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The Science of the Total Environment Sep 2023Considering the significance of PM aerosol in assessing health impacts of air pollution, an extensive analysis of PM samples collected at an urban site in Delhi is...
Considering the significance of PM aerosol in assessing health impacts of air pollution, an extensive analysis of PM samples collected at an urban site in Delhi is presented in this study. Overall, PM contributed to about 50 % of PM mass which is alarming especially in Delhi where particle mass loadings are usually higher than prescribed limits. Major portion of PM consisted of organic matter (OM) that formed nearly 47 % of PM mass. Elemental carbon (EC) contributed to about 13 % of PM mass, whereas SO (16 %), NH (10 %), NO (4 %) and Cl (3 %) were the major inorganic ions present. Sampling was performed in two distinctive campaign periods (in terms of meteorological conditions and heating (fire) activities), during the year 2019, each spanning two-week time, i.e. (i) September 3-16 (clean days), and (ii) November 22-December 5 (polluted days). Additionally, PM and black carbon (BC) were measured simultaneously for subsequent analysis. The 24-h averaged mean concentrations of PM and BC during clean days (polluted days) were 70.6 ± 26.9 and 3.9 ± 1.0 μg m (196 ± 104 and 7.6 ± 4.1 μg m), respectively, which were systematically lower (higher) than that of the annual mean (taken from studies conducted at same site in 2019) of 142 and 5.7 μg m, respectively. Changes in characteristic ratios (i.e., organic carbon (OC)/elemental carbon (EC) and K/EC) of chemical species detected in PM show an increase in biomass emissions during polluted days. Increase in biomass emission can be attributed to increase in heating practices (burning of biofuels such as wood logs, straw, and cow-dung cake) in- and around- Delhi because of fall in temperature during second campaign. Furthermore, a significant increase in NO fraction of PM is observed during second campaign which shows fog processing of NO due to conducive meteorological conditions in winters. Also, comparatively stronger correlation of NO with K during second campaign (r = 0.98 as compared to r = 0.5 during first campaign) suggests the increased heating practices to be a contributing factor for increased fraction of NO in PM. We observed that during polluted days, meteorological parameters such as dispersion rate also played a major role in intensifying the impact of increased local emissions due to heating activities. Apart from this, change in the direction of regional emission transport to study site and the topology of Delhi are the possible reasons for the elevated pollution level, especially PM during winter in Delhi. This study also suggests that black carbon measurement techniques used in current study (optical absorbance with heated inlet and evolved carbon techniques) can be used as reference techniques to determine the site-specific calibration constant of optical photometers for urban aerosol.
Topics: Particulate Matter; Air Pollutants; Environmental Monitoring; Seasons; Aerosols; Carbon; Soot; India
PubMed: 37225098
DOI: 10.1016/j.scitotenv.2023.164266 -
Journal of Contaminant Hydrology May 2023Seawater intrusion has become a common problem in coastal and island aquifers with the rise in climate change that greatly affects the majority of developing countries....
Seawater intrusion has become a common problem in coastal and island aquifers with the rise in climate change that greatly affects the majority of developing countries. The island hydrology is very complex and associated with a unique set of environmental characteristics with the dynamic interaction of groundwater, surface water, and seawater. Further, Sea level rise, erratic rainfall, and over-extraction of groundwater triggered salt-water intrusion. A study on seawater intrusion and the effect of limestone caves on groundwater was carried out in middle Andaman using a combination of ionic ratios of major ions. A total of 24 samples and a reference sample from the sea were collected and analysed using ICP, spectrophotometer, and flame photometer. A combination of 10 ionic ratios Cl/HCO, Ca/(HCO + SO), (Ca + Mg)/Cl, Ca/Mg, Ca/Na, Cl/(SO + HCO), Ca/SO, K/Cl, Mg/Cl, and SO/Cl was used to assess the dissolution of limestone minerals and the level of saltwater intrusion into groundwater. The geospatial method was used to extract and combine all the hydrogeochemical parameters and ionic ratios in the GIS platform. Durov plot was used for the interpretation of groundwater chemistry and the identification of natural processes controlling the hydrogeochemistry of the area. The dominance of Ca-HCO and Na-HCO was confirmed in 48% and 24% of the sample respectively. The equiline graph of chloride with other major ions showed the enrichment of alkali and alkaline earth metal salt in groundwater. Schoeller's diagram depicted the dominance of Cl, Ca, and the sum of CO and HCO in seawater near Mayabunder. The lower concentration of Na with respect to Cl (64%) and Ca (100%) showed the presence of a reverse ion exchange process. Further, the correlation matrix showed a strong relationship between Cl, K, Ca, and Na. The analysis of X-ray diffraction of the rock samples confirmed the presence of limestones such as Aragonite, Calcite, Chlorite, Chromite, Dolomite, Magnetite, and Pyrite in the study area. The integration of ionic ratios showed moderately affected and slightly affected saline regions in 44% and 54% of the region respectively. Finally, the role of tectonic activities and active lineaments connected to the sea was found to play a major role in the intrusion of seawater where interconnected faults created an opening for surface water to recharge groundwater leading to the deep aquifer.
Topics: Environmental Monitoring; Caves; Water Pollutants, Chemical; Calcium Carbonate; Seawater; Groundwater; Water
PubMed: 37178540
DOI: 10.1016/j.jconhyd.2023.104197 -
RSC Advances Apr 2023The demand for the development of portable and low-cost analytical devices has encouraged studies employing additive manufacturing techniques, such as 3D-printing. This...
The demand for the development of portable and low-cost analytical devices has encouraged studies employing additive manufacturing techniques, such as 3D-printing. This method can be used to produce components such as printed electrodes, photometers, and fluorometers for low-cost systems that provide advantages including low sample volume, reduced chemical waste, and easy coupling with LED-based optics and other instrumental devices. In the present work, a modular 3D-printed fluorometer/photometer was designed and applied for the determination of caffeine (CAF), ciprofloxacin (CIP), and Fe(ii) in pharmaceutical samples. All the plastic parts were printed separately by a 3D printer, using Tritan as the plastic material (black color). The final size of the modular 3D-printed device was 12 × 8 cm. The radiation sources were light-emitting diodes (LEDs), while a light dependent resistor (LDR) was used as a photodetector. The analytical curves obtained for the device were: = 3.00 × 10 [CAF] + 1.00 and = 0.987 for caffeine; = 6.90 × 10 [CIP] - 3.39 × 10 and = 0.991 for ciprofloxacin; and = 1.12 × 10 [Fe(ii)] + 1.26 × 10 and = 0.998 for iron(ii). The results obtained using the developed device were compared with reference methods, with no statistically significant differences observed. The 3D-printed device was composed of moveable parts, providing flexibility for adaptation and application as a photometer or fluorometer, by only switching the photodetector position. The LED could also be easily switched, permitting application of the device for different purposes. The cost of the device, including the printing and electronic components, was lower than US$10. The use of 3D-printing enables the development of portable instruments for use in remote locations with a lack of research resources.
PubMed: 37077256
DOI: 10.1039/d3ra01281f -
Scientific Reports Apr 2023This paper reports on developing a low cost but efficient paired emitter-detector diode (PEDD)-based photometer. The photometer consists of a white light-emitting diode...
This paper reports on developing a low cost but efficient paired emitter-detector diode (PEDD)-based photometer. The photometer consists of a white light-emitting diode (LED) as the emitter diode, an RGB LED as the detector diode, and a multimeter for recoding the signal. The developed PEDD-based photometer was utilized for the determination of liquid bleach adulteration in cow milk samples. N,N-Diethyl-p-phenylenediamine sulfate aqueous solution of pH 6 was used as a probe to monitor the presence of residual active chlorine in milk. The results showed that the developed method could be used to determine sodium hypochlorite in the concentration range of 0.5 to 20.0 ppm Cl with 0.14 and 0.46 ppm Cl limit of detection and limit of quantification, respectively. The intraday and interday precisions of the method at two concentration levels of 5.5 and 13.7 ppm Cl were 1.04% and 0.52%, and 1.81% and 1.02%, respectively. The recoveries of 114.2% and 106.9% were obtained for 5.5 and 13.7 ppm Cl concentrations levels, respectively. Real sample analyzes results showed that "maybe" liquid bleach adulteration in milk is the case for local distributors of raw milk.
Topics: Animals; Milk; Sodium Hypochlorite; Photometry
PubMed: 37069217
DOI: 10.1038/s41598-023-33527-y -
The Science of the Total Environment Jun 2023In this study, field measurement was conducted using an integrated online monitoring system to characterize heterogeneous properties and light absorption of refractory...
In this study, field measurement was conducted using an integrated online monitoring system to characterize heterogeneous properties and light absorption of refractory black carbon (rBC). rBC particles are mainly from the incomplete combustion of carbonaceous fuels. With the data collected from a single particle soot photometer, thickly coated (BC) and thinly coated (BC) particles are characterized with their lag times. With different responses to the precipitation, a dramatical decline of 83 % in the number concentration of BC is shown after rainfall, while that of BC decreases by 39 %. There is a contrast in core size distribution that BC is always with larger particle sizes but has smaller core mass median diameters (MMD) than BC. The mean rBC-containing particle mass absorption cross-section (MAC) is 6.70 ± 1.52 m g, while the corresponding rBC core is 4.90 ± 1.02 m g. Interestingly, there are wide variations in the core MAC values which range by 57 % from 3.79 to 5.95 m g, which are also closely related to those of the whole rBC-containing particles with a Pearson correlation of 0.58 (p < 0.01). Errors would be made if we eliminate the discrepancies and set the core MAC as a constant when calculating absorption enhancement (E). In this study, the mean E is 1.37 ± 0.11 while the source apportionment shows that there are five contributors of E including secondary aging (37 %), coal combustion (26 %), fugitive dust (15 %), biomass burning (13 %) and traffic-related emissions (9 %). Secondary aging is found to be the highest contributor due to the liquid phase reactions in formations of secondary inorganic aerosol. Our study characterizes property diversities and provides insights into the sources impacting the light absorption of rBC and will be helpful for controlling it in the future.
PubMed: 36966831
DOI: 10.1016/j.scitotenv.2023.162997 -
African Journal of Laboratory Medicine 2023Haemolysis - one of the major limiting factors of red cell concentrate quality - must be measured as a quality-monitoring requirement. According to international quality...
BACKGROUND
Haemolysis - one of the major limiting factors of red cell concentrate quality - must be measured as a quality-monitoring requirement. According to international quality standards, percentage haemolysis must be monitored in 1.0% of red cell concentrates produced monthly and maintained under 0.8%.
OBJECTIVE
This study assessed three alternative methods for determining plasma haemoglobin concentration in peripheral blood banks that lack a plasma or low haemoglobin photometer - the gold-standard method - in Sri Lanka.
METHODS
A standard haemolysate was prepared using an unexpired whole blood pack of normal haemoglobin concentration. A concentration series from 0.1 g/dL to 1.0 g/dL was prepared by diluting portions of standard haemolysate with saline. The alternative methods, namely visual haemoglobin colour scale, spectrophotometric calibration graph, and standard haemolysate capillary tube comparison, were designed using this concentration series and were used to test red cell concentrates received at the Quality Control Department of the National Blood Center, Sri Lanka, from February 2021 to May 2021.
RESULTS
A strong correlation was observed between the haemoglobin photometer method and the alternative methods ( = ~0.9). Based on the linear regression model, the standard haemolysate capillary tube comparison method was the best of the three alternative methods ( = 0.974).
CONCLUSION
All three alternative methods are recommended for use in peripheral blood banks. The standard haemolysate capillary tube comparison method was the best model.
PubMed: 36873291
DOI: 10.4102/ajlm.v12i1.1987 -
Optics Express Feb 2023In order to increase the optical path and related sensitivity of photometers, multiple axial-reflection of parallel light-beam inside a capillary cavity is one of the...
In order to increase the optical path and related sensitivity of photometers, multiple axial-reflection of parallel light-beam inside a capillary cavity is one of the most effective ways. However, there is a non-optimum trade-off between optical path and light intensity, e.g., smaller aperture on cavity mirror can increase multiple axial-reflection times (i.e., longer optical path) due to the lower cavity-loss, but it would also reduce coupling efficiency, light intensity, and related signal-to-noise ratio. Herein, an optical beam shaper, which is composed of two optical lenses with an apertured mirror, was proposed to focus the light beam (i.e., increasing coupling efficiency) without deteriorating beam parallelism and related multiple axial-reflection. Thus, by combining the optical beam shaper with a capillary cavity, large optical path enhancement (10-fold of capillary length) and high coupling efficiency (>65%) can be realized simultaneously, where the coupling efficiency was improved 50-fold. An optical beam shaper photometer (with a 7 cm long capillary) was fabricated and applied to detect water in ethanol with a detection limit of 12.5 ppm, which is 800-fold and 32∼80 fold lower than that of the commercial spectrometer (1 cm cuvette) and previous reports, respectively.
PubMed: 36859917
DOI: 10.1364/OE.478937 -
Optics Express Feb 2023Aerosol microphysical properties, such as volume concentration (VC) and effective radius (ER), are of great importance to evaluate their radiative forcing and impacts on...
Aerosol microphysical properties, such as volume concentration (VC) and effective radius (ER), are of great importance to evaluate their radiative forcing and impacts on climate change. However, range-resolved aerosol VC and ER still cannot be obtained by remote sensing currently except for the column-integrated one from sun-photometer observation. In this study, a retrieval method of range-resolved aerosol VC and ER is firstly proposed based on the partial least squares regression (PLSR) and deep neural networks (DNN), combining polarization lidar and collocated AERONET (AErosol RObotic NETwork) sun-photometer observations. The results show that the measurement of widely-used polarization lidar can be reasonably used to derive the aerosol VC and ER, with the determination coefficient (R) of 0.89 (0.77) for VC (ER) by use of the DNN method. Moreover, it is proven that the lidar-based height-resolved VC and ER at near-surface are well consistent with independent observations of collocated Aerodynamic Particle Sizer (APS). Additionally, we found that there are significant diurnal and seasonal variations of aerosol VC and ER in the atmosphere at Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL). Compared with columnar ones from the sun-photometer observation, this study provides a reliable and practical way to obtain full-day range-resolved aerosol VC and ER from widely-used polarization lidar observation, even under cloud conditions. Moreover, this study also can be applied to long-term observations by current ground-based lidar networks and spaceborne CALIPSO lidar, aiming to further evaluate aerosol climatic effects more accurately.
PubMed: 36859889
DOI: 10.1364/OE.481252 -
Pediatric Health, Medicine and... 2023The most important anemia next to iron deficiency is anemia of inflammation. Micronutrient deficits, such as those in zinc and iron, can be caused by intestinal...
BACKGROUND
The most important anemia next to iron deficiency is anemia of inflammation. Micronutrient deficits, such as those in zinc and iron, can be caused by intestinal permeability and gut inflammation brought on by environmental enteric dysfunction. This study was aimed to evaluate the prevalence and association of anemia with Environmental Enteropathy.
METHODS
Data on water sanitation and hygiene indicators and sociodemographic characteristics were collected using structured questionnaire. The lactulose to mannitol ratio (L:M) was calculated from the concentration of both sugars in the urine. Level of Hemoglobin was detected by using Hemocue-301 digital photometer. Blood and urine sample was collected from three hundred children aged 12-59 months to determine the status of Anaemia and Environmental Enteropathy respectively.
RESULTS
Data were analyzed by using Descriptive statistics, cross-tabulation, and logistic regression model to indicate prevalence and association of anemia with environmental Enteropathy in children less than five years old. The prevalence of anemia in children with environmental enteropathy was 63.8% (95% CI: 57.6, 71.7), and there was a significant association (p = 0.0001, AOR 3.502, 95% CI: 1.929-6.371) between anemia and environmental enteropathy. In a multivariate analysis, children aged 1-3 years with caretakers who had no or only primary education and with monthly income of less than 3000 ETB were more likely to develop anemia.
CONCLUSION
The result of this study indicated that two-thirds of children less than five with environmental enteropathy had developed anemia, and there is a significant association between environmental enteropathy and anemia. Even though there are other causes of anemia, based on the findings of this study, more research is needed to identify factors associated with environmental enteropathy to mitigate anemia due to intestinal permeability or malabsorption and its impact in children under the age of five.
PubMed: 36798588
DOI: 10.2147/PHMT.S387747 -
Orthopaedic Surgery Apr 2023Leucocyte esterase (LE) strip test is the most rapid, convenient, and cheap method to diagnose chronic periprosthesis joint infection (PJI). However, the determination...
OBJECTIVE
Leucocyte esterase (LE) strip test is the most rapid, convenient, and cheap method to diagnose chronic periprosthesis joint infection (PJI). However, the determination of LE strip mainly relies on colorimetric method with strong subjectivity, which leads to low diagnostic accuracy. Therefore, we try to convert LE strip images into digital data through the RGB photometric system to achieve objective diagnosis. This method will greatly improve the accuracy of LE strip detection and diagnosis of PJI.
METHODS
From January 2021 to September 2021, 46 patients with suspected PJI after total hip and knee arthroplasty underwent diagnostic joint puncture. After effective joint fluid samples were harvested, they were divided into original fluid and centrifuged fluid for LE strip detection. Real-time images of LE strip were taken at 90 s, 3 min, 5 min, 10 min, and 15 min after sampling, and their brightness (Y) was obtained after they were input into an RGB photometric system. Grouping was based on centrifugation, infection, and time points, and then the differences in brightness among groups were compared. The correlation between LE strip image brightness and WBC count was evaluated. Student t-test was used for the parametric data and chi-square test for qualitative data. Simple linear regression was utilized to analyze the correlation between brightness and WBC count in each group.
RESULTS
Included were 19 cases of PJI and 27 Non-PJI subjects diagnosed against ICM2018 diagnostic criteria. The brightness was lower in the PJI group than in Non-PJI group (p < 0.05). The brightness of the uncentrifuged group was lower than that of the centrifuged group (p < 0.05). Irrespective of centrifugation or infection, the brightness of LE strip decreased with the exposure time after sampling. The brightness of LE strip was correlated with WBC count at different time points, with the correlation being strongest 5 min after sampling (R (5 min) = 0.86, p < 0.0001). The correlation between LE strip brightness and WBC count was also found in the centrifugation group, with the correlation being most robust 15 min after sampling (R (15 min) = 0.73, p < 0.0001).
CONCLUSION
A remarkable correlation was found between LE strip brightness and the WBC count. It is feasible to directly quantify LE strip image on a RGB photometer to achieve quantitative detection of LE strip to diagnose PJI.
Topics: Humans; Prosthesis-Related Infections; Synovial Fluid; Arthroplasty, Replacement, Knee; Carboxylic Ester Hydrolases; Arthritis, Infectious; Biomarkers; Sensitivity and Specificity
PubMed: 36782275
DOI: 10.1111/os.13667