Occupational Airborne Exposure Research Articles

Validation of a laboratory spray generation system and its use in a comparative study of hexamethylene diisocyanate (HDI) evaluation methods

Isocyanates are well-known irritants and sensitizers, and measuring their occupational airborne exposure is challenging due to their high chemical reactivity and semi-volatile nature. This study builds on a previous publication...

Health hazards of particles in additive manufacturing: a cross-disciplinary study on reactivity, toxicity and occupational exposure to two nickel-based alloys

The increasing use of additive manufacturing (AM) techniques (e.g., 3D-printing) offers many advantages but at the same time presents some challenges. One concern is the possible exposure and health risk related to metal containing particles of different sizes. Using the nickel-based alloys Hastelloy X (HX) and Inconel 939 (IN939) as a case, the aim of this cross-disciplinary study was to increase the understanding on possible health hazards and exposure. This was done by performing in-depth characterization of virgin, reused and condensate powders, testing in vitro toxicity (cytotoxicity, genotoxicity, oxidative stress), and measuring occupational airborne exposure. The results showed limited metal release from both HX and IN939, and slightly different surface composition of reused compared to virgin powders. No or small effects on the cultured lung cells were observed when tested up to 100 µg/mL. Particle background levels in the printing facilities were generally low, but high transient peaks were observed in relation to sieving. Furthermore, during post processing with grinding, high levels of nanoparticles (> 100,000 particles/cm3) were noted. Urine metal levels in AM operators did not exceed biomonitoring action limits. Future studies should focus on understanding the toxicity of the nanoparticles formed during printing and post-processing.

Airborne occupational exposures associated with pulmonary sarcoidosis: a systematic review and meta-analysis

The aetiology and pathophysiology of sarcoidosis is ill defined—current hypotheses centre on complex genetic–immune–environmental interactions in an individual, triggering a granulomatous process. The aim of this systematic review is to...

126 Emission and Exposure Characterization During Metal Waste Recycling

Abstract Waste of electrical and electronic equipment (WEEE) is one of the fastest-growing waste streams in the EU. The airborne occupational and environmental exposures generated by this waste handling are poorly quantified, and the growing use of nanomaterials in electronics adds to the uncertainty of risk assessment. Emission and personal exposure measurements were carried out during industrial recycling for three different metal waste flows: WEEE, metal scrap and cables. Size distributions and number-, mass- and lung deposited surface area concentrations were assessed by on-line techniques, and filter samples were collected for gravimetric analyses, metal content, and electron microscopy. Samples for elemental analyses with Particle Induced X-ray Emission (PIXE) was collected by a 12-stage low-pressure impactor . Additionally, low-cost sensors were deployed for long term monitoring. By number, the size distributions from all three flows were heavily dominated by particles <100 nm. Electron microscopy showed that there are many different elements in the same particle and that the composition of different particles vary considerably. Abundant elements, according to ICP-MS, were Fe, Al, Zn, and Cu, but Pb, Mn, Ba, and Co were also detected. PIXE analysis showed that the chemical composition indeed is different in different particle sizes, with e.g. Cr almost exclusively being present in particles < 200 nm. Low-cost sensors, not previously used for monitoring in highly polluted industrial settings, functioned well after 30 days. This study shows that detailed particle characterization is crucial for understanding of today’s and tomorrow’s waste recycling exposures, and as input to future toxicological assessments.

Geospatial analysis of patients' social determinants of health for health systems science and disparity research.

Geospatial analysis of patients' social determinants of health for health systems science and disparity research.

Exposure assessment of polycyclic aromatic hydrocarbons in refined coal tar sealant applications.

Refined coal tar sealant (RCTS) emulsions are used to seal the surface of asphalt pavement. Nine of the 22 polycyclic aromatic hydrocarbons (PAHs) evaluated in this study are classified as known, probable, or possible human carcinogens. Exposure assessment research for RCTS workers has not been published previously. The overall objective of this study was to develop a representative occupational exposure assessment of PAH exposure for RCTS workers based on worksite surveys. The specific aims were to: 1) quantify full-shift airborne occupational exposures to PAHs among RCTS workers; 2) quantify workers' dermal exposures to PAHs; 3) quantify biomarkers of PAH exposure in workers' urine; 4) identify specific job titles associated with RCTS exposure; and 5) apply these results to a biological exposure index to assess risk of potential genotoxicity from occupational exposures. A total of twenty-one RCTS workers were recruited from three companies. Personal and area air samples were collected using a modification of NIOSH Method 5515. Dermal exposure was assessed by hand and neck wipes before and after shifts. Twenty-two PAHs were quantified via gas chromatography-mass spectrometry selected ion monitoring. Internal dose was estimated by quantifying select PAH metabolites in pre- and post-shift urine samples using on-line solid phase extraction-high performance liquid chromatography-tandem mass spectrometry. PAH levels in the worker breathing zones were highest for naphthalene, acenaphthene, and phenanthrene, with geometric means of 52.1, 11.4, and 9.8μg/m3, respectively. Hand wipe levels of phenanthrene, fluoranthene and pyrene were the highest among the 22 PAHs with geometric means of 7.9, 7.7, and 5.5μg/cm2, respectively. Urinary PAH biomarkers for naphthalene, fluorene, phenanthrene, and pyrene were detected in all workers and were higher for post-shift samples than those collected pre-shift. Urinary concentrations of the metabolite 1-hydroxypyrene were greater than the American Conference of Governmental Industrial Hygienists (ACGIH) Biological Exposure Index (BEI) for this metabolite in 89 percent of post-shift samples collected on the final day of the work week or field survey. Statistically significances were found between concentrations of fluorene, naphthalene, and phenanthrene in the breathing zone of workers and their corresponding urinary PAH biomarkers. Workers were placed in two work place exposure groups: applicators and non-applicators. Applicators had higher total PAH concentrations in personal breathing zone (PBZ) air samples than non-applicators and were more likely to have post-shift hand wipe concentrations significantly higher than pre-shift concentrations. Concentrations of post-shift urinary biomarkers were higher, albeit not significantly, for applicators than non-applicators. The exposure results from RCTS worker samples cannot be explained by proximal factors such as nearby restaurants or construction. Air and skin concentration levels were substantially higher for RCTS workers than previously published levels among asphalt workers for all PAHs. PAH profiles on skin wipes were more consistent with RCTS sealant product than air samples. Last day post-shift urinary concentrations of 1-hydroxypyrene greatly exceeded the ACGIH BEI benchmark of 2.5μg/L in 25 of 26 samples, which suggests occupational exposure and risk of genotoxicity. When pyrene and benzo[a]pyrene were both detected, concentration ratios from personal exposure samples were used to calculate the adjusted BEI. Concentrations of 1-hydroxypyrene exceeded the adjusted BEIs for air, hand wipes, and neck wipes in most cases. These results indicate the need to increase safety controls and exposure mitigation for RCTS workers.

Airborne occupational exposures and the risk of developing respiratory symptoms and airway obstruction in the Lifelines Cohort Study

ObjectivesTo date, only a few studies have investigated the associations between occupational exposures and respiratory outcomes longitudinally in the general population. We investigated the associations between occupational exposures and the...

Safe-by-design strategies applied to scaffold hybrid manufacturing

The EU-project FAST (GA 685825) has developed a 3D printer machine prototype for the manufacture of bone implants (scaffolds), by merging masterbatches of biodegradable polymer poly(ethylene oxide)terephthalate/poly(butylene terephthalate) [PEOT/PBT] doped with nanofillers [reduced graphene oxide (rGO), hydroxyapatite (HA) and magnesium aluminium hydroxide ciprofloxacin hydrotalcite (LDH-CFX)], and atmospheric plasma technology. This paper focus on the safe design strategies identified by FAST to address the risk to health resulting from the potential airborne emission of nano-objects and their aggregates and agglomerates (NOAAs) by the 3D printer prototype, which might result in occupational exposures by inhalation. The work also includes measurements of airborne emissions and occupational exposures carried out during the verification stage of the prototype design. Nanofillers particles (rGO, n-HA, LDH-CFX) were not observed, neither at source nor in the working area, suggesting no release of free nanofillers to the air one they have been embedded in the polymer masterbatch. Additionally, the exposure in the workplace was far below the selected Occupational Exposure Levels (OELs), for total particle number concentration (PNC), dust, elemental carbon (EC) and volatile organic compounds (VOCs). The results showed that, when working with the current prototype in normal operation (for its intended use) and with controls enabled [enclosure with the doors closed and Local Exhaust Ventilation (LEV) activated], the emission from the machine and the worker’s exposure to NOAAs are well controlled.

Toxicological effects of zinc oxide nanoparticle exposure: an in vitro comparison between dry aerosol air-liquid interface and submerged exposure systems

Engineered nanomaterials (ENMs) are increasingly produced and used today, but health risks due to their occupational airborne exposure are incompletely understood. Traditionally, nanoparticle (NP) toxicity is tested by introducing NPs to cells through suspension in the growth media, but this does not mimic respiratory exposures. Different methods to introduce aerosolized NPs to cells cultured at the air-liquid-interface (ALI) have been developed, but require specialized equipment and are associated with higher cost and time. Therefore, it is important to determine whether aerosolized setups induce different cellular responses to NPs than traditional ones, which could provide new insights into toxicological responses of NP exposure. This study evaluates the response of human alveolar epithelial cells (A549) to zinc oxide (ZnO) NPs after dry aerosol exposure in the Nano Aerosol Chamber for In Vitro Toxicity (NACIVT) system as compared to conventional, suspension-based exposure: cells at ALI or submerged. Similar to other studies using nebulization of ZnO NPs, we found that dry aerosol exposure of ZnO NPs via the NACIVT system induced different cellular responses as compared to conventional methods. ZnO NPs delivered at 1.0 µg/cm2 in the NACIVT system, mimicking occupational exposure, induced significant increases in metabolic activity and release of the cytokines IL-8 and MCP-1, but no differences were observed using traditional exposures. While factors associated with the method of exposure, such as differing NP aggregation, may contribute toward the different cellular responses observed, our results further encourage the use of more physiologically realistic exposure systems for evaluating airborne ENM toxicity.

Assessment of airborne endotoxin in sandstorm dust and indoor environments using a novel passive sampling device in Al Zulfi city, Saudi Arabia - Establishing threshold exposure levels.

The impact of sandstorm dust events affects local air quality and public health. These issues are becoming of greater concern in Saudi Arabia. There is a significant lack of research on airborne endotoxin exposure and analysis in the Middle East countries and no coherent body of research exists focusing on sandstorm dust in worldwide. In this study, we used a novel design of an aluminum foil plate (AFP) electrostatic dust cloth (EDC) for the passive air sampling of sandstorm dust. A total of 38 sandstorm dust samples were collected during sandstorm episodes occurring between January and April 2020 in both indoor (7 days, n = 20) and outdoor environments (24 h, n = 18). After exposure, and following an extraction procedure, bacterial endotoxin levels were measured using the Limulus Amoebocyte Lysate (LAL) gel clot method. The study highlights that the airborne endotoxin level observed was between 10 and 200 EU/m2 in both indoor and outdoor environments, during a sandstorm event. Agricultural activities and farmhouses observed higher airborne endotoxin levels. In general, increased endotoxin levels were related to the severity of the sandstorms. Given that the observed values were high as per existing guidelines for respiratory health, we recommend the setting an occupational airborne exposure limit for bacterial endotoxin. This is the first report and further studies across various sandstorm-hit regions will need to be undertaken, together with various sampling methods, in order to assess for seasonal and geographic trends.

Airborne Occupational Exposures and Lung Function in the Lifelines Cohort Study.

Rationale: The association between airborne occupational exposures and lung function level is inconsistent in the general population. Moreover, little is known about the association between occupational exposures and annual lung function decline.Objectives: We investigated the association between occupational exposures and lung function level and annual lung function decline in the population-based Lifelines cohort study.Methods: We included 55,631 adults with baseline spirometry and reliable job code-13,759 of these subjects were aged ≥30 years and underwent spirometry again after 4.5 years of follow-up. Occupational exposures in the current or last-held job at baseline were estimated with the ALOHA+ job-exposure matrix. Linear regression analyses adjusted for covariates were used to test the association between each occupational exposure-biological dust, mineral dust, gases and fumes, pesticides, solvents, and metals-and lung function level and annual lung function decline. Interactions were used to test effect modification by sex or smoking.Results: Exposures to biological dust, mineral dust, gases and fumes, insecticides, fungicides, and aromatic solvents were associated with a lower lung function level at baseline. The effects were larger in males and smokers compared with females and nonsmokers, respectively. However, no association between occupational exposures and the rate of annual lung function decline was found between baseline and follow-up.Conclusions: In this study, airborne occupational exposures are associated with lower lung function level but not with a faster lung function decline. These negative effects are more pronounced among males and smokers.

Emissions and exposures of graphene nanomaterials, titanium dioxide nanofibers, and nanoparticles during down-stream industrial handling

Today, engineered nanomaterials are frequently used. Nanosized titanium dioxide (TiO2) has been extensively used for many years and graphene is one type of emerging nanomaterial. Occupational airborne exposures to engineered nanomaterials are important to ensure safe workplaces and to extend the information needed for complete risk assessments. The main aim of this study was to characterize workplace emissions and exposure of graphene nanoplatelets, graphene oxide, TiO2 nanofibers (NFs) and nanoparticles (NPs) during down-stream industrial handling. Surface contaminations were also investigated to assess the potential for secondary inhalation exposures. In addition, a range of different sampling and aerosol monitoring methods were used and evaluated. The results showed that powder handling, regardless of handling graphene nanoplatelets, graphene oxide, TiO2 NFs, or NPs, contributes to the highest particle emissions and exposures. However, the exposure levels were below suggested occupational exposure limits. It was also shown that a range of different methods can be used to selectively detect and quantify nanomaterials both in the air and as surface contaminations. However, to be able to make an accurate determination of which nanomaterial that has been emitted a combination of different methods, both offline and online, must be used.

Global and regional burden of chronic respiratory disease in 2016 arising from non-infectious airborne occupational exposures: a systematic analysis for the Global Burden of Disease Study 2016

ObjectivesThis paper presents detailed analysis of the global and regional burden of chronic respiratory disease arising from occupational airborne exposures, as estimated in the Global Burden of Disease 2016 study.MethodsThe...

Association of air pollutants, airborne occupational exposures, and chronic rhinosinusitis disease severity

Previous work has shown that chronic rhinosinusitis (CRS) severity may be associated with particulate matter 2.5 (PM2.5 ) and black carbon (BC) in CRS patients without nasal polyps (CRSsNP). Data regarding occupational exposures, however, are lacking. We assessed the impact of PM2.5 , BC, as well as occupational airborne exposure on CRS disease severity. Patients with CRS with nasal polyps (CRSwNP), CRSsNP, and aspirin-exacerbated respiratory disease (AERD) were identified from an institutionwide database. Spatial modeling from 37 pollutant monitoring sites in Allegheny County was used to estimate exposures. Patient occupations using the 2010 Standard Occupation Classification (SOC10) and airborne occupation exposures to vapors, gases, dusts, fumes, fibers and mists (VGDFFiM) or diesel fumes were recorded. Disease severity was measured by modified Lund-Mackay score (LMS), systemic corticosteroid therapy, and incidence of functional endoscopic sinus surgery (FESS). Two hundred thirty-four patients were included (CRSwNP, n = 113; CRSsNP, n = 96; AERD, n = 25). The prevalence ofAERDamong those with CRSwNP was 18%. Patients exposed to VGDFFiM or diesel fumes required higher steroid doses vs nonexposed patients (p = 0.015 and p = 0.03, respectively); patients with VGDFFiM levels >5% were more likely to undergo FESS vs nonexposed patients (p = 0.0378). There was no difference in PM2.5 and BC with regard to disease severity and FESS between CRSwNP, CRSsNP, and AERD patients. Steroid use was significantly higher in CRSwNP and AERD vs CRSsNP (p = 0.001). LMS was significantly higher in AERD as compared with CRSwNP and CRSsNP (p = 0.001). Occupational airborne exposure to VGDFFiM correlated with increased prevalence of FESS and need for corticosteroids in CRS patients. There was no difference in PM2.5 and BC levels and disease severity outcome measures between CRS subtypes in this subset.

A cross sectional study on the occupational airborne exposure and the prevalence of self-reported asthma, and respiratory symptoms amongst workers in selected factories in Nairobi, Kenya

# Background Inhalation of airborne particulate matter of less than ten microns diameter (PM~10~) in workplaces causes a variety of respiratory ailments and symptoms. This cross-sectional study was conducted on factory production workers (N=388) to investigate the association between occupational airborne exposure to PM~10~ and the prevalence of asthma and respiratory symptoms amongst factory workers in selected Nairobi factories. # Methods The Touhilampi respiratory health questionnaire was modified to include home environment and used in this study. PM ~10~ concentrations of the working environment breathing zones was also measured using air Samplers and a 24-hour average recorded for each of the five factories. Lung function tests of all the respondents using Spirometers were also recorded. # Results The results show that the highest percentage of the factories (33.0%) had a mean concentration of 17.16 mg/m^3^ of PM~10~. A considerable percentage (41.5%) of respondents had cough with wheezing or whistling sound. The mean concentration in mg/m^3^ of PM~10~ for factory environment among respondents who reported cough without flu/cold was significantly higher (14.19mg/m^3^) than to those who indicated otherwise (12.56 mg/m^3^) (*P*=0.005). Respondents with FEV~1~/FVC % (ratio of the forced expiratory volume in the first one second to the forced vital capacity of the lungs) of less than 80 normal predicted value had significantly more proportion of cough without flu/cold (44.3% \[odd ratio OR=1.62; 95% confidence interval CI=1.03-2.56; *P*=0.038\] as compared to those who had FEV~1~/FVC% of 80 and above normal predicted value (33.0%). # Conclusions Most of the factories had high levels of PM~10~ concentration possibly leading to respiratory health problems. The relevant Government agencies should be enabled to make efforts towards reducing the same.

A cross sectional study on the occupational airborne exposure and the prevalence of self-reported asthma, and respiratory symptoms amongst workers in selected factories in Nairobi, Kenya

A cross sectional study on the occupational airborne exposure and the prevalence of self-reported asthma, and respiratory symptoms amongst workers in selected factories in Nairobi, Kenya

Comparison of gaseous polycyclic aromatic hydrocarbon metabolites according to their specificity as biomarkers of occupational exposure: Selection of 2-hydroxyfluorene and 2-hydroxyphenanthrene

Exposure to Polycyclic Aromatic Hydrocarbons (PAHs) occurs by respiratory, digestive and dermal absorption. Biomonitoring takes all pathways into account but sensitive and specific biomarkers are required. Different gaseous PAHs metabolites were used due to their abundance in the atmospheric mixtures but none of them were selected as better biomarker than the others. To identify the best candidates for assessing occupational airborne exposure, relation between atmospheric levels of Naphtalene, Fluorene and Phenanthrene and urinary metabolites concentrations was studied in a carbon electrode workers group. Linear mixed effects models were built to select explanatory variables and estimate variance component. Urinary creatinine was a predictor of metabolites levels confirming the importance of diuresis for interpreting results. High significance of pre-shift sampling time combined with positive coefficients of post-shift indicated that urine should be sampled at the end of the workday in association with pre-shift urine to avoid misinterpretations. Among the 10 metabolites studied, urinary 2-hydroxyfluorene and 2-hydroxyphenanthrene showed the highest increase of variance explained by models after inclusion of individual atmospheric levels as explanatory variable. Priority could be given to 2-hydroxyfluorene due to higher excretion levels than 2-hydroxyphenanthrene.

Occupational airborne exposure in relation to Chronic Obstructive Pulmonary Disease (COPD) and lung function in individuals without childhood wheezing illness: A 50-year cohort study

BackgroundEvidence from longitudinal population-based studies relating occupational exposure to the full range of different forms of airborne pollutants and lung function and airway obstruction is limited. ObjectiveTo relate self-reported COPD and lung function impairment to occupational exposure to different forms of airborne chemical pollutants in individuals who did not have childhood wheeze. MethodsA prospective cohort study was randomly selected in 1964 at age 10–15 years and followed up in 1989, 1995, 2001 and 2014 (aged 58–64) by spirometry and respiratory questionnaire. Occupational histories were recorded in 2014 and occupational exposures assigned using an airborne chemical job exposure matrix. The risk of COPD and lung function impairment was analyzed in subjects, who did not have childhood wheeze, using logistic and linear regression and linear mixed effects models. Results237 subjects without childhood wheeze (mean age 60.6 years, 47% male) were analyzed. There was no association between any respiratory outcomes and exposure to gases, fibers, mists or mineral dusts and no consistent associations with exposure to fumes. Reduced FEV1 was associated with longer duration (years) of exposure to any of the six main pollutant forms - vapors, gases, dusts, fumes, fibers and mists (VGDFFiM) with evidence of a dose-response relationship (p-trend=0.004). Exposure to biological dusts was associated with self-reported COPD and FEV1<Lower Limit of Normal (LLN) (adjusted odds ratio [95%CI] 4.59 [1.15,18.32] and 3.54 [1.21,10.35] respectively), and reduced FEF25–75% (adjusted regression coefficients [95% CIs] −9.11 [−17.38, −0.84] respectively). Exposure to vapors was associated with self-reported COPD and FEV1<LLN (adjOR 6.46 [1.18,35.37] and 4.82 [1.32,17.63]). Longitudinal analysis demonstrated reduced FEV1 and FEF25–75% associated with exposure to biological dusts or vapors. ConclusionsPeople with no history of childhood wheezing who have been occupationally exposed to biological dusts or vapors or had longer duration of lifetime exposure to any VGDFFiM are at a higher risk of reduced lung function at age 58–64 years. Occupational exposure to biological dusts or vapors also increased the risk of self-reported COPD.

Effect of Occupational Exposure to Vapors, Gases, Dusts, and Fumes on COPD Mortality Risk Among Swedish Construction Workers: A Longitudinal Cohort Study

The aim of the present study was to elucidate whether occupational exposure to vapors, gases, dusts, and fumes increases the mortality risk of COPD, especially among never smokers.The study population was a cohort of 354,718 male construction workers; of these, 196,329 were exposed to vapors, gases, dusts, and fumes, and 117,964 were unexposed. Exposure to inorganic dust, wood dust, vapors, fumes, gases, and irritants was based on a job-exposure matrix with a focus on exposure in the mid-1970s. The cohort was followed from 1971 to 2011. Relative risks (RRs) were obtained using Poisson regression models adjusting for age, BMI, and smoking habits.There were 1,085 deaths from COPD among the exposed workers, including 49 never smokers. Workers with any occupational exposure to vapors, gases, fumes, and dust showed an increased mortality due to COPD (RR, 1.32; 95% CI, 1.18-1.47). When comparing different exposure groups, there was a significantly increased mortality due to COPD among those exposed to fumes (RR, 1.20; 95% CI, 1.07-1.36) and inorganic dust (RR, 1.19; 95% CI ,1.07-1.33). Among never smokers, there was high mortality due to COPD among workers with any occupational airborne exposure (RR, 2.11; 95% CI, 1.17-3.83). The fraction of COPD attributable to occupational exposure was 0.24 among all workers and 0.53 among never-smoking workers.Occupational exposure to airborne pollution increases the mortality risk for COPD, especially among never smokers.

Occupational airborne exposure, specific sensitization and the atopic status: evidence of a complex interrelationship

BackgroundWe have investigated the relationship between atopic status and long-term occupational exposure to latex proteins or methyl diethyl diisocyanate (MDI) as high and low molecular weight asthma-inducing agents, respectively.MethodsThis study is based on retrospective analyses of two groups of symptomatic outpatients: 184 healthcare workers with latex exposure and 156 workers with isocyanate (MDI) exposure. We analysed atopic and non-atopic subgroups according to exposure duration and the frequencies of specific sensitization.Results45% of the healthcare subgroup specifically sensitized to latex were atopic, whereas in the non-sensitized healthcare subgroup only 26% were atopic. On the other hand, subjects specifically sensitized to MDI were rarely atopic (only 15%), whereas in the subgroup non-sensitized to MDI atopy was present in 38%. After prolonged durations of exposure, the proportion of atopics was further elevated in most healthcare subgroups but it decreased in the MDI-exposed subjects.ConclusionsWe hypothesize that latex proteins as sensitizing agents might promote the development of atopy, whereas exposure to the low molecular weight MDI might inhibit the atopic status.