There is a plausible association between shift work and cardiovascular disease (CVD), which may be due to disruption of the circadian rhythm causing hormonal changes and metabolic disturbances, resulting in high blood pressure, atherosclerosis, diabetes, and being overweight. However, few studies have investigated the association between several consecutive long work shifts, including night shifts, and risk factors for developing CVD. Moreover, knowledge is lacking on factors that may modify or enhance this suggested relationship. The study period is planned from the third quarter of 2018 to the fourth quarter of 2021, and will involve 125 industrial employees at two Norwegian enterprises producing insulation. The work schedule is either rotating shiftwork (morning, evening, night) or regular day work. At baseline, we will measure blood parameters, including markers of inflammation, lipids, and glycosylated hemoglobin. We will also collect measures of blood pressure, resting heart rate, arterial stiffness, carotid intima-media thickness, and aerobic fitness. At the end of baseline data collection, a subgroup will undergo a supervised high-intensity interval training intervention for eight weeks, initiated by the Occupational Health Service. At one-year follow-up, we repeat baseline measures with added measures of heart rate variability and additional five weeks monitoring of sleep and physical activity, and assessment of respirable dust. At the two year follow-up, we will measure CVD risk factors before and after a planned three-month shutdown in one of the studied plants. We will also assess respirable dust, monitor sleep, and compile a one-year retrospective detailed overview of working hours. A final data collection, similar to the one at baseline, will be carried out after three years. We will use a comprehensive set of methods to identify the effects of shift work with long working hours and night shifts on cardiovascular health. This will provide new knowledge on the association between early manifestations of CVD and occupational exposure to shift work. Further, we can study whether work organization such as extensive overtime, sleep loss, and dust exposure have detrimental effects, and if a three-month cease in shift work or increased physical activity will modify early manifestations of CVD.

Mobilization of asbestos fibers from a 60-year-old corrugated asbestos cement roof was studied in material samples collected from a domestic house in Southern-Norway. Samples included pieces of the roof itself, rainfall simulated run off-water and moss growing on the roof surface. Weathered roof debris below the rain water system was investigated for asbestos fibers leached from the roof, and air samples were collected for asbestos concentrations in ambient air. Micrographs obtained by scanning electron microscopy show that weathering exposed asbestos fibers on the deteriorated roof surface. A high number of fibers found in the run off-water as well as in the weathered roof debris sample illustrates that exposed fibers are prone to mobilization. Investigation of weathering-induced magnesium depletion by scanning electron microscopy energy dispersive X-ray spectroscopy of asbestos fibers collected from the moss, roof underside and surface revealed that fibers had MgO weight % comparable to reference material. The major element chemistry of the fibers is therefore unaltered. Our findings demonstrate that care must be taken when working on and handling old corrugated asbestos cement roof as asbestos fibers might be released. In order to limit exposure to mobile fibers, moss covering asbestos cement roof should not be removed.

Objective To assess changes in cardiovascular disease (CVD) risk factors during a 3-year follow-up among 57 rotating shift workers and 29 day workers in industry. Methods We collected demographics by questionnaire, examined blood pressure (BP), heart rate, pulse wave velocity (PWV), carotid media thickness (IMT), and maximal oxygen uptake (V̇O_2max). We assessed blood samples for determination of lipids, glycosylated hemoglobin (HbA1c), C-reactive protein (CRP), markers of inflammation, and particle concentrations/respirable dust. Baseline comparisons were analyzed using logistic regression (plaque) and linear regression for all other outcomes. We applied mixed models to assess differences in change in health outcomes between the shift workers and the day workers. Results At baseline the adhesion molecules soluble Vascular cell adhesion molecule 1 and soluble P-selectin were elevated among the shift workers compared to that of the day workers. There was a significant difference in change in PWV between shift workers (1.29 m/s increase) and day workers (0.11 m/s increase) over the 3-year follow-up. Respirable dust levels were below the Norwegian occupational exposure limit. Conclusions Shift work in industry is associated with arterial stiffening reflecting increased risk for future CVD. More uncertainly, we found some support for systemic inflammation.

Employees working in cement production plants are exposed to airborne particulate matter (PM) which may lead to lung function impairments and airway symptoms. The PM consists of raw materials, clinker and additives which vary depending on cement blend. The aim of this work was to characterize the thoracic fraction of PM with regard to size, phase composition and mixing state. Both stationary and personal impactors were used to collect size-fractionated samples in a cement production plant in Norway. Stationary samples were measured with aerosol particle counters and collected with a 13-stage cascade impactor, which were stationed at three locations of the cement production plant: at the raw meal mill, clinker conveyor belt and cement mill. Sioutas cascade impactors, and thoracic and respirable dust samplers were used in parallel for personal sampling. Additionally, particles for electron microscopy were collected with the stationary cascade impactor for size-fractionated single particle characterization. Gravimetric measurements and element compositions of the samples from the stationary impactors show that the PM mass is dominated by calcium-rich particles of size >1 μm. The size distribution results of stationary and personal impactors were similar. Characterization of single particles reveals that limestone is the dominating material in the raw meal mill, whereas clinker and limestone dominate at the clinker conveyor belt and at the cement mill. The element composition of clinker PM did not change with particle size. The PM collected on impactor stages with aerodynamic diameter cut-offs below 0.56 μm was dominated by soot and volatile secondary particles at the three locations. The number of ultrafine particles of the cement related compounds was low. Air concentrations of PM in personal respirable and thoracic samples ranged from 0.14–10 mg m⁻³ to 0.37–9.5 mg m⁻³, respectively. Considerable local variations exist, both in composition and air concentration of the PM.

Although the use of asbestos fibres in building materials has been prohibited in Norway since 1985, asbestos-containing materials (ACMs) are still found in many buildings. Lack of knowledge and awareness of these materials may lead to exposure during refurbishing. The aim of this study was to investigate the airborne fibre concentration and classify fibres found during the abatement of various ACMs. The release of fibres during short-term work tasks, such as drilling and sawing, was also investigated. Parallel air samples were collected during asbestos abetment of different building materials and analysed with scanning electron microscope (SEM) and phase-contrast microscope (PCM), respectively. Material samples were analysed with SEM. A real-time fibre monitor was used to measure asbestos during short-term work. The highest fibre concentrations were measured for samples collected during the removal of asbestos insulating boards (1.5–4.5 fibres/cm³ [f/cm³]), and the numbers were relatively similar for SEM and PCM. A large difference in asbestos concentrations was found between SEM and PCM when analysing floor materials, which were probably caused by a high number of gypsum fibres that the PCM operator counted. Thin fibres (<0.2 µm in width) were included in the SEM count and constituted up to 50% of the total fibre concentration for the asbestos cement materials. The presence of other inorganic and organic fibres on these samples probably led to similar results between SEM and PCM. Short-term work led to peak concentrations above 30 f/cm³.

(1) Physicochemical characterisation of single particles collected in an FeMn/SiMn furnace hall. (2) Bioaccessibility of manganese in particulate matter tested in terms of dissolution in Gamble solution.