Occupational Exposure Levels Research Articles

Associations between Awareness of the Risk of Exposure to Pollutants Occurring at Fire Scenes and Health Beliefs among Metropolitan Firefighters in the Republic of Korea.

Firefighters are repeatedly exposed to various pollutants that occur at fire scenes. There are three levels of exposure: primary exposure to pollutants, secondary exposure to pollutants on personal protective equipment (PPE), and tertiary exposure to contaminated fire stations and fire engines due to pollutants on PPE. Therefore, it is important for firefighters to be aware of the risk of exposure to pollutants and to practice health behaviors such as appropriate PPE management. No clear association has been established in the existing literature between firefighters’ risk perception level and their health beliefs about the health impact of awareness of exposure to hazardous substances at fire scenes. This study aims to evaluate the relationship between awareness of the exposure risk to primary, secondary, and tertiary pollutants and health beliefs. It was designed as a cross-sectional study, in which a web-based survey was conducted from 13 May to 31 May 2021. The analysis was conducted in 1940 firefighters working in the Seoul metropolis who agreed to participate in the research. Participants who perceived susceptibility were likely to be aware of the primary (adjusted odds ratio (AOR) = 2.10, 95% confidence interval (CI) 1.16–3.80), secondary (AOR = 2.77, 95% CI 1.77–4.32), and tertiary (AOR = 2.73, 95% CI 1.85–4.03) exposure risks. Participants who perceived barriers were unlikely to be aware of the risk of exposure to primary (AOR = 0.67, 95% CI 0.49–0.91), secondary (AOR = 0.77, 95% CI 0.61–0.96), and tertiary (AOR = 0.75, 95% CI 0.62–0.91) pollutants. Educational intervention is recommended to improve perceived susceptibility and awareness of the risk of exposure to pollutants and reduce perceived barriers. Consequently, educational intervention is expected to positively impact firefighters’ management of appropriate PPE. We confirmed an association between occupational exposure risk and firefighters’ health beliefs. In the health belief model (HBM), health beliefs that affect health behavior also affect awareness of the exposure risk level. Therefore, an intervention for health beliefs can also be used to raise job-related exposure risk awareness. Regular training on the health impacts of fire scenes is necessary for both newcomers and incumbents to enable firefighters to better recognize the risks of each occupational exposure level. Additionally, laws and regulations are necessary for the removal of harmful substances that contaminate PPE, such as self-contained breathing apparatus (SCBA), during exposure to a fire scene. Our research can be used as a basis for improving fire policies and education programs in the future.

Hearing Impairment in French Merchant Seafarers: Retrospective Study on Data from 8308 Audiometric Tests.

Background: A high level of occupational noise exposure has been noted in the fishing sector. Yet, less is known regarding other navigation groups, such as merchant seafarers, since a French study in the 1980s. This study assesses hearing impairment (HI) in a French merchant seafarers’ population. Methods: We collected data of all audiograms performed in 2018 and 2019 for French merchant seafarers. For each seafarer, hearing ability was measured in both ears using pure-tone audiometry at the following frequencies: 0.5, 1, 2, 3, 4, 6, and 8 kHz. Hearing threshold levels (HTLs), or the intensity of sound below which no sound is detected, were measured in decibels Sound Pressure Level (dB SPL) at each frequency and recorded in 5 dB increments. For HI, we used the validated definition of the American Speech–Language–Hearing Association (ASHA). Results: We were able to include statistical analysis results of 8308 audiograms. In a multiple logistic regression adjusted for age, experience, and class of navigation, we found that experience of more than 14 years Odds Ratio OR 1.28 (CI 95% 1.07–1.53), age 31–40 OR 2.2 (CI 95% 1.4–3.4), and >40 years OR 14, 3 (IC 95% 9.7–21) and marine engineers OR 1.26 (IC 95% 1.01–1.57) were still risk factors for HI. Conclusion: In 2018, Marine engineers were still the workers’ group with a higher risk of HI in merchant seafarers but, notch at 4 Hz, specific of noise-induced hearing loss, has improved. They have an HI close to the definition of socioacousis and mean deficit differences with deck and services’ merchant seafarers improved. Our results could be interpreted as a limitation of occupational noise exposure impact in a merchant seafarers’ population, needing an improvement in prevention measures and also encouraged to continue to improve onboard working conditions.

Carcinogenicity of Poorly Soluble Low Toxicity Particles: Commentary on Epidemiology as a Risk Assessment "Reality Check".

Inhaled particles that are poorly soluble or insoluble and of low toxicity (“poorly soluble low toxicity” or “PSLT” particles), can accumulate in the lung and at lung overload levels induce lung cancers in rats. The question of whether PSLT particles increase lung cancer risk in humans is complicated by large differences between rats and humans and the relatively large particle doses administered in animal studies even when compared with heavy human occupational exposures. We review the findings of epidemiological studies on occupational exposure to each of three different PSLT particles (carbon black, talc and taconite). The epidemiological evidence indicates that at even very high occupational exposure levels at which non-malignant respiratory diseases including pneumoconiosis and even talcosis are observed, lung cancer risks appear not to be elevated. Although positive human cancer risks might be predicted based on extrapolation from overload doses in rats to relevant exposures in humans, the epidemiological “reality check” based on the three examples indicates that these PSLT particles are unlikely to increase lung cancer risk in humans even at high occupational levels of exposure. Therefore, we propose that careful evaluation of the epidemiological evidence can serve as a “reality check” for human risk assessment and help balance the risk evaluation process.

Occupational exposure to BTEX and styrene in West Asian countries: a brief review of current state and limits.

The aim of introducing occupational exposure limits (OELs) is to use them as a risk management tool in order to protect workers’ health and well-being against harmful agents at the workplace. In this review we identify OELs for benzene, toluene, ethylbenzene, xylene (BTEX), and styrene concentrations in air and assess occupational exposure to these compounds through a systematic literature search of publications published in West Asian countries from 1980 to 2021. OELs for BTEX and styrene have been set in Iran and Turkey to levels similar to those in European countries and the US. The search yielded 49 full-text articles that cover studies of exposure assessment in six countries, but most (n=40) regard Iran. Average occupational exposure to benzene of workers in oil-related industries is higher than recommended OEL, while average occupational exposure to other compounds is lower than local OELs (where they exist). Currently, information about levels of occupational exposure to BTEX and styrene is insufficient in West Asian countries, which should be remedied through OEL regulation and application. Furthermore, coherent research is also needed to determine actual levels of occupational exposure, dose-responses, and the economic and technical capacity of local industries to address current issues.

The 2-Methoxymethyl Modification of p-Phenylenediamine Reduces the Sensitization Risk for Hairdressers to Hair Dyes—An Occupational Hand Exposure–Based Risk Assessment

BackgroundAllergic contact dermatitis involving the hands is a common occupational skin disease for hairdressers and the potent sensitizers p-phenylenediamine (PPD) and toluene-2,5-diamine (PTD) are associated with the development of occupational allergic contact dermatitis.ObjectiveThe aim of the study was to analyze whether the use of the moderate sensitizer 2-methoxymethyl-PPD (ME-PPD) in professional hair dyes is a suitable tool to reduce the occupational contact allergy risk for hairdressers.MethodsHand exposure of hairdressers (N = 11) to ME-PPD was analyzed under routine hair coloring conditions in commercial salons. By accounting for wet work and uneven hand exposure, the daily hand exposure was derived and compared with the occupational acceptable exposure level (AEL), that is, the sensitization induction threshold of ME-PPD adjusted for interindividual variability among workers.ResultsThe daily hand exposure to ME-PPD was 1.6 μg/cm2, and the occupational AEL was 215 μg/cm2. The ratio of hand exposure to AEL was calculated as the margin of safety (MOS) against occupational sensitization. For ME-PPD, the MOS of 134 indicates a low likelihood of sensitization versus PPD and PTD with MOS values of 2.7 and 5.9, respectively.ConclusionsOur data predict that the use of ME-PPD in professional hair color products improves the protection of hairdressers against hair dye–related contact allergy versus the use of PPD and PTD.

Prevalence of respiratory disease in the population of Queensland communities in proximity to coal mines and coal mining activities

Air quality related to respiratory illness is examined in many settings, including populations that work or reside close to sources of pollution. Industry produced pollution from mining and metal manufacturing, natural environmental pollution as in the case of bushfires and large-scale dust storms are examples. We reviewed any available literature and data concerning the Queensland coal industry and its effect on respiratory health of miners, mining related workers and communities in proximity to coal mines. We searched various databases using keywords related to coal and respiratory diseases, using the five step criteria defined by Denyer and Tranfield. In the Queensland coal mining industry, the negative effect of mining on workers’ respiratory health has been known for many years and has received increased attention in the last five years both nationally and internationally due to the resurgence in Coal Mine Dust Lung Diseases and specifically Coal Worker’s Pneumoconiosis (CWP). A Queensland parliamentary review has prompted regulatory amendments for the permitted (occupational) exposure level (PEL; OEL) to coal dust and silica; amendments have also been enacted for better occupational respiratory health surveillance of Queensland coal miners, both surface and underground. Considering Queensland has a high proportion of Australian coal mines, the literature available on respiratory health in Queensland coal mines and surrounding communities is minimal. There is very limited research into, and possible underreporting of CMDLD amongst the coal mining workers in Queensland. Further studies are required to better understand air pollution and health effects in coal miners in Queensland.

Investigation and analysis of occupational hazards in construction of power transmission and transformation project

Objective: To investigate the occupational hazard factors and exposure levels of workers during the construction of power transmission and transformation projects. Methods: Analysis and identification of occupational hazard factors were carried out for typical construction process of 6 power transmission projects and 3 substation projects in September 2018. The on-site occupational health investigation was carried out to detect and analyze the exposure levels of workers to occupational hazard factors. Results: The time weighted average concentration (C(TWA)) of crushing workers exposed to silica dust and welders exposed to welding fume in substation projects were 2.72 and 14.03 mg/m(3), respectively. The 8 h equivalent sound level results of exposure noise of carpenters in power transmission projects and crushing workers, reinforcement workers, carpenters, scaffolders, road builders in substation projects were 87.9, 92.5, 87.1, 92.5, 93.0 and 90.2 dB (A) , respectively. The 4-hour time equal energy frequency weighted vibration acceleration of hand-transmitted vibration of bricklayer in power transmission projects, bricklayer, general worker 3, road builder 1 and road builder 2 of substation projects were 5.36, 5.21, 5.28, 10.71 and 5.22 m/s(2), respectively. The effective irradiance of electric welding arc light of welders' limbs in power transmission projects and substation projects were 401.19, 319.68 μW/cm(2), respectively. All of the above exceeded the requirements of occupational exposure limits. The occupational radiation levels and exposure limits of hazardous chemical factors met the requirements of each post. Conclusion: During the construction of power transmission and transformation projects, the exposure levels of occupational hazard factors in multiple posts exceed the standard. The main responsibility of employers for occupational disease prevention and control should be implemented, and targeted comprehensive measures should be taken to reduce the exposure levels of occupational hazard factors of workers.

Parental Occupational Exposure and Neurodevelopmental Disorders in Offspring: a Systematic Review and Meta-analysis.

Parental occupational exposures might be associated with neurodevelopmental disorders (NDDs) in offspring. We aimed to conduct a systematic review and meta-analysis to summarize and synthesize the current literature and to estimate the pooled magnitude of the underlying association(s) between parental occupational exposures and subsequent risk of NDDs. In the meta-analysis of 20 included studies, significant associations were found between parental occupational exposure to pesticides or solvents and the risk of attention deficit hyperactivity disorder in offspring. Prenatal occupational exposure to pesticides was significantly associated with motor development or cognition disorders in children. Furthermore, some evidence showed that metals might have a role in the development of autism spectrum disorders. Further studies need to identify the level of parental occupational exposures that can be significantly associated with NDDs. Moreover, utilizing standardized outcome and exposure scales is recommended to incorporate paternal, maternal, and parental as well as both prenatal and postnatal exposure in future studies.

Health Risk Assessment of Ortho-Toluidine Utilising Human Biomonitoring Data of Workers and the General Population.

The aim of this work was to demonstrate how human biomonitoring (HBM) data can be used to assess cancer risks for workers and the general population. Ortho-toluidine, OT (CAS 95-53-4) is an aniline derivative which is an animal and human carcinogen and may cause methemoglobinemia. OT is used as a curing agent in epoxy resins and as intermediate in producing herbicides, dyes, and rubber chemicals. A risk assessment was performed for OT by using existing HBM studies. The urinary mass-balance methodology and generic exposure reconstruction PBPK modelling were both used for the estimation of the external intake levels corresponding to observed urinary levels. The external exposures were subsequently compared to cancer risk levels obtained from the evaluation by the Scientific Committee on Occupational Exposure Limits (SCOEL). It was estimated that workers exposed to OT have a cancer risk of 60 to 90:106 in the worst-case scenario (0.9 mg/L in urine). The exposure levels and cancer risk of OT in the general population were orders of magnitude lower when compared to workers. The difference between the output of urinary mass-balance method and the general PBPK model was approximately 30%. The external exposure levels calculated based on HBM data were below the binding occupational exposure level (0.5 mg/m3) set under the EU Carcinogens and Mutagens Directive.

Blood serum levels of selected biomarkers of oxidative stress among printing workers occupationally exposed to low-levels of toluene and xylene.

Printing workers (PWs) are exposed to a mixture of solvents, yet the health risks associated with such exposuer are unknown. This study aimed to compare the serum levels of selected biomarkers of oxidative stress among occupationally exposed PWs to low-level of toluene and xylenes and unexposed controls. Associations between levels of such biomarkers and occupational exposures to toluene and xylene were also investigated. Urinary levels of hippuric acid (HA) and methyl hippuric acids (MHAs) as exposure biomarkers of toluene and xylenes, respectively, and serum levels of oxidative stress biomarkers, including total antioxidant capacity (TAC), malondialdehyde (MDA), and the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), were measured among the 84 subjects, comprising 44 PWs and 40 unexposed subjects. Mean concentrations of urinary HA and MHAs of PWs showed a significant increase compared with the unexposed controls. Although levels of urinary biomarkers of exposure to toluene (HA) and xylenes (MHAs) were well below the biological exposure indices (BEIs; ACGHI), PWs presented significantly increased serum levels of MDA, and significantly decreased serum activities of SOD and GPx compared to the unexposed controls. However, for serum TAC and CAT activity, no significant difference was observed between the two groups. Correlation analyses indicated that urinary levels of HA and MHAs were positively correlated with MDA levels and negatively correlated with GPx and SOD. Our study suggested that the alterations evidenced in serum levels of MDA, SOD, and GPx could be involved in the oxidative stress caused by co-exposure to low levels of toluene and xylene. Further investigation is needed to clarify the effect of low-level occupational exposure to solvents among PWs.

Ausencia por enfermedad, condiciones médicas y de trabajo durante el embarazo en una cohorte de profesionales sanitarias

To assess the association between sickness absence (SA) trajectories by medical diagnoses and exposure to occupational risk factors during pregnancy. Methods: SA trajectories were identified in a cohort of 367 pregnant workers from a healthcare institution (period 2010-2014), based on most frequent diagnosis using sequence analysis. Trajectory 1 included SA episodes due mainly to musculoskeletal disorders (58.86%), trajectory 2 included SA episodes due to pregnancy-related disorders (25.07%) and trajectory 3 included absences mainly covered by pregnancy-related occupational risk benefits (POR) and few SA episodes (16.08%). Exposure to occupational risk factors was assessed by experts and their association with trajectories was analysed using logistic regression. Relative risks (RR) and their 95% confidence intervals (95%CI) were adjusted for age, type of contract and work shift. Trajectory 1 was negatively associated with exposure to safety and ergonomic risks (RR=0.56, 95%CI=0.35-0.90; RR=0.50, 95%CI=0.33-0.77, respectively) and with the highest global risk index (RR=0.68, 95%CI=0.49-0.96). Trajectory 3 was associated with safety and ergonomic risks (RR=2.75, 95%CI=1.59-4.75; RR=3.64, 95%CI=2.18-6.06, respectively) and with the highest global risk index (RR=2.69, 95%CI=1.43-5.01). Nursing aides and nurses had a higher probability of belonging to trajectory 3 (RR 5.58, 95%CI=2.09-14.95 and RR 5.00, 95%CI 2.18-6.06, respectively). Pregnancy-related and musculoskeletal disorders are the most frequent sickness absence diagnosis during pregnancy. Low levels of occupational risk factors exposure were related to absences from work covered mainly by sickness absence. Current social benefits seem to be used as a complementary way to balance work and health during pregnancy.

Interference thresholds for active implantable cardiovascular devices in occupational low-frequency electric and magnetic fields: a numerical and in vitro study

In light of concerns regarding the occupational safety and health of workers wearing active implantable medical devices (AIMDs), this study aims to investigate the potential risks of electromagnetic interference (EMI) between AIMDs and low-frequency 50/60 Hz electromagnetic fields (EMFs) in the workplace. A total of 58 AIMDs, consisting of pacemakers (PMs) and implantable cardiac defibrillators (ICDs) of different brands, models, and configurations were tested to determine the immunity thresholds for high-voltage electric fields (EFs) and magnetic fields (MFs) at 50/60 Hz. The EFs and MFs at the levels in workplaces are reproduced by setups using Helmholtz coils and aluminum plates, respectively, to ensure that the EM/MF exposures are controllable and reproducible. The EMI thresholds were recorded by observing the occurrences of PM or ICD dysfunctions. In addition, numerical studies on anatomical models were carried out using CST® software. The results indicate that the recorded thresholds all exceed the EF and MF public exposure limits given in the ICNIRP 2010 guidelines. No dysfunction was observed among four ICDs tested under MF exposure up to 2750 µT at 50 Hz and 2480 µT at 60 Hz. However, among the 43 PMs and 11 ICDs tested under EF exposures, potential hazards may occur below the occupational exposure level proposed in the ICNIRP guidelines.

Occupational external exposure to ionizing radiation in research-associated activities in Iran (2015-2020)

Research is an integral part of radiological and nuclear activities; thus, workers may receive different levels of occupational exposure. In the present study, occupational external exposure of workers was studied at the largest radiological and nuclear research institute of Iran from 2015–2020. The activities included research reactors, nuclear fuel cycle, development on radiopharmaceuticals and radioisotopes, particle accelerators, plasma and fusion, and nuclear agriculture. The average doses of the monitored and exposed workers were calculated to be 0.095 and 0.575 mSv, respectively, which were around their corresponding worldwide values. Moreover, the results showed that in comparison with other research activities, the workers in research reactors, nuclear fuel cycle, and development of radiopharmaceuticals and radioisotopes may face higher occupational risks. It could be, therefore, concluded that all the radiation protection measures have been effective at achieving safe research activities in Iran.

Exposure to Antineoplastic Drugs in Occupational Settings: A Systematic Review of Biological Monitoring Data.

The high toxicity of antineoplastic drugs (ADs) makes them dangerous not only for patients, but also for exposed workers. Therefore, the aim of this review was to provide an updated overview of the biological monitoring of occupational AD exposure in order to extrapolate information useful to improve risk assessment and management strategies in workplaces. Several studies demonstrated that remarkable portions of healthcare workers may have traces of these substances or their metabolites in biological fluids, although with some conflicting results. Nurses, directly engaged in AD handling, were the occupational category at higher risk of contamination, although, in some cases, personnel not involved in AD-related tasks also showed quantifiable internal doses. Overall, further research carried out on greater sample sizes appears necessary to gain deeper insight into the variability retrieved in the reported results. This may be important to understand the impact of the extent of ADs use, different handling, procedures, and cleaning practices, spill occurrence, training of the workforce, as well as the adoption of adequate collective and personal protective equipment in affecting the occupational exposure levels. This may support the achievement of the greatest clinical efficiency of such therapies while assuring the health and safety of involved workers.

Association of nanoparticle exposure with serum metabolic disorders of healthy adults in printing centers

Printers are everyday devices in both our homes and workplaces. We have previously found high occupational exposure levels to toner-based printer emitted nanoparticles (PEPs) at printing centers. To elucidate the potential health effects from exposure to PEPs, a total of 124 human serum samples were collected from 32 workers in the printing centers during the repeated follow-up measurements, and global serum metabolomics were analyzed in three ways: correlation between metabolic response and personal exposure (dose response exposure); metabolite response changes between Monday and Friday of a work week (short-term exposure), and metabolite response in relation to length of service in a center (long-term exposure). A total of 52 key metabolites changed significantly in relation to nanoparticle exposure levels. The primary dysregulated pathways included inflammation and immunity related arginine and tryptophan metabolism. Besides, some distinct metabolite expression patterns were found to occur during the transition from short-term to long-term exposures, suggesting cumulative effect of PEPs exposure. These findings, for the first time, highlight the inhalation exposure responses to printer emitted nanoparticles at the metabolite level, potentially serving as pre-requisites for whole organism and population responses, and are inline with emerging findings on potential health effects.

Health risks of inhalation exposure to BTEX in a municipal wastewater treatment plant in Middle East city: Shiraz, Iran.

Benzene, toluene, ethylbenzene, and xylene, known as BTEX, adversely affect human health. This study aimed to measure BTEX concentration and assess the health risk through inhalation exposure to these compounds in a municipal wastewater treatment plant. The ambient air samples were collected using the active sampling method in summer and winter. Sampling sites were close to wastewater treatment units, including bar screen & grit chamber (Site-1), aeration tank & secondary clarifiers (Site-2), anaerobic sludge digester (Site-3), and office & control building (Site-4). Results indicate that the mean levels of benzene and toluene in winter were higher than in summer. The levels of benzene and toluene were below the occupational exposure levels of the American Conference of Governmental Industrial Hygienists (ACGIH) and Occupational Safety and Health Administration (OSHA). The carcinogenic risk (CR) and hazard quotient (HQ) were assessed using the United States Environmental Protection Agency (U.S.EPA) method, and Monte Carlo simulation (MCS) was applied to quantify the uncertainty and sensitivity analysis. The CRs for all sampling sites were below the U.S.EPA threshold limit (1.0×10-4). The HQ values for benzene nearby Site-2 were above 1.0, indicating inhalation exposure could pose a health hazard. Besides, the HQ results for exposure to toluene in all sampling sites were less than 1.0. The sensitivity analysis had shown that the risk determinant for carcinogenic and non-carcinogenic risk was exposure time, followed by concentration.

Quantifying Emission Factors and Setting Conditions of Use According to ECHA Chapter R.14 for a Spray Process Designed for Nanocoatings-A Case Study.

Spray coatings’ emissions impact to the environmental and occupational exposure were studied in a pilot-plant. Concentrations were measured inside the spray chamber and at the work room in Near-Field (NF) and Far-Field (FF) and mass flows were analyzed using a mechanistic model. The coating was performed in a ventilated chamber by spraying titanium dioxide doped with nitrogen (TiO2N) and silver capped by hydroxyethylcellulose (Ag-HEC) nanoparticles (NPs). Process emission rates to workplace, air, and outdoor air were characterized according to process parameters, which were used to assess emission factors. Full-scale production exposure potential was estimated under reasonable worst-case (RWC) conditions. The measured TiO2-N and Ag-HEC concentrations were 40.9 TiO2-μg/m3 and 0.4 Ag-μg/m3 at NF (total fraction). Under simulated RWC conditions with precautionary emission rate estimates, the worker’s 95th percentile 8-h exposure was ≤171 TiO2 and ≤1.9 Ag-μg/m3 (total fraction). Environmental emissions via local ventilation (LEV) exhaust were ca. 35 and 140 mg-NP/g-NP, for TiO2-N and Ag-HEC, respectively. Under current situation, the exposure was adequately controlled. However, under full scale production with continuous process workers exposure should be evaluated with personal sampling if recommended occupational exposure levels for nanosized TiO2 and Ag are followed for risk management.

Demonstrating the protective effect of a 70-year-old occupational exposure limit against pneumoconiosis caused by mica.

Workers involved in crushing, milling, screening, and bagging of mica scrap are at increased risk to develop pneumoconiosis, a progressive material overloading of the lung that can lead to fibrosis and, in the later stages, to dyspnea. Pneumoconiosis is only seen after 10–20 years of respiratory mica exposure, and it can have a latency period of up to 40 years—today’s cases date back to exposures during the second half of the 20th century. An occupational lifetime exposure level of 3 mg/m3 respirable mica dust has been considered to present no risk of pneumoconiosis since 1951 when the American Conference of Governmental Industrial Hygienists (ACGIH) established a 20 million particles per cubic foot (mppcf) (3.5 mg/m3 respirable particles) exposure limit. As a result, numbers of unspecified and other pneumoconioses in the United States have steadily declined since the early 1970s. Data from the National Institute for Occupational Safety and Health documents a 91% decrease between 1972 and 2014 (i.e., the peak of documented cases and the latest reported data) for combined cases of aluminosis, berylliosis, stannosis, siderosis, and fibrosis from production and use of bauxite, graphite fibers, wollastonite, cadmium, Portland cement, emery, kaolin, antimony, and mica. Ample evidence indicates that the 70-year-old occupational lifetime exposure level of 3 mg/m3 respirable mica dust is protective of workers’ health.

Near-Field Exposure in FM Frequencies: New Methodology and Estimation Formulas.

Workers inside transmission pylons with FM antenna arrays are likely to be exposed to near-field radiation exceeding reference levels for occupational exposure. In this study, the near-field behavior of 64 FM pylons was studied using a new methodology. Near-field characterization was done using field metrics without taking into account field sources' size or distance from field source. The specific absorption rate (SAR) was assessed in five hundred different near-field cases using a human phantom. Estimation formulas for both local and whole-body SAR are provided and validated numerically. Local and whole-body SAR are linked to electric field strength. © 2022 Bioelectromagnetics Society.

POTENTIAL RISKS OF COVID-19 AMONG HEALTHCARE WORKERS

Background: Healthcare workers have a potential risk of COVID-19 as they are at the front line of the COVID-19 outbreak response. This study aimed to assess the potential risk of COVID-19 infection among healthcare workers at COVID -19 treatment center. Methods: A hospital based cross-sectional study design was undertaken to conduct this study. A snowball networking sampling method was used to select the participants. Total 387 health care workers participated in the study from July 18, 2020 to September 22, 2020. The WHO COVID-19 risk assessment tool was used to collect data from study participants. Descriptive statistics and inferential statistics binary logistic regression were done through SPSS 16 version. Results: There was a high level of occupational exposure (88.9%) to the COVID-19 virus and a higher potential risk of COVID-19 infection (75%) among exposed healthcare workers. Among those who had occupational exposure 7% and 21 % did not use personal protective equipment during healthcare interaction and performing aerosol generating procedures respectively. Male healthcare workers, registered nurses, medical doctors, and auxiliary nurse midwives were found the potential risk of COVID-19 infection. Healthcare workers with less supply of PPE had three times higher potential risk of COVID-19 infection. Conclusions: Healthcare workers had a higher occupational exposure and higher potential risk of COVID 19 infection. Healthcare workers had poor adherence to infection prevention and control measures. Healthcare workers should ensure proper use of personal protective equipment and adherence to infection control measures and adequate supply of PPE must be there to protect the healthcare workers from COVID-19 infection.