Average Concentration Research Articles

Heavy metal contamination in soil and food crops and associated human health risks in the vicinity of Iringa Municipal dumpsite, Tanzania

Heavy metal contamination and potential risks to human health related to consuming major food crops near Iringa Municipal dumpsite are presented. Soil samples, maize (Zea mays L.) and common beans (Phaseolus vulgaris L.) were collected downslope around the dumpsite during wet season. Soil samples were analyzed using Energy-Dispersive X-Ray Fluorescence (EDXRF) while crop (maize and beans) samples were analyzed using Flame Atomic Absorption Spectrophotometer (FAAS). The potential health risks associated with human exposure to heavy metals in maize and common beans was evaluated according to the method prescribed by the United States Environmental Protection Agency. The concentrations Cd (3.25–10.78 mg/kg), As (1.84–10.98 mg/kg) and Ni (71.74–55.10 mg/kg) in soil samples exceed the maximum allowable limits set by Tanzania Bureau of Standards (TBS). The average heavy metal concentration in food crops followed the trend Cd, As < Cr, Pb < Ni < Cu < Mn < Zn with Pb in maize (0.96 mg/kg) and common beans (0.81 mg/kg) above FAO/WHO regulatory standards of 0.3 mg/kg. This implied health concerns to consuming food crops grown in the vicinity of the dumpsite. Further, lifetime–incremental cancer risk (ILCR) assessment suggest that consuming maize and common beans from the study area could increase the risk of both cancer and non-cancerous diseases in both adults and children. However, the degree of ILCR in children was noticeably higher (1.0 × 10–2) than in adults (5.10. × 10–6) for Pb in common beans. Therefore sustainable waste management should be stressed and continuous monitoring of environments around dumpsites is crucial to mitigate the negative impacts on public and environments.

Metal contamination of the surface water and its effect on the higher gastric cancer incidence of Lujiang County, China

Metal contamination in surface water is one of the major environmental risk factors contributing to the incidence and mortality of gastric cancer (GC) in rural China. In this study, the generalized additive model (GAM) was used to explore the single and interactive effects of metal elements in surface water on GC incidence on the watershed scale in Lujiang County, east of China. Spatially, the areas with a high incidence of GC were concentrated in the northwest watershed where the drainage system was relatively developed. Apart from Sr, the average concentrations of Al, As, Be, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sn, and Zn in the northern watershed were higher than those in the southern watershed. Among them, the average concentrations of Be (0.036 mg/L), Fe (1.539 mg/L), Mn (0.355 mg/L), and Ni (0.040 mg/L) well exceeded China’s Grade III water quality standards. On the sub-watershed scale Be (F(5.130)), Pb (F(4.963)), As (F(3.508)), Cu (F(3.023)), Zn (F(2.922)), Cr (F(2.725)), Sn (F(2.588)), and Co (F(2.140)) in surface water were the main elements contributing to the high incidence of GC in Lujiang County, and the interaction effect mostly showed nonlinear enhancement. Especially, the nonlinear enhancement effect of Be with Cu (F(7.051)), Co (F(5.798)), Sn (F(5.328)), and Pb (F(5.193)) was more significant and had a greater effect on the incidence of GC. This study provides compelling direct evidence on the effects of metal contamination in surface water on the higher GC incidence in Lujiang County, China. It is recommended that there be routine monitoring of metal concentrations in surface water resources.

Soil heavy metals contamination and health risk of an endemic plant in southeast of Damavand Mt., Iran

Considering the toxicological effects of some heavy metals (HMs) in which directly related to mortality and carcinogenicity in the population by their entrance from plants through livestock grazing, and medical skin cream, the rehabilitation of contaminated sites through phytoremediation by native plants might be quite challenging. Diplotaenia damavandica Mozaff. ex-Hedge & Lamond, is used as medical skin creams due to the existence of specific ingredients, which can be effective in treating skin disease. In the present study, the plant and associated soil sampling were performed around the boundary of D. damavandica. The concentration was measured using the Inductively coupled plasma mass spectrometry (ICP-MS). The results revealed the effect of existing endemic plants on reducing the average concentration of lead and zinc in soil by 40 and 60%, respectively, due to phytoremediation. EDX confirmed the presence of Pb and Zn in root and shoot tissues. Based on the results of this study, D. damavandica is an endemic perennial herbaceous plant with 60% biomass and prosperous root systems, which can grow in low contaminated areas of Pb in the southeast of Damavand Mt. Hence, the HMs pattern indicated less often in the aerial parts except for lead, which should be examined more carefully for skin cream uses.

Seasonal and spatial variations in concentration, diversity, and antibiotic resistance of ambient bioaerosols in an arid region

The airborne microbiome significantly influences human health and atmospheric processes within Earth's troposphere and is a crucial focus for scientific research. This study aimed to analyze the composition, diversity, distribution, and spatiotemporal characteristics of airborne microbes in Qatar's ambient air. Air samples were collected using a sampler from ten geographically or functionally distinct locations during a period of one year. Spatial and seasonal variations significantly impacted microbial concentrations, with the highest average concentrations observed at 514 ± 77 CFU/m3 for bacteria over the dry-hot summer season and 134 ± 31 CFU/m3 for fungi over the mild winter season. Bacterial concentrations were notably high in 80% of the locations during the dry-hot summer sampling period, while fungal concentrations peaked in 70% of the locations during winter. The microbial diversity analysis revealed several health-significant bacteria including the genera Chryseobacterium, Pseudomonas, Pantoea, Proteus, Myroides, Yersinia, Pasteurella, Ochrobactrum, Vibrio, and fungal strains relating to the genera Aspergillus, Rhizopus Fusarium, and Penicillium. Detailed biochemical and microscopic analyses were employed to identify culturable species. The strongest antibiotic resistance (ABR) was observed during the humid-hot summer season, with widespread resistance to Metronidazole. Health risk assessments based on these findings indicated potential risks associated with exposure to high concentrations of specific bioaerosols. This study provides essential baseline data on the natural background concentrations of bioaerosols in Qatar, offering insights for air quality assessments and forming a basis for public health policy recommendations, particularly in arid regions.

Aflatoxins in dried chilli products in Gansu Province and health risk.

In order to understand the status of aflatoxin contamination in dried chilli products in Gansu Province and the risk of dietary exposure, a total of 106 samples of dried chilli products from farmers' markets and supermarkets in 14 prefecture-cities of Gansu Province were collected and analysed by isotope dilution liquid chromatography-tandem mass spectrometry. The results showed that the detection rate of aflatoxin in dried chilli products in Gansu Province was 30.2%, and the average level was 1.57 μg/kg. The detection rates of dried chillies, paprika, and chilli powders were 16.7%, 43.6%, and 46.2%, respectively. The detection rates of aflatoxin in dried chilli products from shops and farmers' markets were 22.5% and 40.0%, respectively. The dietary exposure of AFB1 was 0.0001 μg/kg bw/day, and the MOE calculated from its average concentration was 305.

Spatio-temporal trends in microplastic presence in the sediments of the River Thames catchment (UK)

This study investigated the spatio-temporal variability of microplastics (MPs) in the sediments of the River Thames (UK) catchment over 30 months (July 2019 – Dec 2021). The average MP concentration was 61 items kg−1 d.w., with fragments <1 mm being dominant and polyethylene (PE) the most common polymer. Adjacent land use influenced MP concentrations and types, with industrial sites showing particularly high levels and a prevalence of small beads and industrial polymers. MP concentrations generally decreased after higher winter flows, likely due to sediment rearrangement or winnowing. This study describes the seasonal concentrations and characteristics of MPs present in sediment from the River Thames catchment, and attempts to identify their likely origin. Further, the study provides new insights into the mobility and fate of MPs in riverine settings under varying flow conditions, which is vital given the predicted increases in flooding under various global heating scenarios.

Innovative pressurized diesel reforming for sustainable hydrogen production using advanced PtRu-CGO catalyst

This study suggests a novel approach for producing hydrogen through the pressurized reforming of commercial diesel, leveraging the PtRu-CGO catalyst. Foundational experiments were performed with PtRu-CGO powder catalysts at conditions up to 9 bar and 800 °C, achieving complete fuel conversion and stable performance with an average hydrogen concentration of approximately 58.7 mol%. Additionally, the structured catalysts developed herein also could maintain high efficiency and durability under a gas hourly space velocity (GHSV) of 10,000 h−1. Notably, at 6 bar, the system exhibited an extraordinary efficiency of around 75 % over 300 h of continuous operation. These results underscore the practicality of pressurized diesel reforming for hydrogen production with the PtRu-CGO catalyst, highlighting its potential in the development and optimization of hydrogen energy systems and aiding the shift towards a hydrogen-based economy.

Higher Seed Rates Enlarge the Effects of Wide-Belt Sowing on Root Length Density, Thereby Improving Nitrogen Uptake and Use Efficiencies in Winter Wheat.

The optimized sowing method and appropriate seed rate can improve wheat N use efficiency. However, the interactive effect of the sowing method and seed rate on N use efficiency, particularly N uptake and root length density, are unclear. A field experiment was conducted for two growing seasons in southern Shanxi province, China, using a split-plot design with the sowing method as the main plot (wide-belt sowing, WBS, and conventional narrow-drill sowing, NDS) and seed rate as the sub-plot (100-700 m-2). Our results showed that WBS had a significant and positive effect on N use efficiency (yield per unit of available N from the fertilizer and soil, by 4.7-15.4%), and the relatively higher seed rates (>300 or 400 m-2) enlarged the effects. The N use efficiency increases under WBS were mainly attributed to the increases in N uptake before anthesis, resulting from the promoted nodal roots per plant and per unit area, and root length density in the top layer(s). WBS promoted N translocation and the N harvest index, resulting in equivalent grain protein concentration and processing quality compared to NDS. Thus, adopting higher seed rates (>300 m-2) combined with WBS is recommended for achieving greater N efficiencies while maintaining the grain protein concentration and processing quality of winter wheat.

Distribution characteristics, sources and risk assessment of heavy metals in the surface sediments from the largest tributary of the Lancang River in the Tibet Plateau, China.

Angqu, positioned in the eastern expanse of the Tibet Plateau, claims the title of the largest tributary to the Lancang River. In October and December of 2018, in the sediment of Angqu, a comprehensive investigation was conducted on nine heavy metals-arsenic (As), manganese (Mn), chromium (Cr), cadmium (Cd), lead (Pb), mercury (Hg), copper (Cu), zinc (Zn), and nickel (Ni). This investigation aimed to scrutinize the spatial and temporal distribution patterns of these metals, assess the pollution status and ecological risks associated with the sediments, and delve into the sources contributing to their presence. The research results indicate that the average concentrations of As, Hg, and Cd in Angqu sediments exceed the soil background values of Tibet, while the concentrations of other heavy metals are below the soil background values of Tibet. Notably, arsenic poses potential ecological risks. In Angqu sediments, the concentrations of Mn, Cu, Ni, and Pb are generally higher in the wet season, but the seasonal variations of heavy metals in Angqu sediments are not significant. The sediments in the Angqu Basin are predominantly affected by mercury Hg, Cd, and As, with varying degrees of pollution at different sampling points. In the main stream of Angqu (City section), Hg pollution has reached above a moderate level, whereas As pollution near the tributary is only slightly polluted. The analysis of heavy metal sources reveals that there are five primary contributors to heavy metals in surface sediments of Angqu: parent material, agricultural activities, groundwater, atmospheric deposition, and other unidentified sources. Mn, Cr, Pb, and Ni are mainly derived from soil parent material, accounting for more than 50%. About 60.82% of As comes primarily from groundwater. Zn and Cd are mainly sourced from agricultural activities, accounting for 41.25% and 34.33%, respectively. Additionally, 20.6% of Hg originates from atmospheric deposition.

Comprehensive performance evaluation of HVAC systems integrated with direct air capture of CO2 in various climate zones

Direct Air Capture (DAC) is a rapidly evolving technology that extracts CO2 directly from ambient air. This study presents a comprehensive performance evaluation of integrating DAC in HVAC systems, which can reduce indoor CO2 concentration and improve energy efficiency of HVAC systems. The DAC equipment is modeled in Modelica based on isotherm and thermodynamic equations, and pressure drop curves of the CO2 sorbent described in literature. The model is validated with data from the literature, and then integrated into a typical HVAC system available in Modelica Buildings library. The HVAC system is a Variable Air Volume (VAV) with reheater system for a one-floor office building with standard ASHRAE 2006 control sequences. Demand control ventilation strategies are designed to reduce the outdoor air flowrates when indoor CO2 concentrations are lower than the threshold, which is to maximize the benefits of integrating DAC. Four cases are proposed to assess the impacts of integrating DAC and DCV in HVAC systems in 8 different ASHRAE climate zones in the USA. The results show that by integrating DAC unit into the HVAC system, the average indoor CO2 concentration can be significantly reduced by over 45 % against the baseline without a DAC unit. By integrating DCV, 0.39–21.66 % of annual energy savings and 226–9539 kg carbon emissions reduction are observed across different climate zones. The highest energy savings are found to be achieved with cold climatic conditions while the lowest energy savings occur with favorable weather.

Phosphorus removal in surface flow treatment wetlands for domestic wastewater treatment: Global experiences, opportunities, and challenges

Treatment Wetlands (TWs) are widely used for the treatment of domestic wastewater, with an increasing emphasis on provision of multiple co-benefits. However, concerns remain regarding achieving stringent phosphorus (P) discharge limits, system robustness and resilience, and associated guidance on system design and operation. Typically, where P removal is intended with a passive TW, surface flow (SF) systems are the chosen design type. This study analysed long-term monitoring datasets (2–30 years) from 85 full-scale SF TWs (25 m2 to 487 ha) treating domestic sewage with the influent load ranging from 2.17 to 54,779 m3/d, including secondary treatment, tertiary treatment, and combined sewer overflows treatment. The results showed median percentage removals of total P (TP) and orthophosphate (Ortho P) of 28% and 31%, respectively. Additionally, median areal mass removal rates were 5.13 and 2.87 gP/m2/yr, respectively. For tertiary SF TWs without targeted upstream P removal, 80% of the 44 systems achieved ≤3 mg/L annual average effluent total P. Tertiary SF TWs with targeted upstream P removal demonstrated high robustness, delivering stable effluent TP < 0.35 mg/L. Seasonality in removal achieved was absent from 85% of sites, with 95% of all systems demonstrating stable annual average effluent TP concentrations for up to a 30-year period. Only two out of 32 systems showed a significant increase in effluent TP concentration after the initial year and remained stable thereafter. The impact of different liner types on water infiltration, cost, and carbon footprint were analysed to quantify the impact of these commonly cited barriers to implementation of SF TW for P removal. The use of PVC enclosed between geotextile gave the lowest additional cost and carbon footprint associated with lining SF TWs. Whilst the P-k-C* model is considered the best practice for sizing SF TWs to achieve design pollutant reductions, it should be used with caution with further studies needed to more comprehensively understand the key design parameters and relationships that determine P removal performance in order to reliably predict effluent quality.

Characterization, formation mechanism, and human health risk assessment of fluoride in shallow groundwater of Suzhou city, East China

ABSTRACT Groundwater is a vital water source for human consumption and irrigation. Understanding its fluoride content and health implications is crucial for water resource management. This study investigated the quaternary aquifer in Suzhou, China, collecting and analyzing 49 groundwater samples. Thermodynamic simulation, multivariate statistical analysis, and health risk assessment models were employed to determine fluoride concentration characteristics, hydrochemical controlling mechanisms, and noncarcinogenic risks. Results revealed an average fluoride concentration of 0.89 mg/L, with 26.5% of samples exceeding the Grade III groundwater quality standard. High-fluoride groundwater (&amp;gt;1 mg/L) exhibited spatial heterogeneity and was predominantly of the Na-Mg-HCO3 hydrochemical type. Multivariate analysis and thermodynamics simulations indicated that water–rock interactions (e.g., silicate mineral weathering and fluorite dissolution) governed groundwater hydrochemistry. Fluoride primarily originated from fluoride-bearing mineral dissolution, while negative cation exchange and precipitation of calcite and dolomite enhanced fluoride enrichment. pH had minimal impact on fluoride concentrations under weakly alkaline conditions. Health risk assessment suggested that fluoride in shallow groundwater posed a higher noncarcinogenic risk to children than adults via ingestion. These findings provide valuable insights for regional groundwater resource management.

The effect of enzymatic hydrolysis on the flavor improvement of chicken broth by characterizing key taste and odor-active compounds

The flavor of chicken broth is composed of taste and odor, both of which are important indicators of edible quality. As a common meat processing technology, enzymatic hydrolysis appears as an effective way to improve the flavor of chicken broth. But up to now, the corresponding improvement mechanism has not been fully clarified. In this study, various chicken broth products were prepared by enzymatic hydrolysis of Papain (PAP), Flavourzyme (FLA) and Protamex (PRO). Then the samples with relatively better sensory performance including PAP-1.5-0.5, FLA-0.5-1.0, PRO-2.0-0.5 were selected and subjected to flavor compounds analysis. In terms of non-volatile taste-active compounds, glutamic acid (Glu) and 5′-guanosine monophosphate (5′-GMP) were the main taste contributors, their content and equivalent umami concentration (EUC) value were higher in PAP-1.5-0.5 and PRO-2.0-0.5. Regarding volatile odor-active compounds, (E, E)-2,4-decadienal with the highest variable importance (VIP) and odor activity value (OAV) was identified as the most critical odorant, and its content was higher in PRO-2.0-0.5 (41961.49 ± 507.78 μg/L) compared to other samples. Taking all factors into consideration, PRO-2.0-0.5 was regarded as the most ideal chicken broth product, which demonstrated the excellent improvement effect of enzymatic hydrolysis on the flavor of chicken broth.

Determination of the occurrence of and exposure to bisphenol A and its analogues in carbonated beverages and canned tuna using liquid chromatography − tandem mass spectrometry

Bisphenol A (BPA), a known endocrine disruptor, is commonly used in food containers and packaging. Recently, alternatives such as bisphenol AF (BPAF), bisphenol B (BPB), and bisphenol E (BPE) have been introduced to replace BPA. However, these substitutes have been reported to exhibit toxicity levels similar to BPA. In this study, we developed and validated a method for the analysis of trace bisphenols (BPA, BPAF, BPB, and BPE) in food using immunoaffinity column (IAC) clean-up. The method demonstrated satisfactory accuracy and precision. We applied this validated method to analyze 56 carbonated beverage samples and 30 canned tuna samples. In the carbonated beverages, average concentrations of BPA and BPAF were 0.4 and 0.2 μg kg−1, respectively. In canned tuna, BPA and BPAF were found at average concentrations of 22.2 and 0.7 μg kg−1, respectively, while BPB and BPE were not detected in any samples. Estimated exposure levels ranged from 0.13 to 0.18 ng kg bw−1 day−1 in the general population and from 205.2 to 232.0 ng kg bw−1 day−1 among consumers. The commercial IAC-based analytical method used in this study can contribute to the safety management of BPA, BPAF, BPB, and BPE.

Low-current gliding DC discharge in high-speed flows

Abstract A low-current gliding discharge (current range 1–5 A) in high-speed air flows of 100–250 m s−1 was experimentally studied. A high-voltage direct current source with a maximum voltage of 4.5 kV was used to create the discharge. The average electron concentration n e ∼ 1014 cm−3 and the plasma ionization degree were determined by measuring the Stark broadening of the hydrogen H β line (λ Hβ = 486.1 nm). The estimates of the electric field (E ∼ 100 V cm −1 ÷ 600 V cm−1) in the discharge positive column were found using time-synchronized high-speed video recordings and oscillograms. The gas rotational temperature T g = 7000–9500 K and the vibrational temperature T v = 7000–11 000 K were estimated using optical emission spectroscopy. Time-resolved spectroscopy is used to investigate the effective plasma channel spatial regions from which the N, NH, N2 +, O and OH molecules radiate. The difference of the obtained radii indicates the presence of a radial temperature gradient and inhomogeneous plasma composition in the discharge cross section. The possibility of using of gliding discharge to ignite hydrocarbon-air mixtures in the ramjet engines combustors has been experimentally demonstrated.

Solar Cells on Multicrystalline Silicon Thin Films Converted from Low‐Cost Soda‐Lime Glass

AbstractFabrication and characterization of solar cells based on multicrystalline silicon (mc‐Si) thin films are described and synthesized from low‐cost soda‐lime glass (SLG). The aluminothermic redox reaction of the silicon oxide in SLG during low‐temperature annealing at 600 – 650 °C leads to an mc‐Si thin film with large grains of lateral dimensions in the millimeter range, and moderate p‐type conductivity with an average Al acceptor concentration between 5 × 1016 and 1.2 × 1017 cm−3 in the bulk. A residual composite layer of mainly alumina and unreacted Al forms beneath the mc‐Si thin film as the second product of the crystalline silicon synthesis (CSS) process, which can be used as rear contact in a vertical solar cell design. The mc‐Si absorber (≈10 µm) is thin enough that the diffusion length given by a minority carrier lifetime of ≈1 µs exceeds the path length to the top contact several times. Homojunction and heterojunction diodes have been fabricated on the mc‐Si thin films and show great potential of CSS for the realization of high‐performance solar cells.

Inter-annual variability and health risk assessment of summer VOCs in a Plain City of China

This study investigated the inter-annual variations, transport pathways, pollution sources, and health implications of volatile organic compounds (VOCs) in Zhengzhou, China, a city notably affected by ground-level ozone (O3) pollution. Analyzing VOCs data from the summers of 2017–2021 revealed an average summer VOCs concentration of 61.8 ± 18.2 μg/m3, predominantly consisting of alkanes (55.0%), aromatics (22.5%), and alkenes (16.9%). The study identified significant year-to-year disparities in VOC abundances and compositions, which were closely linked to meteorological conditions, including temperature, wind speed, and relative humidity. Additionally, factors like air mass origin, direction and transport distance critically influenced the VOCs characteristics, with local air masses exhibiting higher VOC concentrations than those from distances of 100–500 km to the northwest, west and east. Positive Matrix Factorization (PMF) analysis identified major sources of VOCs as vehicle exhaust, oil and gas evaporation, solvent use, and biogenic emissions, with their contributions varying annually influenced by regional transport, environmental policies, and the COVID-19 pandemic. Health risk assessments, following U.S. Environmental Protection Agency guidelines, indicated negligible non-carcinogenic and carcinogenic risks from VOCs exposure, except for a potential carcinogenic risk from ethylbenzene. Solvent use sources were found to have the highest risks, with non-carcinogenic risks at 4.1 × 10−3 (negligible) and carcinogenic risks at 7.8 × 10−7 (with potentially carcinogenic in 2017 but negligible in subsequent years). This research underscored the complex dynamics of VOCs pollution and provided insights for developing effective pollution control strategies and enhancing public health in urban settings.

Exposure to organophosphate ester flame retardants and plasticizers and associations with preeclampsia and blood pressure in pregnancy

BackgroundOrganophosphate esters (OPEs), flame retardants and plasticizers found widely in consumer products, may impact vascularization processes in pregnancy. Yet, the association between maternal exposure to OPEs and both preeclampsia and blood pressure during pregnancy remains understudied. MethodsWithin the LIFECODES Fetal Growth Study (N = 900), we quantified 8 OPE metabolites from maternal urine collected at up to 3 time points during pregnancy and created within-subject geometric means. Outcomes included diagnosis of preeclampsia and longitudinal systolic (SBP) and diastolic (DBP) blood pressure measurements (mean = 14 per participant). Cox proportional hazards models were used to estimate associations between OPE metabolites and preeclampsia. Associations between average OPE metabolite concentrations and repeated blood pressure measurements were estimated using generalized estimating equations. ResultsFive OPE metabolites were detected in at least 60% of samples; 3 metabolites detected less frequently (5–39%) were examined in an exploratory analysis as ever vs. never detectable in pregnancy. There were 46 cases of preeclampsia in our study population. Associations between OPE metabolites and preeclampsia were null. We noted several divergent associations between OPE metabolites and longitudinal blood pressure measurements. An interquartile range (IQR) difference in average bis(2-chloroethyl) phosphate concentrations was associated with a decrease in SBP (−0.81 mmHg, 95% confidence interval [CI]: −1.62, 0.00), and, conversely, bis(1-chloro-2-propyl) phosphate was associated with a slight increase in SBP (0.94 mmHg, 95% CI: 0.28, 1.61). We also noted a decrease in SBP in association with several metabolites with low detection frequency. ConclusionsWe observed null associations between OPE metabolites and preeclampsia, but some positive and some inverse associations with blood pressure in pregnancy. While our study was well-designed to assess associations with blood pressure, future studies with a larger number of preeclampsia cases may be better poised to investigate the association between OPE metabolites and phenotypes of this heterogenous hypertensive disorder of pregnancy.

A Pharmacologic Evaluation of Buprenorphine in Pregnancy and the Postpartum Period.

The dosing regimen in the package insert for sublingual buprenorphine is similar for pregnant and nonpregnant people despite the physiologic changes seen during pregnancy. To compare plasma buprenorphine pharmacokinetics during and after pregnancy and relate buprenorphine concentration to the pharmacodynamic endpoints of pupil diameter, Clinical Opioid Withdrawal Scale (COWS), and craving scores. Prospective cohort of 22 pregnant people undergoing 33 pharmacologic studies (6-8 hours each) during pregnancy or postpartum. Participants were on a stable daily dose of 2-8 mg sublingual buprenorphine every 6 or 8 hours. The dosing frequency was selected by the participant. On study day, baseline measurements of plasma buprenorphine, pupil diameter, COWS, and craving scores were obtained, then the usual morning dose was taken, and measurements were repeated several times over 1 dosing interval. The dose-normalized area under the plasma buprenorphine concentration time curve was significantly (P = 0.036) lower during pregnancy (155 ± 52 ng × min/mL) than postpartum (218 ± 113 ng × min/mL). Buprenorphine trough concentrations were similar at the start (1.1 ± 0.7 ng/mL) and end of a dosing cycle (1.2 ± 0.8 ng/mL) regardless of dosing frequency. Pupillary diameter, COWS, and craving scores returned to baseline as buprenorphine concentrations approached ~1 ng/mL. Pregnant people require a higher dose of buprenorphine to achieve concentrations comparable to nonpregnant people. There is a temporal relationship between the plasma buprenorphine concentration and the pharmacodynamic markers of pupillary diameter, COWS, and craving scores. An average plasma concentration of ~1 ng/mL was associated with the lowest level of COWS and craving scores.

COVID-19 in the Tibet, China, the roof of the world: a comparative analysis of high-altitude residents and newcomers

BackgroundAfter a 920-day hiatus, COVID-19 resurged in the Tibet Autonomous Region of China in August 2022. This study compares the characteristics of COVID-19 between high-altitude residents and newcomers, as well as between newcomers and lowlanders.MethodsThis multi-center cohort study conducted at the Third People’s Hospital of Tibet Autonomous Region and Beijing University Shenzhen Hospital, included 520 high-altitude resident patients, 53 high-altitude newcomer patients, and 265 lowlander patients infected with the Omicron variant. Initially, we documented epidemiological, clinical, and treatment data across varying residency at admission. We compared the severity of COVID-19 and various laboratory indicators, including hemoglobin concentration and SpO2%, over a 14-day period from the date of the first positive nucleic acid test, as well as the differences in treatment methods and disease outcomes between highlanders and high-altitude newcomers. We also compared several characteristics of COVID-19 between high-altitude newcomers and lowlanders. Univariate analysis, multivariable logistic regression, and the generalized linear mixed model were utilized for the analysis.ResultsNo fatalities were observed. The study found no significant differences in COVID-19 severity or in the physiological measures of hemoglobin concentration and SpO2% between high-altitude and lowland residents. Similarly, there were no statistically significant differences in the values or trends of hemoglobin and SpO2% between high-altitude residents and newcomers throughout the 14-day observation period. However, compared to age- and sex-matched lowlander patients (1:5 ratio), high-altitude newcomers exhibited higher heart rates, respiratory rates, and average hemoglobin concentrations, along with lower platelet counts. There were no significant differences in hospital stays between the two groups.ConclusionsHigh-altitude residents and newcomer patients exhibit clinical similarities. However, the clinical characteristics of high-altitude newcomers and lowlander patients differ due to the impact of the high-altitude environment. These results highlight potential considerations for public health strategies in high-altitude regions such as Tibet.