Coal burning-derived SO2 and traffic-derived NO2 are associated with persistent cough and current wheezing symptoms among schoolchildren in Ulaanbaatar, Mongolia

The risk factors for chronic cough in children: A meta-analysis covering five continents

BACKGROUND

This study aimed to explore the risk factors for chronic cough in children and provide a reference for prevention and healthcare measures.

METHODS

PubMed, Web of Science, Cochrane, and EMBASE were searched for observational studies published up to April 2024. Outcome included risk factors associated with chronic cough in children. Two investigators independently searched and screened the literature, evaluated the qualities and extracted baseline datas. Results were analyzed using random-effects models with odds ratios and their 95 % confidence intervals to address heterogeneity. Subgroup analyses, sensitivity analyses and assessment of publication bias were performed. Stata17 and GRADEwas used for the meta-analysis.

RESULTS

18 studies including 97,462 children were reviewed. Asthma(OR = 4.06, 95%CI: 2.37-6.96, P＜0.01), NO2(OR = 1.19, 95%CI: 1.01-1.39, P = 0.031), Home remodeling history (OR = 1.82,95 % CI: 1.61-2.05, P＜0.01), Environment Tobacco Smoke(OR = 1.41, 95 % CI: 1.15-1.73, P = 0.001), Pet exposure (OR = 1.56, 95%CI: 1.25-1.95, P＜0.01), Mould (OR = 1.64,95%CI: 1.45-1.85, P＜0.01), Age＜1 year(OR = 3.19, 95 % CI: 1.8-5.63, P＜0.01) were reported as risk factors for chronic cough in children, these results were discussed qualitatively in the study.

CONCLUSION

Asthma, NO2, Home remodeling history, Environment Tobacco Smoke(ETS), Pet exposure, Mould, and Age＜1 year are risk factors for chronic coughing in children. Due to the few studies and insufficient evidence, other potential risk factors need to be robustly confirmed by subsequent large-sample and multicenter trials.

A cross-sectional study on domestic use of biomass fuel and the prevalence of respiratory illnesses in a rural community in Thaba-Tseka district of Lesotho

The domestic utilization of biomass fuel for purposes such as cooking, space heating, and water heating has been linked to a number of respiratory ailments, particularly when burned inefficiently. However, there is an existing knowledge gap on the impact of this practice on the health of Basotho. This study aims to explore the impact of biomass fuels use on the prevalence of respiratory illnesses among residents of two rural communities in Thaba-Tseka. A quantitative, cross-sectional design was adopted, using a structured questionnaire, to assess the correlation between biomass fuel use and the prevalence of respiratory symptoms and diseases. Data were collected from 326 randomly selected individuals aged 18 and above. The major source of fuel energy used was firewood (39.6 %), followed by paraffin (29.1 %) and animal dung (15.6 %). The most prevalent respiratory symptom reported was cough, among 27.6 % of participants (n = 326), followed by sneezing (n = 326, 23.0 %), and fever (n = 326, 17.5 %). The lowest prevalent respiratory disease was pneumonia (0.9 %) while lung cancer was not reported. The reporting of respiratory symptoms and diseases was most prevalent in January. A greater prevalence of cough was reported by participants with a higher level of education (r (5) = 1.746, p = 0.008). More male participants reported to have tuberculosis (7.8 %) compared to females (3 %) (r (1) = 3.809, p = 0.051). Asthma was noted to be more prevalent among high income earners (r (3) = 8.169, p = 0.043) and those reported to have an employment (r (1) = 4.277, p = 0.039). Surprisingly, there was no association between respiratory diseases and symptoms, and the type of domestic fuel used. In the rural communities of Thaba-Tseka, about 4 in 10 Basotho rural communities, relied on firewood for cooking, space heating and water heating. Respiratory symptoms and diseases were observed mostly in the month of January. Several factors, including education level, marital status, gender, and income level, were significantly associated with specific respiratory symptoms and diseases. Targeted public health interventions are urgently needed to mitigate respiratory symptoms and diseases in the rural communities of Lesotho. More focus should be directed to health behavioral change and provision of improved stoves for exposure reduction of biomass emissions.

Predicting ambient PM2.5 concentrations in Ulaanbaatar, Mongolia with machine learning approaches

BACKGROUND

Accurately assessing individual ambient air pollution exposure is a crucial part of epidemiological studies looking at the adverse health effect of poor air quality. This is particularly challenging in developing countries with high levels of air pollution, mostly due to sparse monitoring networks with a lack of consistent data.

METHODS

We evaluated the performance of six different machine learning algorithms in predicting fine particulate matter (PM_2.5) concentrations in Ulaanbaatar, Mongolia using data between 2010 and 2018. We found that the algorithms produce robust results based on performance metrics.

RESULTS

Random forest (RF) and gradient boosting models performed the best with leave-one-location-out cross-validated R² of 0.82 for when using data from the entire study period. After applying tuned models on the hold-out test set, R² increased to 0.96 for the RF and 0.90 for the gradient boosting model. We also predicted PM_2.5 concentrations for each administrative area (khoroo) of the city using RF and maps of predictions show spatiotemporal variations that are in line with the location of the high-emission area (ger district), city center, and population density.

CONCLUSION

Our results provide evidence of the advantage and feasibility of machine learning approaches in predicting ambient PM_2.5 levels in a setting with limited resources and extreme air pollution levels.

Association between household solid fuel use and tuberculosis: cross-sectional data from the Mongolian National Tuberculosis Prevalence Survey

BACKGROUND

Tuberculosis (TB) and indoor air pollution (IAP) are equally critical public health issues in the developing world. Mongolia is experiencing the double burden of TB and IAP due to solid fuel combustion. However, no study has assessed the relationship between household solid fuel use and TB in Mongolia. The present study aimed to assess the association between household solid fuel use and TB based on data from the Mongolian National Tuberculosis Prevalence Survey (MNTP Survey).

METHOD

The MNTP Survey was a nationally representative population-based cross-sectional survey targeting households in Mongolia from 2014 to 2015, with the aim of evaluating the prevalence of TB. The survey adopted a multistage cluster sampling design in accordance with the World Health Organization prevalence survey guidelines. Clusters with at least 500 residents were selected by random sampling. A sample size of 98 clusters with 54,100 participants was estimated to be required for the survey, and 41,450 participants were included in the final analysis of the present study. A structured questionnaire was used to collect information on environmental and individual factors related to TB. Physical examination, chest X-ray, and sputum examinations were also performed to diagnose TB.

RESULTS

The use of solid fuels for heating (adjusted odds ratio (aOR): 1.5; 95% confidence interval (CI): 1.1-2.1), male gender (aOR: 2.2; 95% CI: 1.6-3.2), divorced or widowed (aOR: 2.6; 95% CI: 1.7-3.8), daily smoker (aOR: 1.8; 95% CI: 1.3-2.5), contact with an active TB case (aOR: 1.7; 95% CI: 1.2-2.3), being underweight (aOR: 3.7; 95% CI: 2.4-5.7), and previous history of TB (aOR: 4.3; 95% CI: 3.0-6.1) were significantly associated with bacteriologically confirmed TB after adjusting for confounding variables.

CONCLUSION

The use of solid fuels for heating was significantly associated with active TB in Mongolian adults. Increased public awareness is needed on the use of household solid fuels, a source of IAP.

Azithromycin ameliorates sulfur dioxide-induced airway epithelial damage and inflammatory responses

Background

The airway epithelium (AE) forms the first line of defence against harmful particles and pathogens. Barrier failure of the airway epithelium contributes to exacerbations of a range of lung diseases that are commonly treated with Azithromycin (AZM). In addition to its anti-bacterial function, AZM has immunomodulatory effects which are proposed to contribute to its clinical effectiveness. In vitro studies have shown the AE barrier-enhancing effects of AZM. The aim of this study was to analyze whether AE damage caused by inhalation of sulfur dioxide (SO₂) in a murine model could be reduced by pre-treatment with AZM.

Methods

The leakiness of the AE barrier was evaluated after SO₂ exposure by measuring levels of human serum albumin (HSA) in bronchoalveolar lavage fluid (BALF). Protein composition in BALF was also assessed and lung tissues were evaluated across treatments using histology and gene expression analysis.

Results

AZM pre-treatment (2 mg/kg p.o. 5 times/week for 2 weeks) resulted in reduced glutathione-S-transferases in BALF of SO₂ injured mice compared to control (without AZM treatment). AZM treated mice had increased intracellular vacuolization including lamellar bodies and a reduction in epithelial shedding after injury in addition to a dampened SO₂-induced inflammatory response.

Conclusions

Using a mouse model of AE barrier dysfunction we provide evidence for the protective effects of AZM in vivo, possibly through stabilizing the intracellular microenvironment and reducing inflammatory responses. Our data provide insight into the mechanisms contributing to the efficacy of AZM in the treatment of airway diseases.