Personal protective equipment for preventing asbestos exposure in workers.

BACKGROUND: Asbestos exposure can lead to asbestos-related diseases. The European Union (EU) has adopted regulations for workplaces where asbestos is present. The EU occupational exposure limit (OEL) for asbestos is 0.1 fibres per cubic centimetre of air (f/cm3) as an eight-hour average. Different types of personal protective equipment (PPE) are available to provide protection and minimise exposure; however, their effectiveness is unclear. OBJECTIVES: To assess the effects of personal protective equipment (PPE), including donning and doffing procedures and individual hygienic behaviour, compared to no availability and use of such equipment or alternative equipment, on asbestos exposure in workers in asbestos demolition and repair work. SEARCH METHODS: We searched MEDLINE, Embase, CENTRAL, and Scopus (September 2022), and we checked the reference lists of included studies. SELECTION CRITERIA: We included studies that measured asbestos concentration outside and inside PPE (considering outside concentration a surrogate for no PPE), exposure to asbestos after doffing PPE, donning and doffing errors, nonadherence to regulations, and adverse effects of PPE. DATA COLLECTION AND ANALYSIS: Two review authors selected studies, extracted data, and assessed risk of bias using ROBINS-I. We categorised PPE as full-face filtering masks, supplied air respirators (SARs), and powered air-purifying respirators (PAPRs). Values for asbestos outside and inside PPE were transformed to logarithmic values for random-effects meta-analysis. Pooled logarithmic mean differences (MDs) were exponentiated to obtain the ratio of means (RoM) and 95% confidence interval (95% CI). The RoM shows the degree of protection provided by the respirators (workplace protection factor). Since the RoM is likely to be much higher at higher outside concentrations, we presented separate results according to the outside asbestos concentration, as follows. • Below 0.01 f/cm3 (band 1) • 0.01 f/cm3 to below 0.1 f/cm3 (band 2) • 0.1 f/cm3 to below 1 f/cm3 (band 3) • 1 f/cm3 to below 10 f/cm3 (band 4) • 10 f/cm3 to below 100 f/cm3 (band 5) • 100 f/cm3 to below 1000 f/cm3 (band 6) Additionally, we determined whether the inside concentrations per respirator and concentration band complied with the current EU OEL (0.1 f/cm3) and proposed EU OEL (0.01 f/cm3). MAIN RESULTS: We identified six studies that measured asbestos concentrations outside and inside respiratory protective equipment (RPE) and one cross-over study that compared the effect of two different coveralls on body temperature. No studies evaluated the remaining predefined outcomes. Most studies were at overall moderate risk of bias due to insufficient reporting. The cross-over study was at high risk of bias. Full-face filtering masks Two studies evaluated full-face filtering masks. They provided insufficient data for band 1 and band 6. The results for the remaining bands were as follows. • Band 2: RoM 19 (95% CI 17.6 to 20.1; 1 study, 3 measurements; moderate certainty) • Band 3: RoM 69 (95% CI 26.6 to 175.9; 2 studies, 17 measurements; very low certainty) • Band 4: RoM 455 (95% CI 270.4 to 765.1; 1 study, 16 measurements; low certainty) • Band 5: RoM 2752 (95% CI 1236.5 to 6063.2;1 study, 3 measurements; low certainty) The inside measurements in band 5 did not comply with the EU OEL of 0.1 f/cm3, and no inside measurements complied with the proposed EU OEL of 0.01 f/cm3. Supplied air respirators Two studies evaluated supplied air respirators. They provided no data for band 6. The results for the remaining bands were as follows. • Band 1: RoM 11 (95% CI 7.6 to 14.9; 1 study, 134 measurements; moderate certainty) • Band 2: RoM 63 (95% CI 43.8 to 90.9; 1 study, 17 measurements; moderate certainty) • Band 3: RoM 528 (95% CI 368.7 to 757.5; 1 study, 38 measurements; moderate certainty) • Band 4: RoM 4638 (95% CI 3071.7 to 7044.5; 1 study, 49 measurements; moderate certainty) • Band 5: RoM 26,134 (16,647.2 to 41,357.1; 1 study, 22 measurements; moderate certainty) All inside measurements complied with the current OEL of 0.1 f/cm3 and the proposed OEL of 0.01 f/cm3. Powered air-purifying respirators Three studies evaluated PAPRs. The results per band were as follows. • Band 1: RoM 8 (95% CI 3.7 to 19.1; 1 study, 23 measurements; moderate certainty) • Band 2: RoM 90 (95% CI 64.7 to 126.5; 1 study, 17 measurements; moderate certainty) • Band 3: RoM 104 (95% CI 23.1 to 464.1; 3 studies, 14 measurements; very low certainty) • Band 4: RoM 706 (95% CI 219.2 to 2253.0; 2 studies, 43 measurements; very low certainty) • Band 5: RoM 1366 (544.6 to 3428.9; 2 studies, 8 measurements; low certainty) • Band 6: RoM 18,958 (95% CI 4023.9 to 90,219.4; 2 studies, 13 measurements; very low certainty) All inside measurements complied with the 0.1 f/cm3 OEL when the outside concentration was below 10 f/cm3 (band 1 to band 4). From band 3, no measurements complied with the proposed OEL of 0.01 f/cm3. Different types of coveralls One study reported the adverse effects of coveralls. A polyethylene suit may increase the body temperature more than a ventilated impermeable polyvinyl (PVC) coverall, but the evidence is very uncertain (MD 0.17 °C, 95% CI -0.08 to 0.42; 1 study, 11 participants; very low certainty). AUTHORS' CONCLUSIONS: Where the outside asbestos concentration is below 0.1 f/cm3, SARS and PAPRs likely reduce exposure to below the proposed OEL of 0.01 f/cm3. For outside concentrations up to 10 f/cm3, all respirators may reduce exposure below the current OEL, but only SAR also below the proposed OEL. In band 5 (10 to < 100 f/cm3), full-face filtering masks may not reduce asbestos exposure below either OEL, SARs likely reduce exposure below both OELs, and there were no data for PAPRs. In band 6 (100 f/cm3 to < 1000 f/cm3), PAPRs may not reduce exposure below either OEL, and there were no data for full-face filtering masks or SARs. Some coveralls may increase body temperature more than others. Randomised studies are needed to directly compare PAPRs and SARs at higher asbestos concentrations and to assess adverse effects. Future studies should assess the effects of doffing procedures.

How to improve the assessment of the impact of occupational diseases at a national level? The Netherlands as an example.

OBJECTIVE: To explore the impact of occupational diseases (ODs) through estimations of population attributable fractions (PAFs) in a national context. METHODS: PAFs were calculated for eight prevalent ODs using existing data on the prevalence of exposure to risk factors at work and the strength of their association with diseases based on systematic reviews. Six systematic reviews with meta-analyses and two overview papers were selected. All addressed the relationship between occupational exposure to work-related risk factors for these eight prevalent ODs. Prevalence figures for exposure to work-related risk factors were retrieved from the Dutch National Working Conditions Survey (NWCS) based on self-reports by approximately 40 000 workers. The specific risk factors retrieved from the reviews were matched with the available and dichotomised self-reported exposure items from the NWCS by two authors. RESULTS: The eight frequently reported ODs among the Dutch working population revealed PAFs varying between 3% and 25%. Lateral epicondylitis and distress/burnout had the highest attributable fractions, with percentages of 25% and 18%, respectively. For knee osteoarthritis (13%), shoulder soft tissue disorders (10%) and non-specific low back pain (10%) approximately 1 in 10 cases were attributable to work. PAFs for irritant contact dermatitis, noise-induced hearing loss and chronic obstructive pulmonary disease were 15%, 6% and 3%, respectively. CONCLUSION: Data from systematic reviews and self-reported data on exposure provide opportunities to estimate the impact of ODs. For the Netherlands, they revealed substantial and varying attributions of work for prevalent diseases.

An Evidence-Based Multidisciplinary Practice Guideline to Reduce the Workload due to Lifting for Preventing Work-Related Low Back Pain.

We developed an evidence-based practice guideline to support occupational safety and health (OSH) professionals in assessing the risk due to lifting and in selecting effective preventive measures for low back pain (LBP) in the Netherlands. The guideline was developed at the request of the Dutch government by a project team of experts and OSH professionals in lifting and work-related LBP. The recommendations for risk assessment were based on the quality of instruments to assess the risk on LBP due to lifting. Recommendations for interventions were based on a systematic review of the effects of worker- and work directed interventions to reduce back load due to lifting. The quality of the evidence was rated as strong (A), moderate (B), limited (C) or based on consensus (D). Finally, eight experts and twenty-four OSH professionals commented on and evaluated the content and the feasibility of the preliminary guideline. For risk assessment we recommend loads heavier than 25 kg always to be considered a risk for LBP while loads less than 3 kg do not pose a risk. For loads between 3-25 kg, risk assessment shall be performed using the Manual handling Assessment Charts (MAC)-Tool or National Institute for Occupational Safety and Health (NIOSH) lifting equation. Effective work oriented interventions are patient lifting devices (Level A) and lifting devices for goods (Level C), optimizing working height (Level A) and reducing load mass (Level C). Ineffective work oriented preventive measures are regulations to ban lifting without proper alternatives (Level D). We do not recommend worker-oriented interventions but consider personal lift assist devices as promising (Level C). Ineffective worker-oriented preventive measures are training in lifting technique (Level A), use of back-belts (Level A) and pre-employment medical examinations (Level A). This multidisciplinary evidence-based practice guideline gives clear criteria whether an employee is at risk for LBP while lifting and provides an easy-reference for (in)effective risk reduction measures based on scientific evidence, experience, and consensus among OSH experts and practitioners.