This study evaluates the effectiveness of self-assessed exposure (SAE) data collection for characterization of hydrogen sulfide (H2S) risks in water and wastewater management, challenging the adequacy of traditional random or campaign sampling strategies. We compared 3 datasets derived from distinct strategies: expert data with activity metadata (A), SAE without metadata (B), and SAE with logbook metadata (C). The findings reveal that standard practices of random sampling (dataset A) fail to capture the sporadic nature of H2S exposure. Instead, SAE methods enhanced by logbook metadata and supported by reliable detection and calibration infrastructure (datasets B and C) are more effective. When assessing risk, particularly peak exposure risks, it is crucial to adopt measures that capture exposure variability, such as the range and standard deviations. This finer assessment is vital where high H2S peaks occur in confined spaces. Risk assessment should incorporate indices that account for peak exposure, utilizing variability measures like range and standard or geometric standard deviation to reflect the actual risk more accurately. For large datasets, a histogram is just as useful as statistical measures. This approach has revealed that not only wastewater workers but also water distribution network workers, can face unexpectedly high H2S levels when accessing confined underground spaces. Our research underscores the need for continuous monitoring with personal electrochemical gas detector alarm systems, particularly in environments with variable and potentially hazardous exposure levels.

The clinical anteroposterior (AP) chest images taken with a mobile radiography system were analyzed in this study to utilize the clinical exposure index (EI) as a patient dose-monitoring tool. The digital imaging and communications in medicine header of 6048 data points exposed under the 90 kVp and 2.5 mAs were extracted using Python for identifying the distribution of clinical EI. Even under the same exposure conditions, the clinical EI distribution was 137.82-4924.38. To determine the cause, the effect of a patient\'s body shape on EI was confirmed using actual clinical chest AP image data binarized into 0 and 255-pixel values using Python. As a result, the relationship between the direct X-ray area of the chest AP image, the higher the clinical EI, the larger the rate of the direct X-ray area. A conversion equation was also derived to infer entrance surface dose through clinical EI based on the patient thickness. This confirmed the possibility of directly monitoring patient dose through EI without a dosimeter in real-time. Therefore, to use the clinical EI of the mobile radiography system as a patient dose-monitoring tool, the derivation method of clinical EI considers several factors, such as the relationship between patient factors.

Workers at sewage treatment plants are exposed to a complex mixture of toxins, including hydrogen sulphide (H2S). An issue of concern among sewage workers, is possible negative nervous system effects from low-level H2S exposure. Empirical neuropsychological evidence indicates both that low-dose exposure to H2S exposure affects the nervous system, and the contrary, that such exposure may facilitate nervous system function, since H2S is an endogenously produced central nervous system (CNS) gasotransmitter. The aim of this study is to describe a possible association between the H2S component of the total exposure and long-term effects on neuropsychological motor function among wastewater workers.
Workers (N = 138) treating wastewater in 6 sewage-treatment plants, or in the sewer net system participated in a cross-sectional study. H2S exposure was expressed in a dichotomous exposure variable defining currently H2S-exposed (N = 112) and unexposed referent workers (N = 26), and a variable defining a job-exposure matrix for long-term total typical workplace H2S exposure. The participants went through neuropsychological tests for hand coordination, reaction time (SRT), and balance, and completed questionnaires. Pearson chi-square test or independent samples t-test was used when comparing the currently H2S-exposed workers with the unexposed control group. Multiple linear regression was used to assess associations between the independent variables age, smoking and exposure variables, and the neuropsychological tests.
The analyses indicate increased SRT in the currently H2S-exposed group compared to controls (mean [SD] = 225.8 [29.9] versus 210.7 [26.3] ms, P = 0.019), and an association between increased SRT and current H2S-exposure in the total study sample (β = 14.7, P = 0.026, R2 = 0.06, P = 0.050). Blindfolded balance testing indicates a nonsignificant trend in the total study sample, of reduced balance in the highest versus lowest H2S total long-term exposure-index group (Sway area [mean {SD}, mm2: 702 [410] versus 581 [278]), and a significant association between total long-term H2S exposure and reduced balance among smokers (Sway area, mm2 [β = 38.7, P = 0.039], mean sway, mm [β = 0.3, P = 0.015]).
The observed trends and associations may be due to exposure peaks in certain work operations and pinpoint the importance of minimizing and avoiding exposure peaks, also when H2S time-weighted average measurements do not exceed an occupational exposure limit of 5 ppm.

The optimum X-ray tube voltage for chest radiographic examinations remains unclear; hence, the tube voltage varies between medical facilities. An exposure index (EI) was proposed to standardize the parameters for radiographic examinations. However, even if identical EI values are used to examine the same person, organ doses may vary due to differences in tube voltages. In this study, the variation in organ doses between different beam qualities under identical EI values for chest radiographic examinations was investigated using Monte Carlo simulations. A focused anti-scatter grid as well as standard and larger physique-type medical internal radiation dose (MIRD) phantoms were studied under tube voltages of 90, 100, 110, and 120 kVp. The organ doses in the MIRD phantom increased as the X-ray tube voltage decreased, even with identical EI values. The absorbed doses in the lungs of standard and large-sized MIRD phantoms at 90 kVp were 23% and 35% higher than those at 120 kVp, respectively. The doses to organs other than the lung at 90 kVp were also higher than those at 120 kVp. From the perspective of reducing radiation doses, a tube voltage of 120 kVp is considered better for chest examinations compared with a tube voltage of 90 kVp under identical EI values.

BACKGROUND: Digital radiography (DR) still presents many challenges and could have complex imaging acquisition and processing patterns in a clinical practice hindering quality standardization.
OBJECTIVE: This technical note aims to report the 4-year experience with utilizing a custom DICOM metadata analytics program in clinical DR at a large institution.
METHODS: Thirty-eight DR systems of three vendors at multiple locations were configured to automatically send clinical DICOM images to a DICOM receiver. A suite of custom MATLAB programs was established to extract and store public and private header data weekly. Specific use cases are provided for systematic image acquisition investigation, image processing harmonization, exposure index (EI) longitudinal monitoring and EI target optimization.
RESULTS: For systematic acquisition investigation, an example of adult lumbar spine exam analysis was provided with statistics on manual acquisition versus the use of automatic exposure control (AEC, including AEC dose level, active cell, and backup timer), grid usage, and collimation for various projections. For processing harmonization, up to 12.6% of protocols were revealed to have processing parameter differences in an example of a mobile radiography fleet. In addition, inconsistent use of a post-acquisition image size function was also demonstrated, which resulted in anatomy size display variations. Bimonthly monitoring of median EI values showed expected trends, including changes after an AEC dose level adjustment for adult posterior-anterior chest imaging on a scanner system. An example of adult axillary shoulder EI target refinement was shared using the median value, eμ , based on the lognormal EI data distribution after parsing down to acquisitions with appropriate techniques.
CONCLUSIONS: This analytics program enables systematic analysis of image acquisition and processing details. The information provides invaluable insights into real practice patterns, which can support data-driven quality standardization and optimization.

Exposure Index (EI) is incorporated into Digital Radiography (DR) systems to indicate incorrect exposure to enable matching exposure to the desired speed class of operation. However, knowledge of the utilization of EI by radiographers in a low-income country has not been investigated.
A pre-tested questionnaire designed using Google forms, with open and close-ended questions was shared online with radiographers working with DR systems in public and private health facilities in some cities located in southern Nigeria. The 32-item questionnaire had two parts: Part A focused on socio-demographic characteristics and Part B focused on the respondents\' awareness and knowledge of EI in DR systems. A 5-point Likert scale with 5 test items was used to assess the respondents\' knowledge of EI. Statistical analyses were conducted using the Statistical Package for Social Sciences (SPSS) version 21.0. The probability value of p < 0.05 was considered statistically significant.
About 8.3% of the respondents had good knowledge of EI in DR systems in spite of the awareness level of 24.7%. The absence of the EI concept in DR curriculum for undergraduates, the lack of EI software in DR systems, and equipment training by the vendor engineers were reasons for the low level of knowledge of EI in DR systems.
There is low awareness and knowledge of EI by radiographers in this study, which suggests the need to maximize the benefits of EI concepts by ensuring its integration into clinical radiography practice and curriculum for undergraduates program, to improve knowledge, awareness, and practice in DR.

UNASSIGNED: The exposure index (EI) is used in routine quality control (QC) tests performed in the radiographic equipment installed in our hospitals. This study aimed at investigating the factors affecting the calculation of EI in QC and clinical images, and the implementation of target EI (EIT) and deviation index (DI) in clinical practice.
UNASSIGNED: The EI is 100 times the incident air kerma (IAK) in μGy on the image receptor, using the RQA-5 X-ray beam quality. Conformance to this relationship was investigated in QC images and clinical images acquired using anthropomorphic phantom body parts and different examination protocols, tube potential settings and radiation field sizes. Furthermore, a survey on EIT and DI data from clinical images was performed.
UNASSIGNED: Though automatic exposure control (AEC) systems have been adjusted for an IAK of 2.5 μGy, for most anthropomorphic phantom images the EIs were far from 250, depending on the manufacturer, the anatomy imaged, and the examination protocol. Regarding the survey results, DI calculation was feasible in only 38 % of the systems, since for the rest EIT values have not been set. However, the rationale based on which EIT have been selected is unclear. Some systems use only one while others many different EIT values.
UNASSIGNED: Before using EI for quality control of clinical images image all receptors and AEC systems should be properly calibrated. Then, the methodology of selecting appropriate EIT should be refined, since the EI calculation may vary, depending on the manufacturer, the anatomy imaged, and the examination protocol.

In many digital X-ray imaging systems, although air kerma on a surface of each detector is used, a standardized dose index called an exposure index (EI) has been proposed by the IEC, which is expected to be utilized for dose management. In clinical practices, EI is effectively utilized using a deviation index (DI), which is a deviation between a target EI (EIT) set for each imaging region and an EIT of the acquired image. However, an important issue in clinical uses of EI is a suppression of excessive doses. It is difficult to achieve a reliable reduction in exposure doses by indicating DI. In this study, physical image characteristics of detectors, visual detectability by charts, and observer experiments using a chest phantom were examined to determine upper (DImax) and lower (DImin) limits of the EIT and DI to achieve a reliable dose reduction in chest examinations. As the result, the tolerance ranges indicated by DImax and DImin, which were set based on the results of physical and visual evaluations, proved to be almost consistent with the distribution of EI values in 735 clinical images taken with a photo-timer control in real clinical practices.

Indoor air pollution from the combustion of biomass fuel and associated health risks is a critical issue in developing countries. Concentrations of PM2.5 and PM10 are measured in Birbhum, West Bengal, during 2017-2018. PM2.5-bound elemental concentrations of twelve metals are determined in rural kitchens. The results showed higher toxicological risks in BMF (1.15) than the LPG users (0.14). The risk of non-carcinogenic exposure related with dermal contact and ingestion was observed in the acceptable limits (HQ < 1) for all age groups, and the risk associated with inhalation exposure from Cr, Ni, As, and Mn exceeded the acceptable limit. Results also suggest that carcinogenic risks from ingestion and dermal contact are within the acceptable limit (1 × 10-4-1 × 10-6) except Cr and As which were found to exceed the range. The deposition flux (Dφ) for multiple metals in the head airway region, tracheobronchial region, and alveolar regions was found to be higher in teenagers as compared to other groups, whereas the value was lower in infants. Further, it was notified from the Dφ that the metals could pass through the head airways and harm the tracheobronchial tree and alveolar region, increasing the risk of human health.

The International Electrotechnical Commission established the concept of the exposure index (EI), target exposure index (EIT) and deviation index (DI). Some studies have conducted to utilize the EI as a patient dose monitoring tool in the digital radiography (DR) system.
To establish the appropriate clinical EIT, this study aims to introduce the diagnostic reference level (DRL) for general radiography and confirm the usefulness of clinical EI and DI.
The relationship between entrance surface dose (ESD) and clinical EI is obtained by exposure under the national radiography conditions of Korea for 7 extremity examinations. The EI value when the ESD is the DRL is set as the clinical EIT, and the change of DI is then checked.
The clinical EI has proportional relationship with ESD and is affected by the beam quality. When the clinical EIT is not adjusted according to the revision of DRLs, there is a difference of up to 2.03 in the DI value and may cause an evaluation error of up to 1.6 times for patient dose.
If the clinical EIT is periodically managed according to the environment of medical institution, the appropriate patient dose and image exposure can be managed based on the clinical EI, EIT, and DI.