Parks and playground soils constitute a critical matrix for children exposure to hazardous substances due to their high exposure rate. However, minimal investigation has been conducted in Ghana on the subject, thus the need for this research. One hundred and twenty (120) soil samples were collected between April 2015 and March 2016 and then analyzed for heavy metals using atomic absorption spectroscopy. The health risk posed to school children by the heavy metals laden in soil was assessed via oral bioaccessibility and hazard index. The oral bioaccessibility of the metals was estimated using the simple bioaccessibility extraction test (SBET) method. Iron (Fe) measured the highest range of total metal concentrations of 2785.0-15275.0 mg kg-1 followed by Pb of 2.1-284.0 mg kg-1. The oral bioaccessibility of the metals varied significantly with Pb and Cu exhibiting the highest mean values of 47.80% and 54.45%, respectively. The sequence for the mean bioaccessibility result does not correspond with the mean concentration of metals in the soil. The hazard index (HI) for most of the heavy metals indicated no potential non-carcinogenic health risk to children (HI < 1) except for Pb. The prolonged use of leaded fuel in Ghana prior to its outright ban on January 1 2004 and the persistence of Pb in soil media may account for its high risk. The deleterious health effects of Pb on children call for the adoption and implementation of appropriate environmental management of playgrounds so as to mitigate children\'s exposure to soil-laden heavy metals.

BACKGROUND: Healthcare workers perform various clinical procedures for COVID-19 patients facing an elevated risk of exposure to SARS-COV-2.This study aimed to assess the healthcare workers\' exposure to COVID-19 in Qazvin, Iran in 2020.
METHODS: We conducted this descriptive-analytical study among all healthcare workers on the frontline of exposure to COVID-19 in Qazvin province. We entered the participants into the study using a multi-stage stratified random sampling method. We utilized a questionnaire, \"Health workers exposure risk assessment and management in the context of COVID-19 disease\", designed by the World Health Organization (WHO) to collect data. We analyzed data using descriptive and analytical methods with SPSS software version 24.
RESULTS: The results showed that all participants in the study had occupational exposure to the COVID-19 virus. So of 243 healthcare workers, 186 (76.5%) were at low risk and 57 (23.5%) at high risk of COVID-19 virus infection. Also, from the six domains mentioned in the questionnaire, health workers exposure risk assessment and management in the context of COVID-19 disease, the mean score of the domain of the type of healthcare worker interaction with a confirmed COVID-19 patient, the domain of health worker activities performed on a confirmed COVID-19 patient, the domain of the adherence to infection prevention and control (IPC) during health care interactions, and the domain of the adherence to IPC when performing aerosol-generating procedures in the high-risk group were more than the low-risk group.
CONCLUSIONS: Despite strict WHO guidelines, many healthcare workers are exposed at contracting COVID-19. Therefore, healthcare managers, planners, and policymakers can revise the policies, provide appropriate and timely personal protective equipment, and plan for ongoing training for staff on the principles of infection prevention and control.

Trends in prescribing psychotropic drugs before and during pregnancy may have changed over the years, but actual information is lacking. We therefore compared and assessed the exposure and acceptance rates of classes of antipsychotic (+ lithium), anxiolytic, sedative/hypnotic, antidepressant, and psychostimulant before and during pregnancy in the past two decades. All singleton pregnancies with ≥1 prescription of psychotropic drug from six months before pregnancy until child\'s birthdate were identified in the pregnancy subset of the IADB.nl prescription database. The prescription patterns of psychotropics were distinguished as continuation rate (CR), initiation rate (IR), discontinuation rate (DR), total exposure rate (TER), and acceptance rate. Singleton pregnancies exposed to psychotropic drugs before and during pregnancy increased from 118.4 to 136.5 (per 1000 singleton pregnancies) between decades. Changing trends were observed in decade 2, including a high increase in the TER of antipsychotic class (3.3 to 6.8) and antidepressant class (23.0 to 40.6). A marked increase for individual drugs was seen for sertraline (TER: 0.6 to 6.6 and PAT: 35.3% to 82.5%), citalopram (TER: 2.3 to 10.0 and PAT: 51.1% to 74.6%), and quetiapine (TER: 0.4 to 3.1 and PAT: 57.1% to 66.0%). Although the total exposure rates of five classes of psychotropics in singleton pregnancies increased in decade 2, only antidepressant class had a higher acceptance rate during pregnancy. Certain SSRI antidepressants and atypical antipsychotics were more frequently prescribed in decade 2 than in decade 1, reflecting that treatment options were preferred for safer treatment choices.

A method for calibrating iodine-125 seeds in terms of exposure has been established. The standard free-air ionization chamber, used for measuring soft x rays, was chosen for the measurements. Arrays of four to six seeds were used to enhance the ionization-current-to-background-current ratio. Seeds from an array were measured individually in a re-entrant chamber. The quotient of the exposure rate for the array by the sum of the ionization currents in the re-entrant chamber is the calibration factor for the re-entrant chamber. Calibration factors were established for three types of iodine-125 seeds. The overall uncertainty for the seed exposure calibrations is less than 6%.

This study concerns the concentrations of gaseous and particle-bound mercury present in ambient air of two Polish sites, differing in terms of emission structure, and the estimation of inhalation risks related to those Hg species. The measurements of total gaseous mercury (TGM) and PM2.5-bound mercury (PBM) were performed at an urban station in Zabrze and a rural station in Złoty Potok, in 2014-2015. Both sites are located in Silesia, considered one of the European air pollution hot-spots. TGM was measured on-line (Tekran 2537). PM2.5 samples were taken with the use of low volume samplers. Hg contents in PM were determined by the CVAAS method following thermal decomposition. The median concentrations of TGM and PBM in Zabrze were 2.48 ng m-3 and 37.87 pg m-3, respectively; meanwhile in Zloty Potok, these were 1.69 ng m-3 and 27.82 pg m-3, respectively. Clearly, seasonal variability of TGM and PBM concentrations were observed, reflecting the importance of Hg and PM emissions from coal combustion for power and heating purposes. Health risk assessment was performed using a deterministic approach by the most conservative exposure scenario. The obtained HQ ratios and the cumulative HI indexes were below the limit value (<1). This means an unlikely health hazard due mercury inhalation.

137Cs γ-ray sources, which have been proposed by the Public Health Service as a substitute for radium in the treatment of malignant diseases, require suitable calibration if consistency is to be achieved in radiation treatment. Several 137Cs sources were calibrated using a graphite cavity ionization chamber in an open-air geometry. The contribution of scatter from the room surfaces was calculated and the source measurements corrected for this effect. A large-volume aluminum-walled ionization chamber was designed and fabricated for use in routine calibrations. This chamber will be used as a means for intercomparison of the source to be calibrated with one of the standards.

Mobile X-ray device is widely employed because it is useful for diagnosis in patients having mobility difficulties and in medical emergencies. As various devices for X-ray generation have continued to be developed, X-ray devices can now be used more safely and effectively. However, mobile X-ray devices generate relatively low X-ray doses due to the limitation of the power input. Therefore, the use of mobile X-ray devices is limited to thin parts of body. In this study, a new device was designed in order to increase the usefulness of mobile X-ray devices by offsetting the weaknesses of the existing mobile X-ray devices, rendering them useable independently. A supercapacitor and battery were used as the internal power source for the X-ray generation in the manufactured device. The pulse width modulation (PWM) method is applied to control the tube voltage and current required for generating the X-ray, and the pulse frequency modulation (PFM) method is applied to the control to generate the high voltage in order to enhance the precision and efficiency. The manufactured X-ray device was used to evaluate the control signal, frequency, and output characteristics according to changes in tube voltage and current. Based on the results of X-ray generation, it is confirmed that precise control was achieved by X-ray generation increases linearly with increasing tube voltage and tube current. This means that precise control of the manufactured mobile X-ray device is passible. In addition, the study confirmed that stable output was achieved by checking the tube voltage, tube current and exposure rate during the exposure times by high power condition.

A method for calibrating iodine-125 seeds in terms of exposure has been established. The standard free-air ionization chamber, used for measuring soft x rays, was chosen for the measurements. Arrays of four to six seeds were used to enhance the ionization-current-to-background-current ratio. Seeds from an array were measured individually in a re-entrant chamber. The quotient of the exposure rate for the array by the sum of the ionization currents in the re-entrant chamber is the calibration factor for the re-entrant chamber. Calibration factors were established for three types of iodine-125 seeds. The overall uncertainty for the seed exposure calibrations is less than 6%.

Airborne spectrometric gamma data are used in this paper to estimate the degree of radioactive hazard on humanity in Area-3, Northern Palmyrides, Central Syria. Exposure Rate (ER), Absorbed Dose Rate (ADR), Annual Effective Dose Rate (AEDR), and Heat Production (HP) of the eleven radiometric units included in the established lithological scored map in the study area have been computed to evaluate the radiation background influence in humans. The results obtained indicate that a human body in Area-3 is subjected to radiation hazards in the acceptable limits for long duration exposure. The highest radiogenetic heat production values in Area-3 correspond to the phosphatic locations characterized by relatively high values of uranium and thorium.

{010}-Facet-exposed anatase TiO2 crystals exhibit the highest photoreactivity among the exposed facets. To obtain a higher exposure rate of this facet, the work investigated the transformation of the nanosheets with cavities within the layers derived from a rock-salt-structured Li2TiO3 precursor. All the lithium ions were extracted from the precursor by H+/Li+ ion exchange in HCl aqueous solutions, and after tetramethylammonium ions were intercalated, the precursor can delaminated into the nanosheets. The [TiO3]2- nanosheets were hydrothermally treated under different temperatures and pH values. The results showed that the anatase phase was formed in a wider range of pH and temperature, compared with using nanoribbons of [Ti4O9]2- and nanosheets of [Ti1.73O4]1.07-. At low pH, [111]-faceted nanorod-shaped anatase nanocrystals were formed preferentially, and the nanocrystals preferentially grow along the [001] direction with the increase of solution pH, leading to a large percentage of {010} facets on their surface. The photocatalytic activity increases with the increase of exposure rate of {010} facets.