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A rapid and cost-effective method for detecting bacterial cells from surfaces is critical to food safety, clinical hygiene, and pharmacy quality. Herein, we established an optical detection method based on a gold chip coating with 3-mercaptophenylboronic acid (3-MPBA) to capture bacterial cells, which allows for the detection and quantification of bacterial cells with a standard light microscope under low-magnification (10×) objective lens. Then, integrate the developed optical detection method with swab sampling to detect bacterial cells loading on stainless-steel surfaces. Using Salmonella enterica (SE1045) and Escherichia coli (E. coli OP50) as model bacterial cells, we achieved a capture efficiency of up to 76.0 ± 2.0 % for SE1045 cells and 81.1 ± 3.3 % for E. coli OP50 cells at 103 CFU/mL upon the optimized conditions, which slightly decreased with the increasing bacterial concentrations. Our assay showed good linear relationships between the concentrations of bacterial cells with the cell counting in images in the range of 103 -107 CFU/mL for SE1045, and 103 -108 CFU/mL for E. coli OP50 cells. The limit of detection (LOD) was 103 CFU/mL for both SE1045 and E. coli OP50 cells. A further increase in sensitivity in detecting E. coli OP50 cells was achieved through a heat treatment, enabling the LOD to be reduced as low as 102 CFU/mL. Furthermore, a preliminary application succeeded in assessing bacterial contamination on stainless-steel surfaces following integration with the approximately 40 % recovery rate, suggesting prospects for evaluating the bacteria from surfaces. The entire process was completed within around 2 h, costing merely a few dollars per sample. Considering the low cost of standard light microscopes, our method holds significant potential for practical industrial applications in bacterial contamination control on surfaces, especially in low-resource settings.

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BACKGROUND: Studies have shown that contamination of surfaces by illicit drugs frequently occurs in forensic laboratories when manipulating seized samples as well as in pharmacies and hospitals when preparing medicinal drugs. In this project, we extended these studies to a Drug Consumption Room to investigate drug levels and possible exposure of the staff members. METHODS: We investigated pre and post cleaning contamination by heroin and cocaine and their degradation products 6-monoacetylmorphine and benzoylecgonine on different surfaces (tables, counters, computers and door handles) and in the ambient air. We also collected urine and hair samples from staff members to check for potential short and long term contaminations. RESULTS: Medium to heavy contamination has been detected on most surfaces and door handles; as expected, air contamination was particularly high in the smoking room. Drug levels were < LOD to very low in the urine and the hair samples of staff members tested. CONCLUSION: The cleaning efficiency of the surfaces, carried out by staff and drug users after drug consumption, was often not satisfactory. The very low drug levels in hair indicate that acute health risks for staff members are low.

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Purpose: The osseointegration in dental implants is greatly affected by various surface properties, such as chemistry, texture, and overall cleanliness. This study aimed to investigate the impact of mineral oil lubricants used in rotary instruments on osseointegration within rabbit tibiae, with a specific focus on potential contamination from dental handpices. Materials and Methods: Twelve New Zealand rabbits were included in this study, each receiving two implants in each tibia, resulting in a total of 48 implants across the study. Groups were organized based on the time until euthanasia and the degree of implant contamination. Three contamination levels were defined: the first group received implants without any lubricant in the handpiece (control group); the second group received implants with handpices managed as recommended; the third group had implants placed using fixtures pre-soaked in lubricant. These groups were further subdivided based on euthanization periods of two and four weeks. We measured and analyzed both the removal torque and the bone-implant contact. Results: We observed a non-significant inverse correlation between the severity of fixture contamination and removal torque. However, there was a significant reduction in bone-implant contact associated with higher contamination levels, particularly after four weeks. Conclusions: Even brief exposure to lubricants from handpieces can jeopardize the osseointegration of implants in bone. Therefore, it is imperative to implement thorough procedures for lubricant removal post-application and to employ precise cleaning and suction during implant drilling and placement to minimize residual oil on the implant surface.

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Proper waste sorting is crucial for biodegradable plastics (BDPs) recycling, whose global production is increasing dynamically. BDPs can be sorted using near-infrared (NIR) sorting, but little research is available about the effect of surface contamination on their NIR spectrum, which affects their sortability. As BDPs are often heavily contaminated with food waste, understanding the effect of surface contamination is necessary. This paper reports on a study on the influence of artificially induced surface contamination using food waste and contamination from packaging waste, biowaste, and residual waste on the BDP spectra. In artificially contaminated samples, the absorption bands (ADs) changed due to the presence of moisture (1352-1424 nm) and fatty acids (1223 nm). In real-world contaminated samples, biowaste samples were most affected by contamination followed by residual waste, both having altered ADs at 1352-1424 nm (moisture). The packaging waste-contaminated sample spectra closely followed those of clean and washed samples, with a change in the intensity of ADs. Accordingly, two approaches could be followed in sorting: (i) affected wavelength ranges could be omitted, or (ii) contaminated samples could be used for optimizing the NIR database. Thus, surface contamination affected the spectra, and knowing the wavelength ranges containing this effect could be used to optimize the NIR database and improve BDP sorting.

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BACKGROUND: Surface contamination with antineoplastic drugs (ADs) is persistent. The use of personal protective equipment (PPE) is recommended to reduce exposure to ADs. OBJECTIVES: This study explored the impact of the COVID-19 pandemic on nurses' PPE use and surface contamination with ADs. METHODS: Demographic characteristics, PPE use, and associated factors were assessed on two inpatient oncology units where etoposide and cyclophosphamide were administered before (N = 26) and during the COVID-19 pandemic (N = 31). FINDINGS: PPE use when handling contaminated excreta was significantly higher during the pandemic. Perceived risk of chemotherapy exposure was significantly associated with greater PPE use when handling AD-contaminated excreta, and conflict of interest was related to less PPE use during AD administration and handling of AD-contaminated excreta. During the pandemic, surface contamination with etoposide increased in shared areas and decreased in patient rooms.

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Background: Current recommendations from regulatory authorities suggest quantitative surface sampling for detection of hazardous drugs at least once every 6 months. A more frequent and efficient process for hazardous drug testing might reduce the safety risks associated with exposure to these agents. Objectives: The primary objective was to assess the findings of surface testing based on traditional quantitative sampling methods relative to the findings of qualitative surface sample testing with the BD HD Check system. The secondary objectives included assessment of the ease of integrating qualitative sampling into pharmacy protocols and identification of opportunities to enhance patient and staff education and safety. Methods: Samples from 23 unique surfaces were tested concurrently once a month for 5 months using a quantitative surface sampling method and the qualitative BD HD Check system on adjacent 12 inch × 12 inch (30.5 cm × 30.5 cm) surface areas. The presence or absence of cyclophosphamide, methotrexate, and/or doxorubicin contamination was assessed by each of the 2 testing methods. The BD HD Check system was also assessed for ease of use and efficiency. Results: Ten areas of contamination were identified over the 5-month period. Nine were detected by the BD HD Check system and one by the quantitative system. The BD HD Check system was easy to use, with results available in less than 10 minutes per area tested. Conclusions: The BD HD Check system allows for more timely identification of surface contamination with hazardous drugs than the standard sampling protocol. The discrepancy in results between the 2 methods of hazardous drug surface sampling requires further investigation.

Contexte: Les recommandations actuelles des autorités de réglementation suggèrent de procéder à un échantillonnage de surface quantitatif pour la détection de médicaments dangereux au moins une fois tous les 6 mois. Un processus de test des médicaments dangereux plus fréquent et plus efficace pourrait réduire les risques de sécurité associés à l'exposition à ces agents. Objectifs: L'objectif principal visait à évaluer les résultats de l'échantillonnage de surface basé sur les méthodes d'échantillonnage quantitatives traditionnelles par rapport aux résultats des tests qualitatifs d'échantillons de surface effectués avec le système de détection des médicaments dangereux BD HD Check. Les objectifs secondaires comprenaient l'évaluation de la facilité d'intégration de l'échantillonnage qualitatif dans les protocoles pharmaceutiques et l'identification des occasions d'améliorer l'éducation et la sécurité des patients et du personnel. Méthodologie: Des échantillons provenant de 23 surfaces uniques ont été testés simultanément une fois par mois pendant 5 mois à l'aide d'une méthode d'échantillonnage de surface quantitative et du système BD HD Check sur des surfaces adjacentes de 12 pouces × 12 pouces (30,5 cm × 30,5 cm). La présence ou l'absence de contamination par le cyclophosphamide, le méthotrexate et/ou la doxorubicine a été évaluée à l'aide de chacune des 2 méthodes de test. La facilité d'utilisation et l'efficacité du système BD HD Check ont également fait l'objet d'une évaluation. Résultats: Dix zones de contamination ont été identifiées sur la période de 5 mois. Neuf ont été détectées par le système BD HD Check et une par le système quantitatif. Le système BD HD Check était facile à utiliser et les résultats étaient prêts en moins de 10 minutes par zone testée. Conclusions: Le système BD HD Check permet d'identifier plus rapidement la contamination de surface par médicaments dangereux que le protocole d'échantillonnage standard. L'écart dans les résultats entre les 2 méthodes d'échantillonnage de surface des médicaments dangereux nécessite une étude plus approfondie.

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INTRODUCTION: Antineoplastic drugs (ADs) are frequently used pharmaceuticals in the healthcare, and healthcare workers can be occupationally exposed to ADs. Monitoring of surface contamination is a common way to assess occupational exposure to ADs. The objective was to develop and validate a sensitive and quantitative monitoring method to determine surface contaminations of Pt as a marker for Pt-containing ADs. The surface contaminations of Pt-containing ADs were monitored at four Swedish hospital workplaces. METHODS: An analytical method was developed based on inductively coupled plasma mass spectrometry. The wipe sampling procedure was validated regarding different surface materials. The stability of collected wipe samples was investigated. Workplace surfaces were monitored by wipe sampling to determine contaminations of Pt-containing ADs. RESULTS: A wipe sampling and analytical method with a limit of detection of 0.1 pg Pt/cm2 was developed. Pt was detected in 67% of the wipe samples collected from four workplaces, and the concentrations ranged from <0.10 to 21100 pg/cm2. In 4% of samples, the detected surface contaminations of Pt in three hospital wards were above proposed hygienic guidance value (HGV) of Pt. In the hospital pharmacy, 9% of the detected surface contaminations of Pt were above lowest proposed HGV. CONCLUSIONS: A user-friendly, specific, and sensitive method for determination of surface contaminations of Pt from ADs in work environments was developed and validated. A large variation of contaminations was observed between detected surface contaminations of Pt in samples collected in wards, and it likely reflects differences in amounts handled and work practices between the wards.

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The COVID-19 pandemic has provided valuable lessons that deserve deep thought to prepare for the future. The decay pattern of surface contamination by SARS-CoV-2 RNA in the residences of COVID-19 patients is important but still unknown. We collected 2,233 surface samples from 21 categories of objects in 141 residences of COVID-19 patients in Shanghai when attacked by the omicron variant in spring 2022. Several characteristics of the patients and their residences were investigated to identify relevant associations. The decay of contamination was explored to determine the persistence. Approximately 8.7% of the surface samples were tested positive for SARS-CoV-2 RNA. The basin, water tap, and sewer inlet had the highest positive rates, all exceeding 20%. Only time was significantly associated with the level of surface contamination with SARS-CoV-2, showing a negative association. The decrease fit a first-order decay model with a decay rate of 0.77 ± 0.07 day-1, suggesting a 90% reduction in three days. Positive associations between the cumulative number of newly diagnosed patients in the same building and the positive rate of SARS-CoV-2 RNA in the public corridor were significant during the three days. Our results, in conjunction with the likely lower infectivity or viability, demonstrate that fomite transmission played a limited role in COVID-19 spread. The time determined SARS-CoV-2 RNA contamination, which was reduced by three days. This study is the first to show the decay patterns of SARS-CoV-2 contamination in real residential environments, providing insight into the patterns of transmission, as well as community-based prevention and control of similar threats.

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Measurement of tritium surface contamination is important for tritium related facilities, especially for fusion devices. A novel detector has been designed for tritium surface contamination measurements based on CaF2(Eu) sheet and Microchannel plate photomultiplier tube (MCP-PMT). Self-coincidence technology has been introduced to obtain lower detection limit by diminishing the background noise caused by γ-rays and hot electrons. Performance of the detector was optimized by specifying the key parameters including the distance of the scintillator and sample, the thickness of light guide, the number of annular electrodes et al., using Monte Carlo method. Results indicate that detection efficiency of 49.4 % and the response deviations at different positions less than 0.5 % could be achieved. The detection limit of tritium under the simulation conditions is 0.09 Bq/cm2 and 0.03 Bq/cm2 when the counting time is 10 s and 60 s, respectively.

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Recreational methamphetamine production and heavy use can result in dwelling contamination that is difficult to detect. First responders and public health officials may use commercially available trace methamphetamine detection (presumptive) test kits to understand apparent and hidden dangers in impacted dwellings. Here, we assessed the limit of detection (LOD) of several commercially available presumptive test kits using simulated contaminated hard surfaces. Pyrex petri dishes were spiked with aliquots of methanolic methamphetamine solutions to reach desired simulated contamination levels. Commercially available presumptive tests were conducted according to manufacturer instructions and using included sample preparation materials, when available. Additionally, a laboratory-based liquid chromatography-triple quadrupole mass spectrometer (LC-MS/MS) trace methamphetamine quantification method was developed and validated using the EZSTATSG2 tool. For the LC-MS/MS method, samples were collected using 2-ply alcohol prep pads and methamphetamine was extracted using a 1:1 (v:v) methanol: water solution. Most presumptive tests considered were able to detect trace levels of methamphetamine extracted from hard surfaces, with LOD ranging from 0.10-15.00 µg/sample. Comparatively, the laboratory-based LC-MS/MS LOD was 0.05 µg/sample and limit of quantitation was 0.10 µg/sample. The LC-MS/MS method may be useful when the presence of dust or other contaminants interferes with presumptive test interpretation or reliability. Costs of presumptive tests varied from several dollars to tens of dollars, which is included alongside LOD results to aid stakeholders in identifying which test(s) are the best fit for purpose. Therefore, first responders, public health officials, and other stakeholders have several options for assessing trace methamphetamine contamination.

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Environmental surface surveillance is a valuable tool for detecting and controlling infectious diseases. During the COVID-19 pandemic, concerns have been raised regarding the potential for indirect transmission of SARS-CoV-2 via contaminated surfaces. However, few studies have evaluated environmental contamination in non-clinical settings during outbreaks. We conducted a study in a school community during a major outbreak, collecting 35 surface samples from high-traffic areas and testing them for SARS-CoV-2 RNA using RT-qPCR. Our results showed that 31.4% of samples were positive, including high-touch surfaces such as drinking fountains and washbasins. These findings emphasize the importance of environmental monitoring to identify and address specific areas for attention, and implementing such strategies can help prevent the indirect transmission of COVID-19 in various settings.

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Objective:To develop a new type of detection window protective device for surface contamination monitor,and to verify its testing effect.Methods:The new type of surface contamination monitor detection window protection device was composed of the protective film and fixed frame,which was of integrated design and one-off production.The protective film was made of transparent flat Myra film,thickness≤2.5μm,the fixed frame was a rectangular hollow structure surrounded by four edges and provided with a working surface and a mounting surface.The protective film was pasted on the inner wall of the working surface of the fixed frame by adhesive,and the protective film and fixed frame were installed on the outside of the detection window of the surface contamination monitor by means of fixing buckles.Two commonly used surface contamination detection instruments,RDa150 and Como170,were selected to measure artificial radiation sources under three protection states:no film protection,plastic wrap protection and new protection device to test the detection efficiency and operability of the new surface contamination monitor's detection window protection device.Results:Compared with the traditional protective measures of plastic wrap,the detection efficiency of α,β and γ rays was more effectively ensured by the new detection window protective device for surface contamination monitor,and the detection efficiency of α rays was increased from about 40%to about 70%.Conclusion:The new detection window protection device for surface contamination monitor can significantly improve the detection efficiency of radioactive contamination,especially alpha-ray pollution,and effectively protect the instrument and equipment,and effectively improve the detection efficiency of surface contamination detection operators.

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INTRODUCTION: Exposure of healthcare workers to hazardous drugs can lead to adverse health effects supporting the importance of a continuous monitoring program, for example, by taking surface wipe samples. The objective was to describe the results of repeated monitoring of contamination with hazardous drugs on multiple surfaces in a hospital pharmacy and at two wards using standardized preparation techniques and cleaning procedures. METHODS: Twelve surfaces in the hospital pharmacy and at two wards were sampled and analyzed for contamination with the hazardous drugs cyclophosphamide, doxorubicin, 5-fluorouracil, gemcitabine, methotrexate, and paclitaxel. The drugs were prepared with a closed-system drug transfer device (CSTD). Sampling of the drugs was performed in four trials during eight months. Liquid chromatography tandem mass spectrometry was used for the analysis of the drugs. RESULTS: During the four trials, contamination with five of the six hazardous drugs was found on half of the surfaces in the pharmacy and in a ward. Seventeen out of 288 possible outcomes were positive (6%), with the biological safety cabinet grate (n = 6) and scanner (n = 5) most frequently contaminated. The highest level of contamination was observed on the pass-thru window (cyclophosphamide: 2.90 ng/cm2) and the touch screen of the Diana device (5-fluorouracil: 2.38 ng/cm2). Both levels were below the action level of 10 ng/cm2. CONCLUSIONS: The long-term use of a CSTD in combination with appropriate cleaning has proven effective in achieving low levels of surface contamination with hazardous drugs.

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Numerous epidemic outbreaks related to cold chains have occurred since the coronavirus disease 2019 (COVID-19) outbreak, suggesting the potential danger of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission through cold chain foods (CCFs). By analyzing SARS-CoV-2 RNA contamination of CCFs imported from Fuzhou ports, this study evaluated the contamination and transmission of SARS-CoV-2 RNA via maritime cold chains, with the aim of provide suggestions for CCFs supervision and public health management. The statistical analysis included 131,385 samples. The majority of the CCFs imported into Fuzhou ports was aquatic raw food that originated in Southeast Asia (57.08 %), South America (19.87 %), and South Asia (11.22 %). South Asia had the highest positivity rate of 0.37 %, followed by Southeast Asia (0.21 %) and South America (0.08 %). The positivity rate showed that the outer packaging of CCFs was the most easily contaminated, accounting for 81.33 % of all positive samples. This suggested that CCFs storage and loading processes were the weak links vulnerable to SARS-CoV-2 contamination. The positivity rates in outer packaging, inner packaging, and content of raw food were 0.48 %, 0.08 %, and 0.05 %, respectively, which were obviously higher than those of processed and refined food. This indicated that increasing the mechanization of factories and implementing sensible worker management practices may decrease viral contamination. The monthly positivity rates varied widely from 0 % (March 2021) to 0.40 % (January 2021), with an average of 0.19 %. The positivity rates in outer packaging, inner packaging and content of crustaceans from Southeast Asia were 2.47 %, 0.41 %, and 0.69 %, which were approximately 5-14 times higher than those of fish and cephalopods. Meanwhile, the monthly detection number show that SARS-CoV-2 epidemic prevention strategies affected the trade of imported CCFs.

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Effective disinfection procedures in healthcare facilities are essential to prevent transmission. Chemical disinfectants, hydrogen peroxide vapour (HPV) systems and ultraviolet (UV) light are commonly used methods. An emerging method, violet-blue light at 405 nm, has shown promise for surface disinfection. Its antimicrobial properties are based on producing reactive oxygen species (ROS) that lead to the inactivation of pathogens. Studies have shown significant efficacy in reducing bacterial levels on surfaces and in the air, reducing nosocomial infections. The aim of this study was to evaluate the antimicrobial effectiveness of violet-blue (405 nm) LED lamps on high-contact surfaces in a hospital infection-control laboratory. High-contact surfaces were sampled before and after 7 days of exposure to violet-blue light. In addition, the effect of violet-blue light on MRSA-contaminated surfaces was investigated. Exposure to violet-blue light significantly reduced the number of bacteria, yeasts and moulds on the sampled surfaces. The incubator handle showed a low microbial load and no growth after irradiation. The worktable and sink showed an inconsistent reduction due to shaded areas. In the second experiment, violet-blue light significantly reduced the microbial load of MRSA on surfaces, with a greater reduction on steel surfaces than on plastic surfaces. Violet-blue light at 405 nm has proven to be an effective tool for pathogen inactivation in healthcare settings Violet-blue light shows promise as an additional and integrated tool to reduce microbial contamination in hospital environments but must be used in combination with standard cleaning practices and infection control protocols. Further research is needed to optimise the violet-blue, 405 nm disinfection method.

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Introduction: The exposures to hazardous antineoplastic drugs (AD) represent serious risks for health care personnel but the exposure limits are not commonly established because of the no-threshold effects (genotoxic action, carcinogenicity) of many ADs. In this study, we discussed and derived practically applicable technical guidance values (TGV) suitable for management of AD risks. Methods: The long-term monitoring of surface contamination by eight ADs was performed in pharmacies and hospitals in the Czech Republic and Slovak Republic in 2008-2021; in total 2,223 unique samples were collected repeatedly in 48 facilities. AD contamination was studied by LC-MS/MS for cyclophosphamide, ifosfamide, methotrexate, irinotecan, paclitaxel, 5-fluorouracil and gemcitabine and by ICP-MS for total Pt as a marker of platinum-based ADs. Results: The study highlighted importance of exposure biomarkers like 5-fluorouracil and especially carcinogenic and persistent cyclophosphamide, which should be by default included in monitoring along with other ADs. Highly contaminated spots like interiors of laminar biological safety cabinets represent a specific issue, where monitoring of contamination does not bring much added value, and prevention of staff and separated cleaning procedures should be priority. Rooms and surfaces in health care facilities that should be virtually free of ADs (e.g., offices, kitchenettes, daily rooms) were contaminated with lower frequency and concentrations but any contamination in these areas should be carefully examined. Discussion and conclusions: For all other working places, i.e., majority of areas in pharmacies and hospitals, where ADs are being prepared, packaged, stored, transported, or administered to patients, the study proposes a generic TGV of 100 pg/cm2. The analysis of long-term monitoring data of multiple ADs showed that the exceedance of one TGV can serve as an indicator and trigger for improvement of working practices contributing thus to minimizing of unintended exposures and creating a safe work environment.

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A method has been developed for solving the Fredholm equation in the barrier geometry for reconstructing the surface activity density (SAD) from the results of measuring the ambient dose equivalent rate (ADER). Inclusion of the barrier geometry means that the method takes into account the shielding effect of buildings and structures on the contaminated site. The method was based on the representation of the industrial site, buildings and radiation fields in the form of a raster and the use of the visibility matrix (VM) of raster cells to describe the barrier geometry. The developed method was applied to a hypothetical industrial site with a size of 200 × 200 conventional units for four types of SAD distribution over the surface of the industrial site: 'fragmentation', 'diffuse', 'uniform' and 'random'. The method of Lorentz curves was applied to estimate the compactness of the distributions of SAD and the ADER for the considered radiation sources. It was shown that the difference between the Lorentz curve for SAD and ADER means that the determination of the spatial distribution of SAD over the industrial site by solving the integral equation is essentially useful for determining the location of radiation source locations on the industrial site. The accuracy of SAD reconstruction depends on the following parameters: resolution (fragmentation) of the raster, the height of the radiation detector above the scanned surface, and the angular aperture of the radiation detector. The measurement of ADER is simpler and quicker than the direct measurement of SAD and its distribution. This represents a significant advantage if SAD distribution needs to be determined in areas with high radiation dose-rate during limited time. The developed method is useful for supporting radiation monitoring and optimizing the remediation of nuclear legacies, as well as during the recovery phase after a major accident.

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A method for reconstructing surface activity density (SAD) maps based on the solution of the Fredholm equation has been developed and applied. The construction of SAD maps was carried out for the site of the temporary storage (STS) of spent fuel and radioactive waste (RW) in Andreeva Bay using the results of measuring campaign in 2001-2002 and for the sheltering construction of the solid RW using the results of measurements in 2021. The Fredholm equation was solved in two versions: under conditions of a barrier-free environment and taking into account buildings and structures located on the industrial site of the STS Andreeva Bay. Lorenz curves were generated to assess the compactness of the distributions of SAD and ambient dose equivalent rate (ADER) for the industrial site and the sheltering construction at STS Andreeva Bay, the area of the IV stage uranium tailing site near the city of Istiklol in the Republic of Tajikistan, and for roofs of the Chernobyl nuclear power plant. The nature of impact of the resolution (fragmentation) of the raster, the value of the radius of mutual influence of points (contamination sites), the height of the radiation detector above the scanned surface and the angular aperture of the radiation detector on the accuracy of the SAD reconstruction is shown. The method developed allows more accurate planning of decontamination work when only ADER measurements data is available. The proposed method can be applied to support the process of decontamination of radioactively contaminated territories, in particular during the remediation of the STS Andreeva Bay.

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INTRODUCTION: This study investigated the extent of contamination with antineoplastic agents on floor surfaces of the ward and the outpatient chemotherapy center of a Japanese cancer center to evaluate healthcare workers' risk of occupational exposure to antineoplastic agents outside of the designated drug preparation areas. METHODS: In this study conducted at Aichi Cancer Center, the amount of fluorouracil detected on various floor surfaces was measured using liquid chromatography-tandem quadrupole mass spectrometry. Areas around the toilets were cleaned with a surfactant two or three times a day, whereas other floor surfaces were cleaned only with dry and wet mops. RESULTS: Fluorouracil was detected on all surveyed floor surfaces, with particularly high amounts detected around the toilet areas in the ward. Additionally, areas with more human traffic tended to have higher fluorouracil contamination. CONCLUSIONS: This survey suggested that antineoplastic agent contamination occurring through patient excretions might spread throughout the hospital with human traffic. Therefore, controlling the spread of antineoplastic agent contamination in hospitals should include the review of measures to mitigate contamination around toilets and to implement effective cleaning methods for floor surfaces.

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BACKGROUND: Exposure to pathogens in public transport systems is a common means of spreading infection, mainly by inhaling aerosol or droplets from infected individuals. Such particles also contaminate surfaces, creating a potential surface-transmission pathway. METHODS: A fast acoustic biosensor with an antifouling nano-coating was introduced to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on exposed surfaces in the Prague Public Transport System. Samples were measured directly without pre-treatment. Results with the sensor gave excellent agreement with parallel quantitative reverse-transcription polymerase chain reaction (qRT-PCR) measurements on 482 surface samples taken from actively used trams, buses, metro trains and platforms between 7 and 9 April 2021, in the middle of the lineage Alpha SARS-CoV-2 epidemic wave when 1 in 240 people were COVID-19 positive in Prague. RESULTS: Only ten of the 482 surface swabs produced positive results and none of them contained virus particles capable of replication, indicating that positive samples contained inactive virus particles and/or fragments. Measurements of the rate of decay of SARS-CoV-2 on frequently touched surface materials showed that the virus did not remain viable longer than 1-4 h. The rate of inactivation was the fastest on rubber handrails in metro escalators and the slowest on hard-plastic seats, window glasses and stainless-steel grab rails. As a result of this study, Prague Public Transport Systems revised their cleaning protocols and the lengths of parking times during the pandemic. CONCLUSIONS: Our findings suggest that surface transmission played no or negligible role in spreading SARS-CoV-2 in Prague. The results also demonstrate the potential of the new biosensor to serve as a complementary screening tool in epidemic monitoring and prognosis.

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