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In determining whether a new permissible exposure limit is technologically feasible, the Occupational Safety and Health Administration (OSHA) and various courts have used poorly defined criteria such as whether "most employers most of the time" are able to comply with a standard. This vague definition creates problems when employers try to determine the best way to protect their workers and estimate the costs to remain in compliance with the permissible exposure limit. This article proposes a more rigorous approach to determine feasibility. By utilizing the best available statistical methods, employers and rule makers can better understand the variability within existing exposure data to determine the feasibility of new exposure limits. There are several readily available statistical tools that can be used for this purpose. To illustrate these techniques, a subset of data from the foundry industry and analysis from the OSHA respirable crystalline silica rulemaking proceeding are compared to methods published by the National Institute for Occupational Safety and Health in 1977 and a more sophisticated Bayesian approach. The results of this analysis suggest that complying with a new permissible exposure limit is more challenging than what is implied by OSHA's analysis, and calls into question its method of determining compliance. In the same vein, OSHA should move away from assessing compliance based on individual measurements and instead use a statistical approach to determine if a workplace is in compliance. These changes will encourage employers to better characterize occupational exposures, and will ultimately lead to better protection for employees while also providing employers protection from violations due to one-off overexposures.

Objective: The association of occupational noise-induced hearing loss (NIHL) with noise energy was well documented, but the relationship between occupational noise and noise temporal structure is rarely reported. The objective of this study was to investigate the principal characteristics of the relationship between occupational NIHL and the temporal structure of noise. Methods: Audiometric and shift-long noise exposure data were collected from 3102 Chinese manufacturing workers from six typical industries through a cross-sectional survey. In data analysis, A-weighted 8-h equivalent SPL (LAeq.8h), peak SPL, and cumulative noise exposure (CNE) were used as noise energy indicators, while kurtosis (β) was used as the indicator of noise temporal structure. Two NIHL were defined: (1) high-frequency noise-induced hearing loss (HFNIHL) and (2) noise-induced permanent threshold shift at test frequencies of 3, 4, and 6 kHz (noise-induced permanent threshold shift [NIPTS346]). The noise characteristics of different types of work and the relationship between these characteristics and the prevalence of NIHL were analyzed. Results: The noise waveform shape, with a specific noise kurtosis, was unique to each type of work. Approximately 27.92% of manufacturing workers suffered from HFNIHL, with a mean NIPTS346 of 24.16 ± 14.13 dB HL. The Spearman correlation analysis showed that the kurtosis value was significantly correlated with the difference of peak SPL minus its LAeq.8h across different types of work (p < 0.01). For a kurtosis-adjusted CNE, the linear regression equation between HFNIHL% and CNE for complex noise almost overlapped with Gaussian noise. Binary logistic regression analysis showed that LAeq.8h, kurtosis, and exposure duration were the key factors influencing HFNIHL% (p < 0.01). The notching extent in NIPTS at 4 kHz became deeper with the increase in LAeq.8h and kurtosis. HFNIHL% increased most rapidly during the first 10 years of exposure. HFNIHL% with β ≥ 10 was significantly higher than that with β < 10 (p < 0.05), and it increased with increasing kurtosis across different CNE or LAeq.8h levels. When LAeq.8h was 80 to 85 dB(A), the HFNIHL% at β ≥ 100 was significantly higher than that at 10 ≤ β < 100 or β < 10 (p < 0.05 and p < 0.01, respectively). Conclusions: In the evaluation of hearing loss caused by complex noise, not only noise energy but also the temporal structure of noise must be considered. Kurtosis of noise is an indirect metric that is sensitive to the presence of impulsive components in complex noise exposure, and thus, it could be useful for quantifying the risk for NIHL. It is necessary to re-evaluate the safety of permissible exposure limit of 85 dB(A) as noise with a high kurtosis value can aggravate or accelerate early NIHL.

In the decade since the last published comprehensive report of occupational exposures in the glass wool insulation industry, many process and regulatory changes have occurred in the glass wool manufacturing sector. This paper assesses whether any significant changes in worker exposures to glass wool fibers have resulted from these process and regulatory changes. The analysis compares worker exposures to glass wool overall and across different product and job categories in the manufacturing sector prior to and after 2007, the data cutoff period for the last comprehensive update of occupational exposures in this industry. The exposure data were downloaded from the North American Insulation Manufacturers Association's synthetic vitreous fiber (SVF) exposure database, which has been continually updated with all new available SVF exposure data for the past two decades. This analysis finds no major changes in worker exposures in the glass wool manufacturing industry over the past decade, with exposures remaining well below the 1 f/cc voluntary permissible exposure limit.

Beryllium exposure remains an ongoing occupational health concern for workers worldwide. Since the initial Occupational Safety and Health Administration (OSHA) ruling on a permissible exposure limit (PEL) for beryllium in 1971, our understanding of the risks of beryllium sensitization and chronic beryllium disease (CBD) has evolved substantially. A new OSHA ruling released in early 2017 and implemented in late 2018 reduced the PEL for beryllium, increased requirements for medical screening and monitoring, and may ultimately enhance worker protection. This review highlights advances in our understanding of the pathway from beryllium exposure to sensitization and progression to CBD that guided the development of this OSHA ruling. Screening workers exposed to beryllium and management of CBD will also be discussed. Finally, we will discuss the role of beryllium as a cause of morbidity and mortality among exposed workers in this potentially preventable occupational lung disease.

This paper presents the development of gold-doped tin oxide (SnO2) film, realized by radiofrequency (RF) sputtering, which is highly sensitive for carbon monoxide (CO) gas. According to the Occupational Safety and Health Administration (OSHA), human exposure to 50 ppm CO is safe up to 8 h (as permissible exposure limit), but inhalation of higher concentrations of CO can cause headache, dizziness, nausea, etc. Hence, it is imperative to detect CO gas in low concentrations. The receptor films were prepared via reactive co-sputtering of high-purity Sn and Au targets and characterized by x-ray diffraction (XRD), which confirmed the presence of SnO2 and gold. The thin films of pristine SnO2 and gold-doped SnO2 were also examined through field emission scanning electron microscopy (FESEM) images, showing the distinction in their structures. A reasonably enhanced response of ~ 56.4% was exhibited by gold-doped SnO2 compared to 15.5% for pristine SnO2 for 50 ppm CO at operating temperature of each film.

Background . Noise pollution is a burden exerting a harmful and irritating effect on human health. Children are particularly sensitive to noise burden. In this connection, it is especially important to control the noise pollution level in public education organizations where children spend significant time. Objective . The study is aimed at determining objective and subjective parameters of noise pollution in public education organizations based on the analysis of data obtained by measuring noise levels in school campuses in Saransk and directly in classrooms, as well as by questioning the teachers of these schools. Methods . The measurement of noise burden was carried out in 10 schools using the noise and vibration level meter “Assistant” with class I accuracy. Noise measurements in school campuses and classrooms were performed in accordance with the GOST 23337-2014 requirements. Assessment of results was conducted in accordance with sanitary standards 2.2.4/2.1.8.562-96 “Noise in the workplace, residential and public buildings and housing developments”. Results . Based on noise measurement results, the highest noise levels were found in school № 2 (65.5 dBА on the campus, 51.2 dBA in the classroom) which is located in the center of a traffic interchange. The lowest noise parameters were found in school № 35 (45.2 dBА on the campus, 37.7 dBА in the classroom) which is located in the residential quarter quite far away (242-321 m) from the main source of noise, the motorway. Conclusion . Study results attest that maximum noise levels at school campuses do not exceed the permissible exposure limit of 70 dBA. In all schools noise values conform to the noise standards (maximum sound pressure level in classrooms did not exceed 55 dBA).

Background Little is known about the different risk of silicosis in metal mines and pottery factories. We aimed to compare the silicosis risks among silica-exposed workers in different industrial circumstances. Research Question Are the silicosis risks among silica-exposed workers in industrial circumstances different? Study Design and Methods We studied 39,808 workers followed up from January 1, 1960 to December 31, 2003 in China. Cumulative respirable silica dust exposure (CDE) was estimated by linking a job-exposure matrix to personal work history. Silicosis of stage I or higher was diagnosed by Chinese pneumoconiosis Roentgen diagnostic criteria. Results A total of 9,377 silicosis patients were diagnosed during 1,153,580.9 person-years' follow-up in the cohort. Hazard ratios of silicosis for each 1 mg/m3-year increase in CDE were 1.08 (1.07-1.08) for tungsten mines, 1.41 (1.33-1.48) for iron and copper mines, 1.14 (1.11-1.17) for tin mines, and 1.03 (1.02-1.04) for pottery factories, respectively. When exposed to 0.05 mg/m3 of respirable silica dust for 45 years, the cumulative risks in metal mines (2.3%, 9.9%, 1.5% for tungsten mines, iron and copper mines, and tin mines, respectively) were still higher than those in pottery factories (0.6%). The joint effect of silica and smoking on silicosis was more than multiplicative. Interpretation The risk of silicosis in metal miners is higher than that in pottery workers when exposed to the same level of silica dust. The silica dust exposed years should be under 10 years for metal miners and 40 years for pottery workers at 0.05 mg/m3 to keep lifetime risk within 0.1%. Current exposure limits should take into account differences in various industrial circumstances. Smoking cessation could help reduce silicosis risk for silica-exposed workers.

Aim. To study the structure of psychosocial maladjustment in chemical workers and assess the contribution of industrial and non-industrial risk factors in the formation of mental illness. Methods. It was analysed of hygienic assessment of the leading harmful production factors chemical, physical, factors of severity and intensity of labor. During the periodic medical examination, the mental health status of 1,226 people was examined, with a focus on professional experience, mental hygiene aspects of production factors, as well as individual and personal characteristics of employees. Confidence intervals and standard errors estimating, the logistic regression models fitting were performed using R Statistical Software with significance level 0.05. Results. The working environment hazards in organic synthesis included chemical risk factor, continuous noise exceeding the permissible exposure limit, emotional stress and life-threatening conditions (fire and explosion hazards in the work). The general assessment of working conditions was performed using clauses 5.15.11 P 2.2.2006-05-harmful working conditions of the second-third degree (3.23.3). Working conditions at all stages of the manufacturing process of pyroxylin powders were assessed as harmful to the third-fourth degree (3.33.4), including the chemical factor, the severity and intensity of work, fire and explosion hazards in the work. It was revealed the dependence of the development of psychosocial maladjustment on non-work-related factors (such as the level of education, marital status), conditional work-related factors (level of material security). Also, the dependence of the structure of pre-existing mental health condition on the work-related and developmental characteristics (work experience) of labor in chemical production was found. Conclusion. Working conditions in the studied industries correspond to the 3rd harmful class, 2nd and 3rd degrees in the production of organic synthesis (3.23.3), while at the production of pyroxylic powders, it is close to dangerous (3.33.4); the structure and risk of the developmental process of employee maladjustment are determined by the feature effect of workplace hazards.

Objective To evaluate the pulmonary alterations in workers from a dental prosthesis laboratory and explore dust and bacterial dissemination generated in the laboratory. Methods Spirometry and computerized axial tomography were performed on 67 workers. Dust in workplace air was determined using the filtration-gravimetric method, and bacterial detection was explored using 16S rDNA gene sequencing. Results Pulmonary alterations were detected in 37% of the workers. Airborne dust concentrations were determined to be higher than the maximum permissible exposure limit, and bacterial detection analysis revealed 23 bacterial genera. The most frequently detected bacterial genus was Sphingomonas sp., which has been described as microbiota associated with disease of the oral cavity. Conclusions The results of this study highlight the importance of the implementation of biosecurity measures, improvement of ventilation systems and routine disinfection of dental impressions.

Rail maintenance routines are necessary to enable the all rail operations to achieve its aim in maintaining a safe and efficient operation. The maintenance tasks expose the workers to vibration and noise, as they handle specialized machineries and heavy self-propelled vehicles. Exposure of noise above the permissible exposure limit and over the daily allowable duration may cause noise-induce hearing loss (NIHL). Investigation on the type of task that has high noise level exposure on the maintenance workers was conducted to justify the needs to further detailed of this study. This paper will describe the task analysis on maintenance workers and to identify possible tasks with exposure to high level of noise. It scopes down to grinding crew of the maintenance department of light rail transit. Methods used were real-time sound measurement using a sound level meter, observation and interviews. Then, data were analysed to understand the situation of exposure of noise during rail maintenance. An ergonomic risk assessment was also conducted by adoption of the latest guideline on Ergonomic Risk Assessment (ERA) at Workplace Guidelines recommended by Department of Occupational Safety and Health (DOSH), Malaysia. A hierarchical task analysis (HTA) was generated on the task of the maintenance worker, focusing on rail grinding crew. The newly generated HTA had allowed better understanding about the nature of work and the task conducted by a rail grinder during the work shifts. Tasks involving high noise level was identified. Data recorded shows that the noise level for the blowing activity was relatively high and exceeded the permissible exposure limit of 90dBA. The exposure level was currently controlled by practicing the usage of hearing protection equipment (HPE) and by controlling exposure time in accordance to recommendations of the Factory and Machinery Act (FMA). Thus, it had confirmed that maintenance workers were exposed to high noise levels when performing their daily task. Further studies are needed to investigate the relationship between the duration of exposure and noise-induce hearing loss (NIHL) with consideration of the lifestyles of the maintenance workers.

This paper describes the demonstration of a series of heterobimetallic, isoreticular 2D conductive metal-organic frameworks (MOFs) with metallophthalocyanine (MPc, M=Co and Ni) units interconnected by Cu nodes towards low-power chemiresistive sensing of ppm levels of carbon monoxide (CO). Devices achieve a sub-part-per-million (ppm) limit of detection (LOD) of 0.53 ppm toward CO at a low driving voltage of 0.1 V. MPc-based Cu-linked MOFs can continuously detect CO at 50 ppm, the permissible exposure limit required by the Occupational Safety and Health Administration (OSHA), for multiple exposures, and realize CO detection in air and in humid environment. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), density functional theory (DFT) calculations, and comparison experiments suggest the contribution of Cu nodes to CO binding and the essential role of MPc units in tuning and amplifying the sensing response.

In 2012, the Korean Occupational Safety and Health Agency developed Chemical Hazard Risk Management (CHARM) as a risk assessment tool. This study aims to reorganize the CHARM technique by complementing its logical loopholes, while evaluating the risk to enterprises and verifying this technique by applying it to some enterprises in Korea. The optimized technique changed the method of quantitative assessment and evaluation criteria, matched the risk level with the required control level, and specified the use of control practice. For the target enterprises, for several assessment methods, risk levels, hazard bands, exposure bands, and the risk assessment results were derived, and the same types of options were compared. Fewer informational methods resulted in more conservative results of risk levels and hazard bands. Since the control status of the enterprises could not be confirmed and the substances handled at the target enterprises were limited in this study, a follow-up study should be performed with more target materials and additional information on the current control status of the enterprises.

Exposure to respirable crystalline silica (RCS) remains a serious health hazard to the US mining workforce who are potentially exposed as various ore bodies are drilled, blasted, hauled by truck, crushed, screened, and transported to their destinations. The current Mine Safety and Health Administration (MSHA) permissible exposure limit (PEL) for RCS remains at approximately 100 μg/m(3), but it is noteworthy that the Occupational Safety and Health Administration (OSHA) has lowered its PEL to 50 μg/ m(3) (with enforcement dates staggered through 2022 for various sectors), and the National Institute for Occupational Safety and Health (NIOSH) has held a 50 μg/m(3) recommended standard since 1976. To examine a method for reducing RCS exposure using a NIOSH-developed video exposure monitoring (VEM) technology (referred to as Helmet-CAM), video and respirable dust concentration data were collected on eighty miners across seven unique mining sites. The data was then collated and partitioned using a thresholding scheme to determine exposures that were in excess of ten times the mean exposure for that worker. Focusing on these short duration, high magnitude exposures can provide insight to implement controls and interventions that can dramatically lower the employee’s overall average exposure. In 19 of the 80 cases analyzed, it was found that exposure could be significantly lowered by 20% or more by reducing exposures that occur during just 10 min of work per 8-hour shift. This approach provides a method to quickly analyze and determine which activities are creating the greatest health concerns. In most cases, once identified, focused control technologies or behavioral modifications can be applied to those tasks.

NoCement mineral dust contains a variety of carcinogenic and non-carcinogenic substances. The study aimed to determine the probability of health risk among cement workers due to respirable silica (Si), arsenic (As), and chromium (Cr) VI dust exposure. A cross-sectional study was carried out among 123 cement workers. A personal air sampling pump was used to assess respirable cement dust exposure. Inductively coupled plasma mass spectrometry (ICP-MS) was used for As, and Cr analysis, and X-ray powder diffraction (XRD) was used for Si analysis. The Fractional Exhaled Nitric Oxide levels and lung function test were obtained by using NIOX MINO and Chestgraph H1-105 spirometer. Risk assessment was calculated by using the incremental lifetime cancer risk (ILCR) and non-cancerous hazard quotient (HQ). The geometric mean and standard deviation of respirable Si and Cr dust concentrations were 5.27 ± 2.36 mg m-3 and 1.53 ± 2.47 mg m-3, respectively, in manufacturing workers. The mean concentration for As in administrative workers was 0.07 ± 0.02 mg m-3. After controlling for confounders, the abnormalities of FVC% predicted and FEV₁% predicted were significantly associated with the respirable Si dust among cement workers (OR = 6.913; CI = 1.965-24.322 and OR = 18.320; CI = 3.078 - 109.027). FENO concentrations in administrative workers were significantly influenced by the exposure to respirable Si dust (R2 = 0.584, p = 0.006). Manufacturing workers had a high probability of getting cancer due to Si exposure in cement respirable dust at 29.81 x 10-4 times compared to administrative workers at 4.14 x 10-4 times. After reducing for control factors, the probability of manufacturing workers reduced to 0.45 x 10-4 times. As and Cr (VI) dust exposures among cement workers had a probability of cancer risk of 7.49 x 10-4 and 44.09 x 10-4 times, respectively, after reducing for control factors. The non-cancerous disease risk of the workers from exposure to cement mineral dust exceeded the acceptance limit (HQ > 1). Cement workers were at high risk of developing cancerous and non-cancerous diseases due to exposure while working. Cement workers were highly exposed to respirable Si, As, and Cr dust above the permissible exposure limit.

Background In Indian mines, the prescribed exposure limit (PEL) for free silica dust is 0.15 mg/m3 which is much higher than those of OSHA and the ACGIH. Because of the reporting of high numbers of silicosis cases among Indian sandstone mine workers, the present study was designed to assess the dust exposure profile of the workers and to substantiate correlation of silica exposure with radiographic findings of silicosis. Methods A cross-sectional study of 1012 workers actively engaged in sandstone mining was conducted. Chest x-rays were evaluated by the ILO Classification for the detection of pneumoconiosis. Representative 26 personal dust samples were collected using a personal dust sampler and free silica content estimated. Results Radiographs compatible with silicosis were seen in 12.3% of workers, of which about 90% were ILO category 1 & 2. Prevalence of abnormal profusion increased from 2.9% to 13.1% to 22% as work exposure increased from 20 years, respectively. In dust samples, the mean silica concentration was 0.12 mg/m3 with 70% samples below the prescribed standard of 0.15 mg/m3 . Conclusion The study indicates that silica exposure below the prescribed limit in India is likely to be harmful. The PEL for crystalline silica in India of 0.15 mg/m3 is not adequately protective. Hence, there is an urgent need to reduce exposure to silica in these workplaces to prevent silicosis and to review the present standards as the government of India remains committed to the elimination of silicosis by 2030.

Lead poisoning is an emerging worldwide public health concern, especially in the developing countries. Occupational tasks such as spray painting and welding in informal automobile repair enterprises present risks of exposures to lead generally through inhalation and ingestion. The artisans therefore risk high blood lead (BPb) levels, which is critical to chronic adverse health effects of lead. The study aimed at assessing the influence of occupational tasks on personal airborne lead exposures and to evaluate the association between these exposures with blood lead (BPb) levels among the artisans. A cross-sectional study was conducted in ten informal automobile repair workshops. Task-specific personal inhalable air samples and blood samples were collected concurrently for 20 participants performing five distinct occupational tasks. Lead levels were analysed using inductively coupled plasma atomic emission spectroscopy and data analysed by analysis of variance, simple and multiple linear regressions. The results indicated significant differences in airborne lead (PbA) exposure levels in different occupational tasks (p = 0.000). Lead–acid battery repairs recorded mean PbA exposure level of [76.11 ± (10.81 SE) µg/m3] exceeding the WHO 50 µg/m3 airborne lead permissible exposure limit. The average (PbA) exposure level was 22.55 ± (5.05 SE) µg/m3, while the mean (BPb) level was 25.08 ± (3.48 SE) µg/dl. A significant positive correlation between task-based airborne lead with blood lead levels was observed (r = 0.68, p = 0.001). In conclusion, the occupational tasks influenced personal airborne lead exposure levels, which in turn was an important predictor of blood lead levels. The study recommends lead exposure assessments, medical screening and intervention measures to minimize the risk and consequences of occupational exposures to lead among the study population.

Anthropogenic activities in the environment have an impact on climate change. Among these activities is the use of the chainsaw which plays an important role by releasing greenhouse gas emissions in the atmosphere. Hence, the need for research on improved logging operations is of importance. The present study compares carbon monoxide (CΟ) and nitrogen dioxide (NO2) emissions generated by the engines of one catalytic chainsaw and two conventional chainsaws, of which one is professional and the other amateur. Measurements were carried out under three functional modes (infrequent accelerator use, use of quality oils, use of clean filters). Measurements that were conducted under normal conditions were named “witness measurements” and were used for future comparisons. Additionally, a set of measurements for CΟ and ΝΟ2 emissions was collected under different operation modes for all three types of saws (frequent accelerator use, use of low-quality oils, use of impure filters). Data collection was carried out in real conditions using a portable gas detector. Average concentration values of CΟ and ΝΟ2 under normal conditions for all three types of chainsaws found in the air of the operator’s breathing zone were 88.32 ppm and 0.07 ppm, respectively. Results show that CO concentrations exceed the permissible exposure limit (50 ppm), whereas CO concentrations in excess of the short-term exposure limit (300 ppm) were only found in the case of the amateur chainsaw operated with low-quality oils. These results are of use towards efforts to reduce the CO and NO2 to the atmosphere.

BACKGROUND: This study summarized the mass concentration and quartz mass percent of respirable coal mine dust samples (annually, by district, and by occupation) from underground coal mines during 1982–2017. METHODS: Respirable dust and quartz data collected and analyzed by Mine Safety and Health Administration (MSHA) were summarized by year, coal mining occupation, and geographical area. The older (before August 2016) 2.0 mg/m(3) respirable dust MSHA permissible exposure limit (PEL) was used across all years for comparative purposes. For respirable dust and quartz, geometric mean and percent of samples exceeding the respirable dust PEL (2.0 mg/m(3) or a reduced standard for samples with >5% quartz content) were calculated. For quartz samples, the average percent quartz content was also calculated. RESULTS: The overall geometric mean concentration for 681 497 respirable dust samples was 0.55 mg/m(3) and 5.5% of the samples exceeded the 2.0 mg/m(3) PEL. The overall respirable quartz geometric mean concentration for 210 944 samples was 0.038 mg/m(3) and 18.7% of these samples exceeded the applicable standard. There was a decline over time in the percent of respirable dust samples exceeding 2.0 mg/m(3). The respirable dust geometric mean concentration was lower in central Appalachia compared to the rest of the United States. However, the respirable quartz geometric mean concentration and the mean percent quartz content were higher in central Appalachia. CONCLUSION: This study summarizes respirable dust and quartz concentrations from coal mine inspector samples and may provide an insight into differences in the prevalence of pneumoconiosis by region and occupation.

Mechanized underground mines suffer from noise overexposure. Noise levels are often above the Permissible Exposure Limit (PEL) where underground fans are used. Sound levels in active workings can reach up to 121 A-weighted decibels (dB(A)), especially when fans are not equipped with silencers. Use of silencers seldom ensures PEL. Overexposure of noise induces permanent hearing loss among mine workers. A NIOSH-funded research project and field studies at six coal and non-coal mines revalidated the findings. The University of Utah undertook laboratory studies to reduce fan noise at the source. A new silencer prototype with varying noise dampening material was designed and tested. The silencer and associated extension can be repacked with different dampening materials. The silencer and the extension were used in various configurations. Attempts were also made to simulate field conditions. The tests demonstrated a maximum sound level attenuation of about 14 dB(A) at the fan discharge. A properly designed silencer offers lesser resistance and thereby better fan performance and lower energy cost. The re-packable silencer is more likely to be maintained properly. Lowering of noise level happens in audible frequencies (4000 to 8000 Hz) which are important in A-weighting.

Cabin air quality and thermal conditions have a direct impact on passenger and flight crew’s health and comfort. In this study, in-cabin thermal environment and particulate matter (PM) exposures were investigated in four China domestic flights. The mean and standard deviation of the in-cabin carbon dioxide (CO2) concentrations in two tested flights are 1440 ± 111 ppm. The measured maximum in-cabin carbon monoxide (CO) concentration is 1.2 ppm, which is under the US Occupational Safety and Health Administration (OSHA) permissible exposure limit of 10 ppm. The tested relative humidity ranges from 13.8% to 67.0% with an average of 31.7%. The cabin pressure change rates at the end of the climbing stages and the beginning of the descending stages are close to 10 hPa·min−1, which might induce the uncomfortable feeling of passengers and crew members. PM mass concentrations were measured on four flights. The results show that PM concentrations decreased after the aircraft cabin door closed and were affected by severe turbulences. The highest in-cabin PM concentrations were observed in the oldest aircraft with an age of 13.2 years, and the waiting phase in this aircraft generated the highest exposures.

OBJECTIVE: The primary objective of this work was to characterize employee exposure to radon and progeny while performing guide/interpretation and concessions duties in a tourist cavern. METHODS: Radon gas and progeny concentrations, fraction of unattached progeny, and other environmental parameters were evaluated in a popular tourist cavern in Southeastern New Mexico. Alpha-track detectors were used to measure radon gas in several cavern locations during a nine-month period. Additionally, radon gas and attached and unattached fractions of radon progeny were measured at three primary cavern work locations during a one-day period using a SARAD EQF 3220. RESULTS: Radon gas concentrations in the cavern were elevated due to extremely low air exchange rates, with substantial seasonal variation. Mean measured radon concentrations ranged from 970 to 2600 Bq m(−3) in the main cavern and from 5400 to 6000 Bq m(−3) in a smaller cave associated with the regional cave system. Measurements of unattached fractions (0.40–0.60) were higher than those commonly found in mines and other workplaces, leading to the potential for relatively high worker dose. CONCLUSIONS: Although radon gas concentrations were below the Occupational Safety and Health Administration Permissible Exposure Limit, employees working in the cavern have the potential to accrue ionizing radiation dose in excess of the annual effective dose limit recommended by the National Council on Radiation Protection and Measurements due to high unattached fraction of radon progeny. There was a strong negative correlation between unattached fractions and equilibrium factors, but these parameters should be further evaluated for seasonal variation. Introduction of engineering controls such as ventilation could damage the cavern environment, so administrative controls, such as time management, are preferred to reduce employee dose.

Noise-Induced Hearing Loss (NIHL) is a global issue that is caused by many factors. The purpose of this study was to survey noise level to identify NIHL and its relationship with other factors in cement plants in Vietnam. Noise level was measured at one cement plant and three cement grinding stations located in the South of Vietnam. The audiometric data of exposed workers were surveyed to determine NIHL. Finally, the relationship between NIHL and noise level in cement plants was determined. The results show that noise level in almost all processes exceeded the permissible exposure limit (PEL). In this study, 42 cases (10% of exposed workers) with occupational NIHL were found with mean age (SD) of 49 (9.0) years. All NIHL cases were found in the departments in which the noise level exceeded the PEL, which included quarry (n = 16), maintenance (n = 12), production (n = 10), co-waste processing (n = 3) and quality assurance (n = 1). There was a positive and significant correlation between the NIHL and the excessive noise exposure in the cement plants (r = 0.89, p = 0.04).

Phosphine is categorized as toxic gas that is generally present in the atmosphere at a very low percentage. It can be obtained by decaying organic matter through partial reduction and disproportionation reactions which lead to the reduction of phosphate directly into phosphine. Due to its wide applicability, viz., rodenticide, grain fumigant, and microchip manufacturing, phosphine is preferably used within the permissible exposure limit (PEL) of 0.4 mg/m3. It acts as a redox toxin that causes cell damage by inducing oxidative stress and mitochondrial dysfunction. Phosphine may cause headache, dizziness, and fatigue and also acts as a respiratory poison. Therefore, for safe and secure use of phosphine, proper assessment of risk is necessary. In the present chapter, the toxicological impact of phosphine on the chemical, biological, and environmental system has been elaborated. Various routes of exposure, toxicity, risk management, current research, safety, and sources of contamination have also been discussed.

Lunar dust will arise as an issue for remediation in the earliest lunar settlements. The natural environment will pose risks that are becoming an important focus for research. Since Apollo 12 astronaut Alan Bean became accidentally exposed to lunar regolith in 1970, the toxic effects of Moon dust (

The emergence of dust generated from the process of removal orthopedic cast materials pose a significant potential hazardous to respiratory health among the healthcare workers (HCWs) in the orthopedic casting room. The study was carried out to determine the total dust concentrations in the casting room were exposed to environmental and personnel. The personnel and environmental air sampling were conducted for 6 hours followed the standard method from NIOSH Manual of Analytical Method 0501. Determination of personnel dust exposure were established for selected six HCWs, who are highly risk of dust exposed based on their jobs scope in the casting room. The determination of environmental air sampling was conducted in the casting room for six hours continuously. A set of questionnaires was administered to evaluate the level of knowledge, attitude and practice related to the awareness of occupational safety and health among the 43 HCWs from public hospital in Kuala Lumpur, Malaysia. The result on total dust from the environmental air sampling (casting room) showed mean concentration are 3.402±0.003 mg/m³ and personal air sampling showed the mean concentration are 5.573± 0.040 mg/m³. The mean total concentration obtained were below the standard permissible exposure limit of 15 mg/m³ set by OSHA USA 2005. The result shows the level of knowledge were 96.75%, attitude 83.7% and practical 82.85% among the HCWs. There are significant relationship (p

Crude oil is extremely flammable & can cause eye, skin, gastrointestinal, and respiratory irritation. Breathing the fumes from crude oil are known to cause chemical pneumonia, irritation of the nose, throat, & lungs, etc.. In the shipyard, workers are exposed to the fumes of crude oil while doing maintenance on ships. Their safety & health can be at risk while doing their job. This research aims to develop a device that will detect & assess specific types of gases in order to determine the permissible and impermissible time of work for employees' safety precaution. Unmanned ground vehicle is the machine that operates while in contact with the ground and without an on-board human presence. By gathering the data from the sensors who has a specific sensitivity on the substances in crude oil fumes, the data will then convert to a gas concentration in a unit of ppm where distinct values can be analyzed. Using data sets and Gradient Boost Algorithm, the system can train data based on the output of the acquired signal which eventually will be more accurate in determining the permissible exposure limit of a worker to the crude oil fume. Results shows Gradient Boost Algorithm has an average accuracy of 93.75% with a failure rate of 0.0823. The time response of the design is 2.98 seconds. It is recommended that the device used for getting the input gas sensor should be accurate to the gas decomposition of the oil / petroleum you are trying to test.

Thirty (30) personal noise-exposure samples were collected on 20 tire-changing and repair technicians in three tire-changing facilities to determine their personal noise exposures and to estimate the maximum number of tire changes that could be performed without exceeding occupational exposure limits. Of the 30 projected 8-h time-weighted average noise samples, none exceeded the Occupational Safety and Health Administration’s Permissible Exposure Limit, 1 (3%) exceeded the Occupational Safety and Health Administration’s Action Level, and 18 (60%) exceeded the American Conference for Governmental Industrial Hygienists Threshold limit Value of 85 dBA, indicating the need for a hearing loss prevention program. The average shift time for the technicians was 6 h and 42 min and the average number of tire changes was 18. Based on the projected 8-h noise exposure 95% upper confidence limits, the estimated maximum number of tires that could be changed without exceeding the Occupational Safety and Health Administration’s noise action level was 32 tires, the permissible exposure limit greater than 40 tires, and the American Conference of Industrial Hygienists’ Threshold Limit Value was less than 20 tires. In addition, area noise samples of tire-changing equipment were taken with a sound-level meter to identify the noise sources that contributed to the tire technicians’ exposures. The air ratchet, tire-changing machine, and tire-bead seater were measured at noise levels >85 dBA, increasing the risk of noise-induced hearing loss to the technicians.

Since the past several decades, chemicals have undoubtedly played an essential role in human activities...

The purpose of this study was to assess employees’ exposure to lead and noise, and to recommend control strategies for reducing these exposures at eight registered electronics recycling facilities in Eastern China. Jiangsu Provincial Center for Disease Control and Prevention (JSCDC) performed a walkthrough and review of health and safety programs during a first visit and conducted full-shift personal and area air monitoring for lead, as well as personal noise exposure measurements on a second visit. Monitoring was performed over two work shifts for a total of 168 employees. Results indicated that employees working at glass breaking and cathode ray tubes dismantling were overexposed both to noise and lead. Airborne lead concentration ranged from 0.1 to 148 μg/m3; and 4 of the 101 samples were above the Chinese permissible exposure limit of 50 μg/m3. Overexposures to lead involved cathode ray tubes dismantling and glass breaking. Employees working at plastics shredding and glass breaking areas were overexposed to noise. Full-shift time-weighted average noise levels ranged from 64 to 107 dBA; and 85 of the 123 samples were above the Chinese permissible exposure limit of 85 dBA. Control measures to reduce exposure to lead and noise, including improvements in their lead protection and hearing conservation programs, at these electronics recycling facilities were recommended.

Methylamine (MA) is highly toxic even at low concentrations. The current U.S.A. Occupational Safety and Health Administration Permissible Exposure Limit (OSHA PEL) is 10 ppm in the gas phase. In this study we have developed low-cost, robust and stable copper sulphide film on flexible plastic and paper substrate. The sensitivity of the film towards MA as a function of print density is studied at room temperature. The electrical and colorimetric response of the sensing films is optimized with respect to print density. The performance parameters of the sensing films including, sensitivity, a lower limit of detection (LOD), selectivity and onset time of detection are determined. X-ray photoelectron spectroscopy is employed for chemical characterization of the sensing film. It is demonstrated that copper sulphide films register either change in resistance or colour when exposed to methylamine in a range of 1 to 100 ppm. A LOD of 1 ppm is achieved which is lower than the current OSHA PEL. The optimized sensing film has shown over three and six orders of magnitude change in resistance when exposed to 10 ppm and 500 ppm of MA respectively. The low cost, room temperature operation, electrical and colorimetric response of the developed sensing films make them promising candidates to be used for medical diagnostics as well as industrial use for example in chemical industry and environmental applications.