Response to letter to the editor from Elinder and Nordberg concerning Byber et al. 2016. Cadmium or cadmium compounds and chronic kidney disease in workers and the general population: a systematic review, Crit Rev Toxicol. 46(3):191-240. DOI: 0.3109/10408444.2015.1076375.

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Cadmium or cadmium compounds and chronic kidney disease in workers and the general population: a systematic review

Background: Cadmium (Cd) is abundantly documented as a metal mainly affecting tubular function both in workers and in the general population indirectly exposed via the environment. Results from epidemiological studies linking Cd exposure and risk of progression to chronic kidney disease (CKD) are, however, conflicting. Objectives: To perform a systematic review of the association between Cd exposure and CKD. Methods: A systematic appraisal of publications found in MEDLINE (1946–2014), EMBASE (1974–2012) and an in-house database (1986–2013) was conducted. Additional studies were searched for by contacting experts and checking reference lists. Search terms used key and text words. No language restriction was applied. Cohort, case–control and case-series with follow-up including individual and objective assessment of occupational or environmental exposure were eligible. Studies were selected and data extracted by two independent reviewers using predefined forms. Study characteristics and results were extracted to structured tables. Synthesis was qualitative and results appraised with causality criteria. Results: Thirty-four exposed groups, totaling more than 3000 participants, were eligible. Overall, results disclosed no convincing evidence supporting a risk of progression to CKD in populations exposed to Cd. Lack of information about methods, risk of bias and heterogeneity were identified as limitations and precluded conducting a meta-analysis. Publication bias did not appear as a major problem. Conclusions: This qualitative systematic review does not support the contention that human exposure to Cd leads to progressive CKD. Abbreviations: AQC: analytical quality control; A1MG: a1-microglobulin; B2MG: b2-microglobulin; Cd: cadmium; Cd-B: cadmium in blood; Cd-kidney: Cd in kidney; Cd-liver: Cd in liver; Cd-U: cadmium in urine; CI: confidence interval; ClC5: chloride channel 5; CKD: chronic kidney disease; CKD-EPI: CKD Epidemiology Collaboration; CKDu: chronic kidney disease of unknown origin; ESRD: end-stage renal disease (kidney failure treated by dialysis or transplantation); GFR: glomerular filtration rate; eGFR: estimated glomerular filtration rate; GM: geometric mean; GSD: geometric standard deviation; HMW: high-molecular-weight; ICD: International Classification of Diseases; KDIGO: Kidney Disease Improving Global Outcomes; LMW: low-molecular-weight; MDRD: Modification of Diet in Renal Disease; mGFR: measured GFR; NA: non-applicable; NAG: N-acetyl-b-D-glucosaminidase; NI: no information; ND: not done; ns: non-significant; P: plasma; RBP: retinol-binding protein; RRT: renal replacement therapy; S: serum; SD: standard deviation; SMR: standardized mortality ratio; U: urin

Predicted Mercury Soil Concentrations from a Kriging Approach for Improved Human Health Risk Assessment

Health-risks from contaminated soils are assessed all over the world. An aspect that many risk assessments share is the heterogeneity in the distribution of contaminants. In a preceding study, we assessed potential health-risks for mothers and children living on mercury-contaminated soils in Switzerland using human biomonitoring-values (HBM) and soil samples. We assessed 64 mothers and 107 children who had resided in a defined area for at least 3 months. HBM-concentrations for mercury in urine and hair were measured, a detailed questionnaire was administered for each individual, and more than 4000 individual mercury soil values were obtained in 2015. In this study, we aimed at investigating possible associations of mercury soil- and HBM-values by re-analyzing our data, using predictions of the mercury concentrations at the exact location of the participant’s homes with a kriging approach. Although kriging proved to be a useful method to predict mercury soil concentrations, we did not detect an association between mercury soil- and HBM-values, in agreement with earlier findings. Benefits of geostatistical methods seem to be limited in the context of our study. Conclusions made in our preceding study about potential health risks for the residential population are robust and not altered by the current study

Human-biomonitoring and individual soil measurements for children and mothers in an area with recently detected mercury-contaminations and public health concerns: a cross-sectional study

In this study, we assessed intracorporal mercury concentrations in subjects living on partially mercury-contaminated soils in a defined area in Switzerland. We assessed 64 mothers and 107 children who resided in a defined area for at least 3 months. Mercury in biological samples (urine and hair) was measured, a detailed questionnaire was administered for each individual, and individual mercury soil values were obtained. Human biomonitoring results were compared with health-related and reference values. Mothers and children in our study had geometric means (GMs) of 0.22 µg Hg/g creatinine in urine (95th percentile (P95) = 0.85 µg Hg/g) and 0.16 µg Hg/g (P95 = 0.56 µg Hg/g), respectively. In hair, mothers and children had GMs of 0.21 µg Hg/g (P95 = 0.94 µg/g) and 0.18 µg/g (P95 = 0.60 µg/g), respectively. We found no evidence for an association between mercury values in soil and those in human specimens nor for a health threat in residential mothers and children

Humidification of indoor air for preventing or reducing dryness symptoms or upper respiratory infections in educational settings and at the workplace

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To evaluate the effectiveness of interventions that increase indoor air humidity to prevent or reduce dryness symptoms of the eyes, the skin and the upper respiratory tract (URT) or URT infections at work and in educational settings. Background Following the progress of industrialisation, workplaces have increasingly moved from outdoor to indoor locations. This shift has changed the spectrum of conditions to which workers are exposed. This fact is not only relevant to the adult working population, but also to children and young adults, as they stay indoors for a significant part of the day throughout their education (Angelon‐Gaetz 2014; Jaakkola 1991; Seppanen 2002). At most workplaces, indoor air is a predefined condition. Its components vary considerably among different occupational and educational settings. Emissions from indoor sources like building materials, furnishings, office equipment and human activities result in the release of dust as well as chemical and biological compounds. Following natural ventilation, outdoor factors, such as pollen and particulate matters, may also contribute to indoor air quality (Alsmo 2014). Indoor air climate results from a combination of four physical parameters: temperature, radiation temperature, air velocity and humidity. Humidity is defined as absolute humidity (water vapour content of the air) whilst relative humidity (RH) is the ratio of vapour pressure and saturation vapour pressure. RH, expressed as a percentage, increases relative to a decrease in temperature. A humidity level of 100% means that the air is completely saturated with water vapour. The influence of different humidity levels on pathogens, allergens and chemical factors is presented in Figure 1 (Alsmo 2014)

Humidification of indoor air for preventing or reducing dryness symptoms or upper respiratory infections in educational settings and at the workplace

Background Indoor exposure to dry air during heating periods has been associated with dryness and irritation symptoms of the upper respiratory airways and the skin. The irritated or damaged mucous membrane poses an important entry port for pathogens causing respiratory infections. Objectives To determine the effectiveness of interventions that increase indoor air humidity in order to reduce or prevent dryness symptoms of the eyes, the skin and the upper respiratory tract (URT) or URT infections, at work and in educational settings. Search methods The last search for all databases was done in December 2020. We searched Ovid MEDLINE, Embase, CENTRAL (Cochrane Library), PsycINFO, Web of Science, Scopus and in the field of occupational safety and health: NIOSHTIC‐2, HSELINE, CISDOC and the In‐house database of the Division of Occupational and Environmental Medicine, University of Zurich. We also contacted experts, screened reference lists of included trials, relevant reviews and consulted the WHO International Clinical Trials Registry Platform (ICTRP). Selection criteria We included controlled studies with a parallel group or cross‐over design, quasi‐randomised studies, controlled before‐and‐after and interrupted time‐series studies on the effects of indoor air humidification in reducing or preventing dryness symptoms and upper respiratory tract infections as primary outcomes at workplace and in the educational setting. As secondary outcomes we considered perceived air quality, other adverse events, sick leave, task performance, productivity and attendance and costs of the intervention. Data collection and analysis Two review authors independently screened titles, abstracts and full texts for eligibility, extracted data and assessed the risks of bias of included studies. We synthesised the evidence for the primary outcomes 'dry eye', 'dry nose', 'dry skin', for the secondary outcome 'absenteeism', as well as for 'perception of stuffiness' as the harm‐related measure. We assessed the certainty of evidence using the GRADE system

Human-biomonitoring and individual soil measurements for children and mothers in an area with recently detected mercury-contaminations and public health concerns: a cross-sectional study

<p>In this study, we assessed intracorporal mercury concentrations in subjects living on partially mercury-contaminated soils in a defined area in Switzerland. We assessed 64 mothers and 107 children who resided in a defined area for at least 3 months. Mercury in biological samples (urine and hair) was measured, a detailed questionnaire was administered for each individual, and individual mercury soil values were obtained. Human biomonitoring results were compared with health-related and reference values. Mothers and children in our study had geometric means (GMs) of 0.22 µg Hg/g creatinine in urine (95th percentile (P95) = 0.85 µg Hg/g) and 0.16 µg Hg/g (P95 = 0.56 µg Hg/g), respectively. In hair, mothers and children had GMs of 0.21 µg Hg/g (P95 = 0.94 µg/g) and 0.18 µg/g (P95 = 0.60 µg/g), respectively. We found no evidence for an association between mercury values in soil and those in human specimens nor for a health threat in residential mothers and children.</p