The Contribution of High Levels of Somatic Symptom Severity to Sickness Absence Duration, Disability and Discharge

Introduction: The primary objectives were to compare the duration of sickness absence in employees with high levels of somatic symptom severity (HLSSS) with employees with lower levels of somatic symptom severity, and to establish the long-term outcomes concerning return to work (RTW), disability and discharge. Secondary objective was to evaluate determinants of the duration of sickness absence in employees with HLSSS. Methods: 489 sick-listed employees registered with five Occupational Health Physician (OHP) group practices were included in this study. We measured their baseline scores for somatic symptoms severity, depressive disorders, anxiety disorders, health anxiety, distress and functional impairment. The OHPs filled in a questionnaire on their diagnosis. A prospective 2-year follow-up was carried out to assess the long-term outcomes concerning sickness absence, and retrospective information was gathered with regard to sickness absence during the 12 months before the employees were sick-listed. Results: The median duration of sickness absence was 78 days longer for employees with HLSSS. They more often remained disabled and were discharged more often, especially due to problems in the relationship between the employer and the employee. HLSSS, health anxiety and older age contributed to a longer duration of sickness absence of employees. Conclusion: High levels of somatic symptom severity are a determinant of prolonged sickness absence, enduring disabilities and health-related job loss. Occupational health physicians should identify employees who are at risk and adhere to guidelines for medically unexplained somatic symptoms

The quality of the indoor environment: ventilation and moisture

De kwaliteit van het binnenmilieu hangt samen met chemische factoren, die van de woningventilatie afhankelijk zijn en met biologische factoren, die samenhangen met ventilatie van en vocht in de woning. Ventilatie is van belang omdat het de binnenlucht-concentratie van stoffen uit consumentenproducten, apparaten en bouwmaterialen bepaalt. Als chemische stoffen in voldoende hoge concentratie voorkomen kunnen ze nadelige effecten voor de gezondheid veroorzaken door geurhinder, irriterende effecten en via het totaal aan vluchtige organische koolwaterstoffen. Ook kunnen bepaalde stoffen de kans op kanker verhogen. Doordat het aantal huizen met een dichte bouwschil toeneemt en daarmee de intrinsieke ventilatie af, wordt de ventilatie een kritische factor ten aanzien van blootstelling aan chemische stoffen. Daarom wordt verwacht dat daaraan gerelateerde gezondheidsproblemen toenemen in de toekomst. Vochtigheid is een factor die via biologische agentia als huisstofmijt en schimmel de gezondheid nadelig beinvloedt. Op basis van het Nederlands huizenbestand wordt verwacht dat de vochtigheid van de huizen, en daarmee de volksgezondheidseffecten, afneemt in de toekomst. Deze studie is uitgevoerd voor de milieuverkenning 5.The quality of the indoor environment is described in terms of chemical agents, as indicated by ventilation, and biological agents, as indicated by moisture. Ventilation is a general factor that determines levels of chemicals from consumer products, appliances and building materials in indoor air. Health effects that are caused by peak levels of chemicals are expected to be related to odour, irritation of mucous membranes and eyes, total volatile organic compound concentrations. In addition, chronic exposure may be linked to effects like carcinogenicity. These health effects are expected to increase towards 2020-2030 because an increasing number of houses will have an intrinsic low ventilation rate. Moisture is a general factor related to health effects caused by biological agentia such as house dust mite and moulds. The expected development in the Dutch housing stock is that moisture problems will be decreasing towards 2020-2030. The present study serves as background for Environmental Outlook 5.VRO

The quality of the indoor environment: ventilation and moisture

The quality of the indoor environment is described in terms of chemical agents, as indicated by ventilation, and biological agents, as indicated by moisture. Ventilation is a general factor that determines levels of chemicals from consumer products, appliances and building materials in indoor air. Health effects that are caused by peak levels of chemicals are expected to be related to odour, irritation of mucous membranes and eyes, total volatile organic compound concentrations. In addition, chronic exposure may be linked to effects like carcinogenicity. These health effects are expected to increase towards 2020-2030 because an increasing number of houses will have an intrinsic low ventilation rate. Moisture is a general factor related to health effects caused by biological agentia such as house dust mite and moulds. The expected development in the Dutch housing stock is that moisture problems will be decreasing towards 2020-2030. The present study serves as background for Environmental Outlook 5.De kwaliteit van het binnenmilieu hangt samen met chemische factoren, die van de woningventilatie afhankelijk zijn en met biologische factoren, die samenhangen met ventilatie van en vocht in de woning. Ventilatie is van belang omdat het de binnenlucht-concentratie van stoffen uit consumentenproducten, apparaten en bouwmaterialen bepaalt. Als chemische stoffen in voldoende hoge concentratie voorkomen kunnen ze nadelige effecten voor de gezondheid veroorzaken door geurhinder, irriterende effecten en via het totaal aan vluchtige organische koolwaterstoffen. Ook kunnen bepaalde stoffen de kans op kanker verhogen. Doordat het aantal huizen met een dichte bouwschil toeneemt en daarmee de intrinsieke ventilatie af, wordt de ventilatie een kritische factor ten aanzien van blootstelling aan chemische stoffen. Daarom wordt verwacht dat daaraan gerelateerde gezondheidsproblemen toenemen in de toekomst. Vochtigheid is een factor die via biologische agentia als huisstofmijt en schimmel de gezondheid nadelig beinvloedt. Op basis van het Nederlands huizenbestand wordt verwacht dat de vochtigheid van de huizen, en daarmee de volksgezondheidseffecten, afneemt in de toekomst. Deze studie is uitgevoerd voor de milieuverkenning 5

Thermodynamic Driving Force of Hydrogen on Rumen Microbial Metabolism: A Theoretical Investigation

Hydrogen is a key product of rumen fermentation and has been suggested to thermodynamically control the production of the various volatile fatty acids (VFA). Previous studies, however, have not accounted for the fact that only thermodynamic near-equilibrium conditions control the magnitude of reaction rate. Furthermore, the role of NAD, which is affected by hydrogen partial pressure (PH 2), has often not been considered. The aim of this study was to quantify the control of PH 2 on reaction rates of specific fermentation pathways, methanogenesis and NADH oxidation in rumen microbes. The control of PH 2 was quantified using the thermodynamic potential factor (FT), which is a dimensionless factor that corrects a predicted kinetic reaction rate for the thermodynamic control exerted. Unity FT was calculated for all glucose fermentation pathways considered, indicating no inhibition of PH 2 on the production of a specific type of VFA (e.g., acetate, propionate and butyrate) in the rumen. For NADH oxidation without ferredoxin oxidation, increasing PH 2 within the rumen physiological range decreased FT from unity to zero for different NAD+ to NADH ratios and pH of 6.2 and 7.0, which indicates thermodynamic control of PH 2. For NADH oxidation with ferredoxin oxidation, increasing PH 2 within the rumen physiological range decreased FT from unity at pH of 7.0 only. For the acetate to propionate conversion, FT increased from 0.65 to unity with increasing PH 2, which indicates thermodynamic control. For propionate to acetate and butyrate to acetate conversions, FT decreased to zero below the rumen range of PH 2, indicating full thermodynamic suppression. For methanogenesis by archaea without cytochromes, FT differed from unity only below the rumen range of PH 2, indicating no thermodynamic control. This theoretical investigation shows that thermodynamic control of PH 2 on individual VFA produced and associated yield of hydrogen and methane cannot be explained without considering NADH oxidation.</p