Annals Of Work Exposures and Health最新文献

Objectives: Many South African workers rely on respirators for protection from airborne hazards. To our knowledge, there is no public head and face anthropometric database for Black South African respirator users to inform the design of respirators for these individuals. The objective of our study was to determine the facial dimensions of Black South African respirator users using the 13 facial dimensions recommended by the United States National Institute for Occupational Safety and Health (NIOSH).

Methods: This was a descriptive and analytical cross-sectional study of Black South African respirator users working in Gauteng. Industries and companies known to use respirators in their operations were approached, and 693 participants between the ages of 18 to 65 were enrolled. Our study followed the methodology used in a NIOSH 2005 study that conducted a head and face anthropometric survey of US respirator users. Traditional measurement tools such as a tape measure, sliding caliper, spreading caliper, and pupillometer were used. Student's t-test was used to analyze data.

Results: The study found statistically significant differences between the facial dimensions of Black South African men and women respirator users and those of 3,000 Chinese respirator users studied in 2009 to develop a fit test panel. All the dimensions of males and females differed significantly, with the largest differences being in head circumference, neck circumference, and minimal frontal breadth. The majority of the facial dimensions of Black South Africans were also significantly different from the 3,997 American NIOSH 2007 fit test panel population, with only face width and nose protrusion not significantly different.

Conclusions: The mean values of Black South African facial dimensions differed significantly from those of the American and the Chinese populations. It may be that respirators designed and tested using the 2007 NIOSH and the 2009 Chinese fit test panels do not include dimensions representative of Black South Africans. Currently supplied respirators are likely to leave some Black South Africans unprotected due to poor fit.

This study investigated the compatibility of Tetrahydrofuran (THF) dissolution, following the procedures outlined in NIOSH Method 7500 and the similar OSHA ID-142 method, as a sample preparation technique for respirable crystalline silica (RCS) analysis in engineered stone materials compared to the muffle furnace (MF) ashing method. Our results revealed considerable variability in RCS content across different batches of engineered stone tested, underscoring the inherent material heterogeneity in engineered stone products. A statistically significant underestimation of RCS concentrations was observed when using THF dissolution for Stone A (polyester-based) samples collected on 47 mm polyvinyl chloride (PVC) filters, particularly at lower analyte loadings. In contrast, no statistically significant differences in RCS measurement were found between THF dissolution and MF ashing for the other 3 stone types, including one laboratory-synthetic material. The observed discrepancy in Stone A is likely attributed to the interaction of THF with its polyester resin binder, leading to swelling of the filter matrix and forming a non-volatile residue. This residue may physically entrap silica particles, hindering their complete recovery and subsequent quantification by X-ray diffraction (XRD). The suitability of THF processing as a sample preparation method is therefore highly dependent on the specific composition of the engineered stone. Based on these findings, MF ashing is recommended as the more reliable and universally applicable sample preparation method for engineered stone samples, especially those containing polyester resin binders. Caution should be exercised when considering THF dissolution for RCS analysis in engineered stones due to the potential for significant underestimation of actual RCS values, which could have implications for exposure assessments and regulatory compliance.

Simultaneous sampling of diisocyanates and diamines is of great importance since occupational exposure to both diamines and diisocyanates may occur during production of the diisocyanates and polyurethane (PU) products or during thermal degradation of PU material. A methodology for the simultaneous collection and determination of diisocyanates and diamines using ASSET EZ4-ICA dry sampler (Supelco, PA, United States) was presented. The sampler was previously validated and is sold commercially for isocyanate detection. This work investigated to also include diamine determinations (specifically MDA and TDA) to enable a user-friendly approach, without the use of fragile glassware and solvents during sampling. In addition, a sampler based on the same design as the ASSET-sampler but with a modified impregnation with dibutyl amine (DBA) and sulfuric acid was also demonstrated. During sampling, isocyanates were collected and derivatized with DBA and the diamines were derivatized in a subsequent work-up procedure with ethyl chloroformate to form carbamate esters. For the ASSET-ICA sampler, no breakthrough was observed for 2,4'-MDA or 4,4'-MDA for sampling at 200 mL/min for up to 4 h (240 min). For 2,4-TDA and 2,6-TDA, no breakthrough was observed for up to 60 min of sampling. For the sampler with modified impregnation, no breakthrough of TDA was observed for up to 240 min of sampling. No losses were observed for the MDA isomers when storing the samplers in a refrigerator (8 °C) for up to 21 d after sampling. However, for the TDA isomers, minor losses could be observed after storage for 8 d. Storing the samplers in a freezer (-18 °C) or performing the addition of 500 µL of 3M sulphuric acid to the sampler filter media after sampling improved the stability of the TDA isomers during storage and no losses were observed for 21 d of storage. Also, for the sampler with modified impregnation, storage for up to 21 d could be made without any significant losses of TDA. Comparable concentrations were measured in ASSET-ICA samplers and in impinger-filter samples when sampling of a controlled test atmosphere was performed at different relative humidity (30% to 70% RH) and also during sampling of thermal degradation products from PU foam.

Crystalline silica was categorized by the International Agency for Research on Cancer as a known human carcinogen. Activities related to the processing of ceramic tiles, releasing crystalline silica, may vary considerably in terms of hours worked per day and days worked per week. This variability could be particularly high for craftsmen who process ceramic materials directly on-site during installation. The aim of this study is to measure the likely exposure to respirable crystalline silica (RCS) during ceramic tiles installation, evaluating the exposure to RCS of workers processing these tiles. Exposure assessments to RCS were conducted via both fixed-site and personal sampling for 2 working hours. The measured concentrations were calculated as 8-h time-weighted average (TWA) exposures, assuming no further RCS exposure in the time period. The permitted exposure time, not to exceed the occupational exposure limit (OEL) value, was then calculated also considering the assigned protection factor of selected respiratory protective equipment. The results of this study, considered as a worst-case simulation, show that, during the processing of ceramic tiles releasing RCS, the worker exposure can be very high (up to 240.9 µg/m3), exceedance of several OELs, including the European OEL of 100 µg/m³. Even working for a few hours a day, the RCS 8-h TWA OEL is likely to be exceeded. Inhaled exposure concentrations can be reduced by using appropriate respiratory protection, by a factor equal to 10 or 20. The assumption of this work was that (i) the cutting/grinding times are not always necessarily equal to 2 h and that (ii) these processes are not characterized by pre-established and continuous processing times. For these reasons, it is important to carefully evaluate the duration of exposure to RCS during the various tasks/activities performed, as these may vary depending on different factors.

Objectives: To understand the total exposure of a human population to a chemical, it is necessary to aggregate exposures from different exposure routes (ingestion, inhalation, dermal uptake) and exposure sources (eg food, air, consumer products) from different environments (ie general, occupational, consumer use). Preventive actions or regulatory decisions require decisions to be taken on priority exposure routes and sources. This study explores the development of a quantitative decision tree to identify relevant exposure sources in the context of aggregate exposure. As a case study for spray applications, it focuses on joint exposure to a specific chemical in a consumer product through domestic use of hairspray, and exposure at the workplace involving surface spraying, such as spray application of paints.

Methods: Determinant of the exposure models ART (for workers) and ConsExpo (for the general population) were used to generate a wide range of realistic exposure scenarios. The dominance of one source over another was analyzed through pairwise random comparisons. Exposure estimates from one source containing a specific determinant are compared with those from the other source, scaled by a dominance ratio that defines how much higher one source's exposure must be to be considered dominant. For each comparison, the number of times one source exceeds the other by at least a dominance ratio is counted, resulting in the occurrence. The occurrence is compared with a predefined threshold (eg 80%). If the threshold is met or exceeded, the higher-contributing source is considered dominant and no exposure aggregation is needed; otherwise, aggregation of both sources is recommended.

Results: The findings indicated that the use of high- or medium-specification glove boxes, as forms of permanent encapsulation or encasing of the emission source, results in occupational exposure that is negligible compared with the exposure from consumer product use. When these glove boxes were used, hair spray exposure was the dominant source in 89% and 82% of cases, for high and medium specifications, respectively. A spraying activity with surface liquids performed outdoors (close to buildings) showed a significant trend toward occupational exposure dominance in 81% of cases. Using these three determinants, a three-layer quantitative decision tree was built to help users quickly decide whether aggregation was relevant before performing calculations. Aggregation was suggested in 91% of cases and avoided it in 9%.

Introduction: Tris (chloropropyl) phosphate (TCPP) is an organophosphate flame retardant (PFR) added to flexible polyurethane foam to adhere to national or sectorial flammability requirements. During the manufacturing of flexible polyurethane foam, workers can be potentially exposed to TCPP dermally or through inhalation.

Objective: We aimed to determine the exposure to TCPP in European polyurethane foam workers and perform a risk assessment based on a newly determined derived no effect level (DNEL).

Methods: In this study, 28 workers from 5 European flexible polyurethane foam production factories participated. Levels of the urinary metabolites of TCPP: bis(1-chloro-isopropyl) hydroxy-isopropyl phosphate (BCIPHIPP) and bis(1-chloro-isopropyl) phosphate (BCIPP) were measured using LC-MS/MS and risk assessment was performed by calculating estimated daily intakes (EDIs) of TCPP and comparing these with the DNEL.

Results: BCIPHIPP was detected in 100% of samples, with a median of 5.56 ng/mL (maximum 420 ng/mL). BCIPP had an overall detection frequency of 31%, but in workers from one individual factory it was detected in 93% (n = 13) of samples, with a median of 9.41 ng/mL (maximum 58.6 ng/mL). A DNEL of 3.0 mg/kg bw/day for TCPP was determined for an occupationally exposed population by evaluating a recently published chronic in vivo study on TCPP carcinogenicity. EDIs were all more than 2 orders of magnitude below the DNEL.

Conclusions: Although BCIPHIPP levels detected in this study were higher than in the general population, the performed risk assessment indicated that the included workers are not expected to be at risk for carcinogenic effects following TCPP exposure at the measured levels and that the applied safety measures are sufficiently protecting the workers under these conditions.

Objectives: The aim was to estimate the prevalence and risk of respiratory symptoms among workers exposed to epoxy resin systems in the wind turbine industry.

Methods: We conducted a cross-sectional study including 180 epoxy-exposed production workers from two Danish wind turbine blade factories and 41 non-exposed office workers. Respiratory symptoms were defined as having two or more symptoms (i.e. wheezing in chest, waking up with chest tightness, shortness of breath, attack of coughing, or asthma attack) within the last 12 mo. Epoxy exposure was defined as exposure status (epoxy-exposed production worker or non-exposed office worker) and years of epoxy-exposure (years of employment as production worker). Epoxy skin sensitization status was obtained through a patch-test. The association between epoxy-exposure and respiratory symptoms was estimated using modified Poisson regression (prevalence ratio (PR)) adjusting for smoking and age.

Results: A total of 13.3% of the epoxy-exposed production workers and 4.9% of non-exposed office workers reported two or more respiratory symptoms (PRadj=1.8, 95% CI 0.4-9.5). For years of exposure, PRadj values were 1.2 (<1 yr), 1.0 (≥1-<5 yr), and 2.6 (≥5 yr). Higher PRadj were found among men. Epoxy-sensitized production workers had a PRadj of 0.4, while non-sensitized workers had a PRadj of 1.9, compared to non-exposed office workers.

Conclusion: Epoxy-exposed production workers showed a tendency to report respiratory symptoms more often than non-exposed office workers. However, we found no clear association between exposure duration and symptoms. Further studies are highly warranted to evaluate the potential association between epoxy exposure and respiratory symptoms.

Pressure to increase rates of recycling in Great Britain is expected to increase to meet circular economy and net zero drivers. There are concerns about worker exposure to persistent organic pollutants (POPs) during the processing and recycling of waste upholstered domestic seating (WUDS). The aim of this study was to understand worker exposures to POPs, specifically the flame retardants polybrominated diphenyl ethers (PBDEs), and other airborne substances hazardous to health, when WUDS go through the recycling process. Five WUDS processing sites were visited by a health and safety executive occupational hygienist, who collected worker and static air samples, bulk dust and bulk material samples, and assessed control measures in use. All exposures to inhalable dust and PBDEs were significantly below occupational exposure limits, while exposures to airborne bacteria and fungi were elevated at most sites. Exposures to endotoxins were above the recommended health-based nonbinding occupational exposure limits at 4 sites. Across all sites, recommended control measures were only partially met, indicating that exposures to airborne dust and biological agents could be reduced that these sites.

Background: Smelter workers and chimney sweepers may be exposed to heavy metals via particulate matter through airways and skin uptake. We hypothesized that these workers have higher blood concentrations of arsenic, cadmium, chromium, lead, and mercury compared to an office-worker group. Furthermore, we hypothesized that their concentrations increased cross-week despite the use of properly fitted respiratory protective equipment (RPE). Our aim was to uncover workers' general heavy metal concentrations and cross-week changes to provide further insight into industrial occupational exposure.

Methods: We conducted a cross-sectional study with 2 repeated measures. We quantified whole blood arsenic, cadmium, chromium, lead, and mercury 4 d apart. Participants answered a standardized questionnaire and log scheme on work exposure. Samples were analyzed using inductively coupled plasma mass spectrometry, and we used Wilcoxon's signed-rank test and multiple linear regression to assess heavy metal differences across the 4-d workweek and occupational groups.

Results: Out of 226 participants (99 smelter workers, 80 chimney sweepers, and 47 office workers), 185 participants provided blood samples. The final dataset included 151 participants. Overall, heavy metal concentrations were below Mayo Clinic's cutoff concentrations. Multiple linear regression analysis with confounders did not show higher concentrations of heavy metals in the exposed occupations compared to office workers. Instead, we found statistically significant lower chromium in smelter workers. Sensitivity power analysis showed that our nonsignificant findings in the other metals were underpowered. Wilcoxon's signed rank test did not show cross-week increase.

Conclusions: In our population of chimney sweepers and smelter workers with high percentage use of RPE, occupational exposure to heavy metals does not seem to increase workers blood heavy metals; lifestyle factors seem more important. Further studies with higher number of participants are warranted to ensure our findings.

Safe Work Australia is currently considering reducing the occupational exposure limit for respirable crystalline silica to a health-based level near the detection limits of current sampling and analytical methods. Some stakeholders have argued that the limit should consider measurement uncertainty. Given the large day to day variability in exposure measurements and that occupational exposure limits (based on limited data) are not fine lines, we argue that this is unnecessary and risks failing to adequately protect worker health.