Health impacts of indoor air pollution from household solid fuel on children and women

Risk assessment of unclean cooking energy usage from the perspective of subjective wellbeing: The mediating role of perceived physical and mental health

Although outdoor air pollution has been associated with adverse health outcomes and decreased subjective welfare, there has been a lack of research investigating the potential risks associated with indoor unclean cooking energy usage from the perspective of subjective wellbeing. This paper systematically assesses the risks of unclean cooking fuel usage from the novel perspective of subjective welfare and examines the mediating role of perceived physical and mental health applying a large-scale nationally representative dataset. Analytical results demonstrate that the usage of unclean cooking energy has significantly negative impacts on subjective wellbeing, and this finding has been confirmed through various robustness tests. The mechanism behind this impact is that unclean cooking fuel usage reduces people's perceived physical and mental health status, which in turn decreases their subjective wellness. Furthermore, the negative consequences of using unclean cooking energy on subjective wellbeing are particularly pronounced among certain demographic groups, including older, lower educated, married individuals as well as those with lower economic status, uncovered by medical insurance and having less social capital. Findings of this study highlight the risks linked to unclean cooking energy usage, as evidenced in the negative impact on perceived health and subjective wellbeing. In light of the increasing focus on improving indoor environment as well as enhancing people's health and wellbeing, results of this paper emphasize the significance of promoting access to cleaner and healthier energy.

Solid fuel use and low birth weight: a systematic review and meta-analysis

Solid fuel use is increasingly linked to low birth weight (LBW), but conclusions were inconsistent. We aimed to summarize the association between solid fuel use and LBW. Twenty-one studies that met the inclusion criteria were identified through PubMed, Qvid Medline, and Web of Science databases. The final search occurred on March 20, 2024. Summary relative effect and 95 % confidence intervals were estimated with a random-effects model. Subgroup analyses and sensitivity analyses were performed to investigate possible sources of heterogeneity and to test the stability of the results. Nineteen studies evaluated the association between solid fuel use in pregnant woman and LBW (1.188 for solid fuels: 1.055 to 1.322). No significant heterogeneity was identified among the included studies (p=0.010, Tau2=0.02, I2=48.1 %). Subgroup analysis found positive correlations for Asia, data years prior to 2014, and rural studies (1.245 for Asia: 1.077 to 1.412; Tau2=0.03, I2=56.0 %; 1.243 for data years prior to 2014: 1.062 to 1.424; Tau2=0.04, I2=60.98 %; 1.514 for rural: 1.258 to 1.771; Tau2=0.00, I2=0.0 %). Our meta-analysis showed that solid fuel use in pregnant women had an impact on LBW. Measures and policies are also needed to promote energy conversion and to limit and reduce the use of solid fuels.

Association of solid fuel use with cognitive function and the modifying role of lifestyle: A nationwide cohort study in China

BACKGROUND

As opposed to a healthy lifestyle, indoor air pollution from solid fuel use may be harmful for cognitive function. However, the extent to which lifestyle modifies the association between solid fuel use and cognitive function remains unknown.

METHODS

A total of 21,008 individuals aged 16 to 92 were enrolled in 2010 and followed up to 2014 in the China Family Panel Studies (CFPS). Cognitive function was assessed using standardized math and word tests in two waves. Solid fuel use at baseline was assessed by self-reporting of firewood, straw, or coal used for cooking. Lifestyle profile was classified into two groups (favorable vs. unfavorable) based on five modifiable lifestyle factors including alcohol drinking, smoking, body mass index, diet, and physical activity. Linear mixed-effects models were employed to assess the association of solid fuel use and lifestyle with cognitive function. The effect modification of lifestyle was analyzed.

RESULTS

A total of 49.7% of the study population used solid fuels for cooking and 17.4% had a favorable lifestyle. Solid fuel use was associated with a significant decrease in cognitive function (β = -0.29, 95% CI: -0.39, -0.19 for math test; β = -0.62, 95% CI: -0.84, -0.41 for word test). Lifestyle significantly modified this association (p-interaction: 0.006 for math test; 0.016 for word test), with the corresponding association being less pronounced among participants adhering to a favorable lifestyle compared to those with an unfavorable lifestyle.

CONCLUSION

A favorable lifestyle may attenuate the adverse association between solid fuel use and cognitive function. Adopting a favorable lifestyle has the potential to mitigate the adverse neurological effects due to indoor air pollution.

Assessing the health consequences of indoor air pollution from biomass fuel combustion on pediatric populations in rural communities of Pakistan

Indoor air pollution arising from burning of biomass fuels poses a significant threat to child health in rural areas of Pakistan. This cross-sectional study aimed to assess health implications associated with indoor air pollution resulting from biomass burning among children under 12 years of age in rural Punjab. A questionnaire-based survey was conducted in six randomly selected rural districts of Punjab, characterized by their primary reliance on biomass fuels. The findings revealed that several characteristics, such as monthly household income, number of living rooms, secondary use of solid fuels, kitchen type, type of cooking stove, and presence of child in the kitchen with their mother, exhibited significant associations (p < 0.05) with negative health impacts among children. Reported health effects among the children included coughing (18.7%), watery eyes (17.7%), eye irritation (12.3%), runny nose (11.8%), breathing difficulties (8.5%), phlegm (38%), headache (25%), nausea (20.1%), dizziness (6.7%), asthma (6.4%), tuberculosis (1.8%), and pneumonia (1.5%).

Air pollution and climate change as grand challenges to sustainability

There is a cross-disciplinary link between air pollution, climate crisis, and sustainable lifestyle as they are the most complex struggles of the present century. This review takes an in-depth look at this relationship, considering carbon dioxide emissions primarily from the burning of fossil fuels as the main contributor to global warming and focusing on primary SLCPs such as methane and ground-level ozone. Such pollutants severely alter the climate through the generation of greenhouse gases. The discussion is extensive and includes best practices from conventional pollution control technologies to hi-tech alternatives, including electric vehicles, the use of renewables, and green decentralized solutions. It also addresses policy matters, such as imposing stricter emissions standards, setting stronger environmental regulations, and rethinking some economic measures. Besides that, new developments such as congestion charges, air ionization, solar-assisted cleaning systems, and photocatalytic materials are among the products discussed. These strategies differ in relation to the local conditions and therefore exhibit a varying effectiveness level, but they remain evident as a tool of pollution deterrence. This stresses the importance of holistic and inclusive approach in terms of engineering, policies, stakeholders, and ecological spheres to tackle.

An integrated agroforestry-bioenergy system for enhanced energy and food security in rural sub-Saharan Africa

Most people in rural sub-Saharan Africa lack access to electricity and rely on traditional, inefficient, and polluting cooking solutions that have adverse impacts on both human health and the environment. Here, we propose a novel integrated agroforestry-bioenergy system that combines sustainable biomass production in sequential agroforestry systems with biomass-based cleaner cooking solutions and rural electricity production in small-scale combined heat and power plants and estimate the biophysical system outcomes. Despite conservative assumptions, we demonstrate that on-farm biomass production can cover the household's fuelwood demand for cooking and still generate a surplus of woody biomass for electricity production via gasification. Agroforestry and biochar soil amendments should increase agricultural productivity and food security. In addition to enhanced energy security, the proposed system should also contribute to improving cooking conditions and health, enhancing soil fertility and food security, climate change mitigation, gender equality, and rural poverty reduction.

The role of liver enzymes in the association between ozone exposure and diabetes risk: a cross-sectional study of Zhuang adults in China

Background: Growing evidence has demonstrated the role of ambient air pollutants in driving diabetes incidence. However, epidemiological evidence linking ozone (O3) exposure to diabetes risk has been scarcely studied in Zhuang adults in China. We aimed to investigate the associations of long-term exposure to O3 with diabetes prevalence and fasting plasma glucose (FPG) and estimate the mediating role of liver enzymes in Zhuang adults. Methods: We recruited 13 843 ethnic minority adults during 2018-2019 based on a cross-sectional study covering nine districts/counties in Guangxi. Generalized linear mixed models were implemented to estimate the relationships between O3 exposure and diabetes prevalence and FPG. Mediation effect models were constructed to investigate the roles of liver enzymes in the associations of O3 exposure with diabetes prevalence and FPG. Subgroup analyses were conducted to identify potential effect modifications. Results: Long-term exposure to O3 was positively associated with diabetes prevalence and FPG levels in Zhuang adults, with an excess risk of 7.32% (95% confidence interval [CI]: 2.56%, 12.30%) and an increase of 0.047 mmol L-1 (95% CI: 0.032, 0.063) for diabetes prevalence and FPG levels, respectively, for each interquartile range (IQR, 1.18 μg m-3) increment in O3 concentrations. Alanine aminotransferase (ALT) significantly mediated 8.10% and 29.89% of the associations of O3 with FPG and diabetes prevalence, respectively, and the corresponding mediation proportions of alkaline phosphatase (ALP) were 8.48% and 30.00%. Greater adverse effects were observed in females, obese subjects, people with a low education level, rural residents, non-clean fuel users, and people with a history of stroke and hypertension in the associations of O3 exposure with diabetes prevalence and/or FPG levels (all P values for interaction < 0.05). Conclusion: Long-term exposure to O3 is related to an increased risk of diabetes, which is partially mediated by liver enzymes in Chinese Zhuang adults. Promoting clean air policies and reducing exposure to environmental pollutants should be a priority for public health policies geared toward preventing diabetes.

First temporal distribution model of ambient air pollutants (PM2.5, PM10, and O3) in Yangon City, Myanmar during 2019-2021

Air pollution has emerged as a significant global concern, particularly in urban centers. This study aims to investigate the temporal distribution of air pollutants, including PM2.5, PM10, and O3, utilizing multiple linear regression modeling. Additionally, the research incorporates the calculation of the Air Quality Index (AQI) and Autoregressive Integrated Moving Average (ARIMA) time series modeling to predict the AQI for PM2.5 and PM10. The concentrations and AQI values for PM2.5 ranged from 0 to 93.6 μg/m3 and 0 to 171, respectively, surpassing the Word Health Organization's (WHO) acceptable threshold levels. Similarly, concentrations and AQI values for PM10 ranged from 0.1 to 149.27 μg/m3 and 2-98 μg/m3, respectively, also exceeding WHO standards. Particulate matter pollution exhibited notable peaks during summer and winter. Key meteorological factors, including dew point temperature, relative humidity, and rainfall, showed a significant negative association with all pollutants, while ambient temperature exhibited a significant positive correlation with particulate matter. Multiple linear regression models of particulate matter for winter season demonstrated the highest model performance, explaining most of the variation in particulate matter concentrations. The annual multiple linear regression model for PM2.5 exhibited the most robust performance, explaining 60% of the variation, while the models for PM10 and O3 explained 45% of the variation in their concentrations. Time series modeling projected an increasing trend in the AQI for particulate matter in 2022. The precise and accurate results of this study serve as a valuable reference for developing effective air pollution control strategies and raising awareness of AQI in Myanmar.

Indoor PM from residential coal combustion: Levels, chemical composition, and toxicity

Indoor air quality is crucial for human health due to the significant time people spend at home, and it is mainly affected by internal sources such as solid fuel combustion for heating. This study investigated the indoor air quality and health implications associated with residential coal burning covering gaseous pollutants (CO, CO2 and total volatile organic compounds), particulate matter, and toxicity. The PM10 chemical composition was obtained by ICP-MS/OES (elements), ion chromatography (water-soluble ions) and thermal-optical analysis (organic and elemental carbon). During coal combustion, PM10 levels were higher (up to 8.8 times) than background levels and the indoor-to-outdoor ratios were, on average, greater than unity, confirming the existence of a significant indoor source. The chemical characterisation of PM10 revealed increased concentrations of organic carbon and elemental carbon during coal combustion as well as arsenic, cadmium and lead. Carcinogenic risks associated with exposure to arsenic exceeded safety thresholds. Indoor air quality fluctuated during the study, with varying toxicity levels assessed using the Aliivibrio fischeri bioluminescence inhibition assay. These findings underscore the importance of mitigating indoor air pollution associated with coal burning and highlight the potential health risks from long-term exposure. Effective interventions are needed to improve indoor air quality and reduce health risks in coal-burning households.

The relationship between cooking fuel use and sex hormone levels: A cross-sectional study and Mendelian randomization study

PURPOSE

The aim of this study was to investigate the effect of solid fuel use on serum sex hormone levels. Furthermore, the effects of improved kitchen ventilation and duration of cooking time on the relationship between solid fuel use and serum sex hormone levels will be further explored.

METHODS

In this cross-sectional study, 5386 individuals were recruited. Gender and menopausal status modified associations between solid fuel type and serum sex hormone levels was investigated through generalized linear models and further analyzed by improving kitchen ventilation and length of cooking time on the relationship between solid fuel use and serum sex hormone levels. To identify the causal association, mendelian randomization of two-sample was performed.

RESULTS

In observational analyses, for ln-17-hydroxyprogesterone, ln-testosterone, and ln-androstenedione among premenopausal women, the estimated β and 95 % CI of sex hormone levels for the effect of solid fuel users was -0.337 (-0.657, -0.017), -0.233 (-0.47, 0.005), and - 0.240 (-0.452, -0.028) respectively, and - 0.150 (-0.296, -0.004) in ln-progesterone among postmenopausal women. It was found that combining solid fuels with long cooking periods or no ventilation more effectively reduced testosterone and androstenedione in premenopausal women. We further found the adverse effects of using solid fuel on progesterone, testosterone, and androstenedione levels were enhanced with the increases of PM1, PM2.5, PM10, and NO2. Corresponding genetic, the causal risk effect of solid fuel were - 0.056 (-0.513, 0.4) and 0.026 (-3.495, 3.547) for testosterone levels and sex hormone binding globulin, respectively.

CONCLUSION

Using gas or solid fuel was negatively related to sex hormone levels. A combination of using solid fuels, cooking for a long time, or cooking without ventilation had a stronger effect on sex hormone levels. However, genetic evidence did not support causality for the associations. WHAT IS ALREADY KNOWN ON THIS TOPIC?: The mechanisms underlying these associations household air pollution (HAP) from incomplete combustion of such fuels and occurrence of chronic diseases remained obscure. Recent years, extensive evidences from animal as well as human researches have suggested that progestogen and androgen hormones are involved in the development of diabetes, hypertension, and cardiovascular disease, which indicated that changes in serum progestogen and androgen hormones levels might play a role in these pathological mechanisms. However, limited evidence exists examining the effect of HAP from solid fuel use on serum sex hormone levels.

Impact of indoor air pollution from cooking fuel usage and practices on self-reported health among older adults in India: Evidence from LASI

This research aims to explore the impact of various components of Indoor air pollution (IAP) on the Self-Reported Health (SRH) of older adults in India. Using a sample of 27,090 from the Longitudinal Aging Study in India (LASI) Wave-1, a multiple binary logistic regression model was employed to identify specific risk factors associated with poor SRH among older adults. Adjusting for demographic, socioeconomic, and IAP-related components, it was revealed that IAP significantly contributes to poor SRH. The adjusted model indicated that individuals using solid cooking fuels face a higher risk of poor SRH compared to those using liquid fuels. Additionally, individuals not using electric chimneys and cooking near windows are associated with an elevated risk of poor SRH, highlighting the importance of adequate ventilation. Health risk factors, including lung disease, diabetes, cough, and depression, further contribute to poor SRH among older adults exposed to IAP. Overall, the study offers crucial insights for policymakers, healthcare professionals, and environmentalists to improve the well-being of the vulnerable older population in India.

Current trends on dry photocatalytic oxidation technology for BTX removal: Viable light sources and highly efficient photocatalysts

One of the main gaseous pollutants released by chemical production industries are benzene, toluene and xylene (BTX). These dangerous gases require immediate technology to combat them, as they put the health of living organisms at risk. The development of heterogeneous photocatalytic oxidation technology offers several viewpoints, particularly in gaseous-phase decontamination without an additional supply of oxidants in air at atmospheric pressure. However, difficulties such as low quantum efficiency, ability to absorb visible light, affinity towards CO2 and H2O synthesis, and low stability continue to limit its practical use. This review presents recent advances in dry-phase heterogeneous photodegradation as an advanced technology for the practical removal of BTX molecules. This review also examines the impact of low-cost light sources, the roles of the active sites of photocatalysts, and the feasible concentration range of BTX molecules. Numerous studies have demonstrated a significant improvement in the efficiency of the photodegradation of volatile organic compounds by enhancing the photocatalytic reactor system and other factors, such as humidity, temperature, and flow rate. The mechanism for BTX photodegradation based on density functional theory (DFT), electron paramagnetic resonance (EPR) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) investigations is also discussed. Finally, the present research complications and anticipated future developments in the field of heterogeneous photocatalytic oxidation technology are discussed.

Epigenetic studies in children at risk of stunting and their parents in India, Indonesia and Senegal: a UKRI GCRF Action Against Stunting Hub protocol paper

INTRODUCTION

In 2020, an estimated 150 million children under the age of 5 years were stunted. Stunting results from early-life adversity and it is associated with significant physical and cognitive deficit, lifelong socioeconomic disadvantage and reduced life expectancy. There is a need to understand the causes of stunting and its effects in order to develop strategies to avoid it and to mitigate the consequences once stunting has occurred. Epigenetics is an important mechanism through which early-life factors are thought to influence biological function, with long-term consequences. We describe a series of epigenetic studies designed to understand how early-life adversity results in stunting and to inform the development of practical tools such as predictive markers and therapeutic targets. This work is part of the UKRI GCRF Action Against Stunting Hub.

METHODS AND ANALYSIS

The project-in India, Indonesia and Senegal-comprises an observational study of mothers, fathers, and offspring (n=500) spanning the first 1000 days of life, and an intervention study in each country. Epigenetic status (DNA methylation) is determined in saliva from babies collected within 1 month of birth and again at 18 months of age, and from mothers and fathers around the time of birth. Epigenome-wide analysis is carried out using the Illumina EPIC array, augmented by high-definition sequencing approaches. Statistical analysis is carried out at the level of candidate genes/regions, higher dimensional epigenetic states and epigenome-wide association. Data analysis focuses on the determinants of stunting, the effectiveness of interventions, population comparisons and the link between epigenetics and other thematic areas, which include anthropometry, microbiome, gut health, parasitology, cognition, nutrition, food hygiene and water sanitation, food systems and the home environment.

ETHICS AND DISSEMINATION

This study has been approved by the relevant Ethics Committees in Indonesia, India and Senegal, and the UK. Research data will be published and posted in public repositories.

Household polluting cooking fuels and intrinsic capacity among older population: A harmonized nationwide analysis in India and China

BACKGROUNDS

Household polluting cooking fuels, as an important changeable behavior, are related to various detrimental health effects among the elderly. There is limited research on the association between polluting cooking fuel use and intrinsic capacity (IC) as an indicator of healthy aging. This study aimed to evaluate the above-mentioned association in India and China, where polluting cooking fuel use is common.

METHODS

We enrolled 33,803 participants aged ≥60 years from two nationally representative studies: the Longitudinal Aging Study in India and the China Health and Retirement Longitudinal Study. Polluting cooking fuel use was defined as a self-report of using wood, coal, kerosene, crop residue, or dung. IC was measured by five aspects, including locomotion, cognition, vitality, sensory, and psychological capacity. The random-effects mixed linear regression and logistic regression with population weighting were performed. Multivariable-adjusted model and propensity score were used to adjust for potential confounders.

RESULTS

A total of 47.54 % and 59.32 % of elderly adults reported primary cooking using polluting fuels in India and China, respectively. Using polluting cooking fuels was consistently associated with IC decline; particularly, cognitive capacity was the most susceptible domain. In India, participants using polluting fuels had a 1.062 (95 % confidence interval [CI]: 1.047-1.078) times risk for IC deficits, whereas more prominent results were observed in China (odds ratio [OR]: 2.040, 95 % CI: 1.642-2.533). Such harmful effects might be alleviated by transferring from polluting to clean fuels. Additionally, the duration of polluting fuel use was also positively associated with IC deficits.

CONCLUSION

This study provided substantial public implications on healthy aging for the elderly population at a global scale, strengthening the importance of health education and policy efforts to accelerate the transition from polluting to clean fuels.

Association between residential proximity to major roadways and chronic multimorbidity among Chinese older adults: a nationwide cross-sectional study

BACKGROUND

Multiple negative health outcomes were linked to residential proximity to major roadways. Nevertheless, there is limited knowledge regarding the association between residential proximity to major roadways and chronic multimorbidity.

METHODS

We used data from the 2018 wave of the Chinese Longitudinal Healthy Longevity Survey, which included 12,214 individuals aged ≥ 60. We derived the residential proximity to major roadways from self-reported data, defining chronic multimorbidity as the presence of two or more concurrent chronic diseases. A binary logistic regression model was utilized to investigate the association between residential proximity to major roadways and chronic multimorbidity. The model accounted for some demographic features, socioeconomic conditions, social participation, and health conditions. Subsequently, we conducted subgroup analyses to examine potential interaction effects.

RESULTS

Residential proximity to major roadways was associated with chronic multimorbidity, even after adjusting for confounding factors. Compared with those living > 300 m from major roadways, the OR for those living 201-300 m, 101-200 m, 50-100 m, and < 50 m were increased. When subgroup analyses were conducted using a cutoff point of 200 m, the risk of chronic multimorbidity associated with residential proximity to major roadways was stronger in participants with education levels > 6 years (P = 0.017).

CONCLUSION

Our findings provide important implications for improving residential area siting, transportation policies, and environmental regulations to reduce the risk of chronic multimorbidity caused by traffic-related exposure.

Spatiotemporal characteristics and driving mechanisms of household energy transition in rural China: Micro-evidence from 2005 to 2017

Facilitating the household energy transition in rural China conducive to mitigate climate change, improve population health, and achieve 'carbon peaking and carbon neutrality' goals. However, there was no consensus in existing research on the regularity of rural household energy transition from a micro perspective. Based on data from 339 villages spanning 2005-2017, with the help of kernel density estimation(KDE), exploratory spatial data analysis (ESDA), and logistic regression, we evaluated the effectiveness of household energy transition and comprehensively analyzed the temporal and spatial characteristics of the energy transition process from geographic perspective, revealed the driving mechanisms behind household energy transition, with important findings. (i) In 2005-2015, 19.22 % and 13.08 % of rural households achieved fuel and heating transition, but there were evident regional differences and correlation effects in energy transition. (ii) The proportion of energy transitions increases, yet always a polarised lattice phenomenon, and the spatial adjacent spillover effect makes the energy transition present the spatial pattern of 'villages divided into clusters'. (iii) The drivers of different types household energy transition vary, income and topography continued to limit the energy transition of rural households. Therefore, designing differentiated policies and pathways by region is critical in the clean energy transition. In addition, local governments can increase incentives for clean energy utilization by setting reasonable subsidies for continuous clean energy transition.

Air particulate pollution exposure associated with impaired cognition via microbiota gut-brain axis: an evidence from rural elderly female in northwest China

This study aimed to reveal harm of exposure to indoor air pollution to cognitive function through "gut-brain-axis" among rural elderly residents. There were 120 participants recruited in rural villages of northwest China from December 2021 to February 2022. The cognitive level was assessed by eight-item ascertain dementia (AD) questionnaire, and indoor air pollution exposure was measured by air quality sensor. Inflammatory cytokines and oxidative stress-related index were detected in blood serum. Fecal samples were collected for gut microbiota analysis. The 120 participants were divided into impaired cognition (AD8) (81/67.5%) and cognition normal (NG) (39/32.5%). And there had more female in AD8 (FAD) (55/67.9%) than NG (FNG) (18/46.2%) (P = 0.003). Exposure of air pollution in FAD was higher than FNG (PM1, PM2.5, PM10, P < 0.001; NO2, P < 0.001; CO, P = 0.014; O3, P = 0.002). The risk of cognitive impairment increases 6.8%, 3.6%, 2.6%, 11%, and 2.4% in female for every 1 μg/m3 increased in exposure of PM1, PM2.5, PM10, NO2, and O3, separately. And GSH-Px and T-SOD in FAD were significantly lower than the FNG group (P = 0.011, P = 0.019). Gut microbiota in FAD is disordered with lower richness and diversity. Relative abundance of core bacteria Faecalibacterium (top 1 genus) in FAD was reduced (13.65% vs 19.81%, P = 0.0235), while Escherichia_Shigella and Akkermansia was increased. Correlation analysis showed Faecalibacterium was negatively correlated with age, and exposure of O3, PM1, PM2.5, and PM10; Akkermansia and Monoglobus were positively correlated with exposure of PM1, PM2.5 and PM10; Escherichia_Shigella was significantly positively correlated with NO2. Indoor air pollution exposure impaired cognitive function in elderly people, especially female, which may cause systemic inflammation, dysbiosis of the gut microbiota, and ultimately leading to early cognitive impairment through the gut-brain axis.

Moss-bag technique as an approach to monitor elemental concentration indoors

The moss-bag technique has been used for many decades to monitor outdoor pollution. More recently, however, the method has been used to monitor indoor air pollution (IAP), as humans spend the majority of their time indoors. The purpose of the research conducted was to evaluate indoor air pollution using active moss biomonitoring. Pleurozium schreberi moss bags were exposed for two seasons (summer and winter), hanging over tile stoves and coal stoves. The selected elements: Al, Cu, Cd, Co, Pb, Zn, V, Ba, Cr, Fe, Mn, Sr, P, Ni, and S were determined by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) and, for Hg, by a direct mercury analyzer. The study found the exposure season affected the concentrations of selected elements in 62.5% of cases, and their source was identified. The average concentrations of Co, Ba, Cr, and Sr were higher, and statistically significant, in winter, after a 12-week exposure period of the mosses, regardless of the type of heating or cooking stove owned. The higher phosphorus concentrations obtained in summer indicate physiological stress caused by unfavorable winter exposure conditions. In the future, the number of species used to assess indoor air pollution should be increased and the range of pollutants expanded, along with the identification of their sources, taking residents' lifestyles into account.

Impact of indoor environment on children's pulmonary health

INTRODUCTION

A child's living environment has a significant impact on their respiratory health, with exposure to poor indoor air quality (IAQ) contributing to potentially lifelong respiratory morbidity. These effects occur throughout childhood, from the antenatal period through to adolescence. Children are particularly susceptible to the effects of environmental insults, and children living in socioeconomic deprivation globally are more likely to breathe air both indoors and outdoors, which poses an acute and long-term risk to their health. Adult respiratory health is, at least in part, determined by exposures and respiratory system development in childhood, starting in utero.

AREAS COVERED

This narrative review will discuss, from a global perspective, what contributes to poor IAQ in the child's home and school environment and the impact that indoor air pollution exposure has on respiratory health throughout the different stages of childhood.

EXPERT OPINION

All children have the right to a living and educational environment without the threat of pollution affecting their health. Action is needed at multiple levels to address this pressing issue to improve lifelong respiratory health. Such action should incorporate a child's rights-based approach, empowering children, and their families, to have access to clean air to breathe in their living environment.

Joint effects of prenatal exposure to air pollution and pregnancy-related anxiety on birth weight: A prospective birth cohort study in Ma'anshan, China

BACKGROUND

A growing number of studies have shown that prenatal exposure to chemical and non-chemical stressors has effects on fetal growth. The co-exposure of both better reflects real-life exposure patterns. However, no studies have included air pollutants and pregnancy-related anxiety (PrA) as mixtures in the analysis.

METHOD

Using the birth cohort study method, 576 mother-child pairs were included in the Ma'anshan Maternal and Child Health Hospital. Evaluate the exposure levels of six air pollutants during pregnancy using inverse distance weighting (IDW) based on the pregnant woman's residential address and air pollution data from monitoring stations. Prenatal anxiety levels were assessed using the PrA Questionnaire. Generalized linear regression (GLR), quantile g-computation (QgC) and bayesian kernel machine regression (BKMR) were used to assess the independent or combined effects of air pollutants and PrA on birth weight for gestational age z-score (BWz).

RESULT

The results of GLR indicate that the correlation between the six air pollutants and PrA with BWz varies depending on the different stages of pregnancy and pollutants. The QgC shows that during trimester 1, when air pollutants and PrA are considered as a whole exposure, an increase of one quartile is significantly negatively correlated with BWz. The BKMR similarly indicates that during trimester 1, the combined exposure of air pollutants and PrA is moderately correlated with a decrease in BWz.

CONCLUSION

Using the method of analyzing mixed exposures, we found that during pregnancy, the combined exposure of air pollutants and PrA, particularly during trimester 1, is associated with BWz decrease. This supports the view that prenatal exposure to chemical and non-chemical stressors has an impact on fetal growth.

Association of indoor solid fuel use and long-term exposure to ambient PM2.5 with sarcopenia in China: A nationwide cohort study

BACKGROUND

Little is known about the association between air pollution exposure and sarcopenia in Asia. We aimed to investigate the associations of indoor solid fuel use and long-term exposure to ambient fine particulate matter (PM2.5) with sarcopenia in China.

METHODS

Using a nationally population-representative study, 12,723 participants aged at least 45 years across 125 cities from the China Health and Retirement Longitudinal Study were enrolled in 2011, and further 3110 participants were followed up until 2013. Sarcopenia status was classified according to the Asian Working Group for Sarcopenia 2019 criteria. Household fuel types used for heating and cooking were assessed using a standard questionnaire. Ambient annual PM2.5 was estimated using satellite-based spatiotemporal models. Multinomial logistic regression as well as the multiplicative interaction and additive interaction analysis were used to explore the associations of indoor solid fuel and ambient PM2.5 with different status of sarcopenia.

RESULTS

Of the 12,723 participants, 6071 (47.7%) were men. In the cross-sectional analyses, compared with clean fuel, using solid fuel for heating and cooking, separately or simultaneously, was significantly associated with a higher risk of both possible sarcopenia and sarcopenia. Each 10 μg/m3 increment of PM2.5 was positively related to possible sarcopenia (adjusted odds ratio, [aOR] 1.04, 1.02-1.07) and sarcopenia (1.06, 1.01-1.12). We found a significant interaction between solid fuel use for heating and ambient PM2.5 exposure with possible sarcopenia. During a two-year follow-up, solid fuel use was associated with incident possible sarcopenia (aOR 1.59, 1.17-2.15). These associations did not differ by sex and age, while participants living in a house with poor cleanliness might have a higher risk of sarcopenia.

CONCLUSIONS

Indoor solid fuel use and long-term exposure to ambient PM2.5 were associated with a higher risk of sarcopenia among Chinese adults. These findings provide implications for promoting healthy aging by reducing air pollution.

Asthma and Other Respiratory Diseases of Children in Relation to Personal Behavior, Household, Parental and Environmental Factors in West China

Asthma and other respiratory diseases, which are of great concern in public health, are paid less attention in areas that are less economically developed. This research aimed to study the prevalence of critical respiratory diseases of children living in West China and figure out the potential influencing factors. A total of 575 children under the age of 14 were recruited from Xinjiang, China, to participate in the study in 2022. Information on activity patterns, socioeconomic and parental factors, and household and surrounding environment situations was obtained using a questionnaire survey. Logistic regression models were applied to estimate the odds ratios of respiratory disease prevalence in relation to behavior patterns, household, parental and environmental factors, respectively. The prevalence of ever doctor-diagnosed asthma, doctor-diagnosed bronchitis and current bronchitis were 4.7%, 19.0% and 14.4%, respectively. The prevalence of doctor-diagnosed pneumonia was 8.2%, which was two times higher in urban than rural areas. Longer annual heating duration was significantly associated with higher risks in children's asthma and bronchitis, with an odds ratio (OR) and 95% confidence interval (95% CI) of 3.363 (95% CI: 1.215-9.298) and 1.267 (95% CI: 1.002-1.601), respectively. Opening the window longer in autumn would lead to higher risks of bronchitis, with ORs of 1.165 and 1.133, respectively, for doctor-diagnosed bronchitis and current bronchitis. Residential air pollution and having a residence close to waste incineration plant or garbage station were, respectively, significantly associated with higher risks of doctor-diagnosed bronchitis and asthma. Parental disease history was associated with a higher prevalence of children's asthma and respiratory diseases, whereas breastfeeding and doing physical exercise were, respectively, significantly associated with a lower risk of asthma. A high prevalence of respiratory diseases in children in West China may be partly attributed to longer annual heating time, opening windows longer in autumn, surrounding environmental pollution, as well as parental disease history, whereas promoting physical activity and breastfeeding could be an effective measure to reduce the risk of childhood asthma in West China.

Association between heavy metal exposures and the prevalence of pelvic inflammatory disease: a cross-sectional study from the National Health and Nutrition Examination Survey 2013-2018

Pelvic inflammatory disease (PID) is a common medical condition in women. However, the correlation between exposure to heavy metals, including cadmium (Cd), lead (Pb), manganese (Mn), mercury (Hg), and selenium (Se), and PID, is unclear. Using a large sample size from the National Health and Nutrition Examination Survey, these relationships were studied and verified. PID diagnosis was acquired through a self-reported questionnaire (2013-2018). Heavy metal exposure (Cd, Pb, Mn, Hg, and Se) was measured using mass spectrometry of blood samples. Covariate data were obtained through questionnaires and physical tests. Individuals with complete covariate data were included in the study. The relationship between heavy metal exposure (Cd, Pb, Mn, Hg, and Se) and PID was demonstrated using logistic regression analysis, weighted quantile sum (WQS) regression analysis, and restricted cubic splines (RCS). Overall, 2743 participants were included. Of these, 183 were diagnosed with PID. Through weighted univariate and multivariate regression analyses, the heavy metals of Cd and Pb were positively correlated with the prevalence of PID. However, no significant relationship was observed in the heavy metals of Mn, Hg, and Se. The joint effect of heavy metals further confirmed the important role of Cd and Pb in WQS analysis. After visualizing the RCS, significant curved and linear relationships were observed for Cd and Pb, respectively. Most subgroup analyses confirmed these results. In conclusion, exposure to Cd was nonlinearly correlated with the risk of PID, whereas exposure to Pb showed a linear relationship. Our findings increase the awareness of the environmental effects of exposure to heavy metals in PID. However, further studies are needed to elucidate the causality and underlying mechanisms between heavy metal exposure and the prevalence of PID.

Achieving better indoor air quality with IoT systems for future buildings: Opportunities and challenges

With the development of IoT technology and low-cost indoor air quality (IAQ) sensors, the IoT-based IAQ monitoring platform has garnered significant research interest and demonstrated its potential in enhancing IAQ management. This study presents a comprehensive review of previous research on the development and application of IoT-based IAQ platforms in different built environments. It offers detailed insights into the design and implementation of recent IoT-based IAQ platforms. The findings indicate that the IoT-based IAQ platforms are able to provide reliable information for IAQ monitoring. To ensure quality control of the IoT-based IAQ platform, it is suggested to replace the sensors every 4-6 months for reliable monitoring. In another aspect, integrating data-driven technology into the platform is crucial for IAQ prediction and efficient control of ventilation systems, leveraging the wealth of data available from the IoT platform. According to recent studies that applied data-driven algorithms for IAQ management, it can be confirmed that the data-driven algorithms are able to prompt IAQ by providing either more information or a control strategy. However, it should be noted that only 9.1 % of the developed platforms integrated data-driven models for IAQ management. Based on our findings, current challenges and further opportunities are discussed. Future studies should focus on integrating data-driven algorithms into IoT-based IAQ platforms and developing digital twins that can be used for real building IAQ management. However, there is obvious tension between controlling ventilation for energy efficiency versus better air quality. It is important to make a balance between energy efficiency and better air quality according to the current situations of specific built environments. Also, the next generation of IoT-based IAQ platforms should include occupants in the loop to create a more occupant-centric IAQ management approach.

Reduction of household air pollution through clean fuel intervention and recovery of cellular immune balance

BACKGROUND

We conducted a clean fuel intervention trial (Bangladesh Global Environmental and Occupational Health (GEOHealth) (NCT02824237) with liquefied petroleum gas (LPG) for 26 months among rural Bangladeshi women chronically exposed to household air pollution (HAP) from biomass fuel (BMF) use. We aimed to evaluate the effect of HAP reduction following LPG intervention on immune response outcome.

METHODS

We supplied LPG cook stove and refills in cylinder in 200 households for 26 months. We measured personal exposure to HAP [particulate matter 2.5 (PM2·5), black carbon (BC) and carbon monoxide (CO)] in 200 women (main cook) by personal monitors at pre- and post-intervention. Immune function was assessed before and after intervention, in blood collected within 2 weeks of HAP measurements. Primary endpoints included reduction in HAP, lymphocyte proliferation and oxidative stress response, and alterations in T and B cell proportions.

FINDINGS

Exclusive LPG use for 26 months resulted in significant reduction in PM2·5 (43.5%), BC (13%) and CO (48%) exposure in the women. For one unit decrease in BC, Treg cells and memory B cells increased by 7% and 34% respectively, in the peripheral circulation. One unit decrease in CO was significantly associated with increase in early B cells and plasmablasts by 66% and 5% respectively. For one unit decrease in BC, percent-dividing cells, proliferation and expansion indices increased by 2%, 0.4%, and 1%, respectively.

INTERPRETATION

Reduced personal exposure to HAP through clean fuel intervention was related to a return towards cellular immune balance.

The impact of household fuel usage on adverse pregnancy outcomes in rural Ma'anshan City, Anhui Province: a birth cohort study

The combustion of cooking fuels generates detrimental gases significantly impacting human health, particularly for vulnerable populations like expectant mothers. Prenatal exposure of such hazardous emissions raises the probability of adverse pregnancy outcomes, including preterm birth (PTB) and low birth weight (LBW). Our research aims to explore the association between cooking fuel utilization and adverse birth outcomes in rural Ma'anshan, Anhui Province. A prospective cohort study was executed, employing the Maternal and Infant Health Assessment questionnaire to classify fuels into clean (natural gas, electricity) and polluting energy sources (coal, coal gas, firewood). Multivariate logistic regression models were conducted to evaluate the association between fuel consumption and postpartum maternal and infant outcomes. Among the 442 surveyed pregnant women, 38.2% (N=169) utilized polluting fuels. After adjusting for covariates such as age and BMI, the relative risks of preterm birth, low birth weight, and postpartum hemorrhage in the polluting fuel group compared to the clean fuel group were OR: 3.27, 95% CI: 1.34, 8.00; OR: 3.50, 95% CI: 1.12, 10.90; and OR: 3.18, 95% CI: 1.06, 9.46, respectively. These results indicate that the usage of polluting fuels during pregnancy may heighten the risk of adverse birth outcomes. Consequently, additional research is advised to mitigate the harmful emissions generated by cooking fuels and advocate for clean energy adoption, enhancing maternal and infant well-being.

Particulate Matter Pollution Remains a Threat for Cardiovascular Health: Findings From the Global Burden of Disease 2019

Background Particulate matter (PM) pollution is a significant risk factor for cardiovascular diseases, causing substantial disease burden and deaths worldwide. This study aimed to investigate the global burden of cardiovascular diseases attributed to PM from 1990 to 2019. Methods and Results We used the GBD (Global Burden of Disease) study 2019 to investigate disability-adjusted life-years (DALYs), years of life lost (YLLs), years lived with disability (YLDs), and deaths attributed to PM as well as its subgroups. It was shown that all burden measures' age-standardized rates for PM were in the same decreasing trend, with the highest decline recorded for deaths (-36.7%). However, the all-age DALYs increased by 31%, reaching 8.9 million in 2019, to which YLLs contributed the most (8.2 million [95% uncertainty interval, 7.3 million-9.2 million]). Men had higher deaths, DALYs, and YLLs despite lower years lived with disability in 2019 compared with women. There was an 8.1% increase in the age-standardized rate of DALYs for ambient PM; however, household air pollution from solid fuels decreased by 65.4% in the assessed period. Although higher in men, the low and high sociodemographic index regions had the highest and lowest attributed YLLs/YLDs ratio for PM pollution in 2019, respectively. Conclusions Although the total age-standardized rate of DALYs for PM-attributed cardiovascular diseases diminished from 1990 to 2019, the global burden of PM on cardiovascular diseases has increased. The differences between men and women and between regions have clinical and policy implications in global health planning toward more exact funding and resource allocation, in addition to addressing inequity in health care access.

Association between usage of household cooking fuel and congenital birth defects-18 months multi-centric cohort study in Nepal

BACKGROUND

- An estimated 240,000 newborns die worldwide within 28 days of birth every year due to congenital birth defect. Exposure to poor indoor environment contributes to poor health outcomes. In this research, we aim to evaluate the association between the usage of different type household cooking fuel and congenital birth defects in Nepal, as well as investigate whether air ventilation usage had a modifying effect on the possible association.

METHODS

- This is a secondary analysis of multi-centric prospective cohort study evaluating Quality Improvement Project in 12 public referral hospitals of Nepal from 2017 to 2018. The study sample was 66,713 women with a newborn, whose information was available in hospital records and exit interviews. The association between cooking fuel type usage and congenital birth defects was investigated with adjusted multivariable logistic regression. To investigate the air ventilation usage, a stratified multivariable logistic regression analysis was performed.

RESULTS

-In the study population (N = 66,713), 60.0% used polluting fuels for cooking and 89.6% did not have proper air ventilation. The prevalence rate of congenital birth defect was higher among the families who used polluting fuels for cooking than those who used cleaner fuels (5.5/1000 vs. 3.5/1000, p < 0.001). Families using polluting fuels had higher odds (aOR 1.49; 95% CI; 1.16, 1.91) of having a child with a congenital birth defect compared to mothers using cleaner fuels adjusted with all available co-variates. Families not using ventilation while cooking had even higher but statistically insignificant odds of having a child with congenital birth defects (aOR 1.34; 95% CI; 0.86, 2.07) adjusted with all other variates.

CONCLUSION

- The usage of polluted fuels for cooking has an increased odds of congenital birth defects with no significant association with ventilation. This study adds to the increasing knowledge on the adverse effect of polluting fuels for cooking and the need for action to reduce this exposure.

Air pollution weaken your muscle? Evidence from a cross-sectional study on sarcopenia in central China

BACKGROUND

As the world experiences a demographic shift towards aging populations, there will be a significant surge in the number of sarcopenia patients, along with an unprecedented expansion in the associated economic burden. The multitudinous risk factors for sarcopenia have been reported, but evidence for air pollution remains rare.

METHODS

This cross-sectional study employed multi-stage random sampling to select 1592 participants over 40 years of age from Hubei Province. Daily mean concentrations of air pollutants were collected ChinaHighAirPollutants dataset. Unconditional logistic regression models were utilized to investigate the associations between air pollution and sarcopenia.

RESULTS

For each 1 μg/m³ increase in PM_2.5, PM₁₀, SO₂ and O₃, there were corresponding elevations of 11.1% [95% confidence interval (CI): 4.9, 17.7], 4.3% (95% CI: 1.4, 7.2), 22.6% (95% CI: 7.2, 40.1) and 9.3% (95% CI: 0.7, 18.7) in the risk of sarcopenia, respectively. The associations of PM_2.5/PM₁₀/O₃-sarcopenia were more pronounced in females, with corresponding odds ratios (ORs) and 95% CIs of 1.179 (1.062, 1.310), 1.079 (1.027, 1.135) and 1.180 (1.026, 1.358), separately. Additionally, individuals residing in rural areas were more susceptible to the effects of PM_2.5 and PM₁₀. Current/ever smokers or drinkers were also at higher risk of developing sarcopenia caused by PM_2.5, PM₁₀ and O₃ exposure. Mixture analyses show a surge of 48.4% (95% CI: 3.6%, 112.5%) in the likelihood of suffering from sarcopenia, and the joint impacts of the air pollution were mainly driven by PM_2.5.

CONCLUSIONS

Our results produced evidence for a relationship between air pollution exposure and the increased prevalence of sarcopenia in China. Public health and relevant departments should make efforts to prevent sarcopenia, particularly in China experiencing rapid demographic aging.

The effects of fine particulate matter, solid fuel use and greenness on the risks of diabetes in middle-aged and older Chinese

BACKGROUND

Previous studies provided clues that environmental factors were closely related to diabetes incidence. However, the evidence from high-quality and large cohort studies about the effects of PM_2.5, solid fuel use and greenness on the development of diabetes among middle-aged and older adults in China was scarce.

OBJECTIVE

To separately investigate the independent effects of PM_2.5, solid fuel use and greenness on the development of diabetes among middle-aged and older adults.

METHODS

A total of 9242 participants were involved in this study extracted from the China Health and Retirement Longitudinal Study. Time-varying Cox regression was applied to detect the association of diabetes with PM_2.5, solid fuel use and greenness, separately. The potential interactive effect of air pollution and greenness were explored using the relative excess risk due to interaction (RERI).

RESULTS

Per 10 μg/m³ increases in PM_2.5 were associated with 6.0% (95% CI: 1.9, 10.2) increasing risks of diabetes incidence. Females seemed to be more susceptible to PM_2.5. However, the effects of solid fuel use only existed in older and lower BMI populations, with hazard ratios (HRs) of 1.404 (1.116, 1.766) and 1.346 (1.057, 1.715), respectively. In addition, exposure to high-level greenness might reduce the risks of developing diabetes [HR = 0.801 (0.687, 0.934)]. Weak evidence of the interaction effect of PM_2.5/solid fuel use and greenness on diabetes was found.

SIGNIFICANCE

Both PM_2.5 and solid fuel use were associated with the increasing incidence of diabetes. In addition, high-level greenness might be a beneficial environmental factor for reducing the risks of developing diabetes. All in all, our findings might provide valuable references for public health apartments to formulate very fruitful policies to reduce the burden of diabetes.

IMPACT STATEMENT

Both PM_2.5 and solid fuel use were associated with the increasing incidence of diabetes while high-level greenness was not, which might provide valuable references for public health apartments to make policies.

Critical review on emerging health effects associated with the indoor air quality and its sustainable management

Indoor air quality (IAQ) is one of the fundamental elements affecting people's health and well-being. Currently, there is a lack of awareness among people about the quantification, identification, and possible health effects of IAQ. Airborne pollutants such as volatile organic compounds (VOCs), particulate matter (PM), sulfur dioxide (SO2), carbon monoxide (CO), nitrous oxide (NO), polycyclic aromatic hydrocarbons (PAHs) microbial spores, pollen, allergens, etc. primarily contribute to IAQ deterioration. This review discusses the sources of major indoor air pollutants, molecular toxicity mechanisms, and their effects on cardiovascular, ocular, neurological, women, and foetal health. Additionally, contemporary strategies and sustainable methods for regulating and reducing pollutant concentrations are emphasized, and current initiatives to address and enhance IAQ are explored, along with their unique advantages and potentials. Due to their longer exposure times and particular physical characteristics, women and children are more at risk for poor indoor air quality. By triggering many toxicity mechanisms, including oxidative stress, DNA methylation, epigenetic modifications, and gene activation, indoor air pollution can cause a range of health issues. Low birth weight, acute lower respiratory tract infections, Sick building syndromes (SBS), and early death are more prevalent in exposed residents. On the other hand, the main causes of incapacity and early mortality are lung cancer, chronic obstructive pulmonary disease, and cardiovascular disorders. It's crucial to acknowledge anticipated research needs and implemented efficient interventions and policies to lower health hazards.

Global, regional, and national burden of preterm birth attributable to ambient and household PM2.5 from 1990 to 2019: Worsening or improving?

BACKGROUND

Maternal exposure to fine particular matter (PM_2.5) during pregnancy, including ambient and household PM_2.5, has been linked with increased risk of preterm birth (PTB). However, the global spatio-temporal distribution of PTB-related deaths and disability-adjusted life years (DALYs) attributable to PM_2.5 is not well documented. We estimated the global, regional, and national patterns and trends of PTB burden attributable to both ambient and household PM_2.5 from 1990 to 2019.

METHODS

Based on the Global Burden of Disease Study (GBD) 2019 database, we obtained the numbers of deaths and DALYs as well as age-standardized mortality rate (ASMR) and age-standardized DALY rate (ASDR) of PTB attributable to total, ambient, and household PM_2.5 by socio-demographic index (SDI) and sex during 1990-2019. The average annual percentage changes (AAPCs) were calculated to assess the temporal trends of attributable burdens.

RESULTS

In 2019, 126,752 deaths and 11.3 million DALYs related to PTB worldwide (two-thirds in Western Sub-Saharan Africa and South Asia) could be caused by excess PM_2.5 above the theoretical minimum-risk exposure level (TMREL), of which 39 % and 61 % were attributable to ambient PM_2.5 and household PM_2.5, respectively. From 1990 to 2019, the global ASMR due to ambient PM_2.5 increased slightly by 7.08 % whereas that due to household PM_2.5 decreased substantially by 58.81 %, although the latter still dominated the attributable PTB burden, especially in low and low-middle SDI regions. Similar results were also observed for ASDRs. In addition, PTB burden due to PM_2.5 was higher in male infants and in lower SDI regions.

CONCLUSIONS

Globally in 2019, PM_2.5 remains a great concern on the PTB burden, especially in Western Sub-Saharan Africa and South Asia. Between 1990 and 2019, age-standardized burden of PTB due to ambient PM_2.5 increased globally, while that due to household PM_2.5 decreased markedly but still dominated in low and low-middle SDI regions.

Kitchen ventilation attenuated the associations of solid fuel use and long duration for cooking with the increased prevalence of normocytic anemia

Evidence on the potential risk factors of normocytic anemia, the most prevalent morphology subtype of anemia, was scarce to date. The purpose of this study is to investigate the association of cooking fuel use or daily cooking duration with normocytic anemia and further explore the modification effect of mechanical ventilation. Participants totaling 29,448 from the Henan Rural Cohort were included in this study. Normocytic anemia was defined by hemoglobin (based on the World Health Organization criteria) and mean corpuscular volume. Cooking-related data was collected by questionnaire, and the average daily cooking duration was calculated by the weekly cooking frequency and the cooking duration of each meal. Logistic regression models were employed to derive the combined and independent associations of cooking fuel type and daily cooking duration with normocytic anemia and the modification effect of ventilation. Compared with people who never cooked, both clean fuel and solid fuel users were significantly associated with increased prevalent normocytic anemia [OR (95% CI) = 1.196 (1.014, 1.411) and 1.335 (1.105, 1.614), respectively], and the effect estimates on normocytic anemia risk were 1.260 (1.043, 1.523), 1.320 (1.104, 1.578), and 1.310 (1.081, 1.587) in participants who daily cooked < 1 h/day, 1-2 h/day, and ≥ 2 h/day, respectively. These relationships were attenuated in subjects with mechanical ventilation (All P < 0.05). Cooking with solid fuel or for a long duration are independently associated with prevalent normocytic anemia in rural population, and mechanical ventilation could attenuate these associations. Future efforts to reduce the burden of anemia could target the universal use of ventilation and solid fuel use or cooking duration reduction.Clinical trial registration: The Henan Rural Cohort Study has been registered at Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). Date of registration: 06 July, 2015. http://www.chictr.org.cn/showproj.aspx?proj=11375.

Gas composition during thermochemical conversion of dry solid fuels and waste-derived slurries

Coal has long remained a promising and widely used energy resource all over the world. Special emphasis is usually put on the research and development of environmentally friendly technologies for the use of coal and coal processing waste. The development of slurry fuels based on coal waste is one of the promising ways to use raw materials with energy potential, recover wastes, and reduce the environmental load. However, no combustion technology has yet been created for heterogeneous wastes as water-based slurries. The physical principles and parameters of the corresponding processes have not been studied adequately. In this research, the environmental combustion indicators (CO₂, CO, H₂, NO_x, and SO₂ concentrations) of slurries based on water and petrochemical, coal, and plant wastes were analyzed for the first time in a wide range of temperatures covering all the typical stages of thermochemical fuel conversion: pyrolysis (400-700 °C), gasification (700-900 °C), and combustion (700-1000 °C). We established the key patterns and aspects of changes in gas concentrations at all the main stages during the thermal decomposition of fuels. The use of water-based fuels at the pyrolysis stage was notable for up to 96% higher concentrations of the key combustible gases (CO, H₂). The temperature extrema were 50-100 °C lower than those of bituminous coal. In terms of the key anthropogenic emissions (CO₂, NO_x, and SO₂), the combustion of slurries also appeared to be 20-77% more environmentally friendly than that of coal depending on the temperature conditions and fuel composition. The maximum positive effect from adding biomass to coal-water slurries was achieved in the temperature range of 850 to 1000 °C. The research findings can be used for developing the technologies for thermal recovery of waste as water slurries, in particular, by intensifying the pyrolysis, gasification, and combustion.

The increased medical burden associated with frailty is partly attributable to household solid fuel: A nationwide prospective study of middle-aged and older people in China

BACKGROUND

Frail individuals often face a high medical burden, and household solid fuel use is associated with a range of functional declines or diseases, but evidence on the relationship between household solid fuel and frailty and the resulting medical burden is limited. We aim to investigate the effect of household solid fuel on frailty and further quantify how much of the increased medical burden associated with frailty is attributable to household solid fuel.

METHODS

The prospective data were from the China Health and Retirement Longitudinal Study, 4685 non-frail participants at baseline were included. Inverse probability weighting was used to balance the covariates between groups. The modified Poisson regression was used to analyze the association of household solid fuel (including baseline and switching across three-wave survey) with frailty, and the generalized linear model was used to analyze the association of frailty with the change in medical burden. Further, the increased medical burden associated with frailty attributable to household solid fuel was quantified.

RESULTS

Using solid fuel for cooking (RR = 1.29, 95%CI, 1.07-1.57), heating (RR = 1.38, 95%CI, 1.09-1.73), or both (RR = 1.40, 95%CI, 1.05-1.86) had a higher risk of frailty than using clean fuel. In addition, the risk of frailty generally increases with the times of solid fuel use across the three-wave survey. Then, frailty participants had a greater increase in the annual number of hospitalizations (β = 0.11, 95%CI, 0.02-0.19) and annual costs of hospitalizations (β = 2953.35, 95%CI, 1149.87-4756.83) than those non-frailty. Heating coal caused the largest frailty-related increase in the annual number of hospitalizations and annual costs of hospitalizations, with 0.04 and 1195.40, respectively.

CONCLUSION

The increased medical burden associated with frailty was partly attributable to household solid fuel, which suggested that intervention targeting household solid fuels can delay frailty and thus reduce individual medical burden.

Indoor air pollution and human ocular diseases: Associated contaminants and underlying pathological mechanisms

People spend a long time indoors, especially young children. The risk of indoor pollution on human health is one of the current hotspots in environmental and public health. The human ocular surface is highly susceptible to indoor environment quality. Epidemiological data have linked human ophthalmological disorders with exposure to indoor pollution. In this review, we summarized the adverse impacts of indoor pollution on the human ocular surface. Several studies demonstrated that indoor contaminants including particulate matter, volatile/semi-volatile organic compounds, heavy metals, and fuel combustion and cigarette smoke exposure were associated with the incidence of human dry eye, conjunctivitis, glaucoma, cataracts, age-related macular degeneration, and keratitis. In addition, toxicological investigations revealed that indoor pollution-induced induced chronic inflammation, oxidative damage, and disruption of tight junctions are the main underlying pathological mechanisms for ocular surface diseases. Taken together, this review may expand the understanding of pollution-induced eye disorder and highlight the importance of reducing associated contaminants to decrease their detrimental effects on human eyes.

Long-term air pollution and risk of amyotrophic lateral sclerosis mortality in the Women's Health Initiative cohort

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with no cure. Although the etiology of sporadic ALS is largely unknown, environmental exposures may affect ALS risk.

OBJECTIVE

We investigated relationships between exposure to long-term ambient particulate matter (PM) and gaseous air pollution (AP) and ALS mortality.

METHODS

Within the Women's Health Initiative (WHI) cohort of 161,808 postmenopausal women aged 50-79 years at baseline (1993-1998), we performed a nested case-control study of 256 ALS deaths and 2486 matched controls with emphasis on PM constituents (PM_2.5, PM₁₀, and coarse PM [PM₁₀-_2.5]) and gaseous pollutants (NO_x, NO₂, SO₂, and ozone). Time-varying AP exposures estimates were averaged 5, 7.5, and 10 years prior to ALS death using both a GIS-based spatiotemporal generalized additive mixed model and ordinary kriging (empirical and multiple imputation, MI). Conditional logistic regression was used to estimate the relative risk of ALS death.

RESULTS

In general, PM_2.5 and PM₁₀-related risks were not significantly elevated using either method. However, for PM_10-2.5, odds ratios (ORs) were >1.0 for both methods at all time periods using MI and empirical data for PM_10-2.5 (coarse) except for 5 and 7.5 years using the kriging method with covariate adjustment.

CONCLUSION

This investigation adds to the body of information on long-term ambient AP exposure and ALS mortality. Specifically, the 2019 US Environmental Protection Agency (EPA) Integrated Science Assessment summarized the neurotoxic effects of PM_2.5, PM_10, and PM₁₀-_2.5. The conclusion was that evidence of an effect of coarse PM is suggestive but the data is presently not sufficient to infer a causal relationship. Further research on AP and ALS is warranted. As time from symptom onset to death in ALS is ∼2-4 years, earlier AP measures may also be of interest to ALS development. This is the first study of ALS and AP in postmenopausal women controlling for individual-level confounders.

Effects of ambient air pollution on outpatient visits for psoriasis in Wuhan, China: a time-series analysis

BACKGROUND

Psoriasis can be provoked by both external and internal factors. The effects of environmental factors on psoriasis remain unclear.

OBJECTIVES

To investigate the effects of air pollution on outpatient visits for psoriasis.

METHODS

A distributed lag nonlinear model following quasi-Poisson regression was used to evaluate the lag effects of air pollutants on psoriasis outpatient visits, adjusting for potential confounders. Stratified analyses were performed to identify potential effect modifications by sex, age and season.

RESULTS

In total, 13 536 outpatient visits for psoriasis were recorded in Wuhan, China from 1 January 2015 to 31 December 2019. In the single-pollutant model, exposures to particulate matter (PM) smaller than 2.5 μm (PM2.5), PM smaller than 10 μm (PM10), NO2 and SO2 were found to be significantly associated with increased daily psoriasis outpatient visits. For the largest effects, a 10-μg m-3 increase in concentrations of PM2.5 (lag1), PM10 (lag1), NO2 (lag0) and SO2 (lag3) corresponded to 0.32% [95% confidence interval (CI) 0.01-0.63], 0.26% (95% CI 0.05-0.48), 0.98% (95% CI 0.01-1.96) and 2.73% (95% CI 1.01-4.47) increases in psoriasis outpatient visits, respectively. In the two-pollutant model, only NO2 showed significant and stable effects on the outpatient visits for psoriasis.

CONCLUSIONS

Ambient air pollution, especially NO2, appears to be significantly associated with an increased risk of outpatient visits for psoriasis in Wuhan, China. Air pollution control and exposure prevention could be effective measures to relieve the symptoms of psoriasis among these patients.

Effects of pain and depression on the relationship between household solid fuel use and disability among middle-aged and older adults

Household air pollution (HAP) is suggested to increases people's risk of disability, but mediating mechanisms between HAP and disability remains under-investigated. The aim of this study was to investigate the underlying mechanisms between household air pollution and disability in middle-aged and older adults (i.e., older than 45 years) using a nationally representative prospective cohort. In total, 3754 middle-aged and older adults were selected from the China Health and Retirement Longitudinal Study. Correlation analysis and logistic regression analysis were employed to estimate the association between HAP, pain, depression and disability. Finally, three significant mediation pathways through which HAP directly impacts disability were found: (1) pain (B = 0.09, 95% CI 0.01, 0.02), accounting for 15.25% of the total effect; (2) depression (B = 0.07, 95% CI 0.004, 0.02), accounting for 11.86% of the total effect; (3) pain and depression (B = 0.04, 95% CI 0.003, 0.01), accounting for 6.78% of the total effect. The total mediating effect was 33.89%. This study clarified that HAP can indirectly affect disability through the respective and serial mediating roles of pain and depression. These findings potentially have important implications for national strategies concerning the widespread use of clean fuels by citizens.

Impact of solid fuel usage on respiratory symptoms among reproductive aged women: a cross-sectional study in Sri Lanka

BACKGROUND

Worldwide, around 3 billion people rely on solid fuel for their daily energy needs. Household air pollution secondary to solid fuel burning is a major risk factor for respiratory mobility among vulnerable populations. This study aimed to investigate the respiratory symptoms associated with solid fuel usage, the level of kitchen fuel smoke exposure and its association with respiratory symptoms among reproductive-aged women in Sri Lanka, where most households exclusively use firewood as the primary cooking fuel.

METHODS

A descriptive cross-sectional study was conducted among 403 reproductive-aged women (15 to 49 years) in the Central Province, Sri Lanka. A structured interviewer-administered questionnaire was used to collect data, and an exposure assessment was done using a breath carbon monoxide monitor.

RESULTS

After adjusting for potential confounding factors by the logistic regression models, the odds ratios (OR) of the liquid petroleum gas-only users for at least one respiratory symptom relevant to cough (OR: 0.39; 95% confidence interval [CI]: 0.20-0.78), wheezing (OR: 0.47; 95% [CI]: 0.26-0.87), and dyspnea (OR: 0.44; 95% CI: 0.24-0.84) were significantly lower compared to firewood-only users. The mean of expired air carbon monoxide and estimated carboxyhemoglobin levels of liquid petroleum gas-only users (2.84 ± 2.85 ppm; 1.08 ± 0.46%) were significantly lower than those of firewood-only users (5.27 ± 4.64 ppm; 1.47 ± 0.74%).

CONCLUSIONS

The use of firewood increased the risk of respiratory symptoms among reproductive-aged women in Sri Lanka. Health education focused on positive behavioral changes and effective and efficient clean energy policies are recommended to mitigate the risk associated with solid fuel smoke exposure.

Association between household air pollution from solid fuel use and risk of chronic diseases and their multimorbidity among Chinese adults

BACKGROUND

Given the increasing burden of chronic conditions, multimorbidity is now a priority for public health systems worldwide. However, the relationship between household air pollution (HAP) exposure with multimorbidity remains unclear.

METHODS

We used three waves data (2011, 2013, and 2015) including 19,295 participants aged ≥ 45 years from the China Health and Retirement Longitudinal Study, to investigate the association between HAP exposure from solid fuel use for heating and cooking with the risk of chronic multimorbidity. Multimorbidity was defined as the coexistence of two or more of 15 chronic diseases (hypertension, diabetes, dyslipidemia, heart disease, stroke, cardiovascular disease, chronic lung disease, asthma, kidney disease, liver disease, digestive disease, cancer, psychiatric disease, memory-related disease, and arthritis). Multiple logistic regression investigated the association between solid fuel use for heating and cooking, separately or simultaneously, with the risk of multimorbidity. Poisson regression with quasi-likelihood estimation explored whether solid fuel exposure could increase the number of morbidities. Stratified analyses and sensitivity analyses examined the effect modification and robustness of the association.

RESULTS

Of the 19,295 participants (mean age: 58.9 years), 40.9 % have multimorbidity. Compared with participants who used clean fuels for heating and cooking, the risk was higher in mixed fuel (adjusted odds ratio, aOR = 1.26, 95 %CI:1.16-1.36) and solid fuel users (aOR = 1.81, 1.67-1.98) separately. HAP from solid fuel use was positively associated with an increased number of morbidities (adjusted β = 0.329, 0.290 to 0.368), after controlling for confounders. Those living in a one-story building, with poor household cleanliness have a higher risk of multimorbidity. No significant modifications of those associations by the socio-demographic and behaviour characteristics was observed.

CONCLUSIONS

HAP from solid fuel use is associated with a high risk of chronic multimorbidity in Chinese adults. Our findings provide important implications for reducing chronic disease burden by restricting solid fuel use.

Associations between household solid fuel use and activities of daily living trajectories: A nationwide longitudinal study of middle and older adults in China

BACKGROUND

More studies focus on reporting the effects of ambient air pollution on physical activity while ignoring the hazards of indoor air pollution caused by household solid fuel use. Moreover, the impact of individual cognitive and depressive status on the health effects of air pollution is often overlooked.

OBJECTIVE

We examined the association between household solid fuel and activities of daily living (ADL) trajectories, and further examined this association in homogeneous subgroups of cognitive or depressive trajectories.

METHODS

Participants were from the China Health and Retirement Longitudinal Study, which conducted four waves of surveys from 2011 to 2018. We collected information on participants' household fuel use, then the ADL, cognitive and depressive performances were assessed in each wave. The latent growth mixture model (LGMM) was used to identify the optimal trajectory class for ADL, cognition, and depression. Then, the multinomial logistic regression was used to assess the association between solid fuel use and ADL trajectories in total population, as well as subgroups with different cognitive or depression trajectories. Furthermore, we examined the association between switching household fuel types and ADL trajectories across the four-wave survey.

RESULTS

The study sample included 7052 participants. We identified three ADL trajectory classes in total population: "Low-stable", "Moderate-anterior rise", and "Moderate-posterior rise". The multinomial logistic regression results showed that solid fuel use was associated with elevated odds for the adverse ADL trajectories, and this association was still shown in homogeneous subgroups of cognitive or depressive trajectories, while some effects were less significant. In addition, the risk of adverse ADL trajectories generally increases with the times of solid fuel use across the four-wave survey.

CONCLUSIONS

For middle and older adults in China, household solid fuel use was not conducive to physical activity development, which inspires that a further transformation to cleaner fuels is an important intervention.

Household air pollution and childhood stunting in China: A prospective cohort study

Background

Exposure to air pollution, especially indoor air pollution, was associated with an increased risk of childhood stunting. However, few longitudinal studies have explored the long-term impacts of indoor air pollution from household solid fuel use on child growth. We aimed to investigate the association between household air pollution (HAP) from solid fuel use and childhood stunting in Chinese children.

Method

The longitudinal data from the Chinese Family Panel Study over 2010-2018 were included in this study with a total of 6,013 children aged 0-15 years enrolled at baseline. Exposure to HAP was measured as solid fuel use for cooking, while solid fuel was defined as coal and firewood/straw according to the questionnaire survey. Stunting was defined as-2SD below the height-for-age z-score (HAZ) of the reference children. Logistic regression and Cox proportional hazards models with time-varying exposures were employed to estimate the association between childhood stunting and HAP exposure.

Results

At baseline, children with exposure to HAP from combusting solid fuels had a relatively higher risk of stunting [OR (95%CI): 1.42 (1.24-1.63)]. Among children without stunning at baseline, those living in households with solid fuel use had a higher stunting risk over an 8-year follow-up [HR (95%CI): 2.05 (1.64-2.57)]. The risk of childhood stunting was increased for those with HAP exposure from firewood/straw combustion or with longer exposure duration [HR (95%CI): 2.21 (1.74-2.79) and 3.01 (2.23-4.08), respectively]. Meanwhile, this risk was significantly decreased among children from households switching from solid fuels to clean fuels [HR (95%CI): 0.53 (0.39-0.70)]. Solid fuel use was suggested to be a mediator of the relationship between poor socioeconomic factors (i.e., household income and parental education level) and childhood stunning, with a mediation effect ranging from 11.25 to 14.26%.

Conclusions

HAP exposure from solid fuel use was associated with childhood stunting. Poor parental education and low household income might be socioeconomic factors contributing to solid fuel use. Therefore, household energy policies to facilitate access to clean fuels are urgently needed, especially for low-income and low-educated households.

Risk of functional disability associated with solid fuel use and population impact of reducing indoor air pollution in China: A national cohort study

Background

In China, numerous people still rely on solid fuel for household use. To date, the association between household solid fuel use and functional disability, and what benefit reducing household solid fuel usage could bring at the population level to China remain unclear.

Method

Data were from the China Health and Retirement Longitudinal Study. Household fuel was classified as clean or solid for cooking or heating. Functional disability was defined as difficulties in any item of activities of daily living (ADL) or instrumental activities of daily living (IADL). The associations of household fuel use in 2011 and its transitions between 2011 and 2013 with subsequent ADL or IADL disability were assessed with Cox proportional-hazards models. The number of events prevented in a population (NEPP) was generated to estimate how many functionally disabled patients could be prevented by reducing solid fuel usage.

Results

A total of 6,216 and 9,716 participants without prior ADL or IADL disability in 2011 were included. Solid (vs. clean) fuel users were more likely to develop ADL and IADL disability, with hazard ratios (HRs) and 95% confidence intervals (CIs) of 1.37 (1.28~1.45) and 1.38 (1.31~1.46) for using both solid cooking and heating fuel. Furthermore, participants that switched heating fuel from solid to clean (vs. keep solid) were about 20% less likely to develop functional disability. Cooking fuel use switching from solid to clean (vs. keep solid) was also negatively associated with IADL disability (HR = 0.84, 95% CI 0.74~0.96). Over the next 7 years, raising clean fuel usage to 80% could prevent about 4.9 million ADL disability and 2.6 million IADL disability among Chinese aged 45 and older.

Conclusion

Household solid fuel use was a risk factor for functional disability. Reducing solid fuel usage could help reduce the burden of functional disability in the current aging society of China.

Lower socioeconomic status strengthens the effect of cooking fuel use on anemia risk and anemia-related parameters: Findings from the Henan Rural Cohort

The established evidence of cooking fuel use and socioeconomic status related to anemia is limited in low- and middle-income countries. The current study aims to examine the independent and combined effects of cooking fuel use and socioeconomic status on anemia risk as well as anemia-related parameters in rural China. A total of 21,050 participants were included from the baseline of the Henan Rural Cohort. Anemia was determined according to the World Health Organization criteria. Data on cooking fuel use (electricity, gas and solid fuel) and socioeconomic status (education and income levels) were collected using a standardized questionnaire by face-to-face interview. Logistic and linear regression models were applied to evaluate the effects of cooking fuel use or socioeconomic indicators on anemia risk, hemoglobin (HGB), red blood count (RBC), and hematocrit (HCT) levels. Using gas or solid fuel for cooking was positively associated with prevalent anemia risk and negatively related to HGB, RBC, and HCT levels compared to using electricity. Significant independent associations were also found between socioeconomic status (education and income levels) and prevalent anemia risk as well as these anemia-related parameters. In general, with decreased socioeconomic status, associations of using gas or solid fuel for cooking with advanced anemia risk as well as lower anemia-related parameters were increased. Furthermore, participants using gas or solid fuel for cooking and with lower education or income level were related to increased high anemia risk as well as low HGB, RBC and HCT levels, compared to those using electricity for cooking and with high education or income level (P <0.05 for all). The finding suggested that lower socioeconomic status strengthens the adverse effect of cooking fuel use on the higher anemia risk and lower HGB, RBC, and HCT levels in rural China.

Air pollution: A culprit of lung cancer

Air pollution is a global health problem, especially in the context of rapid economic development and the expansion of urbanization. Herein, we discuss the harmful effects of outdoor and indoor pollution on the lungs. Ambient particulate matters (PMs) from industrial and vehicle exhausts is associated with lung cancer. Workers exposed to asbestos, polycyclic aromatic hydrocarbons (PAHs), and toxic metals are also likely to develop lung cancer. Indoors, cooking fumes, second-hand smoke, and radioactive products from house decoration materials play roles in the development of lung cancer. Bacteria and viruses can also be detrimental to health and are important risk factors in lung inflammation and cancer. Specific effects of lung cancer caused by air pollution are discussed in detail, including inflammation, DNA damage, and epigenetic regulation. In addition, advanced materials for personal protection, as well as the current government policies to prevent air pollution, are summarized. This review provides a basis for future research on the relationship between lung cancer and air pollution.

Inhalable particle-bound marine biotoxins in a coastal atmosphere: Concentration levels, influencing factors and health risks

Characterizing marine biotoxins (MBs) composition in coastal aerosol particles has become essential to tracking sources of atmospheric contaminants and assessing human inhalable exposure risks to air particles. Here, coastal aerosol particles were collected over an almost 3-year period for the analysis of eight representative MBs, including brevetoxin (BTX), okadaic acid (OA), pectenotoxin-2 (PTX-2), domoic acid (DA), tetrodotoxin (TTX), saxitoxin (STX), ciguatoxin (CTX) and ω-Conotoxin. Our data showed that the levels of inhalable airborne marine biotoxins (AMBs) varied greatly among the subcategories and over time. Both in daytime and nighttime, a predominance of coarse-mode AMB particles was found for all the target AMBs. Based on the experimental data, we speculate that an ambient AMB might have multiple sources/production pathways, which include air-sea aerosol production and direct generation and release from toxigenic microalgae/bacteria suspended in surface seawater or air, and different sources may make different contribution. Regardless of the subcategory, the highest deposition efficiency of an individual AMB was found in the head airway region, followed by the alveolar and tracheobronchial regions. This study provides new information about inhalable MBs in the coastal atmosphere. The coexistence of various particle-bound MBs raises concerns about potential health risks from exposure to coastal air particles.

Indoor Air Quality in Tujia Dwellings in Hunan, China: Field Tests, Numerical Simulations, and Mitigation Strategies

Air pollution is a major health hazard. The traditional habits and unique ethnic fire culture in Hunan Tujia region result in the long-term exposure of residents, especially elderly people, to pollutants. In this study, we conducted field monitoring and assessment of indoor pollutants in the residential houses of Hunan Tujia families and subsequently visualised and simulated fire pollutants in representative residential houses by using fire-dynamic-simulator software. Pollutant-control strategies, using passive smoke collectors and resizing windows, were proposed and simulated for validation. The results revealed that passive smoke collectors reduced the pollutant concentration in the hall house by 43.96%. Furthermore, the optimal window size was 1500 mm × 1500 mm, and the most reasonable windowsill height of the firepit was 1800 mm. The results of the study can be used to improve the indoor air quality of Tujia dwellings and mitigate the adverse health effects of exposure to indoor air pollution without restricting ethnic beliefs and traditional customs.

Socioeconomic and Environmental Aspects of Traditional Firewood for Cooking on the Example of Rural and Peri-Urban Mexican Households

Firewood is a solid biofuel that is widely used for cooking in Mexico’s residential sector. This study seeks to identify relevant factors in firewood consumption patterns, and their implications for climate change, gender, and health, and for energy poverty in Mexico, by climate region and socioeconomic level. For this purpose, a statistical analysis was conducted of recently published official information. We estimate that a total of 31.3 million Mexicans—26% of the total population—use firewood, and we have identified three main types of users: (i) exclusive firewood users (30%); (ii) mixed firewood users using firewood as their primary fuel (18%) and (iii) mixed firewood users using firewood as their secondary fuel source (52%). Total consumption of firewood was estimated at 116.6 PJ, while estimated greenhouse gas emissions were 8.1 million tCO2e. Out of all the households studied, 53% were in the tropical climate region; 59% were categorized as being in the “low” socioeconomic level; and 75% were in population centers comprising fewer than 2500 inhabitants. Some 68% of households do not pay for the acquisition of firewood, and for those households that do pay for the resource, estimated transactions total USD 286.9 million. Expenditures on firewood for energy represent up to 10% of household income. Finally, it was estimated that 15.7 million direct users of firewood are women who use the resource in three-stone fires, in which they expose themselves to health risks in doing so. In conclusion, main universal findings, the study’s limitations, and future research are presented.

Effects of PM2.5 and its constituents on hemoglobin during the third trimester in pregnant women

Anemia has been a public health issue evoking global concern, and the low hemoglobin (Hb) concentration links to adverse pregnancy outcomes. However, the associations of PM_2.5 and its constituents with Hb and anemia in pregnant women remain unclear. In this retrospective birth cohort study, 7932 pregnant women who delivered in the First Affiliated Hospital of Xi'an Jiaotong University from 2015 to 2018 were included. The Hb during the third trimester in pregnant women was assessed before delivery. PM_2.5 and its constituents (BC, NH₄⁺, NO₃^-, OM, SO₄^2-, and Dust) during pregnancy were retrieved from the V4.CH.03 product constructed by the Atmospheric Composition Analysis Group. Generalized linear regression model was applied to investigate the effects of PM_2.5 and its constituents on Hb and anemia during the third trimester in pregnant women. The means and standard deviations of PM_2.5, BC, NH₄⁺, NO₃^-, OM, SO₄^2-, and Dust were 69.56 (15.24), 10.02 (2.72), 8.11 (1.77), 14.96 (5.42), 15.36 (4.11), 10.08 (1.20), and 10.98 (1.85) μg/m³, respectively. Per IQR increase (μg/m³) of PM_2.5, BC, NO₃^-, and OM linked to - 0.75 (- 1.50, - 0.01), - 0.85 (- 1.65, - 0.04), - 0.79 (- 1.56, - 0.03), and - 0.73 (- 1.44, - 0.03) g/L decrease of Hb during the third trimester in multiparous pregnant women, but not for NH₄⁺, SO₄^2-, Dust, and primiparous pregnant women. PM_2.5 and its constituents had no significant association with anemia, except for Dust (OR: 0.90, 95% CI: 0.82, 0.99, per IQR increase) in primiparous pregnant women. Besides, SO4^2- was of lag effects on Hb and anemia in multiparous pregnant women. Moreover, non-linear associations were found among PM_2.5 and its constituents, Hb, and anemia. Therefore, exposure to PM_2.5 and some constituents of PM_2.5 was associated with reduced Hb level during the third trimester in multiparous pregnant women. Related departments and pregnant women should take targeted actions to eliminate the detrimental effects of PM_2.5 and its constituents on pregnancy outcomes.