Assessing the effect of COVID 19 lockdowns on the composition of organic compounds and potential source of PM2.5 in Hanoi, Vietnam.

The ambient air quality during COVID-19 lockdowns has been improved in many cities in the world. This study is to assess the changes in persistent organic pollutants in PM2.5 during the COVID-19 lockdown in Hanoi. Individual organic species in PM2.5 ((e.g., polycyclic aromatic hydrocarbons (PAHs), polychlorobiphenyls (PCBs), and organochlorine pesticides (OCPs)) were measured in an urban residential area in Hanoi from before the March 10th to April 22nd, 2020, including before the partial lockdown (BL) and the partial lockdown (PL) phases. During the PL phase, the concentration of Σ14PAHs and Σ28PCBs was reduced by 38 and 52% compared with the BL period, respectively. The diagnostic ratio method implied that the sources of PAHs within the PL phase had a less effect on traffic and industrial activities than in the BL phase. The characteristic ratio method indicated that PCBs were mixed by commercial product and combustion process in both the BL and the PL periods, however, the source of PCBs in the BL phase was influenced by municipal waste incineration more than those in the PL phase. The decreasing concentration of Σ20OCPs during the partial lockdown was attributed to the restriction of human activities during the quarantine period. The results suggested that the source of OCPs was probably derived from the usage of pesticides in current and, historical degradation or the transportation of pesticides from the soil to the atmosphere.

Source identification and health risk assessment of PM2.5 in urban districts of Hanoi using PCA/APCS and UNMIX.

Comparing results obtained by different models with different physical assumptions and constraints for source apportionment is important for better understanding the sources of pollutants. Source apportionment of PM2.5 measured at three sites located in inner urban districts of Hanoi was performed using two receptor models, UNMIX and principal component analysis with absolute principle component score (PCA/APCS). A total of 78 daily samples were collected consecutively during the dry and wet seasons in 2019 and 2020. The average PM2.5 concentration (66.26 µg/m3 ± 29.70 µg/m3 with a range from 23.57 to 169.04 µg/m3) observed in Hanoi metropolitan exceeded the National Ambient Air Quality standard QCVN 05:2013/BTNMT (50 µg/m3). Both UNMIX and PCA/APCS expressed comparable ability to reproduce measured PM2.5 concentrations. Additionally, both models identified similar potential sources of PM2.5 including traffic-related emissions, scrap metal recycling villages, crustal mixed with construction sources, coal combustion mixed with industry, and biomass burning. Both UNMIX and PCA/APCS confirmed that traffic-related emission was the most influential PM2.5 with a high percentage contribution of 59% and 55.97%, respectively. All the HQ and Cr values for both children and adults of toxic elements apportioned by both UNMIX and PCA/APCS in every source were within the acceptable range.

Emission and distribution profiles of polycyclic aromatic hydrocarbons in solid residues of municipal and industrial waste incinerators, Northern Vietnam.

The concentrations and profiles of 18 polycyclic aromatic hydrocarbons (PAHs) in particulate matter (PM10), fly ash (FA), and bottom ash (BA) were examined in three incineration residues. Samples were collected from different municipal and industrial solid waste incinerators in Northern Vietnam. The average concentrations of total PAHs in PM10, fly ash, and bottom ash were 9.55 × 103 ng/Nm3, 215 × 103 ng/g, and 2.38 ng/g, respectively. Low-molecular-weight PAHs (2 to 3 rings) were predominant in most samples. The emission factor of total PAHs decreased in the order of FA > BA > PM10. A higher concentration of total PAHs was found in industrial facilities than that in municipal ones. The high carcinogenic proportion of PAHs together with significantly high annual emissions reflect the high pollution risk to the ecosystem by PAHs in the case of reuse of incineration ashes (e.g., brick production). Regarding the carcinogenic risk of PAH-bounded ashes or particles, calculations from this study imply the significant threat for workers who have been manipulated in the incineration facilities, directly exposed to fly and bottom ashes. Meanwhile, the risk from PAH-bound particulate was not considered a significant threat for both normal adults and children. Further study on PAHs contained in incinerator waste dumps should be conducted in Vietnam to assess the potential contamination risk of these incineration by-products.

Four novel mutations in the androgen receptor gene from Vietnamese patients with androgen insensitivity syndrome.

BACKGROUND: Androgens and androgen receptor (AR) are critical regulators of the masculinization process in male sexual development. The absence of a functioning AR results in the development of the androgen insensitivity syndrome (AIS), a rare disorder of sexual development (DSD) characterized by the external genitalia feminization, gynecomastia, and impaired spermatogenesis. OBJECTIVE: To determine the AR gene mutations associated with male DSD in four unrelated Vietnamese patients. METHODS: To detect the disease-causing mutations, whole exome sequencing (WES) was performed on four patients diagnosed with AIS. Sanger sequencing was then used for validation of the identified mutations. Finally, 12 web-based tools, three-dimensional protein modeling software, and the guidelines issued by the American College of Medical Genetics and Genomics were used to assess the potential pathogenicity of these mutations. RESULTS: Four distinct novel mutations, namely c.1834T > A (p.Cys612Ser), c.2122 C > G (p.Leu708Val), c.2630T > G (p.Phe877Cys), and c.2641 C > A (p.Leu881Met) in the AR gene, were identified in four AIS patients using WES. The in silico analysis results revealed that the Cys612, Leu708, Phe877, and Leu881 sites are important for an appropriate response to androgens of the AR, and mutation at these sites can have adverse effects on the AR functions, androgen-AR interaction, and AR signaling pathway. CONCLUSIONS: WES and in silico analyses strongly suggested that four novel AR mutations are pathogenic and have led to the development of AIS in the four Vietnamese patients under consideration.

Distribution characteristics and ecological risks of heavy metals in bottom ash, fly ash, and particulate matter released from municipal solid waste incinerators in northern Vietnam.

Residue concentrations of heavy metals, including As, Cd, Cr, Cu, Ni, Pb, and Zn, were determined in bottom ash, fly ash, and particulate matter (PM10) samples collected from five municipal incinerators in northern Vietnam to assess their occurrence, distribution characteristics, and potential risks. Concentrations and profiles of heavy metals are presented, showing the dominance of Zn in all types of samples. Highly volatile elements (Cd, Pb, and Zn) were found at elevated proportions in PM10 but not fly ash. The large difference in the heavy metal profiles could be explained by the variation of input raw materials, the absence of an appropriate cycle for the material feeding process, and post-combustion technology applied. Mass balance of heavy metals in the bottom ash, fly ash, and PM10 varied significantly between the investigated incinerators, largely due to the difference in incineration technology and air pollution control system. Emission factors and annual emissions were also estimated, indicating the highest value and amount in bottom ash, followed by PM10 and fly ash. Our results are among the first studies reporting contents and emissions of toxic elements in incinerated solid wastes in Vietnam.

Impact of Covid-19 partial lockdown on PM2.5, SO2, NO2, O3, and trace elements in PM2.5 in Hanoi, Vietnam.

Covid-19 lockdowns have improved the ambient air quality across the world via reduced air pollutant levels. This article aims to investigate the effect of the partial lockdown on the main ambient air pollutants and their elemental concentrations bound to PM2.5 in Hanoi. In addition to the PM2.5 samples collected at three urban sites in Hanoi, the daily PM2.5, NO2, O3, and SO2 levels were collected from the automatic ambient air quality monitoring station at Nguyen Van Cu street to analyze the pollution level before (March 10th-March 31st) and during the partial lockdown (April 1st-April 22nd) with "current" data obtained in 2020 and "historical" data obtained in 2014, 2016, and 2017. The results showed that NO2, PM2.5, O3, and SO2 concentrations obtained from the automatic ambient air quality monitoring station were reduced by 75.8, 55.9, 21.4, and 60.7%, respectively, compared with historical data. Besides, the concentration of PM2.5 at sampling sites declined by 41.8% during the partial lockdown. Furthermore, there was a drastic negative relationship between the boundary layer height (BLH) and the daily mean PM2.5 in Hanoi. The concentrations of Cd, Se, As, Sr, Ba, Cu, Mn, Pb, K, Zn, Ca, Al, and Mg during the partial lockdown were lower than those before the partial lockdown. The results of enrichment factor (EF) values and principal component analysis (PCA) concluded that trace elements in PM2.5 before the partial lockdown were more affected by industrial activities than those during the partial lockdown.

Clinical and functional characteristics of OSA in children with comorbid asthma treated by leukotriene receptor antagonist: A descriptive study.

Background: Obstructive sleep apnea (OSA) is the most common form of respiratory disorders during sleep in children, especially those with severe asthma. However, optimal treatment of asthma might significantly improve OSA severity. Methods: It was a cohort study including children aged >5 years old and diagnosed with asthma according to GINA (Global Initiative for Asthma). The data related to age, gender, height, weight, body mass index (BMI), clinical symptoms and medical history of asthma, spirometry (FEV1: forced expiratory in 1 s), and exhaled nitric oxide (FENO) were recorded for analysis. Respiratory polygraphy (RPG) was done for each study subject to diagnose OSA and its severity. Results: Among 139 asthmatic children, 99 patients with OSA (71.2%) were included in the present study (9.3 ± 0.2 years): 58.6% with uncontrolled asthma and 32.3% with partial controlled asthma. The mean ACT (asthma control testing) score was 19.0 ± 3.4. The most frequent night-time symptoms were restless sleep (76.8%), snoring (61.6%), sweating (52.5%), and trouble breathing during sleep (48.5%). The common daytime symptoms were irritable status (46.5%) and abnormal behavior (30.3%). The mean AHI (apnea-hypopnea index) was 3.5 ± 4.0 events/h. There was a significant correlation between BMI and snoring index (R = 0.189 and P = 0.027), bronchial and nasal FENO with AHI (R = 0.046 and P < 0.001; R = 0.037 and P < 0.001; respectively). There was no significant correlation between asthma level, FEV1 and AHI. The severity of asthma and respiratory function were improved significantly after 3 months and 6 months of asthma treatment in combination with leukotriene receptor antagonist (LRA) treatment. The symptoms related to OSA were significantly improved after treatment with LRA. The severity of OSA was decreased significantly after 3 months and 6 months of treatment. Conclusion: The treatment of asthmatic children with comorbid OSA by LRA in combination with standard therapy for asthma could improve the control of asthma and the symptoms and severity of OSA.

Clinical-functional characteristics of children with asthma and obstructive sleep apnea overlap associated with attention deficit hyperactivity disorder: A cross-sectional study.

Background: Asthma and obstructive sleep apnea (OSA) are common chronic respiratory disorders in children. The relationship between asthma and OSA is bidirectional; these conditions share multiple epidemiological risk factors. Untreated OSA may cause attention deficit hyperactivity disorder (ADHD) symptoms. This study aimed to assess the prevalence of ADHD in asthmatic children with OSA and the link between asthma control and lung function of children with asthma and OSA. Methods: A total of 96 children aged 6-15 years diagnosed with asthma, according to the Global Initiative for Asthma (GINA) 2020, were enrolled in this study. All demographic data, including age, gender, body mass index, asthma control status, therapy, the Vanderbilt ADHD Diagnostic Parent Rating Scale, lung function, and exhaled nitric oxide, were collected. In addition, home respiratory polygraphy was used to identify OSA in study subjects. Results: A total of 96 patients (8.4 ± 2.4 years) were included in the present study. OSA was identified in 60.4% of asthmatic children with a mean apnea-hypopnea index (AHI) of 3.5 ± 3.0 event/h. The inattentive ADHD subtype was significantly lower in the non-OSA asthmatic group than in the OSA asthmatic group (7.9 vs. 34.5%, p < 0.05). ADHD had a higher probability of presence (OR: 3.355; 95% CI: 1.271-8.859; p < 0.05) in the OSA group (AHI >1 event/h). Children with poorly controlled asthma had a significantly high risk of OSA (83.0 vs. 17.0%, p < 0.001) than children with well-controlled asthma. Allergic rhinitis increased the odds of having OSA in patients with asthma [OR: 8.217 (95% CI: 3.216-20.996); p < 0.05]. Conclusion: The prevalence of OSA is increased among poorly controlled asthma. ADHD may have a higher prevalence in children with OSA. Therefore, prompt diagnosis of OSA will lead to an accurate asthma control strategy in patients with asthma.

Evaluation of in vitro cytotoxicity and in vivo potential toxicity of the extract from in vitro cultivated Anoectochilus roxburghii Lindl.

Anoectochilus roxburghii Lind. (A. roxburghii) has promising anti-oxidant, hyperglycemic, hepatoprotective, and immunomodulatory activities as well as anti-tumor effects. However, the pharmacological actions of in vitro cultured plants remain to be determined. Therefore, the objective of the study was to assess in vitro cytotoxicity and in vivo potential toxicity of an extract derived from in vitro cultivated A. roxburghii, termed as iARE. The total flavonoid content and predominant flavonoid compounds of extract were identified and quantitatively analyzed. The in vitro cytotoxicity of iARE was examined using several cancer and normal cell lines. The apoptotic activity and expression of apoptosis-associated genes were also examined in MCF7 cells to determine the underlying mechanisms related to anti-proliferative effects. In vivo potential toxicity of iARE was assessed following acute and subchronic oral administration in Sprague Dawley rats. Quercetin, kaempferol, and isorhamnetin were three flavonoid components identified in iARE. The extract exerted cytotoxic effects on various cancer cells but not normal fibroblasts. Apoptosis in MCF7 cells was induced by iARE in a concentration-dependent manner associated with increased Bax/Bcl-2 ratio and reduced mitochondrial membrane potential ΔΨm, leading to release of cytochrome c, activation of caspase-3/7 and caspase-9, and cleavage of PARP. In the acute oral toxicity study, no mortality or toxicological signs were observed in rats at 1000 or 5000 mg/kg. In a subchronic oral toxicity study, iARE at a dosage of up to 1000 mg/kg produced no mortality or treatment-related adverse effects on general behavior, food intake, body weight, relative organ weights. No apparent marked changes in the histopathology of the liver and kidney were detected. Data demonstrated that iARE induced in vitro cytotoxic effects in cancer cells are associated with lackof invivo toxicity. Thus, iARE was suggested to be considered as apotential therapeutic candidate for cancer treatment.

A novel homozygous mutation IVS6+5G>T in CYP11B1 gene in a Vietnamese patient with 11ß-hydroxylase deficiency.

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disease which is characterized by a deficiency of one of the enzymes involved in the synthesis of cortisol from cholesterol by the adrenal cortex. CAH cases arising from impaired 11ß-hydroxylase are the second most common form. Mutations in the CYP11B1 gene are the cause of 11ß-hydroxylase deficiency. This study was performed on a patient with congenital adrenal hyperplasia and with premature development such as enlarged penis, muscle development, high blood pressure, and bone age equivalent of 5 years old at 2 years of chronological age. Biochemical tests for steroids confirmed the diagnosis of CAH. We used PCR and sequencing to screen for mutations in CYP11B1 gene. Results showed that the patient has a novel homozygous mutation of guanine (G) to thymine (T) in intron 6 (IVS6+5G>T). The analysis of this mutation by MaxEntScan boundary software indicated that this mutant could affect the gene splicing during transcription.