [95% confidence interval {CI} 1.14-1.17] and 1.87 [95% CI 1.82-1.90]). Being foreign-born modified the adjusted risk of PCR test positivity (test for interaction P < 0.0001), primarily because of higher risk in at-risk occupations among men born in Eastern European countries (incidence rate ratio [IRR] 2.39 [95% CI 2.09-2.72] versus IRR 1.19 [95% CI 1.14-1.23] in native-born men). For COVID-19-related hospital admission, no overall interaction was seen, and in women, country of birth did not consistently modify the occupational risk. CONCLUSIONS: Workplace viral transmission may contribute to an excess risk of COVID-19 in male workers born in Eastern Europe, but most foreign-born employees in at-risk occupations seem not to be at higher occupational risk than native born.

Prenatal exposure to airborne polychlorinated biphenyl congeners and male reproductive health.

STUDY QUESTION: Is fetal exposure to lower-chlorinated polychlorinated biphenyls (LC-PCBs) in indoor air of private homes built with PCB-containing materials associated with semen characteristics and testicular volume in adult men? SUMMARY ANSWER: We observed only marginal and inconsistent associations between maternal exposure to PCBs in indoor air and semen quality, testicular size and reproductive hormones in the adult offspring. WHAT IS KNOWN ALREADY: Recent studies have shown LC-PCBs to exhibit endocrine-disrupting properties and increase the risk of cryptorchidism. Although exposure to LC-PCBs in indoor air is relatively common, the long-term impact of prenatal exposure on male reproductive health has not yet been investigated. STUDY DESIGN, SIZE, DURATION: In this cohort study, participants were men (18+ years) whose mothers carried them while living in one of two residential areas where indoor air had been contaminated by LC-PCB evaporating from building materials in subsets of the apartments. Men were considered prenatally exposed if their mother had lived in a PCB-contaminated apartment and unexposed if their mother had lived in an uncontaminated apartment for a minimum of 1 year during the 3.6 years before conception or during the first trimester. Mothers of prenatally unexposed men could not have lived in a contaminated apartment at any point. Recruitment lasted from 2017 to 2019. In total, 73 exposed and 111 unexposed men gave a blood and semen sample. PARTICIPANTS/MATERIALS, SETTING, METHODS: Percentage differences in semen volume, sperm concentration, total sperm count, morphologically normal spermatozoa, progressively motile spermatozoa and DNA fragmentation index (DFI) between prenatally exposed and unexposed men were estimated using negative binomial regression. Associations with total and calculated free testosterone (CFT), LH and FSH were modeled using the linear regression. Odds of small testicular volume was estimated with logistic regression. MAIN RESULTS AND THE ROLE OF CHANCE: Overall, the results of this study were conflicting. No differences in semen volume, sperm concentration, testosterone and CFT were observed between the groups, but there were slight indications of lower total sperm count, increased FSH and risk of small testicles, alongside lower sperm DFI and a higher proportion of normal spermatozoa in men exposed to LCB-PCBs from indoor air during fetal life. There is no apparent biologically plausible explanation for the apparently improved measures of DNA fragmentation and morphology, and these findings may have occurred purely by chance. LIMITATIONS, REASONS FOR CAUTION: Owing to the indirect measure of exposure, lack of adjustment for paternal factors, the potential for self-selection due to known exposure status and fertility issues, inability to take time spent away from the residence, limited statistical power and lack of comparable literature, independent replication of the study in larger cohorts is warranted. WIDER IMPLICATIONS OF THE FINDINGS: While our findings may appear reassuring for the large number of people residing and/or working in buildings with indoor air contaminated with LC-PCBs, further efforts to understand the full range of health consequences of fetal LC-PCB exposure are needed. STUDY FUNDING/COMPETING INTEREST(S): The study was supported by the Independent Research Fund Denmark (ref no. 6110-00085B), Bispebjerg Hospital, Landsbyggefonden, Realdania (ref. no. PRJ-2017-00176), Grundejernes Investeringsfond (ref. no. 18-58) and Helsefonden (ref. no. 16-B-01-22 and 21-B-0412). K.S.H. was supported by FFIKA, Focused Research Effort on Chemicals in the Working Environment, from the Danish Government. The authors declare that they have no financial, personal or professional competing interests. TRIAL REGISTRATION NUMBER: Not applicable.

Job change facilitates healing in a cohort of patients with occupational hand eczema.

BACKGROUND: Occupational hand eczema is a frequent and often chronic disease and knowledge of the consequences of change of profession is sparse. OBJECTIVES: To compare severity of hand eczema and health-related quality of life (HR-QoL) in patients who after 5 years were still in the same profession and those who were not. METHODS: The study is a register-based cohort study including patients with recognized occupational hand eczema in Denmark in 2010 and 2011. Outcomes were eczema-related parameters and Dermatology Life Quality Index (DLQI) scores obtained from a follow-up questionnaire after 5 years. RESULTS: A total of 1496 participants were included in the study. More participants who changed profession or left the labour market reported complete healing of hand eczema at follow-up, compared with participants still in the same profession [odds ratio (OR) 1·62, 95% confidence interval (CI) 1·06-2·47 and OR 2·85, 95% CI 1·83-4·42, respectively], in addition to increased improvement at follow-up (OR 1·91, 95% CI 1·44-2·54 and OR 1·51, 95% CI 1·09-2·10, respectively). However, DLQI scores for participants who changed profession or left the labour market had increased at follow-up [incidence rate ratio (IRR) 1·12 (95% CI 0·98-1·28 and IRR 1·29, 95% CI 1·11-1·51, respectively]. The results from subgroup analyses of patients with irritant or allergic occupational hand eczema did not differ markedly. Change of work procedures was positively associated with improvement (OR 2·31, 95% CI 1·51-3·54), and did not markedly influence DLQI. CONCLUSIONS: Change of profession has a beneficial effect on eczema parameters, but a negative effect on HR-QoL, indicated by increased DLQI scores. Change of work procedures while staying in the same profession positively influenced improvement, with no marked influence on HR-QoL, and should be considered as an alternative to job change.

Indices of methylation in sperm DNA from fertile men differ between distinct geographical regions.

STUDY QUESTION: Which are the main determinants, if any, of sperm DNA methylation levels? SUMMARY ANSWER: Geographical region resulted associated with the sperm methylation status assessed on genome-wide repetitive sequences. WHAT IS KNOWN ALREADY: DNA methylation level, assessed on repetitive sequences from peripheral blood lymphocyte, can vary with age, gender, alcohol consumption and white blood cell counts. STUDY DESIGN, SIZE, DURATION: A cross-sectional study. Individual data were collected from 269 young healthy men of proven fertility living in three geographical regions: Inuits from Greenland, Caucasians from Warsaw (Poland) and Kharkiv (Ukraine). Semen samples were collected between May 2002 and February 2004 and aliquots were immediately frozen. PARTICIPANTS/MATERIALS, SETTING, METHODS: We estimated sperm DNA global methylation level (DGML) in two ways. First DNA methylation in repetitive DNA sequences (LINE-1, Satα and Alu) was quantified by PCR pyrosequencing after bisulfite conversion and second by flow cytometry (FCM) using fluorescently labeled monoclonal antibodies anti-5-methylcytosine. We analyzed whether personal characteristics and habits, body mass index, semen quality parameters, sperm chromatin integrity, biomarkers of accessory gland function and the plasma concentration of reproductive hormones were associated with sperm DNA methylation levels in men. Associations were evaluated by analysis of variance and linear regression analyses. MAIN RESULTS AND THE ROLE OF CHANCE: The geographical location emerged as the main determinant when using the methylation level in repetitive sequences. FCM DGML results were not associated with those from repetitive sequence analysis. No other consistent associations between methylation markers and the assessed variables were identified across countries. LIMITATIONS, REASONS FOR CAUTION: The methods used are only surrogates of the actual sperm methylome and the methylation levels at individual specific loci were not explored. WIDER IMPLICATIONS OF THE FINDINGS: Sperm DGML is relatively independent from semen quality parameters and is a new candidate biomarker for epidemiological studies of the impact of environmental contaminants on male fertility. STUDY FUNDING/COMPETING INTERESTS: The study is part of the project CLEAR (Climate change, Environmental contaminants and Reproductive health) supported by the European Commission 7th framework program, contract no: FP7-ENV-2008-1-226217. No competing interest is declared.

Psychosocial factors at work and risk of depression: a systematic review of the epidemiological evidence.

OBJECTIVES: Major depression is a leading cause of psychiatric morbidity and may be influenced by psychosocial factors in the workplace, although evidence so far remains circumstantial. This paper reviews follow-up studies addressing the risk of major depression and depressive symptoms relative to psychosocial stressors in the working environment and evaluates the evidence for causality. METHOD: Follow-up studies were identified by a systematic Medline search combining search terms for the outcome and measures of job-related psychosocial factors. The quality of the studies was evaluated using 22 criteria related to their potential for bias and confounding. RESULTS: Sixteen company or population-based studies including some 63,000 employees were identified. Validated multi-item scales were used to measure perceived psychosocial stressors in most of the studies. Major depression was defined by clinical criteria in seven studies and by symptom scales in another seven. The follow-up period ranged from 1 to 13 years. The prevalence of depressive disorder varied substantially, suggesting a high degree of study heterogeneity. The adjusted relative risk for onset of a major depressive episode according to job stressors ranged from 0.5 to 1.5 in 44 of 61 reported associations with various psychosocial factor dimensions. Associations were strongest and most consistent for job strain defined as high demand and low decision latitude among men. Most studies shared common limitations such as lack of independent measures of exposure and outcome and potential confounding. Although a meta-analysis would technically be possible, heterogeneity across studies evidenced by variation in the prevalence of depression made this unfeasible. CONCLUSION: This review provides consistent findings that perception of adverse psychosocial factors in the workplace is related to an elevated risk of subsequent depressive symptoms or major depressive episode; however, methodological limitations preclude causal inference. Studies implementing objective measures of job stressors or independent outcome ascertainment are warranted.