Personal Air Samples Research Articles

Organophosphate ester exposure in nail salons: Health implications for workers

Organophosphates esters (OPEs) have become a preferred alternative in nail polish as plasticizers due to health concerns over previously used additives like dibutyl phthalate. However, the true extent of nail technicians' exposure to OPEs is largely unknown. This study shows that nail salon workers are significant exposed to OPEs, with varied concentrations found in air, dust, masks, and urine. The total concentrations of 11 OPEs in ultrasonic personal air samplers (UPAS) ranged from 251 to 1007 ng/m³, and in air conditioner filter dust from 371 to 14473 ng/g. Triphenyl phosphate (TPHP) was the most abundant compound found in the nail polishes used in these salons. On average, the concentrations of TPHP and diphenyl phosphate (DPHP) in workers' urine after work were 5.2 and 1.8 times higher than those before work, respectively. Two nail salons that had the highest nail polish usage also had very high concentrations of TPHP in surgical masks, dust, and UPAS. TPHP concentrations in workers’ urine after work were 19 and 13 times those before work, respectively, in these two salons. Human internal exposure assessment showed that the average exposure dose of TPHP after work was 1.8 times higher than that before work. On average, use of masks reduced OPEs in urine by 77%. In conclusion, frequent mask replacement is highly recommended, especially in long working circumstances. Without regular replacement, masks may accumulate OPEs from the air, potentially becoming another source of human exposure to OPEs. Therefore, more attention should be paid to the occupational exposure of nail salon workers to OPEs, particularly considering that most practitioners in this industry are young women of reproductive age.

Assessing personal PM2.5 exposure using a novel neck-mounted monitoring device in rural Rwanda

There is growing global concern regarding the detrimental health impacts of PM2.5 emissions from traditional stoves that utilize polluting fuels. Conventional methods for estimating daily personal PM2.5 exposure involve personal air samplers and measuring devices placed in a waist pouch, but these instruments are cumbersome and inconvenient. To address this issue, we developed a novel neck-mounted PM2.5 monitoring device (Pocket PM2.5 Logger) that is compact, lightweight, and can operate continuously for 1 week without recharging. Twelve participants who utilized charcoal, firewood, or propane gas for cooking in rural regions of Rwanda wore the Pocket PM2.5 Logger continuously for 1 week, and time-series variations in personal PM2.5 exposure were recorded at 5-min intervals. Individual daily exposure concentrations during cooking differed significantly among users of the different fuel types, and PM2.5 exposure was at least 2.6 and 3.4 times higher for charcoal and firewood users, respectively, than for propane gas users. Therefore, switching from biomass fuels to propane gas would reduce daily individual exposure by at least one-third. An analysis of cooking times showed that the median cooking time per meal was 30 min; however, half the participants cooked for 1.5 h per meal, and one-third cooked for over 4.5 h per meal. Reducing these extremely long cooking times would reduce exposure with all fuel types. The Pocket PM2.5 Logger facilitates the comprehensive assessment of personal PM2.5 exposure dynamics and is beneficial for the development of intervention strategies targeting household air pollution.

Personal air sampling for pesticides in the California San Joaquin Valley.

California is a leading agricultural state and with that, has significant applications of pesticides. Levels of exposure have been measured to be higher among residents in agricultural areas, but measures of personal inhalation exposure to a wide range of pesticides are lacking. Community members in the San Joaquin Valley have expressed concern over pesticide exposures. Working with community members, a wide range of pesticides in personal air samples were measured. Adult and school-aged participants were recruited from small agricultural towns in the San Joaquin Valley. Participants wore a backpack sampler for 8-14 h on 1-3 days. Samples were collected on two tubes, one with Tenax-TA resin and the other with XAD-2 resin. In total, 21 pesticides were analyzed using both LC/MS and GC/MS methods. Thirty-one adult participants and 11 school aged participants were recruited, and sampling occurred on a total of 92 days. Seven adults, 22% of adult participants, and one school child had detectable levels of at least one pesticide. Pesticides detected above the limit of detection were 1,3-dichloropropene, chlorpyrifos, pyrimethanil, burprofezin and penthiopyrad. When these samples were collected, chlorpyrifos was not permitted to be used in California. California, a leading agricultural state, has significant pesticide use, leading to concern about exposures among community members. Thirty-one adult and 11 school aged participants wore personal air sampling backpacks from 1-3 days. Twenty-two percent of adult participants had detectable levels of at least one pesticide. Two pesticides with established toxicity, 1,3-dichloropropene and chlorpyrifos were detected, along with first time measurements of pyrimethanil, burprofezin and penthiopyrad in the United States, which all have potential indications of toxicity. This study suggests the need to expand which pesticides are measured in agricultural communities.

Follow-up Biomonitoring Study of Metal Exposure in Apprentice Welders in Montreal, Quebec, During Gas Metal Arc Welding (GMAW).

Welding activities are known to expose workers to metal fumes, but few studies have focused on assessing the internal exposure of apprentices in learning environments. This study aimed at determining internal doses of metals in apprentices performing gas metal arc welding (GMAW) during their training course. A total of 85 apprentice welders were assessed, and multi-elements were measured in urine, hair, fingernail, and toenail samples collected at the beginning of the program, and at the beginning and end of GMAW practical training. Concentrations of welding fumes and metals were also determined in personal respirable air samples. Serial measurements of metal concentrations in urine and hair, which reflect more recent exposure, showed an increase in arsenic (As), chromium (Cr), iron (Fe), and manganese (Mn) (and to a lesser extent nickel (Ni)) levels at the end of the GMAW process. Metal concentrations in fingernails and toenails showed a time-dependent increase in Fe, Mn, and Ni (and to a lesser extent cobalt (Co)) levels, reflecting cumulative exposure. Levels of Mn and Fe were high in personal air samples with respective median concentrations (95th percentiles) of 21 (300) and 230 (1900) µg/m3. Results show that even short-term exposure to welding fumes in a learning environment leads to a significant increase in absorbed metal doses, particularly for Fe and Mn. This follow-up study confirmed the interest and usefulness of measuring multi-elements in multiple matrices to assess internal exposure to welding fumes and its applicability to occupational or even population exposure to metals.

A detailed methodology for estimating health-related hazards of workplace exposure to indoor formaldehyde vapours

A comprehensive risk assessment method was applied to examine the risks associated with airborne formaldehyde occupational exposure among hospital laboratory staff. The method assessed exposure levels and health impacts by integrating area and personal air sampling, biological monitoring, and self-reported health data. Samples were collected from 74 workplaces across various departments using NIOSH method 3500 and were analyzed via UV-vis spectrophotometry. The data showed significant differences in exposure levels between departments (p≤0.05) and confirmed the efficacy of the method in identifying risk differences. Despite average personal exposure levels being measured lower than occupational limits, individual assessments indicated that some participants surpassed these limits, emphasizing the necessity of personal monitoring for workers with higher risks. The high prevalence of respiratory symptoms, such as cough and wheezing among staff, indicated the need for further investigation and targeted interventions. Although estimated cancer and non-cancer risks were within safe thresholds, the study emphasized the importance of continuous exposure monitoring and the implementation of effective control measures in hospital laboratory departments with formaldehyde emission. This integrated method improved the reliability and generalizability of formaldehyde exposure risk assessments and aided in the development of safe occupational health practices.•The method integrated personal and area sampling with advanced calibration for precise occupational exposure evaluation in laboratories.•The method used of biomarkers to assess formaldehyde absorption in the body estimating both cancerous and non-cancerous health risks associated with occupational exposure.•Addressed traditional method limitations and integrated risk components to improve data reliability for workplace safety and health risk management.

Feasibility of respirable crystalline silica exposure reduction in small-scale tanzanite mining in Tanzania.

Respirable crystalline silica (RCS) exposures in tanzanite gem mining have been linked to tuberculosis and silicosis among miners. We conducted a plot study to assess RCS exposures and to introduce safer mining practices in one small-scale underground tanzanite mine. Personal and area air samples for RCS were collected during tanzanite mining operations before and after improved work practices employed to reduce exposures and analyzed using X-ray diffraction. Area samples were collected at the rest area, located approximately 300 m underground and 100 m from other work activities. Improved practices included the use of wet drilling methods and drilling with new bits. A total of 33 personal and 4 area air samples were collected. Pre-intervention, mean exposures for all operations, drilling operations, non-drilling activities, and area samples were 122 mg/m3, 247 mg/m3, 34.3 mg/m3, and 1.95 mg/m3, respectively which exceeded the U.S. OSHA Permissible Exposure Limit (PEL) by 2,440 times for all operations, by 4,946 times for drilling operations, by 686 times for non-drilling activities and 39 times for area samples collected at an underground rest area. The post-intervention results showed a 99% reduction of RCS exposures for wet drilling operations, 98.5% reduction for non-drilling activities, and 36% reduction for area samples. Despite improvements, post-intervention RCS exposures during drilling had a mean of 2.08 mg/m3 or more than 41 times the OSHA PEL. We successfully piloted a program to work with small-scale tanzanite miners to reduce RCS exposures and raise awareness about the occupational health risks of RCS, though additional measures are recommended to further reduce RCS exposures. Similar programs should be taken to scale throughout underground mining sites in Tanzania and other countries.

Assessment of Health Risk from Exposure to Respirable Particulate Matter (RPM) among Motorcycle Taxi Drivers in Bangkok and Adjacent Provinces, Thailand

Exposure to outdoor air pollutants, particularly respirable particulate matter (RPM), can cause adverse health outcomes. The cross-sectional study aimed to assess motorcycle taxi driver’s health risk from exposure to RPM. A total of 153 motorcycle taxi drivers were recruited in Bangkok and five adjacent provinces during May and June 2022. The standardized questionnaire for data collection contained exposure time (hour/day), frequency of exposure (days/years), duration of exposure (year), body weight (kg), and averaging time (days). The average RPM concentration from six provinces were assessed personal air sampling pumps and ranged from 0.006-0.031 mg/m3. Bangkok showed the highest average RPM concentration (0.031 mg/m3), followed by Pathumthani (0.028 mg/m3), Samut Prakan (0.009 mg/m3), Nakhon Pathom (0.008 mg/m3), Nonthaburi (0.007 mg/m3), and Samut Sakhon (0.006 mg/m3), respectively. The Hazard Quotient (HQ) values for a non-carcinogenic risk to human health caused by RPM exposure in each province indicated a negligible risk (HQ=0.005-0.028). HQ averages (HQ=0.013) from all provinces were also at an acceptable level (≤1). Not all motorcycle taxi drivers are safe from RPM exposure, although their exposure is within acceptable limits depending on their individual susceptibility. Therefore, this is the first report on quantifying exposure to RPM from personal air sampling and health risk assessment among motorcycle taxi drivers. These findings would be useful information for further preventing and controlling ambient air pollution including policies and strategies to mitigate the risks for motorcycle-taxi drivers and the other exposed populations.

The impact of respirable dust exposure on lung function parameters of motorcycle taxi drivers in Bangkok and adjacent provinces, Thailand

AbstractThe motorcycle taxi drivers of Bangkok and adjacent provinces in Thailand may have been heavily exposed to ambient air pollution and the impact of this on their lungs has been neither documented nor studied. In this study, we recruited a total of 343 motorcycle taxi drivers in Bangkok and adjacent provinces in Thailand and their lung function parameters were analyzed using spirometry in May and June 2022. Of these, 153 participants were selected and their exposure to respirable dust during working was measured by personal air sampling. Respirable dust concentrations collected with personal air sampling suggested that motorcycle taxi drivers working at workstations where they were exposed to respirable dust at high concentrations tended to have a low percent predicted FEV1. Twelve% and 7.3% of motorcycle taxi drivers recruited in this study had the symptoms of chronic bronchitis and acute bronchitis, respectively. These results suggested that some motorcycle taxi drivers around Bangkok and adjacent provinces had a high risk of occupational exposure to ambient air pollution. The government needs to establish a medical check-up system for motorcycle taxi drivers to monitor their health status.

Evaluation of airborne asbestos concentrations associated with the maintenance of brakes on an industrial overhead crane

Objectives To evaluate potential airborne asbestos exposures during brake maintenance and repair activities on a P&H overhead crane, and during subsequent handling of the mechanic’s clothing. Methods Personal (n = 27) and area (n = 61) airborne fiber concentrations were measured during brake tests, removal, hand sanding, compressed air use, removal and reattachment of chrysotile-containing brake linings, and reinstallation of the brake linings. The mechanic’s clothing was used to measure potential exposure during clothes handling. Results All brake linings contained between 19.9% to 52.4% chrysotile asbestos. No amphibole fibers were detected in any bulk or airborne samples. The average full-shift airborne chrysotile concentration was 0.035 f/cc (PCM-equivalent asbestos-specific fibers, or PCME). Average task-based personal air samples collected during brake maintenance, sanding, compressed air use, and brake lining removal tasks ranged from 0 to 0.48 f/cc (PCME). The calculated 30-minute time-weighted average (TWA) airborne chrysotile concentration associated with 5-15 minutes of clothes handling was 0–0.035 f/cc PCME. Conclusion The results indicated that personal and area TWA fiber concentrations measured during all crane brake maintenance and clothes handling tasks were below the current OSHA 8-h TWA Permissible Exposure Limit for asbestos of 0.1 f/cc. Further, no airborne asbestos fibers were measured during routine brake maintenance tasks following the manufacturer’s maintenance manual procedures. All short-term airborne chrysotile concentrations measured during non-routine tasks were below the current 30-minute OSHA excursion limit for asbestos of 1 f/cc. This study adds to the available data regarding chrysotile exposure potential during maintenance on overhead cranes.

Fragrance chemicals in nail salons: Personal inhalation exposures and potential sources

The indoor air of nail salons is full of volatile organic compounds (VOCs), many of which have fragrances. Little is known about the fragrance chemicals in nail salons, as fragrance ingredients are not required on nail product labels and are considered trade secrets. This study aimed to identify fragrance chemicals and their potential sources and exposures in nail salons. Indoor air samples were collected in seven nail salons in the Greater Boston Area between November 2016 and June 2017. Personal samples were also collected from ten nail salon workers during their work shifts. Follow-up area sampling was performed in two salons one year after the initial visits. All air samples were collected using thermal desorption (TD) tubes and analyzed on a TD-gas chromatography/mass spectrometry (GC/MS) system targeting 55 fragrance chemicals. Eighteen compounds were detected in air samples, including terpenes, alcohols, carbonyls, ethers, and esters. The concentrations displayed limited spatial variation within a salon but moderate variation over time. The highest median personal inhalation concentrations were benzaldehyde (36.4 μg/m3), 2-ethylhexanol (30.0 μg/m3), d-limonene (16.6 μg/m3), and 2-butoxyethanol (12.6 μg/m3). Highest personal levels were reached by maximum concentrations of 2-butoxyethanol (<1611 μg/m3)), d-limonene (<413 μg/m3), and methyl salicylate (<113.5 μg/m3). Personal concentrations of most compounds were highly correlated with area concentrations (Spearman correlations = 0.69−0.92). Fragrance concentrations from area and personal air samples did not correlate significantly with the ventilation rate. Cleaning agents, personal care products, and nail products were identified as important possible emission sources. This study reveals a subset of fragrance chemicals in nail salons’ indoor air and calls for future research on a full spectrum of these chemicals, their health effects among nail salon workers, and ways to reduce these exposures.

Assessing exposure to airborne fungi and bacteria in the horse-riders environment: A pilot study

Among airborne biological contaminants, several pathogenic and/or allergenic fungi and bacteria can affect the health of horses and humans. Exposure to primary biological aerosol particles (PBAP) in the equine environment remains poorly understood, although environmental factors play a major role in the development of respiratory diseases and impaired performance in horses. This pilot study was conducted during a training course for young racers. Ambient and personal air samples provided original data on the microbial composition of PBAP in the riders’ immediate environment (stable, outdoor, riding arena), using culture-based and metagenomic approaches. The culture-based approach showed average levels of fungi and bacteria of 2.3 × 104 and 8.3 × 105 CFU/m3 respectively during training. Seventy-one and 50 fungal and bacterial species were respectively identified, while the metagenomic approach identified 211 and 285, respectively. It should be noted, however, that two-thirds of the bacterial and fungal genera were found by both approaches. Among these species, various pathogenic and/or allergenic fungi (Alternaria spp., Aspergillus spp., Cladosporium spp. and Lichtheimia ramosa) and bacteria (Aeromonas spp., Bacillus spp., Pseudomonas spp. and Staphylococcus spp.) were highlighted. This study underlines the value of the combined use of culture-based and metagenomic approaches to provide an overview of the distribution of different fungal and bacterial phyla, genera and species in the equine environment. Statistical analysis also suggests interactions between microbiological contaminants (bacteria and mold) and climatic parameters (rain, wind, temperature).

Assessment of Occupational Exposure to Inhalable Aerosols in an Instant Powdered Food Manufacturing Plant in Norway

BackgroundIn the food manufacturing industry, exposure to inhalable aerosols contributes to respiratory illnesses such as occupational asthma and rhinitis. However, there is a lack of comprehensive exposure assessment studies. This study evaluated occupational exposure to inhalable aerosols in an instant powdered food manufacturing plant during work operations involving dried food and powders. MethodsIn total, 50 workers from an instant powdered food manufacturing plant were recruited. Personal inhalable aerosol exposure measurements were taken for both full-shift and task-based activities. The concentrations of inhalable aerosols were analyzed to identify any variation within and across departments, as well as between seasons, handedness, and sex. ResultsIn total, 134 personal air samples were collected, and the particulate mass was determined gravimetrically. The concentrations of inhalable aerosols ranged from 0.1 to 27 mg/m3 for full-shift exposure measurements and 3.1 to 73 mg/m3 for task-based measurements. Statistically significant differences in mean aerosol concentrations were found across departments (A:B p < 0.001, A:C p < 0.05, B:C p < 0.001) and between seasons (p < 0.001). ConclusionThis study revealed high exposure to inhalable aerosols among workers, particularly those involved in manual weighing, mixing, and adding powders. The significant differences between departments highlight the specific activities contributing to increased inhalable aerosol concentrations. Seasonal variations were also evident, with autumn showing higher concentrations of inhalable aerosols in all departments compared with summer. These findings emphasize the importance of understanding the distribution of aerosol concentrations across different work tasks and departments, particularly during different seasons.

Asbestos exposures associated with the use and handling of drilling mud additives.

This paper summarizes historical asbestos exposure data collected during the handling of short-fiber chrysotile asbestos that was used as an additive to drilling fluid in oil and gas exploration. A total of 1171 industrial hygiene (IH) personal and area air samples were collected and analyzed from more than 20 drilling rigs between 1972 and 1985. The dataset consists of 1097 short-term samples (<240min) with more than 80% having sample durations less than 30min. Average airborne fiber concentrations measured during asbestos handling activities ranged from 0.62 f/cc to 3.39 f/cc using phase-contrast microscopy (PCM). An additional 14 samples were considered long-term samples (>240min) and there were 60 samples with no reported sample duration. Eight-hour time-weighted average (8-h TWA) results, calculated using short-term samples, along with long-term samples greater than 240min, did not exceed contemporaneous Occupational Safety and Health Administration (OSHA) permissible exposure limits (PELs). This analysis fills a data gap in the evaluation of asbestos exposures from the use of drilling mud additives (DMAs) that contained chrysotile asbestos.

Occupational inhalation exposure during surface disinfection—exposure assessment based on exposure models compared with measurement data

BackgroundFor healthcare workers, surface disinfections are daily routine tasks. An assessment of the inhalation exposure to hazardous substances, in this case the disinfectant´s active ingredients, is necessary to ensure workers safety. However, deciding which exposure model is best for exposure assessment remains difficult.ObjectiveThe aim of the study was to evaluate the applicability of different exposure models for disinfection of small surfaces in healthcare settings.MethodsMeasurements of the air concentration of active ingredients in disinfectants (ethanol, formaldehyde, glutaraldehyde, hydrogen peroxide, peroxyacetic acid) together with other exposure parameters were recorded in a test chamber. The measurements were performed using personal and stationary air sampling. In addition, exposure modelling was performed using three deterministic models (unsteady 1-zone, ConsExpo and 2-component) and one modifying-factor model (Stoffenmanager®). Their estimates were compared with the measured values using various methods to assess model quality (like accuracy and level of conservatism).ResultsThe deterministic models showed overestimation predominantly in the range of two- to fivefold relative to the measured data and high conservatism for all active ingredients of disinfectants with the exception of ethanol. With Stoffenmanager® an exposure distribution was estimated for ethanol, which was in good accordance with the measured data.Impact statementTo date, workplace exposure assessments often involve expensive and time consuming air measurements. Reliable exposure models can be used to assess occupational inhalation exposure to hazardous substances, in this case surface disinfectants. This study describes the applicability of three deterministic and one modifying-factor model for disinfection of small surfaces in healthcare settings, in direct comparison to measurements performed and will facilitate future exposure assessments at these workplaces.

Exploring Personal Exposure to Airborne Microplastics across Various Work Environments in Pathum Thani Province, Thailand.

This study used personal air samplers to assess the concentration of airborne microplastics exposed by different occupational groups during their working hours. The personal air sampler was placed in the "breathing zone" of the worker during working hours to collect microplastic exposure data. Occupations examined included housekeepers, laundromat staff, office workers, van drivers, street vendors, maintenance technicians in wastewater treatment plants, and waste segregation officers in the university and market. The level of airborne microplastic exposure was found to be influenced by the daily activities and environmental conditions of the workplace. Waste segregation officers in the university and market exhibited the highest levels of exposure to airborne microplastics, at 3964 ± 2575 microplastics per cubic meter (n/m3) and 3474 ± 678 n/m3, respectively. Further analysis focused on airborne microplastics less than 10 µm in size which can be taken in through inhalation. During the 8 h working period, the waste segregation officer in the university recorded the highest 10 µm airborne microplastic intake, at 5460 pieces, followed by the waste segregation officer in the market at 3301 pieces, housekeepers at 899 pieces, van drivers at 721 pieces, maintenance technicians in WWTPs at 668 pieces, laundromat staff at 454 pieces, street vendors at 249 pieces, and office workers at 131 pieces.

Hexavalent chromium still a concern in Sweden – Evidence from a cross-sectional study within the SafeChrom project

ObjectivesHexavalent chromium (Cr(VI)) is classified as a human carcinogen. Occupational Cr(VI) exposure can occur during different work processes, but the current exposure to Cr(VI) at Swedish workplaces is unknown. MethodsThis cross-sectional study (SafeChrom) recruited non-smoking men and women from 14 companies with potential Cr(VI) exposure (n = 113) and controls from 6 companies without Cr(VI) exposure (n = 72). Inhalable Cr(VI) was measured by personal air sampling (outside of respiratory protection) in exposed workers. Total Cr was measured in urine (pre- and post-shift, density-adjusted) and red blood cells (RBC) (reflecting Cr(VI)) in exposed workers and controls. The Bayesian tool Expostats was used to assess risk and evaluate occupational exposure limit (OEL) compliance. ResultsThe exposed workers performed processing of metal products, steel production, welding, plating, and various chemical processes. The geometric mean concentration of inhalable Cr(VI) in exposed workers was 0.15 μg/m3 (95% confidence interval: 0.11–0.21). Eight of the 113 exposed workers (7%) exceeded the Swedish OEL of 5 μg/m3, and the Bayesian analysis estimated the share of OEL exceedances up to 19.6% for stainless steel welders. Median post-shift urinary (0.60 μg/L, 5th-95th percentile 0.10–3.20) and RBC concentrations (0.73 μg/L, 0.51–2.33) of Cr were significantly higher in the exposed group compared with the controls (urinary 0.10 μg/L, 0.06–0.56 and RBC 0.53 μg/L, 0.42–0.72). Inhalable Cr(VI) correlated with urinary Cr (rS = 0.64) and RBC-Cr (rS = 0.53). Workers within steel production showed the highest concentrations of inhalable, urinary and RBC Cr. Workers with inferred non-acceptable local exhaustion ventilation showed significantly higher inhalable Cr(VI), urinary and RBC Cr concentrations compared with those with inferred acceptable ventilation. Furthermore, workers with inferred correct use of respiratory protection were exposed to significantly higher concentrations of Cr(VI) in air and had higher levels of Cr in urine and RBC than those assessed with incorrect or no use. Based on the Swedish job-exposure-matrix, approximately 17 900 workers were estimated to be occupationally exposed to Cr(VI) today. ConclusionsOur study demonstrates that some workers in Sweden are exposed to high levels of the non-threshold carcinogen Cr(VI). Employers and workers seem aware of Cr(VI) exposure, but more efficient exposure control strategies are required. National strategies aligned with the European strategies are needed in order to eliminate this cause of occupational cancer.

Report-Back of Personal Air Sampling Results and Study Participants' Perceived Knowledge, Attitudes, and Awareness of Air Pollution.

Report-Back of Personal Air Sampling Results and Study Participants' Perceived Knowledge, Attitudes, and Awareness of Air Pollution.

Biomonitoring of exposure to multiple metal components in urine, hair and nails of apprentice welders performing shielded metal arc welding (SMAW)

Welding fumes are associated with various diseases. Increased air levels of metals were reported during welding. However, few multielement biomonitoring studies were conducted to assess the actual dose of metal components absorbed in apprentice welders in a learning environment. This research aimed to establish the nature and level of exposure to welding fumes and their metallic components in apprentice welders performing ‘Shielded Metal Arc Welding’ (SMAW), based on multi-element and multi-matrix analyses. A total of 86 apprentice welders were recruited in three different schools in Montreal, Québec, Canada. Twenty-one elements were measured in urine, hair, fingernail, and toenail samples collected at the beginning of the program and at the end of SMAW practical training. Concentrations of welding fumes and 12 metals were also determined in personal respirable air samples collected over a typical workday in a subgroup of 19 apprentices. Levels of manganese (Mn), iron (Fe) and nickel (Ni) in urine and Mn in hair were higher in samples taken at the end of the SMAW module compared to the beginning of training, while there was no significant difference for the other elements or for nail concentrations. Geometric mean concentrations [5th-95th percentiles] reached 0.31 [0.032–2.84], 9.4 [3.1–51] and 0.87 [0.35–3.1] μg/g creat. in post-shift urine, respectively, for Mn, Fe and Ni, and 0.37 [0.46–6.4] μg Mn/g hair at the end of SWAW. Median concentrations [5th-95th percentiles] were 29 [4.6–1200], 120 [27–3100] and 0.31 [<LOQ-0.92] μg/m3 for Mn, Fe and Ni, respectively. The work showed that even short-term welding fume exposure in controlled environments, as observed in apprentice welders after SMAW process, increases internal exposure to metals. It also confirmed the interest of measurements in multiple matrices to assess internal metal exposure. The follow-up of apprentices during standard curriculum will allow to assess more long-term internal exposure due to other welding processes.

Bacterial contamination of coffee and personal exposure to inhalable dust and endotoxin in primary coffee processing factories in Ethiopia.

Endotoxins from gram-negative bacteria might be released when the coffee cherries are processed and may cause respiratory health problems among workers in the coffee industry. The relationship between bacterial contamination and occupational exposure to endotoxin levels has not been thoroughly explored previously in primary coffee processing factories in Ethiopia, or elsewhere. The aim of this study was to characterize the level of personal endotoxin exposure and its relations with bacterial contamination of coffee cherries in such factories in Ethiopia. A cross-sectional study was conducted from March 2020 - February 2021 in 9 primary coffee processing factories in 3 regions in Ethiopia. A total of 180 personal air samples were collected to analyze workers' exposure to inhalable dust and endotoxin. Correlation tests were performed to assess the relationship between total bacteria and endotoxin levels and between inhalable dust and endotoxin levels. The geometric mean (GM) of personal inhalable dust exposure among machine room workers and hand pickers were 9.58mg/m3 and 2.56mg/m3, respectively. The overall GM of endotoxin exposure among machine room workers and hand pickers were 10,198 EU/m3 and 780 EU/m3, respectively. Gram-negative bacteria were found in all 54 coffee samples. The correlation between inhalable dust and endotoxin exposure was significant (r=0.80; P <0.01). About 92% of the samples from hand pickers and all samples from machine room workers exceeded the occupational exposure limit of 90 EU/m3 recommended by the Dutch Expert Committee on Occupational Standards. Prevention and control of bacterial contamination of the coffee in primary coffee processing are suggested to reduce endotoxin exposure that might cause respiratory health problems among coffee workers.

Use of silicone wristbands to measure firefighters’ exposures to polycyclic aromatic hydrocarbons (PAHs) during live fire training

Firefighters experience exposures to carcinogenic and mutagenic substances, including polycyclic aromatic hydrocarbons (PAHs). Silicone wristbands (SWBs) have been used as passive samplers to assess firefighters' exposures over the course of a shift but their utility in measuring short term exposures, source of exposure, and correlations with other measurements of exposure have not yet been investigated. In this study, SWBs were used to measure the concentrations of 16 priority PAHs inside and outside of firefighters’ personal protective equipment (PPE) while firefighting. SWBs were placed on the wrist and jacket of 20 firefighters conducting live fire training. Correlations were made with matching data from a sister project that measured urinary concentrations of PAH metabolites and PAH concentrations from personal air samples from the same participants. Naphthalene, acenaphthylene and phenanthrene had the highest geometric mean concentrations in both jacket and wrist SWB, with 1040, 320, 180 ng/g SWB for jacket and 55.0, 4.9, and 6.0 ng/g SWB for wrist, respectively. Ratios of concentrations between the jacket and wrist SWBs were calculated as worker protection factors (WPFs) and averaged 40.1 for total PAHs and ranged from 2.8 to 214 for individual PAHs, similar to previous studies. Several significant correlations were observed between PAHs in jacket SWBs and air samples (e.g., total and low molecular weight PAHs, r = 0.55 and 0.59, p < 0.05, respectively). A few correlations were found between PAHs from SWBs worn on the wrist and jacket, and urinary concentrations of PAH metabolites and PAH concentrations in air samples. The ability of the SWBs to accurately capture exposures to various PAHs was likely influenced by short sampling time, high temperatures, and high turbulence. Future work should further examine the limitations of SWBs for PAH exposures in firefighting, and other extreme environments.