Journal of Occupational and Environmental Hygiene最新文献

Engineered stone countertops, popularly known as quartz or artificial stone countertops, have gained significant attraction due to their durability and aesthetic appeal. However, due to their high crystalline silica content, the fabrication of these countertops poses severe health risks to workers, as evidenced by numerous global cases of silicosis. The study aimed to assess occupational exposure to respirable crystalline silica (RCS) among fabricators in Chicago and characterize the elemental composition and physical properties of engineered stone dust. Eight professional fabricators from two local stone workshops were recruited for the study. The exposure levels to RCS were assessed using the NIOSH 7500 method. Bulk dust samples were collected on-site, and the elemental composition of the dust was analyzed using X-ray fluorescence (XRF) and reported in stoichiometric oxide units. A set of real-time air monitors was used to measure particle size distribution, particulate matter (PM) concentrations, and ambient conditions in the workplace. A questionnaire was administered, and worker activities were recorded during the visits. Workers were found to be overexposed to respirable quartz in their workplaces, with time-weighted averaged (TWA) concentrations ranging from 11 to 203 µg/m³, with a median concentration of 90 µg/m³. Seven samples (78%) exceeded the 50 µg/m³ TWA-8 hr occupational exposure limit for RCS. Engineered stone dust samples contain much higher silica content compared to natural stone dust (30%), with silica percentages ranging from 56% to 95%. Over 90% of the particles (90.3-98.7%) emitted from activities involving small hand tools were of size less than 2.5 µm. The use of respiratory protection was not observed during the visits. The study offers firsthand insights into the engineered stone fabrication industry. The findings reveal a combination of risk factors: elevated RCS concentrations, very high silica content in engineered stone, and a high prevalence of fine particles. These factors collectively pose significant health risks to workers that are unequaled in comparison to most other industries. The findings underscore the urgent need for regulatory measures to better protect workers' health in the engineered stone fabrication sector.

Hypochlorous acid (HClO), one of the major reactive oxygen species, is obtained by electrolyzing a sodium chloride solution. HClO is a safe and effective disinfectant and decomposing agent widely used as an alternative to sodium hypochlorite (NaClO). In this study, the authors aimed to evaluate the safety and efficiency of HClO generated by electrolyzing sodium chloride as a decontaminant. Cyclophosphamide (CPA), an antineoplastic drug, was selected as the model drug, and various solvents (HClO, NaClO, etc.) were compared to identify the solvents that could react with and efficiently decompose CPA. To identify a solvent that efficiently decomposes CPA, the CPA concentration was measured using liquid chromatography with photodiode array detection. When either NaClO or HClO was used, the CPA concentration decreased, and a peak corresponding to 3-chloro CPA, identified by mass spectrometry, was detected. Furthermore, to investigate the reversibility of the reaction between CPA and ClO^-, ClO^- was removed from the reaction solution using solid-phase extraction, resulting in the previously decreased CPA concentration returning to nearly its original level. Occupational exposure to antineoplastic drugs poses a significant risk to worker health. This study's results suggest that CPA can be replaced by 3-chloro CPA when HClO is used as the wiping solvent like NaClO, thereby reducing occupational exposure from wiping. Future studies should investigate the wiping and degradation efficiencies of other anti-cancer agents. Occupational exposure to anti-cancer drugs can be significantly reduced by integrating various mitigation measures, thereby contributing to a safer work environment for healthcare professionals.

A significant portion of the work of developing and validating methods for volatile organic compound (VOC) sampling in workplace atmospheres involves the use of laboratory-generated atmospheres. The sample variability was evaluated from the dynamic atmosphere generation system used for VOC atmosphere generation and sampling. Characterization of the bias and variability of samples was done for a variety of atmospheres containing neat n-heptane and mixtures of VOCs sampled on activated coconut shell charcoal. Estimates of sampling variability ranged from 2% for neat n-heptane to 12% for a component in the 10 VOC mix. Sample variability increased for lower concentration samples and for mixtures of VOCs compared to single component atmospheres. This study can serve as a baseline for future atmosphere sampling experiments evaluating performance at lower concentrations and mixed VOC environments.

In public health, risk experts often define acceptable risk targets without community input. We developed a novel method for applying behavioral microeconomics to integrate individuals' risk preferences into risk assessment. To demonstrate this methodology, we explored a risk-risk tradeoff case scenario: increased asthma risk from increased cleaning and disinfection (C&D) and increased infection risk from decreased C&D for healthcare staff. Utilizing a risk-risk tradeoff (RRTO) framework, two datasets were informed with RRTO survey data describing the risks individuals would accept for one outcome to offset risk in another (i.e., "risk target"). A quantitative microbial risk assessment (QMRA) was deployed to output "critical concentrations," viral concentrations on surfaces that yield risk targets for a single contaminated surface touch and a work shift. Critical concentrations were over four orders of magnitude larger for single-touch scenarios. Critical concentrations across risk target datasets were similar. Using the RRTO framework to inform QMRA advances the incorporation of individuals' risk preferences in risk analyses outside economics.

Recently, the misuse of fentanyl and methamphetamine has increased in the United States. These drugs can be consumed via smoking a powder, which can subsequently contaminate air and surfaces with drug residue. With limited access to safe consumption sites, this misuse often occurs in public spaces such as public transit, leading to potential secondhand exposures among transit operators and riders. In the Pacific Northwest, transit operators have reported acute health symptoms and safety concerns regarding these drug exposures. Researchers conducted an exposure assessment, sampling air and surfaces for fentanyl and methamphetamine. A total of 78 air samples and 89 surface samples were collected on 11 buses and 19 train cars from four transit agencies in the Pacific Northwest. Fentanyl was detected above the limit of quantification (LOQ) in 25% of air samples (range of concentrations > LOQ: 0.002 to 0.14 µg/m³) and 38% of surface samples (range of concentrations > LOQ: 0.011 to 0.47 ng/cm²), while methamphetamine was detected in 100% of air samples (range: 0.003 to 2.32 µg/m³) and 98% of surface samples (range of concentrations > LOQ: 0.016 to 6.86 ng/cm²) The highest fentanyl air sample (0.14 µg/m³) was collected in the passenger area of a train for 4 hr, and would exceed the ACGIH^® 8-hr TWA TLV^® of 0.1 µg/m³ if conditions remained the same for the unsampled period. No surface samples exceed the ACGIH fentanyl surface level TLV (10 ng/cm²). The prevalence of fentanyl and methamphetamine on public transit highlights the need to protect transit operators from secondhand exposure and from the stress of witnessing and responding to smoking events. Future work is needed to evaluate the utility of engineering and administrative controls such as ventilation and cleaning upgrades in reducing exposures on transit, as well as the utility of training and increased workplace support for operators in addressing their health and well-being after observing or responding to drug use events.

With mines extending deeper and rising surface temperatures, workers are exposed to hotter environments. This study aimed to characterize heat stress and strain in the Canadian mining industry and evaluate the utility of the Heat Strain Score Index (HSSI), combined with additional self-reported adverse health outcomes. An exploratory web-based survey was conducted among workers (n = 119) in the Canadian mining industry. The survey included 74 questions on workers' risk perception, strategies for heat stress management, and the HSSI-a validated tool to classify workplace heat stress based on various workplace factors and indicators of heat strain. Most workers reported that heat stress is an occupational hazard associated with their duties and tasks (89%). Based on the HSSI, 22% of respondents were classified as high risk, 42% at moderate risk, and 36% at low risk for heat stress and heat strain. Those with higher HSSI scores self-reported more heat-related adverse signs and symptoms with a higher prevalence of self-reported heat-related illness (p < 0.01). Despite workers reporting various self-initiated practices (e.g., drinking water) and management-enforced heat mitigation practices (e.g., rest breaks), many workers reported still having experienced signs or symptoms of heat stress (86%) and heat-related illnesses (37%). The study found elevated heat stress and strain levels among a sample of workers in the Canadian mining industry despite workers employing various heat-mitigating strategies. Heat stress management programs considering mining-specific factors and challenges are needed to safeguard worker health and safety.

The noise exposure levels of workers wearing hearing protective devices (HPDs) depend on ambient noise and the protective effect of hearing protectors. This cross-sectional study aimed to adjust for cumulative noise exposure (CNE) based on the effective protection of hearing protection devices and explore the dose-response relationship between noise-induced hearing loss (NIHL) and adjusted cumulative noise exposure. A questionnaire was used to acquire the basic characteristics and occupational information of noise-exposed workers. Individual noise dosimetry, individual fitting tests, and pure-tone audiometric tests were performed to assess workers' noise exposure levels, HPDs' sound attenuation, and hearing status. A total of 714 workers participated in this study. Four hundred seventy-three participants wore foam earplugs and 241 wore pre-molded earplugs. The median Personal Attenuation Rating (PAR) was 13.0 dB. The median PAR' (the PAR after combining the earplugs usage time) was 8.0 dB. Thirty-one percent of the workers wore earplugs properly during noise exposure and they tended to possess a greater PAR. The median L_Aeq,8h was 94.1 dB (A) and the median unadjusted cumulative noise exposure was 102.3 dB (A)· year. The PAR'-adjusted CNE (CNE_P) was 91.3 dB (A)·year. A total of 161 workers (22.5%) with hearing loss were identified. There was an obvious trend between the prevalence of NIHL and CNE_P (χ_trend² = 31.9, p < 0.01). The Wald values of the CNE and CNE_P logistic regression models were 4.0 and 14.1, respectively. Furthermore, the curve slope of the CNE_P was steeper than that of the unadjusted CNE. The CNE_P can represent the noise exposure level among workers wearing hearing protectors more accurately and has an apparent dose-response relationship with the prevalence of NIHL. For workers utilizing hearing protection devices, wearing them properly and consistently in the workplace is recommended. Assessing noise exposure based on the protective effects of hearing protectors is also essential. Additional studies are needed to quantify the impact of behaviors associated with the improper use of hearing protection.

Face masks are strongly believed to be the best precaution to reduce the transmission of the SARS-CoV-2 virus, which resulted in an unprecedented surge in the production and use of personal respiratory protective equipment. Unfortunately, this surge led to improper disposal of used masks. This study aimed to assess the occurrence of microplastics (MPs) in used and unused surgical and cloth masks and N95 respirators. Respective samples were kept in a rotary shaker with distilled water in an Erlenmeyer flask for 5 hr to assess the release of MPs. Surgical masks showed a greater occurrence of microplastics release; an average of 18.27 items/mask were released from used and discarded surgical masks and 10.87 items/mask were released from unused new masks Fibers and fragments smaller than 0.5 mm in size were found to have a predominant presence in all the observed facemasks and respirators. The ATR-FTIR analysis of all the masks and respirators revealed the presence of four different polymers, namely polyethylene (PE) 46%, polypropylene (PP) 27%, polyamide (PA) 15% and polystyrene (PS) 12%. The microplastics released by face masks and N95 respirators can be carried by the environment or directly inhaled during use. As a result, using masks and N95 respirators repeatedly could expose individuals to microplastics. The proper use of face masks and N95 respirators and proper disposal practices should be maintained to prevent human and environmental exposures to MPs. MPs have been shown to affect individuals at the cellular to systems level, and additional research on the effects of MPs on human health is needed.