Journal of Occupational and Environmental Hygiene最新文献

{"title":"Heat risks in agriculture: Microclimate variability and worker safety in sweet corn and tobacco.","authors":"Ryan Edwards, Noel Lanier, Jo Anne G Balanay, Elizabeth Mizelle","doi":"10.1080/15459624.2025.2473469","DOIUrl":"10.1080/15459624.2025.2473469","url":null,"abstract":"<p><p>Agricultural work is one of the highest-risk U.S. occupations for heat-related illness (HRIs). Some tall-growing crops can block the cooling effects of wind or contribute to environmental humidity creating warm and humid microclimates (environments directly surrounding workers). The purpose of this study was to assess the differences in environmental heat stress within the center of tall-growing crop fields compared to the field perimeter. In the summer of 2023, two heat stress monitors collected daily measurements of wet bulb globe temperature (WBGT) in sweet corn and tobacco fields; results support that WBGT was higher at the field center of sweet corn and significantly higher at the field center of tobacco: 6.7% more hours in sweet corn and 13.6% more hours in tobacco were considered unsafe heat stress risk levels at the field center when compared to unsafe hours at the field perimeter. Unsafe heat stress risk levels were more likely to occur in the afternoons in the corn field while a high majority of all recorded hours in tobacco were considered unsafe, including the morning hours. The risk of laboring inside tall crop rows and heat-related illness should be considered in worker education and heat stress plans.</p>","PeriodicalId":16599,"journal":{"name":"Journal of Occupational and Environmental Hygiene","volume":" ","pages":"474-481"},"PeriodicalIF":1.5,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12140877/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143674066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heat stress and strain in commercial construction workers in the summer: A pilot study.","authors":"Jonathan W Specht, Serena A Garcia, Erica Tourula, M Jo Hite, Charlie Walker, Hillary A Yoder, David H Wegman, Jason Glaser, Zachary J Schlader, Fabiano T Amorim","doi":"10.1080/15459624.2025.2500613","DOIUrl":"https://doi.org/10.1080/15459624.2025.2500613","url":null,"abstract":"<p><p>Construction workers are 13 times more likely to die from heat-related illnesses than workers in other job industries. This elevated risk is attributed to excessive heat stress from environmental exposure, metabolic heat generated from physical labor, and the insulating effects of protective clothing. Levels of heat stress may vary across job types, reflecting the diversity of tasks performed and the work environment. Despite elevated risks, heat strain assessed by core temperature (Tcore) in construction workers during summertime in the United States has not been evaluated previously. Thirty-two construction workers (three females) were monitored over 3 summer workdays. Participants were categorized by job type (carpenter, concrete, laborer, roofer) and work environment (covered, uncovered). Heat index (HI), heart rate (HR), and Tcore were measured throughout the workday, while hydration was assessed through pre- and post-shift measurements of urine specific gravity (USG). Peak HI over the 3 days was 27.3, 35.2, and 33.7 °C, indicating the potential for low to moderate heat stress. Roofers experienced a higher peak HI compared to other job types (<i>p</i> < 0.01), but no differences were observed between workers in covered (28.8 ± 3.7 °C) and uncovered (32.1 ± 4.2 °C) areas (<i>p</i> = 0.37). The estimated peak metabolic rate was higher in workers in uncovered areas (868 ± 238 W) compared to covered (632 ± 130 W) (<i>p</i> < 0.01), with no differences among job types (<i>p</i> = 0.23). Forty-three percent of workers had Tcore exceeding 38.0 °C, with 4% exceeding 38.5 °C. Based on USG, 63% of workers began work dehydrated (1.022 ± 0.005), but urine did not become more concentrated during the workday (post-shift USG; 1.022 ± 0.007) (<i>p</i> = 0.78). Forward stepwise regression identified that peak metabolic rate plus post-shift USG were the combined variables most associated with peak Tcore (r² = 0.55, <i>p</i> < 0.01). Construction workers, even in low to moderate environmental heat exposure, experienced significant heat strain, primarily due to an elevated metabolic rate. Environmental heat exposure and metabolic rate vary by job type and work environment.</p>","PeriodicalId":16599,"journal":{"name":"Journal of Occupational and Environmental Hygiene","volume":" ","pages":"1-14"},"PeriodicalIF":1.5,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144183577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lung cancer risk assessment associated with exposure to hexavalent chromium: Results of pooled analysis of three cohorts.","authors":"Bruce C Allen, Melissa J Vincent, Loren Lipworth, Julie M Panko, Mina Suh, Xiaohui Jiang, Michael T Mumma, Deborah M Proctor","doi":"10.1080/15459624.2025.2502491","DOIUrl":"https://doi.org/10.1080/15459624.2025.2502491","url":null,"abstract":"<p><p>Quantitative risk assessments of inhaled hexavalent chromium (CrVI) have primarily relied on studies of two chromate production worker cohorts, involving male workers exposed to high concentrations of airborne CrVI that caused an exposure-dependent increase in lung cancer and elicited severe respiratory irritation. An additional larger cohort of CrVI-exposed aerospace workers, including women, and with lower intensity exposures, was recently updated with a longer follow-up period and reconstructed cumulative exposure estimates. A risk assessment was conducted using a pooled analysis of individual-level dose-response information from three cohorts, including the aerospace workers, to generate lung cancer inhalation unit risk estimates (IURs). IURs are estimates of the upper-bound of lifetime increased cancer risk from continuous inhalation exposure to 1 µg/m³ and are commonly used in quantitative risk assessment. Use of the pooled cohort broadens the range for dose-response analysis due to the comparatively low exposures to CrVI in the aerospace cohort; moreover, sex-specific risks could be expanded with the inclusion of female workers. Standardized logistic regression using person-year-specific weighted cumulative exposures was used to estimate the probability of lung cancer mortality, with varied weighting approaches. The primary model included male workers from all cohorts with a minimum of one year of CrVI exposure; secondary analyses examined the impacts of sex and short-term exposure. The best fit dose-response function was a Michaelis-Menten relationship. The IUR from the primary model was 0.01 (95%CI: 0.006-0.01) per µg/m³. Best estimates of the three IURs from secondary analyses, which removed the respiratory use adjustment factors, included females from the aerospace cohort and added workers with less than one year of exposure from the chromate production cohorts, were relatively consistent with the primary analyses, ranging from 0.008 to 0.03 per µg/m³. Use of this pooled IUR estimate allows for inclusion of a broader dose-response range and reduced uncertainty through use of a larger population, additional years of follow-up, and incorporation of broader geographical and cohort characteristics with improved relevancy to the general population.</p>","PeriodicalId":16599,"journal":{"name":"Journal of Occupational and Environmental Hygiene","volume":" ","pages":"1-15"},"PeriodicalIF":1.5,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144174075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Residential methamphetamine contamination in Boulder, Colorado: Incidence and implications.","authors":"James E Dennison, Norris Minick","doi":"10.1080/15459624.2025.2499612","DOIUrl":"https://doi.org/10.1080/15459624.2025.2499612","url":null,"abstract":"<p><p>The manufacture and use of methamphetamine (meth) is a significant problem, in part because it can lead to the contamination of properties where it occurs. Meth contamination can lead to health issues for occupants as well as very high remediation costs for property owners. But even in a state like Colorado, where meth testing and remediation are highly regulated, the number of residences or other types of property that are contaminated more than contamination standards is unknown. Generally, testing for meth contamination occurs only after a property is identified as a likely site for meth use or manufacture, whether by law enforcement, the property owner, or a potential buyer. For this paper, a unique data set based on a real estate broker's meth screening program was used to determine the incidence of contaminated residences in general. Brokerage clients put 303 residential properties under contract between 2013 and 2022, of which 288 (95%) were screened for meth contamination. Meth was detected in 45 of the 288 screening tests (16%), often at trace levels, while 84% contained no detectable meth. Comprehensive testing was subsequently performed on 35 of these 45 properties and 10 (3.47%) of the original 288 screened properties contained meth contamination above the Colorado contamination standard of 0.5 µg/100 cm². Of the 288 screened properties, 9% exceeded 0.05 µg/100 cm², 6% exceeded 0.1 µg/100 cm², and 2% exceeded 1.5 µg/100 cm². While the sample size of this analysis was modest, it provides a true estimate of the incidence of meth-contaminated residential property and an indication of the public health significance of this issue.</p>","PeriodicalId":16599,"journal":{"name":"Journal of Occupational and Environmental Hygiene","volume":" ","pages":"1-9"},"PeriodicalIF":1.5,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144127913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving AI object detection in fire scenes through data augmentation.","authors":"Fatima Lois Suarez, Yi-Lin Chen, Ray Hsienho Chang, Yan-Tsung Peng, Changjie Cai","doi":"10.1080/15459624.2025.2499600","DOIUrl":"https://doi.org/10.1080/15459624.2025.2499600","url":null,"abstract":"<p><p>Artificial Intelligence (AI) has been widely used to facilitate disaster response. By connecting cameras to AI software, it can help determine the number of firefighters and apparatus, enhancing efficiency on the fireground. However, we must overcome several challenges to effectively utilize AI in firefighting. One challenge is improving the brightness and resolution of pictures and videos taken at fire scenes. This study examines the impacts of two image enhancement methods, Contrast-Limited Adaptive Histogram Equalization (CLAHE) and Zero-reference Deep Curve Estimation (Zero-DCE), on the accuracy of the AI-based object detector trained using images taken on various fire scenes. The results indicate that, after augmenting the training data with image enhancement techniques, the detector can accurately identify firefighters with a precision of 0.827 and firetrucks with a precision of 0.945. Enhancing the dataset's variety through these techniques improves the model's generalizability, provided that the test images are also enhanced to augment visual quality. Specifically, applying CLAHE during training increased the mean average precision (mAP) value by 8% and the recall by 7% from the baseline. Meanwhile, the integration of Zero-DCE demonstrated particular efficacy in recognizing firetrucks in low-light conditions, achieving the highest precision value of 0.945 among all the cases considered. This paper will benefit future applications of AI in fireground operations. Additionally, we provide directions for future researchers to advance AI recognition research in facilitating disaster response activities and fireground operations.</p>","PeriodicalId":16599,"journal":{"name":"Journal of Occupational and Environmental Hygiene","volume":" ","pages":"1-10"},"PeriodicalIF":1.5,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144119909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Residential washing machine efficacy in removing lead from clothing: A pilot study.","authors":"Chandran Achutan, Krystin Carlson, Kerri LeVanseler, James Couch","doi":"10.1080/15459624.2025.2497871","DOIUrl":"10.1080/15459624.2025.2497871","url":null,"abstract":"<p><p>Workers exposed to lead sometimes wear their work clothes home. It is possible that lead from contaminated work clothing can transfer to uncontaminated clothing, including children's items that may be in the same load, during laundering. This is concerning because lead is especially toxic for children. The purpose of this pilot study was to understand lead extraction from fabrics typically worn by workers, the amount of lead removed during normal laundering, and lead transfer to other fabrics during a laundry washing cycle. The study validated EPA analytical method 200.8 Determination of Trace Elements in Waters and Wastes by Inductively Coupled Plasma-Mass Spectrometry to analyze lead in Dickies pant fabric (DPF), T-shirt material (TSM), and blue jeans material (BJM). Because this methodology of extracting lead from fabrics is novel, a priori definitions of accuracy and precision used were ± 40%. Researchers spiked two levels (9 µg and 9,000 µg) of lead nitrate and three levels (9 µg, 900 µg, and 9,000 µg) of lead carbonate on 9 cm² fabric swatches and extracted lead by microwave-assisted digestion. Across all spike levels, mean recoveries were within 60% and 140% recovery. All percent coefficient of variation values were less than 20% for lead nitrate, indicating that this method for lead nitrate was sufficiently accurate and precise. For lead carbonate, the method was neither accurate nor precise at the 9 and 900 µg levels but was sufficiently accurate and precise at the 9,000 µg level. Eighteen loads of fabric swatches were spiked with either lead form and laundered in a washing machine using a common laundry detergent. The mean amount of lead removed from laundered DPF and TSM was similar (97.4 and 95.9%) and significantly higher (<i>p</i> < 0.05) compared to laundered BJM (70.6%). The amount of lead carbonate removed (92.6%) was significantly higher (<i>p</i> < 0.05) than lead nitrate (83.4%). The levels of lead that transferred from spiked fabric to bedsheets included in the same washing load were less than 0.5 µg. It is important to follow public health recommendations, such as laundering work clothes separately.</p>","PeriodicalId":16599,"journal":{"name":"Journal of Occupational and Environmental Hygiene","volume":" ","pages":"1-9"},"PeriodicalIF":1.5,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12354050/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143970624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An alternative to the HSE/NPL Mark II Phase Contrast Test Slide for airborne asbestos fiber analysis laboratories.","authors":"Geoff Pickford, Joanna Szymanska","doi":"10.1080/15459624.2025.2464587","DOIUrl":"10.1080/15459624.2025.2464587","url":null,"abstract":"<p><p>More than 55 years ago, an analytical method employing phase contrast optical microscopy was developed for the quantitative estimation of airborne asbestos fiber concentration, and it was found that the detection limit of these microscopes was dependent upon microscope design, microscope set-up, and observer performance. In the early 1980s, the HSE/NPL Mark II Phase Contrast Test Slide was developed which facilitated standardizing detection limits of microscopes and observers in laboratories around the world. This paper describes the development and testing of an alternative test slide, known as the Pickford Phase Contrast Test Slide, which employs state-of-the-art nano-fabrication technology. Each Pickford Test Slide is certified by the Environmental Analysis Laboratory of the Southern Cross University stating that it is equivalent in performance to that of the HSE/NPL Mark II test slide, which aligns with the United Kingdom Health and Safety Executive HSG248 Asbestos: The Analysts' Guide (2021) requirement. Users report that the Pickford Test Slide is much easier to use than the HSE/NPL Slide. Since the early 1980s, the certification of phase contrast microscope test slides has been based on subjective visibility testing, which is less than ideal because of variations between certifiers, reference standards, and microscopes. Hence, a unique objective visibility test was developed with the aim of replacing subjective testing, and also of conducting routine testing of the test slide phase objects following nano-fabrication. Routine testing has been useful because each Pickford Test Slide is tested and documented so that intricate nano-fabrication chip processes can be controlled over years of production. However, thousands of comparisons of both forms of testing have shown that it is very unlikely that objective visibility testing will ever replace subjective testing because valid and relevant objective testing depends upon standardizing several dozen microscope camera set-up parameters that vary from one camera to another. Further, because the ultimate use of a test slide has always been based on human visibility, validation may not be achievable.</p>","PeriodicalId":16599,"journal":{"name":"Journal of Occupational and Environmental Hygiene","volume":" ","pages":"425-436"},"PeriodicalIF":1.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143523725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tackling antineoplastic drugs' contamination in healthcare settings: New insights on surface cleaning approaches.","authors":"Maria Francisca Portilha-Cunha, Pedro Norton, Arminda Alves, Ana R L Ribeiro, Adrián M T Silva, Mónica S F Santos","doi":"10.1080/15459624.2025.2449945","DOIUrl":"10.1080/15459624.2025.2449945","url":null,"abstract":"<p><p>Effective decontamination of hospital surfaces is crucial to protect workers from antineoplastic drugs (ADs) since dermal absorption is the main exposure route to these hazardous medicinal products. Sampling after daily cleaning in oncologic settings from a tertiary hospital was initially performed and exhibited low contamination levels; however, cyclophosphamide was still found (up to 957 pg/cm²) above the guidance value (100 pg/cm²) in four locations, evidencing the need to properly assess and update the cleaning protocols. Then, cleaning efficiencies of six solutions and different protocols were evaluated (including, for the first time, four commercial cleaning solutions/disinfectants not designed specifically for AD removal) after deliberate contamination of three model surfaces with 13 pharmaceuticals: bicalutamide, capecitabine, cyclophosphamide, cyproterone, doxorubicin, etoposide, flutamide, ifosfamide, imatinib, megestrol, mycophenolate mofetil, paclitaxel, and prednisone. Wipe sampling and liquid chromatography-tandem mass spectrometry were employed to determine surface contamination after cleaning. Results revealed that: (i) none of the solutions or procedures totally removed all target pharmaceuticals from surfaces; (ii) the removal efficiency increased with cleaning steps (average removals above 90% were attained for Vyclean and Clinell Universal Spray using two cleaning steps); and (iii) the cleaning efficiency was likely favored by the application of the solution/disinfectant directly on the surfaces. Therefore, considering the dissimilar chemical structures and properties of the numerous ADs in use, the cleaning agent and protocol should be adjusted to the reality of each healthcare unit. Still, the scientific community is encouraged to develop a cleaning solution/protocol to simultaneously eliminate/remove as many ADs as possible.</p>","PeriodicalId":16599,"journal":{"name":"Journal of Occupational and Environmental Hygiene","volume":" ","pages":"386-399"},"PeriodicalIF":1.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143006316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regression tools for chemical release modeling: An additive manufacturing case study.","authors":"David E Meyer, Raymond L Smith, Elizabeth Lanphear, Sudhakar Takkellapati, John D Chea, Gerardo J Ruiz-Mercado, Michael A Gonzalez, William M Barrett","doi":"10.1080/15459624.2024.2447320","DOIUrl":"10.1080/15459624.2024.2447320","url":null,"abstract":"<p><p>Chemical release data are essential for performing chemical risk assessments to understand the potential exposures arising from industrial processes. Often, these data are unknown or unavailable and must be estimated. A case study of volatile organic compound releases during extrusion-based additive manufacturing is used here to explore the viability of various regression methods for predicting chemical releases to inform chemical assessments. The methods assessed in this work include linear Least Squares, Least Absolute Shrinkage and Selection Operator (LASSO) and Ridge regression, classification and regression tree, random forest model, and neural network analysis. Secondary data describing polymeric extrusion in multiple applications are curated and assembled in a dataset to support regression modeling using default parameters for the various approaches. The potential to add noise to the dataset and improve regression is evaluated using synthetic data generation. Evaluation of model performance for a common test set found all methods were able to achieve predictions within 10%-error for up to 98% of the test sample population. The degree to which this level of performance was maintained when varying the number and type of features for regression was dependent on the model type. Linear methods and neural network analysis predicted the most test samples within 10%-error for smaller numbers of features while tree-based approaches could accommodate a larger number of features. The number and type of features can be important if the desire is to make chemical-specific release predictions. The inclusion of release data from related processes generally improved test set predictions across all models while the use of synthetic data as implemented here resulted in smaller increases in test sample predictions within 10%-error. Future work should focus on improving access to primary data and optimizing models to achieve maximum predictive performance of environmental releases to support chemical risk assessment.</p>","PeriodicalId":16599,"journal":{"name":"Journal of Occupational and Environmental Hygiene","volume":" ","pages":"375-385"},"PeriodicalIF":1.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12094160/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142978985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The pathogenic burden potential of airborne particles in emanating from the respiratory area of COVID-19 patients (a case study).","authors":"Somayeh Soleimani-Alyar, Rasoul Yarahmadi, Maryam Borhani-Jebeli, Golnaz Yarahmadi, Farah Bokharaei-Salim, Alireza Alipour, Maryam Soleimani-Alyar, Hamid-Reza Monavari, Mohammad-Mehdi Darvishi, Sara Dalvand","doi":"10.1080/15459624.2024.2447317","DOIUrl":"10.1080/15459624.2024.2447317","url":null,"abstract":"<p><p>The pathogenic potential of airborne particles carrying the SARS-CoV-2 viral genome was examined by considering the size distribution of airborne particles at given distances from the respiratory zone of an infected patient after coughing or sneezing with a focus on time, temperature, and relative humidity. The results show an association between the size distribution of airborne particles, particularly PM₁ and PM_2.5, and the presence of viral genome in different stations affected by the distance from the respiratory zone and the passage of time. The correlation with time was strong with all the dependent factors except PM₁. Also, the effect of time intervals on the median concentration of airborne PM in the range of PM₇ and PM₁₀ was significant. Accordingly, in the first 20 min after coughing, the COVID-19 patient was more likely to be exposed to PM-carrying RNA genomes of SARS-CoV-2. The other finding was that the two distances of 0.25 m to the patient's left of the respiratory zone and 1.0 m above the breathing zone showed positive results for the presence of SARS-CoV-2 in all studied time intervals. The patterns of results suggested that there was a high potential for distribution of the virus in an infected patient based on position and airflow and that the severity of infection and viral load may influence the presence of viral load in droplets when coughing. Based on the results, one can conclude that ventilation plays a key role in mitigating the risk of airborne virus transmission in indoor environments, and it has been shown that reductions in particulate concentrations occur when portable air purifiers are placed near the breathing zone. The use of personal protective equipment for the patient and healthcare personnel to minimize the distribution of virus particles in the air is recommended.</p>","PeriodicalId":16599,"journal":{"name":"Journal of Occupational and Environmental Hygiene","volume":" ","pages":"362-374"},"PeriodicalIF":1.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143006638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}