The asbestos-asbestosis exposure-response relationship: a cohort study of the general working population.

Objectives: The association between asbestos exposure and asbestosis in high-exposed industrial cohorts is well-known, but there is a lack of knowledge about the exposure-response relationship for asbestosis in a general working population setting. We examined the exposure-response relationship between occupational asbestos exposure and asbestosis in asbestos-exposed workers of the Danish general working population.

Methods: We followed all asbestos-exposed workers from 1979 to 2015 and identified incident cases of asbestosis using the Danish National Patient Register.

Timing of puberty in relation to semen characteristics, testicular volume, and reproductive hormones: a cohort study.

Objective: To investigate whether the timing of puberty is associated with semen characteristics, testicular volume, and reproductive hormone levels.

Design: Cohort study.

Setting: Not applicable.

Semen quality and reproductive hormones in sons of subfertile couples: a cohort study.

Objective: To study the associations between parental subfecundity, assessed by time to pregnancy and use of medically-assisted reproduction, and reproductive health of young men.

Design: Cohort study.

Setting: Denmark.

Maternal exposure to psychosocial job strain during pregnancy and behavioral problems in the 11-year-old children: a Danish cohort study.

Maternal psychosocial stress may impact child neurodevelopment, but little is known regarding psychosocial job strain. We hypothesized high psychosocial job strain during pregnancy was associated with behavioural problems in the 11-year-old children. Mothers in the Danish National Birth Cohort (1996-2002) were included if they worked, provided information on job strain [Karasek's model: high job strain (often job demand/seldom job control) and passive (seldom or sometimes job demands/seldom job control)] during early pregnancy.

Risk of childhood asthma following prenatal exposure to negative life events and job stressors: A nationwide register-based study in Denmark.

Objectives This study aimed to examine the association between negative life events, job stressors (low job control or high psychosocial job demands) and offspring asthma phenotypes (early-onset transient, early-onset persistent and late-onset asthma). Methods In a population-based cohort study comprising 547 533 liveborn singletons, we determined negative life events and offspring asthma at age six years using data from Danish nationwide registers. We assessed job demands and job control from gender-specific job exposure matrices.

Impact of Di-2-Ethylhexyl Phthalate Metabolites on Male Reproductive Function: a Systematic Review of Human Evidence.

Purpose Of Review: The purpose of this review is to systematically review the literature linking di-2-ethylhexyl phthalate (DEHP) exposure with effects on reproductive health in adult males.

Recent Findings: Thirty-three papers were included of which 28 were cross-sectional. Twenty-one papers investigated semen samples, 18 investigated reproductive hormones, and three studies investigated time to pregnancy.

Response to Dr Stevens' letter ref. Visitisen et al: "Short-term effects of night shift work on breast cancer risk: a cohort study of payroll data".

We thank Dr Richard Stevens for his comments (1) on our recent article that showed no increased risk of breast cancer following recent night shift work when compared with recent day shift work (2). This finding was based on linkage of day-by-day information on working hours and breast cancer incidence data. Results are thus less likely to have been biased by differential misclassification than findings from earlier studies relying on self-report (3).

Short-term effects of night shift work on breast cancer risk: a cohort study of payroll data.

Objectives The objective was to examine if night shift work is a short-term risk factor for breast cancer, including combined estrogen receptor (ER) and human epidermal growth factor 2 (HER2) breast cancer subtypes. Methods The cohort comprised 155 540 public sector female workers in Denmark who were followed from 2007-2012. Day-to-day work-hour information was available from payroll registers and 1245 incident cases of breast cancer were identified in national cancer registries together with receptor subtype information.

Exposure to persistent organic pollutants and sperm DNA methylation changes in Arctic and European populations.

Persistent organic pollutants (POPs), such as PCBs (polychlorinated biphenyls) and DDT [1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane], are environmental contaminants with potential endocrine disrupting activity. DNA methylation levels in peripheral blood lymphocytes have been associated with serum concentrations of POPs in Greenland Inuit and Korean populations. Greenland Inuits are characterized by the highest worldwide POP levels.

Exposure to perfluoroalkyl substances and sperm DNA global methylation in Arctic and European populations.

Perfluoroalkyl substances (PFASs) are widely used in a variety of industrial processes and products, and have been detected globally in humans and wildlife. PFASs are suspected to interfere with endocrine signaling and to adversely affect human reproductive health. The aim of the present study was to investigate the associations between exposure to PFASs and sperm global methylation levels in a population of non-occupationally exposed fertile men.

Associations between serum phthalates and biomarkers of reproductive function in 589 adult men.

Phthalates which are widely used, are ubiquitous in the environment and in some human tissues. It is generally accepted that phthalates exert their toxic action by inhibiting Leydig cell synthesis of testosterone, but in vitro studies have also shown anti-androgenic effects at the receptor level. Some cross-sectional studies have shown inverse associations between urinary levels of phthalates and reproductive hormones, but results are conflicting and the evidence base is limited.

Occupational allergic contact dermatitis diagnosed by a systematic stepwise exposure assessment of allergens in the work environment.

Background: Information on the presence of contact allergens and irritants is crucial for the diagnosis of occupational contact dermatitis. Ingredient lists and Material Safety DataSheets (MSDSs) may be incomplete.

Objectives: To evaluate the workability of a systematic exposure assessment in consecutive patients with suspected occupational contact dermatitis, and to study how it could potentially aid correct diagnostic classification.

Relationship between apoptotic markers in semen from fertile men and demographic, hormonal and seminal characteristics.

Apoptosis in the testis has two putative roles during normal spermatogenesis; limitation of the germ cell population to numbers that can be supported by the Sertoli cells, and, possibly, selective depletion of meiotic and postmeiotic abnormal germ cells. We investigated the demographic and biological correlates of the pro-apoptotic marker Fas and the anti-apoptotic marker Bcl-xL in sperm cells of fertile men. Six hundred and four men from Greenland, Poland and Ukraine were consecutively enrolled during their pregnant wife's antenatal visits.

Sperm DNA integrity in relation to exposure to environmental perfluoroalkyl substances - a study of spouses of pregnant women in three geographical regions.

Perfluoroalkyl substances (PFASs) can interfere with male reproductive function, but evidence in humans is limited. Six hundred four fertile men (199 from Greenland, 197 from Poland and 208 from Ukraine) were enrolled in the study. We measured four PFASs in serum (PFOS, PFOA, PFNA and PFHxS) and concurrent DNA damage in spermatozoa by sperm chromatin structure assay (SCSA) and in situ terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay, apoptotic markers in semen (Fas-receptor and Bcl-xL), and reproductive hormones in serum.

Psychosocial work environment and antidepressant medication: a prospective cohort study.

Background: Adverse psychosocial work environments may lead to impaired mental health, but it is still a matter of conjecture if demonstrated associations are causal or biased. We aimed at verifying whether poor psychosocial working climate is related to increase of redeemed subscription of antidepressant medication.

Methods: Information on all antidepressant drugs (AD) purchased at pharmacies from 1995 through 2006 was obtained for a cohort of 21,129 Danish public service workers that participated in work climate surveys carried out during the period 2002-2005.

Muscle fatigue in relation to forearm pain and tenderness among professional computer users.

Background: To examine the hypothesis that forearm pain with palpation tenderness in computer users is associated with increased extensor muscle fatigue.

Methods: Eighteen persons with pain and moderate to severe palpation tenderness in the extensor muscle group of the right forearm and twenty gender and age matched referents without such complaints were enrolled from the Danish NUDATA study of neck and upper extremity disorders among technical assistants and machine technicians. Fatigue of the right forearm extensor muscles was assessed by muscle twitch forces in response to low frequency (2 Hz) percutaneous electrical stimulation.

[Health examinations in connection with night work].

Some 10% of the labour force work during night hours. According to an EU directive night workers should be offered preventive health examinations. It is well known that night work is related to sleep disorders but the epidemiologic evidence linking night work with increased occurrence of peptic ulcers, breast cancer, cardiovascular disease and spontaneous abortions is still limited and provides no strong rationale for preventive health examinations.

[Multiple chemical sensitivity, a well-defined illness?].

Some people react to smells or chemicals at levels far below toxicological thresholds with nonspecific symptoms, fear and social isolation. They may be diagnosed with multiple chemical sensitivity. There is no empirical evidence indicating that this condition is explained by toxicological mechanisms, even though a number of theories have been proposed.

Job strain and male fertility.

Background: Job strain, defined as high job demands and low job control, has not previously been explored as a possible determinant of male fertility. We collected prospective data on job strain among men, and describe the associations with semen quality and probability of conceiving a clinical pregnancy during a menstrual cycle.

Methods: Danish couples (N = 399) who were trying to become pregnant for the first time were followed for up to 6 menstrual periods.

Reproductive effects of male psychologic stress.

Objectives: Male psychologic stress can affect semen quality and couple fecundability.

Methods: We conducted a prospective study of 430 Danish couples who were trying to become pregnant for the first time. In each menstrual cycle, both partners filled out a 12-item version of the General Health Questionnaire (GHQ-12), an assessment of psychologic stress.

Correlation of scrotal temperature in twins.

Background: Scrotal temperature and semen quality have been found to be inversely correlated in several studies, and variation in scrotal temperature may contribute to the well known variation in semen quality. The reason for the variation in scrotal temperature is not well understood although determinants could be of a genetic nature.

Methods: We monitored scrotal skin temperature for 24 h in a group of monozygotic and dizygotic twins and single-born brothers (n = 48 males).