Safe Limits Research Articles

Current evaluation of radiation hazards from sediments of Manzala Lake, Egypt

AbstractSurface sediment samples were collected from 12 different sites in Manzala Lake for measuring 238U, 226Ra, 232Th and 40K. Those elements were measured using High Purity Germanium (HPGe) detector. The concentrations of radionuclides were within the UNSCEAR limits. Various indices were applied to detect the environmental and human risk assessment for example activity utilization index, external hazard index and others. Environmental Risk from Ionising Contaminants: Assessment and Management (ERICA) tool was applied and showed no considered biological hazards. The results showed that concentrations of radionuclides in sediments of Manzala Lake were within the safe limits for further uses.

Geochemical assessments and human health risk evaluations of selected farm soils within the Abuja metropolis, North-central, Nigeria

Toxin accumulations in agricultural soils decreases the crop quality and productivity, and threatens the safety of foods, which could cause adverse human health effects. This study assessed the risks associated with potential toxins in the agricultural soils obtained from Lugbe and Jikwoyi in Abuja, Nigeria. An analytical technique for absorption spectrophotometry was adopted, and human health risks were evaluated. Twenty soil samples were collected from two farmlands, and two control samples were taken on unpolluted sites at depths 5-20 cm from the surface at the average suspension of plant roots where the soil holds most plant nutrients and water at a space interval of 5 m. The soils generally had low mean concentrations of Ca, Cu, Zn, Mn, Fe, and Co and moderately high mean concentrations of F, Ni, Pb, Cr, and Mo. The pattern of the pollutants reflected that the pollutants were majorly from anthropogenic activities, such as long-term fertilizer applications and other agrochemicals. The contamination indices revealed reassuringly low to moderate pollution risks to humans. The overall pollution loads suggested that the samples were largely unpolluted. The non-carcinogenic and carcinogenic health risks were within the safety limits for inhalation, dermal, and ingestion, which pose no significant risk to children and adults living in the vicinities of the farmlands. The cancer risks for inhalation were higher than dermal and ingestion, with Cr showing the highest values. The samples were slightly contaminated with potentially toxic metals, which could lead to increased phyto-accumulations, soil pollution, and groundwater contamination.

Assessment of radiological hazards in terms of gross α -β activities in groundwater in and around Beldih mine region of eastern India.

In the present study, liquid scintillation counting triple to double coincidence ratio technique is used to ascertain the gross α and β activity in groundwater samples collected from the Beldih mine region in the vicinity of the South Purulia Shear Zone (SPSZ) of Chota Nagpur Plateau in eastern India. A total of sixty samples were collected from deep tube wells located in the study area to assess the potential health threats caused by α and β emitting radionuclides present in these water samples. Average gross α activity in the region of study is 0.09 ± 0.05Bq/L, with a maximum of 3.22 ± 0.07Bq/L. On the other hand, the average gross β activity is found to be 0.13 ± 0.02Bq/L, with a maximum of 0.29 ± 0.02Bq/L. It was observed that gross α activity level in three samples exceeds the safety limit of 0.5Bq/L recommended by the World Health Organization. No significant gross β activity was observed. However, the radiological parameters for assessment of potential health threats due to ionizing radiation have been observed to be significantly high for adults. The results of this study indicate that the radiological assessment of groundwater in the Beldih mine region may be extended in future.

Numerical simulation of three-dimensional seepage field in a tailing pond under multiple operating conditions.

Establishing strong seepage stability for tailings dams is crucial for ensuring their safety and mitigating the risk of failure. This study developed a three-dimensional seepage numerical model using finite element numerical computation for four different elevation conditions (5070m, 5081m, 5159m, and 5213m) encompassing the pond area and dam body. Seepage calculations were conducted under normal and flooding conditions, and the tailings pond's seepage stability was assessed for various stacking scenarios. The spatial distribution pattern of the infiltration surface and the hydraulic stability of the tailings pond were evaluated, which provides insights into the three-dimensional infiltration stability. Examining the seepage stability under different accumulation conditions revealed distinct spatial distribution patterns of the infiltration surface and hydraulic ratio drop values. The findings indicated that the maximum permeability slope at 5070m elevation ranged from 0.66 to 0.75 at normal operation water level and maximum flood level. Most hydraulic ratio drop values at 5081m were below 0.2, while the anti-seepage lining sections at 5159m and 5213m showed larger values, and maintained the overall hydraulic ratio drop within safe limits. Consequently, the dam body's permeability was deemed secure, and no infiltration damage was anticipated with the proposed design of seepage control and drainage facilities. Moreover, sensitivity analysis of the tailing sand's permeability coefficient demonstrated that variations between 0.2 and 5 times the given parameter align with the seepage control requirements for the tailings dam. Additionally, local geomembrane breakage was found to have minimal impact on the tailing pond's seepage field and the dam body's permeability stability, which provides a scientific foundation for analyzing and designing the seismic static-dynamic stability of the tailings pond.

HPLC-MS/MS monitoring and health risk assessment of carbosulfan and its metabolites in date palm fruit (Phoenix dactylifera).

This study investigated residual levels of carbosulfan and its metabolites in date palm fruit in the UAE using HPLC-MS/MS and QuEChERS method. The method demonstrated excellent linearity (R2 > 0.998), low LOD (0.001-0.04 μg/kg) and LOQ (0.003-0.1 μg/kg), and high recoveries (92-103%) with low RSD values (1-9%). The matrix effect was negligible (-16.43-17.09%), and uncertainty measurements did not exceed the 50% limit. Carbosulfan was present in all samples, exceeding its MRL in 46% of the samples. Carbofuran and 3-hydroxycarbofuran exceeded their MRL in 4.87% and 40% of the samples, respectively, while 3-ketocarbofuran levels were below the MRL. Dibutylamine was found in 82% of the samples, with an average concentration of 9.01µg/kg. The health risk assessment for children and adults showed that all HQ values were below the safety limit of 1.0, indicating that date consumption poses no adverse health risks for either adults or children.

Discrete Bio-Hazard Model of EM Radiation for Crowded People

This study investigates the behaviour of electromagnetic (EM) waves in densely populated environments using a Multicomponent Discrete Propagation Model (MCDM). Our analysis focuses on four critical parameters: Specific Absorption Rate (SAR), Electrical Field, Skin Depth, and Effective Radiated Power (ERP) by working on crowd densities and frequencies relevant to mobile technologies. This study is the first to employ a Propagation Model for such an analysis, offering a novel approach. Through comprehensive simulations, we explore how variations in electrical field strengths impact SAR, skin depth, and ERP. The results are compared to established safety limits for whole-body SAR exposure, providing valuable insights for guidelines. This research aims to contribute to designing future electronic devices that minimize overall RF emissions. This innovative approach has the potential to improve public confidence in the safety of wireless technologies significantly

A leadless power transfer and wireless telemetry solutions for an endovascular electrocorticography

Objective. Endovascular brain-computer interfaces (eBCIs) offer a minimally invasive way to connect the brain to external devices, merging neuroscience, engineering, and medical technology. Currently, solutions for endovascular electrocorticography (ECoG) include a stent in the brain with sensing electrodes, a chest implant to accommodate electronic components to provide power and data telemetry, and a long (tens of centimeters) cable travel through vessels with a set of wires in between. Removing this long cable is the key to the clinical viability of eBCIS as it carries risks and limitations, especially for patients with fragile vasculature.Approach. This work introduces a wireless and leadless telemetry and power transfer solution for ECoG. The proposed solution includes an optical telemetry module and a focused ultrasound (FUS) power transfer system. The proposed system can be miniaturised to fit in an endovascular stent, removing the need for long, intrusive cables.Main results. The optical telemetry achieves data transmission speeds of over 2 Mbit/s, capable of supporting 41 ECoG channels at a 2 kHz sampling rate with 24-bit resolution. The FUS power transfer system delivers up to 10 mW of power to the implant through the scalp(6 mm), skull(10 mm), and subdural space(5 mm), adhering to safety limits. Testing on bovine tissue (10 mm thick bone, 7 mm thick skin) confirmed the system's efficacy.Significance. This leadless and wireless solution eliminates the need for long cables and auxiliary implants, potentially reducing complications and enhancing the clinical applicability of eBCIs. The proposed system represents a step forward in enabling safer and more effective ECoG for a broader range of patients.

Dietary Malondialdehyde Impair Intestinal Health and Fillet Quality of Hybrid Grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂)

Aquafeed kept at elevated temperatures and humidity can result in malondialdehyde (MDA) formation, adversely affecting aquafeed quality and triggering negative reactions in fish. To investigate the detrimental effects of dietary MDA on fish, six experimental diets with varying MDA levels (ranging from 0.03 to 17.72 mg/kg, on dietary crude lipid basis) were administered to three replicates of hybrid grouper for 8 weeks. Dietary inclusion of 4.43 mg/kg MDA significantly decreased serum complement 4 content and lysozyme activity, along with intestinal complement 3, complement 4, and immunoglobulin M contents. Furthermore, dietary inclusion of 8.86 mg/kg MDA significantly increased the activities of interleukin-1 receptor-associated kinase, ubiquitin-protein ligase, p38 mitogen-activated protein kinase, and tumor necrosis factor-α, downregulated the relative expression of Occludin but upregulated the relative expression of HSP70 in the hindgut. Additionally, the highest inclusion of MDA (17.72 mg/kg) significantly upregulated the relative levels of pro-inflammatory cytokines (IL-1β and TNF-α), caused intestinal inflammation, and damaged the intestinal microbial structure and fish fillet texture. This study demonstrated a dose-dependent response of MDA on hybrid grouper. A low dietary dose of MDA (<2.21 mg/kg) exhibited minimal impact on immune response and fillet quality. However, higher inclusion levels (≥4.43 mg/kg) impaired the intestinal health and fillet quality. Consequently, the safety limit for MDA content in the diet for hybrid grouper has been established at 4.43 mg/kg based on dietary crude lipid basis.

Optimal dispatch scheme considering system operational flexibility

To enhance the system's capacity to manage emergencies and foster the efficient utilization of newly generated energy, this paper introduces a redefined concept of system operation flexibility and proposes a two-stage optimized economic dispatch model. This model is tailored to ensure the system's operational flexibility. In this method, net load is pinpointed as the primary driver of flexibility demand, and a data-driven approach is employed to capture the uncertainties associated with net load across various risk levels. As flexibility supplier, conventional units work in tandem to optimize their operating points, fulfilling flexibility demand while adhering to the Do Not Exceed (DNE) baseline, thereby ensuring that system flexibility remains within safe limits. A case study on the modified SG-126 bus system demonstrates that the proposed methodology effectively highlights flexibility shortfalls and validates its efficiency in terms of cost and inter-regional coordination.

Radiological risk assessment of phosphate fertilizer application on farmlands in Ondo State, Nigeria.

This study assesses the radiological risks associated with phosphate fertilizer application on farmlands in Ondo State, Nigeria. Soil samples from ten agricultural towns were analyzed for radionuclide concentrations using gamma-ray spectrometry. Primordial radionuclides such as 238U, 232Th, and 40K were examined, with 40K showing the highest concentration due to the potassium-rich nature of phosphate fertilizers. Spatial variability in radionuclide concentrations was observed, attributed to agricultural activities. Despite variations, mean activity concentrations were below global averages, indicating low radiological risks. Hazard indices, radium equivalent concentrations, and absorbed dose rates were all within safe limits. The annual effective dose equivalent was significantly lower than recommended levels, and excess lifetime cancer risk estimates were below the global average. The study emphasizes the importance of educating farmers on the potential adverse effects of radionuclides and recommends reducing the use of inorganic fertilizers to promote eco-friendly agricultural practices.

Model-predictive fault-tolerant control of safety-critical processes based on dynamic safe set

Industrial systems and chemical plants heavily rely on automation and control systems for seamless operations. However, the susceptibility of these systems to various faults poses threats to processes, leading to economic losses and safety risks. Here, a robust fault-tolerant control (FTC) strategy is developed that can take proactive measures during faults involving in-time activation of a backup controller, to ensure that the system remains within safe operational limits. It is based on the Dynamic Safe Set (DSS) which is the set of initial process states that meet safety constraints at all times, and the dynamic safety margin (DSM) which is the minimum distance from the DSS boundary. For just-in-time corrective action, a critical fault function is introduced, defined as the time required by the system to cross the DSS boundary under the nominal controller only. This critical fault function is calculated offline and is integrated with a real-time fault size estimation to formulate the controller reconfiguration logic to keep system within DSS. A linear functional observer is used to estimate fault size, combined with a predictive scheme, to enhance robustness during the transient period of fault estimation. This configuration avoids unnecessary control actions while ensuring timely intervention. The proposed FTC strategy is tested on an exothermic Continuous Stirred Tank Reactor (CSTR) case study. The results demonstrate the strategy's effectiveness in handling process faults, ensuring both stability and safety constraints are met. Thus, this paper contributes to the advancement of FTC ensuring the resilience of industrial systems in the face of unforeseen challenges.

Comparison of the safety of flexible ureteroscopy with the different irrigation methods in a 3D print kidney model.

To compare intrarenal pressure (IRP) and irrigation flow by varying suspended water heights and hand-held pressure pumping during flexible ureteroscopy using an in vitro 3D printed kidney model. A 3D-printed silicone model was used to simulate the kidney. The ureteral access sheath(UAS) was connected to the kidney model and positioned at the ureteropelvic junction. Central venous pressure tubing was used to monitor the pressure in the renal pelvis under different conditions. Sheath sizes of 12Fr and 14Fr were tested with flexible ureteroscope (fURS) sizes of 7.5, 8.5, and 9.5Fr, respectively. The irrigation was gravity-based, with suspended water heights set at 60, 90, 120, 150, and 180cm. The manual pumping as another set of measurement is used to measure the maximum intrarenal pressure. Using a 12Fr sheath with a 9.5Fr fURS loading without additional accessories resulted in IRP ranging from 8.4 to 17.5 cmH2O, while manual pumping perfusion pressure exceeded 60 cmH2O. Loading a 200-um laser fiber reduced the pressure to 6.4-10.5 cmH2O, and using a stone basket decreased it to 4.0-5.0 cmH2O. Using a 14Fr sheath with a 9.5Fr fURS resulted in an IRP of 2.5-6.0 cmH2O, compared to 17 cmH2O with manual pumping. With a 12Fr sheath and a 7.5Fr fURS, the IRP ranged from 5.4 to 8.2 cmH2O, while manual pumping resulted in 25.5 cmH2O. With a 14Fr sheath and a 7.5Fr fURS, the IRP ranged from 1.5 to 4.3 cmH2O, and manual pumping resulted in 9.0 cmH2O. When using a UAS in a flexible ureteroscopy, the IRP can be maintained within a safe range with different fURS/UAS combos with a suspended water height of less than 180cm. However, with specific fURS/UAS(9.5Fr/12Fr) combos, the IRP exceeded the safe limit when using manual pumping. Gravity irrigation with a suspended water height of less than 180cm is safe in this simulated clinical environment.

High-quality multimodal MRI with simultaneous EEG using conductive ink and polymer-thick film nets

Objective. Combining magnetic resonance imaging (MRI) and electroencephalography (EEG) provides a powerful tool for investigating brain function at varying spatial and temporal scales. Simultaneous acquisition of both modalities can provide unique information that a single modality alone cannot reveal. However, current simultaneous EEG-fMRI studies are limited to a small set of MRI sequences due to the image quality and safety limitations of commercially available MR-conditional EEG nets. We tested whether the Inknet2, a high-resistance polymer thick film based EEG net that uses conductive ink, could enable the acquisition of a variety of MR image modalities with minimal artifacts by reducing the radiofrequency-shielding caused by traditional MR-conditional nets.Approach. We first performed simulations to model the effect of the EEG nets on the magnetic field and image quality. We then performed phantom scans to test image quality with a conventional copper EEG net, with the new Inknet2, and without any EEG net. Finally, we scanned five human subjects at 3 Tesla (3 T) and three human subjects at 7 Tesla (7 T) with and without the Inknet2 to assess structural and functional MRI image quality.Main results. Across these simulations, phantom scans, and human studies, the Inknet2 induced fewer artifacts than the conventional net and produced image quality similar to scans with no net present.Significance. Our results demonstrate that high-quality structural and functional multimodal imaging across a variety of MRI pulse sequences at both 3 T and 7 T is achievable with an EEG net made with conductive ink and polymer thick film technology.

Spatial distribution, source apportionment, and health risks assessment of trace elements in pre- and post-monsoon soils in the coal-mining region of North Karanpura basin, India

Coal mining activities in the North Karanpura basin have significantly increased the trace element (TE) concentrations in the soil, resulting in soil pollution and potential health risks. To assess this, 113 soil samples, along with coal, shale, and overburden rocks, were collected from open-cast mining areas during pre-monsoon (Pre-M) and post-monsoon (Post-M) seasons. Seasonal analysis revealed higher TE concentrations in the Post-M period, especially in the SE direction, followed by NE and NW, likely due to surface runoff and deposition, demonstrating temporal variability in TE distribution which corroborated from the spatial distribution maps. Positive matrix factorization (PMF) model identified four factors: mixed sources (F1Pre-M: 37.6 %; F4Post-M: 28.9 %), coal-fired emissions (F2Pre-M: 20.5 %; F3Post-M: 26.0 %), overburden rocks (F3Pre-M: 25.5 %; F2Post-M: 16.7 %), and agricultural and lithogenic origin (F4Pre-M: 16.4 %) during the Pre-M period, attributed to coal mining. Post-M sources were similar, but agricultural and lithogenic origins were replaced by atmospheric deposition (F1Post-M: 28.4 %), enhanced by monsoon effects. Carcinogenic risk assessment revealed that As, Cr, and Ni exceeded acceptable levels for children via ingestion, though adults remained within safe limits. Inhalation and dermal contact were also considered, but ingestion posed the highest risk. The hazard index (HI) via ingestion showed that children had an HI of 1.6 in Pre-M, increasing to 2.66 in Post-M, highlighting their potential vulnerability to non-carcinogenic risks, while adults stayed within safe limits. The expansion of mining areas in the study region led to decrease in vegetative areas which could affect agriculture and local communities, raising a comprehensive environmental and public health issues. These results underline the need for implementing effective biannual soil monitoring and mitigation strategies, such as phytoremediation, bioremediation, rock dust remediation, chemical amendments and improved waste management, to reduce TE contamination.

Optimization of chemical engineering control for large-scale alkaline electrolysis systems based on renewable energy sources

In the context of renewable energy, dynamic control is crucial for large-scale alkaline water electrolysis systems. Under traditional Proportional-Integral-Derivative (PID) control, the system's temperature and impurity levels may exceed safe limits during sudden load changes, compromising system safety. Therefore, this study proposes a control strategy based on mathematical models of system temperature and impurities, including Model Predictive Control (MPC) for temperature and Optimal Curve Tracking (OCT) for impurities. The MPC controller offsets the disturbances in temperature caused by current fluctuations through state prediction, while the OCT controller ensures that impurity levels remain within safe limits. Real-time application of these control strategies is achieved through MATLAB-PLC communication, validating controller performance. Experimental results show that the MPC controller exhibits excellent dynamic response and stability in controlling the stack temperature, with a maximum temperature peak deviation of only 2.9 K and a temperature fluctuation range of 5.9 K. This represents a reduction of 1.6 K in peak deviation compared to traditional PID controllers and significantly decreases the temperature fluctuation range. The OCT controller also demonstrates good safety and stability in controlling hydrogen to oxygen (HTO) impurity levels, consistently maintaining the HTO content at the set upper limit of 1.5%, thereby expanding the safe operational range of the system and reducing the need for frequent adjustments to the system setpoints.

Human Health Risks Assessment of Toxic Metals via Water, Food, and Soil: A Case Study of Northern Areas (Ghizer and Gilgit) of Pakistan

Health concerns have arisen worldwide as a result of contaminated food and water. This study was aimed to determine the levels of selected heavy metals i.e. cadmium (Cd), chromium (Cr), copper (Cu) manganese (Mn), and nickel (Ni) in various sources such as drinking water, vegetables, and soil in districts Ghizer and Gilgit, Pakistan. Human health risks were assessed using deterministic indices, a probabilistic approach, and multivariate analysis. The determinations were carried out by spectrophotometrically (AAS-700, Perkin Elmer, USA) following the standard procedures for heavy metal levels. The mean concentration was recorded as Cd 0.036 mg/L, Cr 0.076 mg/L, and Ni 0.394 mg/L, respectively. It revealed an exceeded level for Cd (0.03 mg/L) and Cr (0.07 mg/L) against the safe limits in drinking water of Gilgit and Ghizer. The highest hazard quotient (HQ) was recorded as Cd 3000, Cr 3863.33, Cu 21.7, Mn 45.71, and Ni 22.35 for children regarding the consumption of vegetables from district Ghizer. Whereas higher HQ values were recorded for adults regarding consumption of vegetables from district Gilgit. A hazard index (HI) indicates significant non-carcinogenic health risks (HI > 1) in Ghizer and Gilgit drinking water and vegetables. Gilgit soil HI values exceeded more than one due to dermal contact, while HI > 1 due to oral and dermal exposure in Ghizer. Furthermore, drinking water samples and vegetables from both districts showed cancer risk (CR) > 1× 10-4. The cumulative lifetime cancer risk (CR) was observed as 88.61 and 65.61 for adults whereas 2. 98 and 0.38 for children pertaining to vegetable consumption from Ghizer and Gilgit. It was found that the lifetime cancer risk (LCR) for Ghizer was higher than that for Gilgit, based on soil dermal and oral contact. Monte Carlo Simulation revealed adverse health risks in children as compared to adults. As a result of exposure to toxic metals, drinking water and vegetable consumption have higher cancer-causing risks. Therefore, we recommend that both districts implement strict monitoring regulations for drinking water and vegetables.

Occupational Radiation Exposure During Intraoperative 3-Dimensional Fluoroscopy in Pelvis and Acetabular Surgery.

To quantify the occupational radiation exposure with a 3-dimensional (3D) fluoroscopic machine during routine use in pelvic and acetabular surgery and to determine whether the additional radiation exposure encountered with the 3D fluoroscopic spin is within previously accepted limits. Prospective cohort study. Level I trauma center. All patients undergoing 3D fluoroscopy intraoperatively during pelvis (OTA/AO 61B,C) or acetabular (OTA/AO 62A-C) surgery between April 2021 and July 2021. Radiation dose at standardized locations around the operating room during the spin portion of the 3D fluoroscopy. Seventy-six 3D spins were performed on 69 patients during the study period. The average emitted radiation dose from the machine for the routine fluoroscopy portion of the case was 74.5 mGy. The average displayed radiation dose in the air for the spin portion of the case was 39.9 mGy, an average of 53.6% less radiation than the routine fluoroscopy portion. For the spin portion, the average radiation exposure seen by the patient was 3.42 mGy (centered on the patient) and the average maximal exposure in the room was 0.062 mGy. Minimal radiation was detected outside the operating room doors. The radiation exposure encountered by operating room personnel with 3D fluoroscopy appears to be within safe occupational limits. The marginal increase in radiation exposure during pelvic and acetabular surgery should not discourage the use of 3D imaging intraoperatively. Level IV, Case Series.

A comparative study concerning the sensory, physicochemical, bacteriological, nutritional quality, heavy metal content, and health risk assessment of some low-cost fish species

Investigating fish quality, nutritional content, and health risk assessment for heavy metals can provide important guidance on eating seafood and protecting human health. Accordingly, the current research aimed to assess the quality and safety of some extensively consumed fish and recognize more types of fish widely available in Egypt with reasonable costs, high nutritional values, good quality, and safe for human consumption. To achieve this goal, 100 fresh fish samples including red porgy, sardine, eel fish, grass carp, and common carp (20 from each) were taken from local fish markets in Giza and examined for chemical composition, bacteriological quality, deterioration criteria, sensory attributes, heavy metal contents, and health risk assessment. Among the examined fish, red porgy exhibited significantly higher protein and sensory scores along with significantly lower fat, bacterial count, pH, total volatile base nitrogen, and trimethylamine values in contrast to carp fish. Nevertheless, sardine and eel fish obtained the highest values of thiobarbituric acid, free fatty acid, and acid number versus red porgy. Surprisingly, the concentrations of lead in grass carp fish, mercury in all examined samples, as well as arsenic in common carp fish, were lower than the detectable limits. Despite the target hazard quotient and hazard index of all examined heavy metals being below 1 in all fish samples, it could not be confirmed that eating such fish causes acceptable non-carcinogenic health risks due to exposure from fish consumption does not account for the total daily exposure to the heavy metal from all dietary sources. Moreover, the carcinogenic risk of all examined heavy metals in fish samples was higher than 10-6 indicating a high risk of carcinogenicity which needs great efforts to be reduced to the safe limits. In conclusion, the current study provides beneficial data to Egyptian society for choosing seafood with high nutritional value, good quality, and affordable prices.

Is there a safe limit for consumption of alcohol?

In order to understand and curb the harms related to alcohol, it will be necessary to think beyond patterns of use that meet criteria for a diagnosis of alcohol use disorder, or addiction. Current research suggests that regular daily alcohol use does not confer a health benefit, and for many persons, even relatively low consumption is associated with a health risk. Determining a safe limit for alcohol consumption is challenging both for the individual person and for society. We conclude that excessive drinking is always risky. We provide a list of circumstances, such as chronic illness, driving a vehicle, or pregnancy where persons should be advised to abstain from alcohol. We recognize the need to encourage less consumption of alcohol, particularly in young adults, and in older adults with co-morbid conditions particularly when taking multiple medications. Finally, we offer the modest proposal that, for persons without the contributing negative influences described above, consumption which adheres to one drink per session, with interspersed abstinent days, does not constitute a meaningful risk to health.

Spray paint-derived microplastics and incorporated substances as ecotoxicological contaminants in the Neotropical Bumblebee Bombus atratus

While bumblebees may be exposed to microplastics (MPs), the effects on them are not well studied. Therefore, in this research, we assessed the cytotoxicity of pristine and photodegraded spray paint-derived MPs on the midgut, Malpighian tubules, and hepato-nephrocitic system cells of Bombus atratus workers exposed to 50mg.L-1 MPs for 96hours. Histological and histochemical analyses revealed that pristine MPs caused subtle cellular changes, while the exposure to photodegraded MPs led to significant vacuolization, nuclear condensation, and pyknosis. These effects are possibly linked to the release of potentially toxic elements (PTEs) like Copper, Manganese, and Iron from photodegraded MPs, which exceeded Brazil's CONAMA safety limits. Photodegraded MPs also reduced body weight, disrupting homeostasis and potentially decreasing bumblebee’s fitness. These findings highlight the importance of studying the toxicity of environmentally realistic MPs, as plastic composition and weathering significantly influence their harmful effects.