High Levels Of Contamination Research Articles

Application of the QuEChERS method combined with UHPLC-QqQ-MS/MS for the determination of isoprocarb and carbaryl pesticides in Indonesian coffee.

The performance of the QuEChERS method in this study, as indicated by a high percentage (>90%) of recovery observations falling within the range of 60-140% and a sample replicate deviation (% RSD) of <20%, for the routine analysis of isoprocarb and carbaryl pesticides, has been evaluated over a 14-month period for the export of Indonesian coffee. Following a seven-day observation of the stability of these pesticides in coffee extract, it was found that the added standard calibration solution remained stable and useable for seven days when stored at 4 °C and -20 °C. This validated method, with high sensitivity (a LOQ of 0.001 mg kg-1 for isoprocarb and carbaryl), has been employed to monitor residues in Indonesian coffee exports to comply with maximum residue limits (MRLs). The samples with higher contamination levels were predominantly from robusta coffee (57.76%), followed by arabica coffee (6.17%). The detection rates for residues decreased by more than 90% in the last two months of the method's application. In the observation of coffee processing, it was found that isoprocarb residues in contaminated samples could be transferred to the processed coffee (roasted and its infusion) to a limited extent, while residues from the carcinogenic carbaryl were not detected due to evaporation. Additionally, chronic dietary risk assessment showed that contaminated samples of robusta and arabica coffees should not be considered a significant public health concern (hazard index HI < 1). However, continuous monitoring of pesticide residues in Indonesian coffee is still recommended, not only to conform to the MRLs of importing countries but also to ensure food trade.

Microbial risk assessment of dairy products from retail marketplaces in Basrah province, Iraq.

Milk-borne bacteria cause degradation of milk products and constitute a significant risk to public health. The objectives of the present study are to determine the microbiological quality of dairy products and to investigate pathogenic microorganisms. A total of 60 samples of raw milk, homemade cheese, and yogurt were randomly selected from different retail marketplaces in Basrah. The bacteriological and biochemical tests were utilized to identify the pathogens in dairy samples, as well as the molecular technique was used as an accurate diagnostic test. The prevalence of contamination of milk products with various isolates was estimated as 50% (95% Cl: 36.8-63.2). The mean of total bacteria count for cheese was 7.29 ± 2.70, raw milk 4.62 ± 2.86, and yogurt 2.87 ± 1.05, with a significant p-value (p = 0.001). The mean count of aerobic spore-forming (ASF) contaminated raw milk was analyzed as 3.77 ± 1.18 and less contamination detected in the yogurt samples with mean of ASF was estimated as 2.52 ± 1.47 SD log 10 CFU/ml. A range of important microorganisms to human health were identified by employing the VITEK_2 system and sequencing 16S rDNA gene, including Staphylococcus aureus, Escherichia coli, Pseudomonas aerogenosa, and Bacillus cereus. The study indicates that there is a high level of bacterial contamination in dairy products with different bacteria species, which is medically important. Therefore, food safety management must be implemented to reduce biological risks carried by dairy products and ensure healthy food for consumers.

Bacterial contamination in neonatal intensive care units in Misurata, Libya: analysis of causative organisms, biofilm formation, and antimicrobial susceptibility

Abstract Background: Intensive care units (ICUs) play a critical role in treating life-threatening conditions. The presence of bacteria on objects and instruments in ICUs is a significant cause of hospital-acquired infections. Aim: This study aimed to assess the level of bacterial contamination on objects and instruments frequently touched by healthcare workers (HCWs) and in contact with neonates. Resistance profile and biofilm producibility were also measured. Methods: A total of 150 swabs were collected from various surfaces in the neonatal intensive care units (NICU) of three hospitals in the city of Misurata, Libya. These samples formed the basis of the study. Standard techniques were used to isolate, identify, and determine biofilm formation ability and antibiotic susceptibility of the bacterial isolates. Results: Out of the 150 samples, bacterial growth was observed in 100. The most commonly isolated potential pathogens were Pseudomonas aeruginosa at a rate of 31.33%, followed by Klebsiella pneumonia (18%), Staphylococcus aureus (9.33%), E. coli (4.66%), and finally Acinetobacter baumanni (3.33%) of the total swabs taken. Bed, ICU floor, doorknob, ICU window, and CPAP were the main sources of bacterial contamination in the ICU unit. Among the S. aureus isolates, 50% (7 out of 14) were found to be methicillin resistant. Most of the bacterial isolates showed resistance to Cefotaxime and Augmentin. The gram-negative bacteria showed high adhesion ability (70.9 %) significantly (P= 0.035) more than S. aureus isolates (35.7%). Conclusion: The study revealed a high level of bacterial contamination on objects and instruments in the NICU. The isolated pathogens like Pseudomonas aeruginosa, Klebsiella pneumonia, S. aureus and Acinetobacter baumanni pose a significant risk of hospital-acquired infections. The extremely high prevalence of beta-lactam antibiotics resistance among isolated bacteria accounts for a great public health danger.

Water Safety Practices Along the Water Service Chain in Addis Ababa: A Cross-Sectional Study in a Cosmopolitan City.

This study investigated water safety practices and risk levels along Addis Ababa's water supply service chain. The data came from 23 random woredas, 384 random households, 115 microbiological water quality tests, and diagnostic inspections from source to point of use. Findings from this study indicate that the surface water sources (53%) and the water source catchments (62%) are characterized by very high-risk and high risk contamination levels respectively. Conversely, the water treatment process (5%) and temporary reservoir (20%) indicates a low risk level. Whereas the water distribution system (40%), water source boreholes (44%), and Household level (29%) water safety practices are identified as medium risk levels. The microbial analysis of the drinking water at the source and point of use indicated low (<11 CFU/100 ml) to high levels (>100 CFU/100 ml) of risk with significant levels of contamination at the household level. Moreover, the household-level water safety practice assessment revealed intermediate to very high levels of risks. The Chi2 test shows that water supply type is significantly associated with occupation(X2(12,384) = 23.44, P < .05) and education(X2(8,384) = 15.4, P < .05). Multinomial regression analysis also showed better occupation is associated with increased access to safe bottled water compared to safe piped water on premises. It can be concluded that the water safety practice encountered low to very high levels of risk of contamination at different components along the water supply service chain and the household level. This study suggests ways to improve Addis Ababa residents' health and well-being through water safety interventions. These include safeguarding water sources, supporting local safe water businesses, providing household water treatment, and handling options, and addressing the barriers and incentives for adopting safe water practices.

Analysis Of Bacterial Contamination By Total Plate Number (ALT) Method In Smoked Fish At One Of The Market Traders

Bacterial contamination can come from the environment as a result of food production processes in the form of biological, chemical and foreign matter contaminants that can interfere with, harm and endanger human health. One of the problems in the processed food sector is the high level of bacterial contamination in the food served on the market. The condition of open food is also the main factor causing food to be contaminated with bacteria. The Total Plate Count (ALT) or total plate count (TPC) is an examination used to determine the number of microorganisms both bacteria and fungi using solid media with the final result being colonies. The aim of the study was to determine bacterial contamination and to determine the total plate number (ALT) of bacterial colonies in smoked fish sold at Ngemplak Market, Tulungagung. This research used a Simple Random Design (RAS) method with four treatments and 3 repetitions. The results showed that for menot fish it was 16.2 x 105 cfu/g, for tuna it was 10.5 x 105 cfu/g, for tuna it was 9.4 x 105 cfu/g, for bader fish it was 16.4 x 105 cfu/g. g, and in whitefish 20.5 x 105 cfu/g. The conclusion is that the bacterial contamination of smoked fish sold at the Ngemplak Market using the ALT method exceeds the normal limit value set by SNI 2725:2013.

Determination of cadmium and copper in the blood of workers in goldsmithing workshops in Najaf Governorate: A field and analytical study

Najaf Governorate in Iraq is considered one of the areas witnessing intense activity in the goldsmithing industry. Pollution with heavy metals such as cadmium and copper is a serious health problem that affects human health and the environment. This research aims to estimate the levels of cadmium and copper contamination in the blood of workers in goldsmithing workshops in Najaf Governorate, especially workers exposed to pollution and smoking factors. The study was carried out by implementing a field and analytical study, which included a sample of 50 smokers in goldsmithing workshops. Blood samples were analyzed to determine the extent of the impact of workshop work on the levels of cadmium and copper contamination in the blood, and evaluated in comparison with previous related studies. The results showed that working in goldsmithing workshops exposes workers to high levels of cadmium and copper contamination, as the levels of cadmium in the blood were (0-1.7) parts per million compared to previous studies, which were (0-0.7) parts per million, and the levels of copper in the blood were (0-1.7) ppm (5-7) ppm compared to previous studies (0-2) ppm. The results indicate the need to take preventive measures and measures to reduce pollution, improve the work environment in goldsmithing workshops, and educate workers about the dangers of heavy metal pollution and its impact on their health. The study period was from October 2022 to April 2023.

Prevalence of Common Microbiological Pathogen Contamination in Processed Milk and Milk Products in Nairobi County, Kenya

Milk has an outstanding nutritional quality but it is also an excellent medium for bacterial growth and an important source of bacterial infection when consumed without pasteurization. This study aimed at establishing the prevalence of Total Viable Count (TVC), Escherichia coli, Staphylococcus aureus and Listeria monocytogenes contamination on processed milk and milk products. The study was carried out in Karen, Kibera and Langata Sub- Counties of Nairobi County which were purposively chosen because they have glaring contrasts in living standards. Samples of fresh milk, yoghurt cheese and ice creams were collected from supermarkets and prepared for analysis of microorganisms. All isolates were characterized and identified based on their morphological and cultural characteristics. TVC were detected in 100% of the samples collected and there was significant statistical variation (P ≤ 0.05) in the contamination level among the products. Of the samples collected in Karen, ice cream had the highest contamination level (3.26 log10 CFU ml-1). Ice cream samples from Langata had the highest TVC contamination levels at 4.35 log10 CFU ml-1. The overall prevalence of E. coli in milk and milk products was 41.6% with a mean count of 0.34 log10 CFU ml-1 in Karen, 0.07 log 10 CFU ml -1 in Kibera and 0.11 log 10 CFU ml -1 in Langata while Staphylococcus aureus was detected in 33.3% of the milk and milk products. The occurrence and detection of E. coli and S. aureus foodborne pathogens in milk and milk products represent a health risk to consumers. Therefore, there is need to improve the microbial quality of milk and milk products by employing measures that will establish proper management practices to ensure improved hygiene, good manufacturing practices and food systems that will help to minimize microbial contamination.

Urban geochemistry of heavy metals in road dust from Cairo megacity, Egypt: enrichment, sources, contamination, and health risks

Traffic emissions, overpopulation, and poor urban planning have degraded the environmental quality of the Greater Cairo megacity. As road dust is considered the main sink of pollutants in urban environments, thirty road dust samples from six major roads were collected. ICP-OES was used to analyze the samples in order to determine the contamination grade using the pollution indices, decipher metal sources and geochemical associations using multivariate analysis, and evaluate the ecological and human health risks. The average contents of heavy metals were arranged in decreasing order: Fe (1181.12), Zn (201.36), Pb (66.10), Ni (32.42), Cu (26.07), Cr (26.00), Co (14.78), As (2.76), and Hg (0.93) mg/kg. The spatial pattern showed that new urban communities exhibited lower contamination levels compared to unplanned old districts, especially for traffic elements (Pb, Zn, and Cu). The highest Igeo mean value was observed for Hg (3.34) followed by Zn (1.34), Pb (1.24), Ni (0.10), As (− 0.19), Co (− 0.24), Cu (− 0.73), and Cr (− 1.05). Additionally, CF values indicated very high contamination levels for Pb and Zn, whereas the highest PLI value was observed at Ramses Street. All EF values were higher than 1.5, indicating the anthropogenic enrichment of metals. RI values classified Cairo as a region with considerable ecological risk, observing that Hg was the main contributor. Correlation analysis and PCA showed that Pb and Zn originated from vehicle exhaust, Hg, Cu, and As from domestic and industrial activities, and Fe and Co from natural origin. Cr and Ni exhibited potential carcinogenic risks for children through ingestion; conversely, the non-carcinogenic risks were within safe levels. As a result, the use of clean energy is recommended to mitigate the accumulation of heavy metals in road dust and to improve the quality of life.

Electrocoagulation Coupled to Electro-Oxidation for the Electrochemical Treatment of Hemodialysis Wastewater

Hemodialysis is an extracorporeal kidney replacement procedure to remove impurities or waste products from the blood used to treat kidney failure. During this process, large amounts of water are used, which, lacking control, end up in sewage systems, potentially flushing high levels of organic and inorganic contaminants into the receiver’s aqua biota. In recent years, a hybrid electrocoagulation (EC) and electro-oxidation (EO) process in sequential or simultaneous coupling has been used for the treatment of wastewater.This research considered synthetic water from hemodialysis under acid and basic conditions. To better simulate the presence of organic compounds, 10 mg L-1 of amoxicillin (AMX), an antibiotic commonly present in wastewater from clinics and hospitals, was added. Laboratory and pilot tests were performed using coupled EC and EO. They used stainless-steel (SS-304) and aluminum (Al-6061) as sacrificial anodes that were compared in acidic and basic pH during EC. The SS-304 rod anode and a titanium (Ti) mesh cathode were used during EC in acidic conditions at a field strength of 3.0 V, which was applied for 60 min. After EC, the solution obtained was filtered to separate precipitates. The supernatant was then treated with EO using an IrO2-Ta2O5|Ti (70:30) anode and the Ti mesh cathode while applying 10 mA for 120 min. The wear of the SS-304 anode was identified by scanning electron microscopy (SEM) and microanalysis (EDS). Removal of organic compounds, including AMX, was significant. This result was confirmed by decreased concentration found by diode coupled chromatography (UPLC-UV-Vis) detection.In conclusion, combining EC and EO in a sequential arrangement for the treatment of hemodialysis wastewater was carried out. EC was performed using a cylindrical SS-304 bar electrode (f = 0.8 cm) as an anode and a concentric Ti mesh as the counter electrode. A 3.0 V cell potential was maintained over one hour of electrolysis in acidic pH (pH = 5.06, s = 227 mS cm-1). This treatment yielded a removal efficiency of 86 ± 1.25 % of AMX contaminate (pH = 8.21, s = 217.26 mS cm-1, i = 11.36 mA, E = 0.568 kWh m-3). After EC, it was necessary to include a filtration or separation process to remove the Fe(OH)3 and [AMX-cation-AMX] sludge generated (2.3 g). This separation employed a settler. Subsequently, the supernatant was placed in an EO cell to remove residual organic compounds as AMX. It used a similar cell arrangement as in EC but changed the anode to IrO2-Ta2O5|Ti (70:30) (f = 0.5 cm) to perform the EO of the pharmaceutical product. During this step, the team achieved an overall removal efficiency of AMX of 100 % (pH = 8.14, s = 179.83 mS cm-1, E = 500 kWh m-3). EO was performed using a continuous 10 mA cell current for 2 h. EO generated reaction products ADP 1, ADP 2, and ADP 3. Additionally, this process decreased the content of ‘salty’ cations: Na+, K+, Ca2+, and Mg2+, while generating Cl2 gas at the electrode.

Quality analysis of groundwater and surface water bodies around the selected brick kilns in Fatehgarh Sahib and Rupnagar Districts in Punjab, India

Brick production is a business that benefits many people, such as providing building materials, employment, and interest to the business owners. However, it has been associated with many adverse impacts various components of ecosystem.Thepresent studyaimed to determine the impact of isolated brick kilns onthe pollution levelof water bodies in Fatehgarh Sahib and Rupnagar Districts of Punjab, India. Physicochemical and microbiological parameters of water were evaluated. The results revealed that the isolated brick kilns partially impacted the water bodies, as the concentration of heavy metals waspresent in surface water near the study area. Parameters such as electrical conductivity (EC), Turbidity, total dissolved solids (TDS), Chloride (Cl), alkalinity and chemical oxygen demand (COD) estimated for surface water samples showed high contamination levels, except for pH, which was acidic (6.2) for surface water. The groundwater was alkaline with pH estimated to be 7.6. The alkalinity and COD levels of groundwater were 693.3 mg/l and 12.4,respectively, as the peak values, and both values were beyond the permissible limits for drinking water. Total coliforms were present in all samples at low health risk (13/15), except two surface water ponds, which showed a health risk. One-third of groundwater was highly contaminated by Escherichia coli, whereas only one of the twelve samples was contaminated withE.coli. The changes of all estimated water parameters in groundwater with distance did not follow any spatial pattern. They could partially be attributed to the lithology of the soil and prominent agricultural activities in the region. The WQI was highly influenced by heavy metals, notably arsenic (As) from both lithologic and brick kilns' origins and lead (Pb) from burning fuels in the brick kilns.

Longitudinal evaluation of environmental contamination with hazardous drugs by surface wipe sampling.

Exposure of healthcare workers to hazardous drugs can lead to adverse health effects supporting the importance of a continuous monitoring program, for example, by taking surface wipe samples. The objective was to describe the results of repeated monitoring of contamination with hazardous drugs on multiple surfaces in a hospital pharmacy and at two wards using standardized preparation techniques and cleaning procedures. Twelve surfaces in the hospital pharmacy and at two wards were sampled and analyzed for contamination with the hazardous drugs cyclophosphamide, doxorubicin, 5-fluorouracil, gemcitabine, methotrexate, and paclitaxel. The drugs were prepared with a closed-system drug transfer device (CSTD). Sampling of the drugs was performed in four trials during eight months. Liquid chromatography tandem mass spectrometry was used for the analysis of the drugs. During the four trials, contamination with five of the six hazardous drugs was found on half of the surfaces in the pharmacy and in a ward. Seventeen out of 288 possible outcomes were positive (6%), with the biological safety cabinet grate (n = 6) and scanner (n = 5) most frequently contaminated. The highest level of contamination was observed on the pass-thru window (cyclophosphamide: 2.90 ng/cm2) and the touch screen of the Diana device (5-fluorouracil: 2.38 ng/cm2). Both levels were below the action level of 10 ng/cm2. The long-term use of a CSTD in combination with appropriate cleaning has proven effective in achieving low levels of surface contamination with hazardous drugs.

Increasing efficiency of irrigation reclamation in potato and soybean agrocenoses using sludge

The purpose of the study was to assess effect of different doses of wastewater sludge on productivity of irrigation water use by agrocenoses of potatoes (Zhukovsky rannii) and soybeans (VNIIOZ 31), on their yield, as well as the index of soil contamination and seed production. Agrometeorological conditions of the periods of vegetation experiments are characterized as dry with hydrothermal coefficient value of no more than 0.39. Considering the current climatic conditions, regulations for watering potatoes and soybeans were drawn up. It was established that application of WWS in doses of 20, 40 and 60 tha-1 had different effects on crops total water consumption. In potato crops, irrigation rate varied from 2590 m3ha-1 in the control to 1850 m3ha-1 in WWS60 variant, and in soybean crops, it varied from 3700 in the control to 2960 m3ha-1 in WWS60 variant. At the same time, amount of irrigation water to obtain a ton of potato and soybean yield in the control averaged 124.5 and 1298.2 m3t-1, respectively, against 118.372.8 and 1213.1886.2 m3t-1 for variants WWS20, WWS40 and WWS60, which corresponded to increase in water use productivity from 5.0 to 41.5 % and from 6.6 to 31.7 %, respectively. Laboratory studies of soil samples of the arable layer showed that pollution index in relation to heavy metals Cd, Pb, Zn, Cu varies from 2.54 in variant WWS20 to 4.04 in variant WWS60, which indicates the absence of soil contamination. Evaluation of potato tubers for values of starch, dry matter, nitrates and heavy metals demonstrates sufficiently high quality and acceptable level of contamination of the seeds.

Microbial Quality Assessment of Fresh Sugarcane Juice in Retail Shops Inside Kathmandu Valley

This study aims to assess the microbial quality of fresh sugarcane juice sold in retail shops inside Kathmandu Valley, as there is limited information available on the safety of popular fresh juices like sugarcane juice, which can cause food-borne illnesses when improperly prepared, despite the known health benefits of consuming fresh fruits juices. Sixty fresh sugar cane juice samples were collected from selected thirteen areas inside Kathmandu Valley. Out of 60 samples, 42 samples were contaminated with bacteria. The quality of each sample was assessed by total plate count, total coliform count, yeast and mold count, and isolation of pathogenic bacteria. The isolated bacteria were identified based on biochemical characteristics. The pH of collected samples ranged from 4.33 to 6.34, acidity from 0.01% to 0.09%, and total soluble solids from 13 to 21⁰Brix. The mean bacterial count was 5.26 log10 CFU/ml, the coliform count was 4.67 log10 CFU/ml, and the yeast mold count was 4.94 log10 CFU/ml. E. coli was present in 38.1%, Citrobacter freundii in 47.6%, and Salmonella species in 14.3% of the total sample. Vibrio cholerae was not detected. Gentamicin, Ciprofloxacin, and Ofloxacin were effective, while Ampicillin was less effective. The study found that sugarcane juice samples from shops in Kathmandu Valley have high levels of contamination, including a high microbial load and slightly acidic pH with high total soluble solid values. The bacterial isolates exhibited varied degrees of antimicrobial susceptibilities and resistances, and the contamination was attributed to poor hygienic conditions during juice processing and handling, possibly due to the use of poor-quality water and a lack of training on food hygiene and safety. These findings suggest potential health hazards for consumers of fresh sugarcane juice.

Perchlorate in honey from China: Levels, pollution characteristics and health risk assessment

The release and accumulation of perchlorate into the environment have raised concerns about safety to food, however, the dietary risk of perchlorate in honey have not yet received attention. Herein, we investigated the pollution characteristics and assessed the human health risks of perchlorate in honey from China. A total of 151 honey samples collected from 20 provinces of China were analyzed, and overall detection frequencies was 95.4 %. The levels of perchlorate ranged from below limit of quantitation to 612 μg/kg, with a mean value of 34.5 μg/kg. Lychee honey samples had the highest mean perchlorate concentration (163 μg/kg). The mean concentration of perchlorate in the honey samples produced in South China was significantly higher than that in honey from Southwest China, East China and North China (P < 0.05). The health risk assessment showed that mean hazard quotient (HQ) values of different honey for children (ranged from 0.0108 to 0.400) and adults (ranged from 0.0123 to 0.453) were less than 1. This result indicated that mean pollution levels of perchlorate in various honey were unlikely to pose health risk. However, perchlorate concentrations in two lychee honey samples had associated HQ values were >1, suggesting potential health risks. This work not only offers valuable information for honey consumer, but also important reference for comparison of honey samples in the future. Environmental implicationPerchlorate contamination has become a hot environmental issue in connection with human health due to its potential thyroid toxicity and widespread occurrence in environment and foods. Honey not only was widely beloved by consumers worldwide but also considered a potential indicator of environmental pollution. Here, a national investigation and risk assessment of perchlorate levels in different types of honey from China was conducted. The results describe the perchlorate contamination were extensive in honey samples, mean levels of perchlorate in various honey were unlikely to cause health risks. However, significantly high level of contamination in lychee honey should be of concern.

Origin, spatial distribution, sediment contamination, ecological and health risk evaluation of trace metals in sediments of ship breaking area of Bangladesh

Eleven trace metals (Cd, Cr, Fe, Mn, Cu, Ni, Co, Zn, As, Pb, and Ag) in sediments of Bangladesh’s ship breaking area were measured by an atomic absorption spectrometer to determine origin, contamination extent, spatial distributions, and associated ecological and human health hazards. This study found considerable quantities of Pb, Cd, Mn, Zn, and Cu when compared with standards and high levels of Pb, Cd, Zn, Cu, As, and Ag contamination according to pollution evaluation indices. Different indices indicate most of the sampling sites were highly polluted. However, spatial distribution maps indicate that trace metals were predominantly deposited in the northern and southern region. The ecological risk index revealed that Cd has the highest while Pb and As had moderate risk. Based on the health index values, Zn for both adults and children were higher than the safe limit while Mn, Pb, Cr, As, Fe, Cu, Ni, and Co for children were close to the threshold. The mean total carcinogenic risk values of Cr, As, and Ni for children and Ni for adults exceeded the permissible threshold. The cancer risk possibilities were further assessed using Monte Carlo simulation. Most trace metals have anthropogenic origins, which were attributed to ship breaking activities.

Association of Exposure to Indoor Air Pollutants and Respiratory Health Symptoms among Photocopy Workers in Bandar Baru Bangi, Selangor

Introduction: Indoor air quality (IAQ) has a significant impact on individual well-being, particularly in photocopy industry workers who are exposed to high levels of contaminants. Improper IAQ is linked to various health issues including respiratory symptoms. This study aimed to determine the association between exposure to indoor air pollutants and respiratory health symptoms among photocopy workers in Bandar Baru Bangi, Selangor. Methods: A cross-sectional comparative study was conducted between exposed and control groups consisted of 76 employees who worked in photocopy premises and 76 employees who worked in offices. A set of questionnaires adapted from the American Thoracic Society was used to collect data on respiratory health symptoms, history of exposure, and socio-demographic background of the employees. Area monitoring was performed using various direct reading devices to measure UFP, PM2.5, PM10, CO, CO2, and TVOCs. Results: In all photocopy centers of exposed group, the mean of PM10 and PM2.5 were at 344.16 µg/m3 and 315.24 µg/m3 (p&lt;0.001), which exceeded the acceptable limit of respirable particulates by ICOP at 150 µg/m3; UFP level at 9068.75 pt/cc (p&lt;0.001); and TVOC at 2.32 ppm (p&lt;0.001), below the limit of 3.0 ppm. High PM10 exposures was reported significantly associated with all respiratory symptoms at p&lt;0.001 (cough OR=3.89 (95% CI=1.00–15.07); phlegm OR=4.82 (95% CI=1.19–14.60); wheezing OR=1.77 (95% CI=1.54–5.79); shortness of breath OR=2.13 (95% CI=0.82–5.55); chest tightness OR=0.37 (95% CI=0.14–0.98)); high PM2.5 exposure was significantly associated with all symptoms except for wheezing (cough at p&lt;0.001, OR=6.71 (95% CI=1.41–32.00; phlegm at p&lt;0.001, OR=5.15 (95% CI=1.41–32.00); shortness of breath at p&lt;0.05, OR=2.13 (95% CI=0.85–5.32); and chest tightness at p&lt;0.05, OR=0.37 (95% CI=0.15–0.95); meanwhile high exposure to UFP had significant relationships with shortness of breath at p&lt;0.001, OR=0.66 (95% CI=0.27–1.64) and chest tightness at p&lt;0.001, OR=1.51 (95% CI=0.61–3.74) among respondents. TVOC also had significant relationships with shortness of breath at p&lt;0.001, OR=1.25, 95% CI=0.47–3.35 and chest tightness at p&lt;0.001, OR=1.04, 95% CI=0.23–1.68. Results also showed that symptoms of cough, phlegm and wheezing were influenced by the PM10 and PM2.5 exposure at 49.4% (Nagelkerke R2= 0.494), 60.1% (Nagelkerke R2= 0.601) and 56.3% (Nagelkerke R2=0.563), respectively. However, there were no significant factors that influenced the symptom of shortness of breath and chest tightness among the respondents. Conclusion: This study concluded that exposure to indoor air pollutants increased the risk of respiratory health symptoms among photocopy workers. This study suggests that regular photocopy machine maintenance and daily workplace housekeeping is required, whereas the photocopy workers should be fully trained in terms of technical, health and safety aspects.

Nationally Representative Trends in Incidence of Procedures Done Concomitantly With Primary and Revision Total Ankle From 2012 to 2020

Background As new literature emerges and practice patterns fluctuate, there is a significant potential for variation with regard to adjunctive procedures performed with primary total ankle arthroplasty (pTAA) and revision total ankle arthroplasty (rTAA). Our study aims to evaluate yearly trends in the incidence of concomitant procedures and compare the incidence of adjunctive procedures between pTAA and rTAA. Methods The 2012-2020 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was queried for all pTAA and rTAA. The number of concurrent procedures was compared between pTAA and rTAA and compared across years available in the most current version of the NSQIP database (2012-2020). Results Patients undergoing pTAA had a higher mean age than patients undergoing rTAA (64 vs 61 years; P &lt; .001), and patients undergoing rTAA had higher wound class (P &lt; .001), indicating higher levels of contamination. Concurrent procedures were performed significantly less frequently with pTAA than rTAA (mean procedures 0.82 vs 1.30; P &lt; .001). Removal of deep implants was more commonly coded with rTAA than pTAA (9.0% vs 17.7%; P &lt; .001). Gastrocnemius recession was more frequently performed with pTAA than rTAA (10.4% vs 3.0%; P = .001). Conclusion As pTAA and rTAA increase in incidence throughout the United States, there is increased importance on furthering our understanding of these procedures. This study provides a nationally representative analysis of adjunctive procedures with pTAA and rTAA from 2012 to 2020. Generally, more adjunctive procedures are performed with rTAA versus pTAA, confirming the high complexity of rTAA. Levels of Evidence: Level III

Biomass-based stochastic model for the transfer of polychlorinated biphenyls in a marine food web

Clarifying the state of marine pollution is important for evaluating the health risk to predators in the marine food web such as fishes and mammals. Although previous studies have generally modeled marine pollution targeting a single organism, this study focused on the transfer of marine pollution in terms of ecological network. In this study, a biomass-based stochastic model was constructed for the transfer of 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB153) in a coupled pelagic–benthic system targeting populations of species. Incorporating the populations of species allows for discussions on predation pressure and anthropogenic activities such as fishing. The biomass parameters representing populations of species were set by using published data on the ecosystem in Tokyo Bay, Japan and were represented by probability density distributions to reflect population uncertainty. The PCB153 concentrations computed by the model were then compared with observations for validation. The results showed that the probability density distributions of PCB153 concentrations in marine species had a long tail to the right, which indicated the occurrence probabilities of individual organisms having considerably high contamination levels. A theoretical analysis was performed to quantify the response of species (e.g., fish, plankton, and benthos) to PCB153 accumulation accounting for population uncertainty, which indicated that a reduction in the population of predator species may contribute to the occurrence of high PCB153 concentrations in individual organisms in other species. The obtained probability density distributions were then used to compare the PCB153 human intake through ingesting seafood with the human's acceptable daily intake. The model can quantitatively demonstrate the probability distributions of PCB153 concentrations in marine species and PCB153 intake by humans through seafood, to which more attention should be paid.

A Comparative Assessment of the Physicochemical and Microbiological Qualities of Some Drinking Water Sources in Diobu, Portharcourt, Nigeria

Diseases caused as a results of drinking contaminated water pose a severe risk to the public's health. In the current study, various drinking water sources in Diobu, Port Harcourt, were evaluated and their microbiological and physicochemical characteristics were compared. Drinking water samples were collected from a borehole and a sachet (packaged) source. Physicochemical and bacteriological investigations were conducted using standard analytical techniques. The results of physiochemical parameters revealed that sachet water samples had higher pH values than borehole water. The borehole water samples had a mean pH of 4.37±1.21 which was much lower than the W.H.O.- recommended range (6.5-8.5). The study’s Total Suspended Solids readings were within the permissible limits of 30.0 mg/l. The borehole samples had the highest concentration of 6.5±4.31mg/l, while the sachet water samples had the lowest concentration of 2.5±1.5 mg/l. Total Dissolved Solids ranged between 15.8±13.5mg/l in sachet water and 55.6±33.4 mg/l in samples from boreholes. The Electrical Conductivity values were recorded as 33.5±28.4 µScm-1 in sachet water and 136.6±73.9 µScm-1 in borehole water. The mean total alkalinity value in sachet water was 0.57±0.29 mg/l whereas in borehole water, it was 3.29±1.39 mg/l. For sachet water and borehole water, the levels of water hardness ranged from 1.95±0.84 mg/l to 10.67±3.21 mg/l, respectively. The range of biological oxygen demand was &lt; 1±0.00 (for sachet water) to 2.13±13 (for borehole water). Dissolved oxygen levels ranged from 1.72±0.70 mg/l in sachet water to 1.95±0.62 mg/l in borehole water. Chemical oxygen demand levels ranged from 2.38±1.18mg/l (Sachet water) to 11.31±9.49 (Borehole water) while Turbidity ranged from &lt;1±0.00 NTU (Sachet water) to 1.1±0.64 NTU (Borehole water). Except for Chemical Oxygen Demand, there was no difference in the values that were observed that was significant at P≥ 0.05 in this study. The mean total bacterial counts ranged from 2.0 x 104 CFU/ml in sachet water to 9.0 x104 CFU/ml in borehole water, demonstrating high levels of contamination in the borehole water from human contamination. Comparatively to the other water sources, sachet water had the lowest overall bacterial and coliform levels. However, because the bacteriological values for total coliform counts was above the WHO threshold of zero per 100 ml, they did not comply with international standards. Salmonella spp., Pseudomonas spp., Staphylococcus spp., and Escherichia coli were the pathogenic bacteria of public health significance that were isolated from the diverse water samples. Five distinct isolates of fungi, including Penicillium spp., Aspergillus niger, Aspergillus flavus, Trichoderma spp., and Mucor spp., were found. In comparison to borehole water, which had the most bacterial pollutants, sachet water tests had the fewest. It is advised that the water sources be treated before being used for any domestic purposes as the water sources in this research area are not suitable for human consumption.

Occurrence of aflatoxigenic fungi and aflatoxins in maize grains and associated awareness and handling practices among farmers and traders in South Sudan

Maize is a popular staple food among the urban population of South Sudan. However, due to inadequate food safety surveillance and enforcement systems, there is limited information on the aflatoxin safety of maize grains at farm and market levels. Therefore, this study aimed at assessing aflatoxins awareness and handling practices of maize grains among randomly selected farmers (n=30) and traders (n=30) as well as determining the moisture content, Aspergillus species counts and aflatoxins contamination. A cross-sectional descriptive study was carried out in Magwi maize producing areas, Juba retail/wholesale markets and Nimule border points of South Sudan. Moisture content, fungal and aflatoxins contamination in maize grain samples were determined using dry air oven method, dilution plating technique, and High-Performance Liquid Chromatography (HPLC), respectively. The respondent results showed that farmers (97%) and traders (83%) were unaware of aflatoxins. About 83% of the farmers dried their maize grains on tarpaulins, for 4 - 5 days (77%). In addition, most farmers (77%) stored their maize grain bags on raised platforms, whereas most traders (73%) stored grains on bare ground. All the maize grains met the required moisture content limit (below 13.5%). Maize from Nimule main park had the highest levels of contamination with Aspergillus flavus (9 log CFU/g), Aspergillus parasiticus (12 log CFU/g), aflatoxin B1 (505.56 µg/kg) and total aflatoxins (1,032.19 µg/kg). Maize from Gudele market was contaminated with Aspergillus parasiticus (12 log CFU/g), and aflatoxin B1 (76.55 µg/kg), and had a total aflatoxin content of 94.09 µg/kg. Omeo farmers’ maize grains had the least levels of contamination of Aspergillus parasiticus (6 log CFU/g), aflatoxin B1 (4.39 µg/kg), and total aflatoxins (7.83 µg/kg). In addition, Aspergillus flavus was not detected from Omeo farmers’ maize grains and no aflatoxins were detected from Agoro and Paluonganyi farmers’ grains. This study recommends wider aflatoxins awareness and regular aflatoxin screening of maize grains by the relevant stakeholders in South Sudan. Key words: aflatoxins, aflatoxigenic fungi, awareness, farmers, handling practices, maize, South Sudan, traders