Air pollution from household solid fuel combustion in India: an overview of exposure and health related information to inform health research priorities

Exploring the cooking energy biomass and its impact on women's health and quality of life in rural households: a micro-environmental study from West Bengal in India

Exposure to household air pollutants has become a significant environmental health concern in developing nations. This study aimed to understand the growing energy consumption within households, particularly for cooking, and its impact on women's health in rural areas. We conducted real-time monitoring of ambient particulate matter (PM2.5) and carbon monoxide (CO) levels in 61 rural kitchens in the Medinipur and Jhargram districts of West Bengal, India. Additionally, we calculated the Standard Living Index (SLI) based on socio-demographic factors from 540 households. Our analyses using ANOVA and chi-square methods revealed significant effects of cooking fuel types and locations on various health indicators among women. Eye irritation was prevalent across all fuel types, followed by shortness of breath (33%), coughing (22%), and dizziness (21%). Alarmingly, nearly half (48%) of children under five consistently accompanied their mothers during cooking, exposing them to health risks. Indoor air pollution, particularly from traditional fuels like fuelwood, cow dung cakes, and leaves, poses a grave threat to families. These fuels emit considerable amounts of PM2.5 and CO, with levels reaching as high as 565 µg/m3 and 12.5 ppm, respectively, leading to respiratory and cardiovascular complications. Clean cooking fuel users, such as those using LPG, reported improved quality of life scores across physical, psychological, social, and environmental categories. This study highlights the urgent need to transition to cleaner cooking fuels to mitigate adverse health effects on women and children in rural households.

Comprehensive analysis of emissions from wood and cow dung burning using chemometrics and two-dimensional gas chromatography

Biomass burning is a global source of climate- and health-affecting emissions. The impacts of biomass burning emissions (BBE) are tied to their complex and variable chemical makeup. For instance, the nitrogen content of BBE influences their capacity to absorb light, and therefore affect the Earth's radiative budget. Factors such as temperature, biomass type, or air flow rate during the combustion all modify the composition of BBE, making accurate characterization challenging. Herein, for the first time, principal component analysis (PCA) was applied to emissions gathered during laboratory-based combustion of wood and cow dung biomass in a tube furnace. A thermal desorption two dimensional time-of-flight gas chromatography mass spectrometry (TD-GC × GC-ToF-MS) setup was employed to separate and identify chemical species. By combining these techniques with a feature selection algorithm, we determined that low temperature and air flow rate lead to greater feature separation on PCA scores plots. Of the 729 variables used to construct the plots, 61 were identified as significant. These species - including sugars such as d-Allose and melezitose, as well as tracers such as levoglucosan and guaiacol - significantly differentiated emissions from wood versus cow dung biomass, especially at lower temperatures. In particular, combustion of either fuel at 0.2 slpm and 500 °C, lead to 20 times the variability in levoglucosan peak area over more efficient furnace parameters. Chemical species evolved only from dung burning contained on average 0.595 nitrogen atoms versus 0.515 for wood, indicating that a higher nitrogen content of the base fuel may not necessarily translate into emission of unique nitrogen containing species, potentially causing the underestimation of dung burning impacts. Overall, TD-GC × GC-ToF-MS coupled to PCA reliably separated emissions from wood and dung biomass while simultaneously identifying significant chemical features, displaying the suitability of this combination of techniques towards characterizing complex BBE matrices in the future.

Association of Exposure to Indoor Air Pollution with Unhealthy Symptoms among Middle-aged and Older Adults in India: Evidence from a Large-scale Survey

Background

The usage of solid cooking fuels is widely prevalent in low and middle-income countries, including India, and contributes to indoor air pollution (IAP), which has detrimental health effects. Moreover, time spent inside the house increases as people age. In this context, the present study tried to understand the association between exposure to indoor air pollution and unhealthy symptoms, including shortness of breath, dizziness, headache, fatigue, wheezing, and cough among middle-aged and older adults in India.

Methods

We extracted the unit-level individual data (N = 63 790) from the Longitudinal Aging Study in India (LASI)-Wave 1 (2017-2018). The statistical analyses used were Chi-square test and binary logistic regression, which estimated the odds ratio to identify the determinants of the unhealthy symptoms.

Results

The odds of shortness of breath (adjusted OR: 1.14, 99% CI: 1.05-1.23), dizziness (adjusted OR: 1.28, 99% CI: 1.21-1.35), fatigue (adjusted OR: 1.32, 99% CI: 1.26-1.39), wheezing (adjusted OR: 1.30, 99% CI: 1.19-1.42), and cough (adjusted OR: 1.36, 99% CI: 1.27-1.45) were higher among individuals from households where solid cooking fuels was used. Similarly, the odds of shortness of breath, headache, wheezing, and cough were higher among individuals with a household member who smoked inside the house. The results indicated that the odds of shortness of breath, headache, and cough were significantly lower among participants exposed to incense use.

Conclusion

Based on the results of this study, we suggest developing programs to combat the sources of indoor air pollution and the associated unhealthy symptoms, especially in rural settings. It is also important to bring awareness and practice clean fuel usage at individual and community levels to improve population health.

Household unclean fuel use, indoor pollution and self-rated health: risk assessment of environmental pollution caused by energy poverty from a public health perspective

The lack of access to clean energy remains one of the major challenges in the global energy sector. Access to clean, sustainable and affordable energy, outlined in the seventh Sustainable Development Goals (SDG 7) of the United Nations, plays a crucial role in advancing health (SDG 3), as unclean cooking energy may endanger people's health by causing air pollution. However, due to endogeneity problems such as reverse causality, the health consequences of environmental pollution caused by unclean fuel usage are difficult to be scientifically and accurately evaluated. This paper aims to systematically assess the health cost of unclean fuel usage based on tackling endogeneity, using the data from Chinese General Social Survey. The ordinary least squares model, ordered regression methods, instrumental variable approach, penalized machine learning methods, placebo test, and mediation models are applied in this research. Analytical results demonstrate that households' unclean fuel use significantly damages people's health. Specifically, the use of dirty fuel leads to an average of about a one-standard-deviation decline in self-rated health, demonstrating its notable negative effect. The findings are robust to a series of robustness and endogeneity tests. The impact mechanism is that unclean fuel usage reduces people's self-rated health through increasing indoor pollution. Meanwhile, the negative effect of dirty fuel use on health has significant heterogeneity among different subgroups. The consequences are more prominent for the vulnerable groups who are female, younger, living in rural areas and older buildings, with lower socio-economic status and uncovered by social security. Therefore, necessary measures should be taken to improve energy infrastructure to make clean cooking energy more affordable and accessible as well as to enhance people's health. Besides, more attention should be paid to the energy needs of the above specific vulnerable groups faced with energy poverty.

Exploring the links between indoor air pollutants and health outcomes in South Asian countries: a systematic review

Indoor air pollution (IAP) has adverse effects on the health of people, globally. The objective of this systematic review was to present the range of health problems studied in association with indoor air pollutants in South Asian countries. We searched five databases, including PubMed, Web of Science, Scopus, Google Scholar, and CAB Direct for articles published between the years 2000 and 2020. We retrieved 5,810 articles, out of which we included 90 articles in our review. Among South Asian countries, only five countries have published results related to relationship between indoor air pollutants and adverse health conditions. All studies have shown adversity of indoor air pollutants on human's health. We found indoor solid fuel burning as a key source of indoor air pollution in the included studies, while women and children were most affected by their exposure to solid fuel burning. More than half of the studies accounted particulate matter responsible for indoor air pollution bearing negative health effects. In the included studies, eyes and lungs were the most commonly affected body organs, exhibiting common symptoms like cough, breathing difficulty and wheezing. This might have developed into common conditions like respiratory tract infection, chronic obstructive pulmonary diseases and eye cataract. In addition to promote research in South Asian countries, future research should focus on novel digital ways of capturing effects of indoor air pollutants among vulnerable segments of the population. As a result of this new knowledge, public health agencies should develop and test interventions to reduce people's exposure levels and prevent them to develop adverse health outcomes.

The association of asthma and air pollution: Evidence from India

In the last two decades, air pollution has increased throughout India resulting in the deterioration of air quality. This paper estimates the prevalence of self-reported asthma in women aged 15-49 years and examines the link between outdoor air pollution and disease prevalence in India by combining satellite data on particulate matter (PM2.5) and the National Family Health Survey (NFHS-4), 2015-16. The results indicate that both indoor pollution as well as outdoor air pollution are important risk factors for asthma in women as both independently increase the probability of asthma among this group. Strategies around the prevention of asthma need to recognize the role of both indoor as well as outdoor air pollution. The other significant risk factors for asthma are smoking, second-hand smoking, type of diet and obesity.

Evaluating the effect and user satisfaction of an adapted and translated mobile health application ASTHMAXcel© among adults with asthma in Pune, India

OBJECTIVE

ASTHMAXcel^© is a mobile application previously shown to improve asthma knowledge, control, and quality of life. In this study, we translated the application to Marathi for pilot testing in Pune, India in order to evaluate its impact on user satisfaction and asthma knowledge among adult asthma patients.

METHODS

ASTHMAXcel^© was adapted to Marathi with the help of asthma patients and clinicians from Bharati Hospital. 57 different asthma patients were then recruited and received the Asthma Knowledge Questionnaire (AKQ), Asthma Control Questionnaire (ACQ), and Mini Asthma Quality of Life Questionnaire (Mini-AQLQ) to complete at baseline. Study participants then completed the adapted ASTHMAXcel^© application. Post-intervention, participants filled out a post-AKQ and Questionnaire for User Interface Satisfaction (QUIS). A subset of participants was also interviewed for qualitative feedback. Paired t-tests and Pearson's correlation were used for statistical analysis.

RESULTS

Mean AKQ improved from 5.0+/-2.4 to 12.4+/-1.6 (p = 0.0001). QUIS results revealed that participants were highly satisfied with the application, scoring an average of 50 out of 54 maximum points. Better baseline asthma control was correlated with greater overall experience with the application (-0.110, p = 0.0417). Finally, the qualitative feedback revealed four themes for future refinement.

CONCLUSION

The adapted version of ASTHMAXcel^© was linked to significant improvement in patient asthma knowledge and a high level of user satisfaction. These results support the potential utility of mHealth applications in promoting guideline-based asthma care in India. However, further studies are needed to establish a causal relationship between ASTHMAXcel^© and improved clinical outcomes.

A scientometric analysis of indoor air pollution research during 1990-2019

Indoor air pollution (IAP) is one of the leading risk factors for various adverse health outcomes including premature deaths globally. Even though research related to IAP has been carried out, bibliometric studies with particular emphasis on this topic have been lacking. Here, we investigated IAP research from 1990 to 2019 retrieved from the Web of Science database through a comprehensive and systematic scientometric analysis using the CiteSpace 5.7.R2, a powerful tool for visualizing structural, temporal patterns and trends of a scientific field. There was an exponential increase in publications, however, with a stark difference between developed and developing countries. The journals publishing IAP related research had multiple disciplines; 'Indoor Air' journal that focuses solely on IAP issues ranked fifth among top-cited journals. The terms like 'global burden', 'comparative risk assessment,' 'household air pollution (HAP)', 'ventilation', 'respiratory health', 'emission factor', 'impact,' 'energy', 'household', 'India' were the current topical subject where author Kirk R. Smith was identified with a significant contribution. Research related to rural, fossil-fuel toxicity, IAP, and exposure-assessment had the highest citation burst signifying the particular attention of scientific communities to these subjects. Overall, this study examined the evolution of IAP research, identified the gaps and provided future research directions.

Relationship of indoor solid fuel use for cooking with blood pressure and hypertension among the elderly in China

Indoor air pollution caused by solid fuel use for cooking affects 2.5 billion people worldwide and may elevate blood pressure (BP) and increase the burden of hypertension. Although the elderly are the most at risk of an elevated BP and hypertension, few studies have evaluated the effect of indoor solid fuel use for cooking on BP in persons over the age of 65. Therefore, in this study, we randomly selected 8067 elderly people over 65 years of age from the 2018 Chinese Longitudinal Healthy Longevity Survey to determine the impact of indoor solid fuel use on BP/hypertension. The results showed that, compared with those who cooked with clean fuel, those who cooked with solid fuel had a 1.87 mmHg higher systolic blood pressure, a 0.09 mmHg higher diastolic blood pressure, a 0.97 mmHg higher pulse pressure, and a 1.22 mmHg higher mean arterial pressure. However, we did not find any association between indoor solid fuel use and hypertension. We further observed that northern China residents, women, people aged over 90 years, hypertensive and heart patients, and those with natural ventilation in the kitchen that used indoor solid fuel experienced a greater BP impact. Replacing solid fuel with clean fuel may be an important way to lower BP. Regarding this, priority access to clean fuel should be given to the susceptible population, including the elderly aged ≥ 75 years, northern China residents, women, and hypertensive and heart patients.

Mediating Factors Explaining the Associations between Solid Fuel Use and Self-Rated Health among Chinese Adults 65 Years and Older: A Structural Equation Modeling Approach

Exposure to indoor air pollution from cooking with solid fuel has been linked with the health of elderly people, although the pathway to their association is unclear. This study aimed to investigate the mediating effects between solid fuel use and self-rated health by using structural equation modeling (SEM) with the baseline data from Chinese Longitudinal Healthy Longevity Survey (CLHLS). We conducted a cross-sectional survey among 7831 elderly people aged >65 years from the CLHLS. SEM was used to analyze the pathways underlying solid fuel use and self-rated health. We estimated indirect effects of sleep quality (β = −0.027, SE = 0.006), cognitive abilities (β = −0.006, SE = 0.002), depressive symptoms (β = −0.066, SE = 0.007), systolic blood pressure (β = 0.000, SE = 0.000), and BMI (β = −0.000, SE = 0.000) on the association between solid fuel and the self-rated health using path analysis. Depressive symptoms emerged as the strongest mediator in the relationship between solid fuel use and self-rated health in the elderly. Interventions targeting sleep quality, cognitive abilities, depressive symptoms, systolic blood pressure, and BMI could greatly reduce the negative effects of solid fuel use on the health of the elderly population.

Chemical properties of emissions from solid residential fuels used for energy in the rural sector of the southern region of India

In the present study, we have estimated the emission factors (EFs) of particulate matter (PM), organic and elemental carbon (OC and EC), oxide of sulfur and nitrogen, and water-soluble ionic species emitted from residential fuels (fuelwood, crop residue, dung cake) used in the rural sector of five states (Kerala, Karnataka, Andhra Pradesh, Telangana, Tamil Nadu) of the southern region of India. Average EFs of PM, OC, and EC from fuelwood (FW), crop residues (CR), and dung cakes (DC) from southern region of India are estimated as follows: PM: 6.35 ± 5.64 g/kg (FW), 6.99 ± 5.46 g/kg (CR), 9.69 ± 3.73 g/kg (DC); OC: 1.60 ± 1.72 g/kg (FW), 1.50 ± 1.52 g/kg (CR), 3.54 ± 0.75 g/kg (DC); and EC: 0.46 ± 0.53 g/kg (FW), 0.29 ± 0.17 g/kg (CR), 0.21 ± 0.11 g/kg (DC), respectively. Similarly, the average EFs of SO₂, NO_x from FW, CR, and DC are determined to be as follows: SO₂: 0.40 ± 0.37 g/kg (FW), 1.17 ± 0.25 g/kg (CR), and 0.18 ± 0.10 g/kg (DC); NO_x: 1.11 ± 1.22 g/kg (FW), 0.69 ± 0.37 g/kg (CR), and 0.91 ± 0.54 g/kg (DC), respectively. PO₄^3- shows the highest EF from FW (646.02 ± 576.35 mg/kg), CR (531.06 ± 678.29 mg/kg) among all anions followed by Cl^- (FW: 512.91 ± 700.35 mg/kg, CR: 661.61 ± 865.46 mg/kg and DC: 104.16 ± 54.01 mg/kg); whereas, Na⁺ shows highest EF from FW (254.05 ± 298.50 mg/kg) and CR (249.36 ± 294.85 mg/kg) among all cations. The total emissions of trace gases, PM, and their chemical composition from FW, CR, and DC have been calculated using laboratory-generated EFs over the southern region of India. CR (1595.58 ± 14.24 Gg) contributes to higher emission of PM as compared to FW (218.78 ± 53.93 Gg), whereas the contribution from DC is negligible.

Visualization and analysis of mapping knowledge domains for the global transition towards clean cooking: a bibliometric review of research output from 1990 to 2020

Current statistics report that 2.6 billion households across the globe rely on polluting and inefficient cooking fuels and technologies, posing death-threatening health risks to people mainly from developing countries/regions. Several studies on clean cooking have been conducted with the emergence of international organizations such as the Clean Cooking Alliance to raise awareness. In the current study, a bibliometric tool, CiteSpace, was employed to analyze the 877 documents retrieved from the SCI-EXPANDED, SSCI, and A&HCI databases on clean cooking research from 1990 to 2020. The results reveal that interest in clean cooking research took a sharp rise in the last decade, especially after 2016. The research field has become increasingly interdisciplinary but has mostly centered on environment, energy, and health. The most productive countries/regions in this field are the USA, India, England, and China. The keyword and citation analyses indicate that research in this field mostly focuses on adverse impacts of household air pollution from unclean cooking fuels and technologies on the environment and public health particularly, in developing countries/regions. Also, the drivers and barriers to the large-scale adoption of clean cooking fuels and technologies have become a topic of interest in recent years. The three most studied clean cooking fuels among various regions are LPG, biogas, and electricity. This study synthesizes global research on clean cooking and may be beneficial to other researchers in understanding current trends in this field and serve as a guide for concentrating on the most important topics.

Environmental factors modulating protein conformations and their role in protein aggregation diseases

The adverse physiological conditions have been long known to impact protein synthesis, folding and functionality. Major physiological factors such as the effect of pH, temperature, salt and pressure are extensively studied for their impact on protein structure and homeostasis. However, in the current scenario, the environmental risk factors (pollutants) have gained impetus in research because of their increasing concentrations in the environment and strong epidemiologic link with protein aggregation disorders. Here, we review the physiological and environmental risk factors for their impact on protein conformational changes, misfolding, aggregation, and associated pathological conditions, especially environmental risk factors associated pathologies.

Lack of access to clean fuel and piped water and children's educational outcomes in rural India

Investments in clean fuel and piped water are often recommended in developing countries on health grounds. This paper examines an alternative channel, the relationship between piped water and access to liquefied petroleum gas (LPG) and children's educational outcomes. Results based on the second round of the India Human Development Survey (2011-12) for rural India show that children aged 6-14 years, living in households that rely on free collection of water and cooking fuel, have lower mathematics scores and benefit from lower educational expenditures than children living in households that do not collect water and fuel. Moreover, gender inequality in this unpaid work burden also matters. In households where the burden of collection is disproportionately borne by women, child outcomes are significantly lower, particularly for boys. The endogeneity of choice to collect or purchase water and cooking fuel are modeled via Heckman selection and the entropy balancing method.

Transition to clean household energy through an application of integrated model: Ensuring sustainability for better health, climate and environment

Sustained use and adoption of clean cooking fuels have become an important concern for developing countries due to the enormous burden of diseases attributable to household air pollution (HAP). The transition and adoption of clean household energy involve various socio-economic, behavioral, and technological barriers at different community levels. Hence, the present paper aims to scrutinize the factors, key determinants, and other interventions among rural households that limit clean cookstoves' sustained uses. The study proposes an integrated model to enhance clean cooking fuel uptake and uses based on the available evidence. The health, climate and environmental factors were identified as the key to trigger the adoption of clean cooking fuel alternatives. The model comprises the integration of components for targeted clean fuel policy interventions and promotes green recovery. The elements include Knowledge, Housing characteristics, Awareness, Interventions, Willingness to pay, Adoption, Lower emissions and Gender Equality (THE KHAIWAL model) to ascertain the intervention focus regions. Integration of model components in policy implementation will promote clean household energy to reduce emissions, leading to improve quality of life, good health, women empowerment, better air quality and climate.

Effect of Indoor Air Pollution on Chronic Obstructive Pulmonary Disease (COPD) Deaths in Southern Asia-A Systematic Review and Meta-Analysis

BACKGROUND

About half of the population in developing countries are exposed to indoor pollution such as combustion fuels at present. Chronic obstructive pulmonary disease (COPD) is one of the leading causes of mortality globally and the primary cause of COPD in women is indoor air pollution exposure, while tobacco smoking is the leading cause in men. The aim of this systematic review and meta-analysis is to evaluate the correlation between the indoor air pollution and deaths related to COPD and COPD prevalence in South Asia.

METHODS

A systematic search on studies with sufficient statistical power has been conducted from 1985 until 30 June 2020, in English electronic databases following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in MEDLINE and PubMed databases with the terms Chronic Obstructive Pulmonary disease COPD or Chronic Bronchitis or Emphysema or COPD Deaths or Chronic Obstructive Lung Disease or Airflow Obstruction or Chronic Airflow Obstruction or Airflow Obstruction, Chronic or Bronchitis, Chronic and Mortality or Death or Deceased was conducted. Studies were eligible if they were Prospective controlled or non-controlled trials conducted in Southern Asia/ Asia and Retrospective studies conducted in Southern Asia/ Asia.

RESULTS

The results have concluded that long term exposure to indoor pollution had a significant effect on COPD deaths as well as its symptoms. Odd's ratio was in a range of 1.05 (Randomized controlled trials) to 7.87 (Cross sectional studies) for all the studies mentioned. Meta-analysis observed a significantly higher Odds Ratio of 2.13 for COPD mortality and 2.08 for COPD prevalence on exposure to indoor air pollution.

CONCLUSION

Exposure to solid fuel smoke is consistently and significantly correlated with COPD mortality and COPD prevalence in South Asian countries, in spite of heterogeneity observed in the studies included. For performing domestic tasks, initiatives are to be taken to reduce dependency on solid fuel by using cleaner alternatives or comparatively cleaner technology.

Understanding the association between gradient of cooking fuels and low birth weight in India

BACKGROUND

Birth weight is positively associated with physical and cognitive development of children and adversely associated with the use of unclean cooking fuels. Though studies have examined the contextual determinants of birth weight, no attempt has been made to understand the association of gradient of cooking fuels with birth weight in India. The objective of this paper is to understand the association of type of cooking fuel with low birth weight in India.

METHODS

Unit data from the fourth round of the National Family Health Survey (NFHS) (2015-16), covering 8206 singleton births from four states of India, was used in the analysis. These states reported more than 80% of birth weights by way of health cards issued by a public authority. Linear regression analysis was used to estimate mean birth weight, adjusting for confounders. We computed a new wealth index, excluding electricity and cooking fuels, using principal component analysis to capture the economic gradient of cooking fuel.

RESULTS

Our results suggest a strong gradient of cooking fuels on mean birth weight. The adjusted mean birth weight in households using electricity was 2957 g (95% CI: 2939-2975). It was 2908 g (95% CI: 2907-2910) for LPG, 2792 g (95% CI: 2784-2801) for biogas, 2819 g (95% CI: 2809-2829) for kerosene, 2841 g (95% CI: 2816-2866) for coal/lignite/charcoal, and 2834 g (95% CI: 2831-2836) in households using biomass. A difference of 165 g in predicted mean birth weight was found among children born in households that used electricity in relation to those that used biogas. The difference in relation to kerosene, coal/lignite/charcoal, and biomass was 138 g, 116 g, and 123 g respectively. Significant differences in mean birth weight were also observed by wealth quintiles, mother's underweight, social groups, birth interval, and mother's anemia status.

CONCLUSION

Findings from the study suggest to strengthen the policies on access to clean fuels and meet the interconnected goals of sustainable development.

Bioaccumulation potential of indigenous plants for heavy metal phytoremediation in rural areas of Shaheed Bhagat Singh Nagar, Punjab (India)

The present study was planned to explore the bioaccumulation potential of 23 plant species via bioaccumulation factor (BAf), metal accumulation index (MAI), translocation potential (Tf), and comprehensive bioconcentration index (CBCI) for seven heavy metals (cadmium, chromium, cobalt, copper, iron, manganese, and zinc). The studied plants, in the vicinity of ponds at Sahlon: site 1, Chahal Khurd: site 2, and Karnana: site 3 in Shaheed Bhagat Singh Nagar, Punjab (India), were Ageratum conyzoides (L.) L., Amaranthus spinosus L., Amaranthus viridis L., Brassica napus L., Cannabis sativa L., Dalbergia sissoo DC., Duranta repens L., Dysphania ambrosioides (L.) Mosyakin & Clemants, Ficus infectoria Roxb., Ficus palmata Forssk., Ficus religiosa L., Ipomoea carnea Jacq., Medicago polymorpha L., Melia azedarach L., Morus indica L., Malva rotundifolia L., Panicum virgatum L., Parthenium hysterophorus L., Dolichos lablab L., Ricinus communis L., Rumex dentatus L., Senna occidentalis (L.) Link, and Solanum nigrum L. BAf and Tf values showed high inter-site deviations for studied metals. MAI values were found to be more substantial in shoots as compared with that of roots of plants. Maximum CBCI values were observed for M. azedarach (0.626), M. indica (0.572), D. sissoo (0.497), and R. communis (0.474) for site 1; F. infectoria (0.629), R. communis (0.541), D. sissoo (0.483), F. palmata (0.457), and D. repens (0.448) for site 2; D. sissoo (0.681), F. religiosa (0.447), and R. communis (0.429) for site 3. Although, high bioaccumulation of individual metals was observed in herbs like C. sativa, M. polymorpha, and Amaranthus spp., cumulatively, trees were found to be the better bioaccumulators of heavy metals.

Exposure contrasts associated with a liquefied petroleum gas (LPG) intervention at potential field sites for the multi-country household air pollution intervention network (HAPIN) trial in India: results from pilot phase activities in rural Tamil Nadu

BACKGROUND

The Household Air Pollution Intervention Network (HAPIN) trial aims to assess health benefits of a liquefied petroleum gas (LPG) cookfuel and stove intervention among women and children across four low- and middle-income countries (LMICs). We measured exposure contrasts for women, achievable under alternative conditions of biomass or LPG cookfuel use, at potential HAPIN field sites in India, to aid in site selection for the main trial.

METHODS

We recruited participants from potential field sites within Villupuram and Nagapattinam districts in Tamil Nadu, India, that were identified during a feasibility assessment. We performed. (i) cross-sectional measurements on women (N = 79) using either biomass or LPG as their primary cookfuel and (ii) before-and-after measurements on pregnant women (N = 41), once at baseline while using biomass fuel and twice - at 1 and 2 months - after installation of an LPG stove and free fuel intervention. We involved participants to co-design clothing and instrument stands for personal and area sampling. We measured 24 or 48-h personal exposures and kitchen and ambient concentrations of fine particulate matter (PM2.5) using gravimetric samplers.

RESULTS

In the cross-sectional analysis, median (interquartile range, IQR) kitchen PM2.5 concentrations in biomass and LPG using homes were 134 μg/m3 [IQR:71-258] and 27 μg/m3 [IQR:20-47], while corresponding personal exposures were 75 μg/m3 [IQR:55-104] and 36 μg/m3 [IQR:26-46], respectively. In before-and-after analysis, median 48-h personal exposures for pregnant women were 72 μg/m3 [IQR:49-127] at baseline and 25 μg/m3 [IQR:18-35] after the LPG intervention, with a sustained reduction of 93% in mean kitchen PM2.5 concentrations and 78% in mean personal PM2.5 exposures over the 2 month intervention period. Median ambient concentrations were 23 μg/m3 [IQR:19-27). Participant feedback was critical in designing clothing and instrument stands that ensured high compliance.

CONCLUSIONS

An LPG stove and fuel intervention in the candidate HAPIN trial field sites in India was deemed suitable for achieving health-relevant exposure reductions. Ambient concentrations indicated limited contributions from other sources. Study results provide critical inputs for the HAPIN trial site selection in India, while also contributing new information on HAP exposures in relation to LPG interventions and among pregnant women in LMICs.

TRIAL REGISTRATION

ClinicalTrials.Gov. NCT02944682 ; Prospectively registered on October 17, 2016.

Gender inequalities and household fuel choice in India

The use of solid cooking fuels-wood, straw, crop residue, and cow-dung cakes-is associated with higher levels of environmental pollution and health burden. However, even in an era when incomes have grown and poverty has declined, the proportion of Indian households using clean cooking fuels such as kerosene or Liquefied Petroleum Gas (LPG) has increased only slightly. Even among the wealthiest quintile, only about 40 percent of the households rely solely on clean fuel. Since the chores of cooking and collection of fuel remain primarily the domain of women, we argue that intra-household gender inequalities play an important role in shaping the household decision to invest in clean fuel. Analyses using data from the India Human Development Survey (IHDS), a panel survey of over 41,000 households conducted in two waves in 2004-05 and 2011-12, respectively, show that women's access to salaried work and control over household expenditure decisions is associated with the use of clean fuel.

Risk of COPD due to indoor air pollution from biomass cooking fuel: a systematic review and meta-analysis

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of mortality in developing nations. In this meta-analysis, we aimed to determine the association between indoor air pollution and risk of COPD. Database searches were conducted using indoor air pollution, biomass and COPD related terms to identify relevant articles. The eligible studies were case-control, retrospective cohort, cross-sectional studies and conducted in adults that assessed COPD using any diagnostic criteria. A total of 35 studies with 73,122 participants were included. The pooled analysis showed that exposure to indoor air pollution due to solid biomass fuels increased risk of COPD by 2.65 (95% confidence interval [CI] 2.13-3.31; n = 73,122) and chronic bronchitis by 2.89 (95% CI 2.18-3.82) times more compared to non-biomass fuels. The risk of COPD was higher in Africa region (odds ratio [OR] 3.19), Asia (OR 2.88), South America (OR 2.15), Europe (OR 2.30) and North America (OR 2.14). The results of our meta-analysis indicated that exposure to indoor air pollution due to biomass smoke is strongly associated with COPD.Abbreviations: CS: cross-sectional; CC: case-control; NR: not reported; ATS: American Thoracic Society; BMRC: British Medical Research Council; GOLD: Global Initiative for Obstructive Lung Disease; IAP: indoor air pollution; BMF: biomass fuel; CB: chronic bronchitis; OR: odds ratio; UCI; upper confidence interval; LCI: lower confidence interval; COPD: chronic obstructive pulmonary disease.

Indoor Sources of Air Pollutants

People spend an average of 90% of their time in indoor environments. There is a long list of indoor sources that can contribute to increased pollutant concentrations, some of them related to human activities (e.g. people's movement, cooking, cleaning, smoking), but also to surface chemistry reactions with human skin and building and furniture surfaces. The result of all these emissions is a heterogeneous cocktail of pollutants with varying degrees of toxicity, which makes indoor air quality a complex system. Good characterization of the sources that affect indoor air pollution levels is of major importance for quantifying (and reducing) the associated health risks. This chapter reviews some of the more significant indoor sources that can be found in the most common non-occupational indoor environments.

Health Effects of Household Solid Fuel Use: Findings from 11 Countries within the Prospective Urban and Rural Epidemiology Study

BACKGROUND

Household air pollution (HAP) from solid fuel use for cooking affects 2.5 billion individuals globally and may contribute substantially to disease burden. However, few prospective studies have assessed the impact of HAP on mortality and cardiorespiratory disease.

OBJECTIVES

Our goal was to evaluate associations between HAP and mortality, cardiovascular disease (CVD), and respiratory disease in the prospective urban and rural epidemiology (PURE) study.

METHODS

We studied 91,350 adults 35–70 y of age from 467 urban and rural communities in 11 countries (Bangladesh, Brazil, Chile, China, Colombia, India, Pakistan, Philippines, South Africa, Tanzania, and Zimbabwe). After a median follow-up period of 9.1 y, we recorded 6,595 deaths, 5,472 incident cases of CVD (CVD death or nonfatal myocardial infarction, stroke, or heart failure), and 2,436 incident cases of respiratory disease (respiratory death or nonfatal chronic obstructive pulmonary disease, pulmonary tuberculosis, pneumonia, or lung cancer). We used Cox proportional hazards models adjusted for individual, household, and community-level characteristics to compare events for individuals living in households that used solid fuels for cooking to those using electricity or gas.

RESULTS

We found that 41.8% of participants lived in households using solid fuels as their primary cooking fuel. Compared with electricity or gas, solid fuel use was associated with fully adjusted hazard ratios of 1.12 (95% CI: 1.04, 1.21) for all-cause mortality, 1.08 (95% CI: 0.99, 1.17) for fatal or nonfatal CVD, 1.14 (95% CI: 1.00, 1.30) for fatal or nonfatal respiratory disease, and 1.12 (95% CI: 1.06, 1.19) for mortality from any cause or the first incidence of a nonfatal cardiorespiratory outcome. Associations persisted in extensive sensitivity analyses, but small differences were observed across study regions and across individual and household characteristics.

DISCUSSION

Use of solid fuels for cooking is a risk factor for mortality and cardiorespiratory disease. Continued efforts to replace solid fuels with cleaner alternatives are needed to reduce premature mortality and morbidity in developing countries. https://doi.org/10.1289/EHP3915.

Emission of black carbon from rural households kitchens and assessment of lifetime excess cancer risk in villages of North India

The use of biomass solid fuels (BSFs) for cooking, contribute significantly to the household air pollution (HAP) in developing countries. Emissions resulting from a variety of BSFs (cow dung cakes, wood, and agriculture residues) contain a significant amount of air pollutants, which are now recognized for their role in climatic change and adverse human health impacts. In the current study, daily variations in black carbon (BC) or Short-Lived Climate Forcer concentrations were studied from rural household kitchens using portable aethalometer. The hourly average concentration of BC ranges from 5.4 μg·m^-3 to 34.9 μg·m^-3 for various types of household kitchens. The peak levels of BC were found to be significantly higher, when compared to World Health Organization PM_2.5 limits for ambient air and hence pose a threat to the health of the vulnerable population, i.e., women, children, older adults and those who have health problems. The study also highlights the variation of BC concentration in different kitchen type. The average BC concentration in indoor, outdoor and semi-open kitchen was observed to be 14.54, 14.28 and 24.69 μg·m^-3, respectively. The excess lifetime carcinogenic risk for cooking 4 h/day in these kitchens in the North Indian villages was estimated to be 1.25 × 10^-7, 1.22 × 10^-7, and 2.12 × 10^-7 respectively. Age-specific excess cancer deaths due to BC exposure were measured highest in children below four years of age in Chandigarh, India. Hence, there is a need to shift the BSF users to clean fuel alternatives to reduce the exposure to HAP. This can be achieved by generating local/regional evidences of BSFs associated health risks to support policy interventions. Further, more research is required to improve the air quality in indoor micro-environments and specifically in kitchens. NOVELTY: The first study reporting the near real-time measurements of BC from different types of rural households kitchens of north India. Diurnal pattern of BC concentration was also studied including the effect of chimney, ventilation and kitchen size on observed BC concentration. This study also estimates lifetime excess cancer risk due to BC exposure in rural households in India. The recent 'Global Burden of Disease' report identifies household air pollutants as a major cause of disease and disability in Asia. The study will help to plan suitable policies and intervention to reduce household air pollution in the region.

Impact of Maternal Air Pollution Exposure on Children's Lung Health: An Indian Perspective

Air pollution has become an emerging invisible killer in recent years and is a major cause of morbidity and mortality globally. More than 90% of the world’s children breathe toxic air every day. India is among the top ten most highly polluted countries with an average PM₁₀ level of 134 μg/m³ per year. It is reported that 99% of India’s population encounters air pollution levels that exceed the World Health Organization Air Quality Guideline, advising a PM_2.5 permissible level of 10 μg/m³. Maternal exposure to air pollution has serious health outcomes in offspring because it can affect embryonic phases of development during the gestation period. A fetus is more prone to effects from air pollution during embryonic developmental phases due to resulting oxidative stress as antioxidant mechanisms are lacking at that stage. Any injury during this vulnerable period (embryonic phase) will have a long-term impact on offspring health, both early and later in life. Epidemiological studies have revealed that maternal exposure to air pollution increases the risk of development of airway disease in the offspring due to impaired lung development in utero. In this review, we discuss cellular mechanisms involved in maternal exposure to air pollution and how it can impact airway disease development in offspring. A better understanding of these mechanisms in the context of maternal exposure to air pollution can offer a new avenue to prevent the development of airway disease in offspring.

Wearable camera-derived microenvironments in relation to personal exposure to PM2.5

Data regarding which microenvironments drive exposure to air pollution in low and middle income countries are scarce. Our objective was to identify sources of time-resolved personal PM_2.5 exposure in peri-urban India using wearable camera-derived microenvironmental information. We conducted a panel study with up to 6 repeated non-consecutive 24 h measurements on 45 participants (186 participant-days). Camera images were manually annotated to derive visual concepts indicative of microenvironments and activities. Men had slightly higher daily mean PM_2.5 exposure (43 μg/m³) compared to women (39 μg/m³). Cameras helped identify that men also had higher exposures when near a biomass cooking unit (mean (sd) μg/m³: 119 (383) for men vs 83 (196) for women) and presence in the kitchen (133 (311) for men vs 48 (94) for women). Visual concepts associated in regression analysis with higher 5-minute PM_2.5 for both sexes included: smoking (+93% (95% confidence interval: 63%, 129%) in men, +29% (95% CI: 2%, 63%) in women), biomass cooking unit (+57% (95% CI: 28%, 93%) in men, +69% (95% CI: 48%, 93%) in women), visible flame or smoke (+90% (95% CI: 48%, 144%) in men, +39% (95% CI: 6%, 83%) in women), and presence in the kitchen (+49% (95% CI: 27%, 75%) in men, +14% (95% CI: 7%, 20%) in women). Our results indicate wearable cameras can provide objective, high time-resolution microenvironmental data useful for identifying peak exposures and providing insights not evident using standard self-reported time-activity.

Sources of household air pollution and their association with fine particulate matter in low-income urban homes in India

INTRODUCTION

Household air pollution (HAP) is poorly characterized in low-income urban Indian communities.

MATERIALS AND METHODS

A questionnaire assessing sources of HAP and 24 h household concentrations of particulate matter less than 2.5 microns in diameter (PM_2.5) were collected in a sample of low-income homes in Pune, India.

RESULTS

In 166 homes, the median 24 h average concentration of PM_2.5 was 167 μg/m³ (IQR: 106-294). Although kerosene and wood use were highly prevalent (22% and 25% of homes, respectively), primarily as secondary fuel sources, high PM_2.5 concentrations were also found in 95 (57%) homes reporting LPG use alone (mean 141 μg/m³; IQR: 92-209). In adjusted linear regression, log PM_2.5 concentration was positively associated with wood cooking fuel (GMR 1.5, 95% CI: 1.1-2.0), mosquito coils (GMR 1.5, 95% CI: 1.1-2.1), and winter season (GMR 1.7, 95% CI: 1.4-2.2). Households in the highest quartile of exposure were positively associated with wood cooking fuel (OR 1.3, 95% CI: 1.1-1.5), incense (OR 1.1, 95% CI: 1.0-1.3), mosquito coils (OR 1.3, 95% CI: 1.1-1.6), and winter season (OR 1.2, 95% CI: 1.1-1.4).

DISCUSSION

We observed high concentrations of PM_2.5 and identified associated determinants in urban Indian homes.

Attributable risk and potential impact of interventions to reduce household air pollution associated with under-five mortality in South Asia

BACKGROUND

Solid fuel use is the major source of household air pollution (HAP) and accounts for a substantial burden of morbidity and mortality in low and middle income countries. To evaluate and compare childhood mortality attributable to HAP in four South Asian countries.

METHODS

A series of Demographic and Health Survey (DHS) datasets for Bangladesh, India, Nepal and Pakistan were used for analysis. Estimates of relative risk and exposure prevalence relating to use of cooking fuel and under-five mortality were used to calculate population attributable fractions (PAFs) for each country. Potential impact fractions (PIFs) were also calculated assessing theoretical scenarios based on published interventions aiming to reduce exposure prevalence.

RESULTS

There are an increased risk of under-five mortality in those exposed to cooking fuel compared to those not exposed in the four South Asian countries (OR = 1.30, 95% CI = 1.07-1.57, P = 0.007). Combined PAF estimates for South Asia found that 66% (95% CI: 43.1-81.5%) of the 13,290 estimated cases of under-five mortality was attributable to HAP. Joint PIF estimates (assuming achievable reductions in HAP reported in intervention studies conducted in South Asia) indicates 47% of neonatal and 43% of under-five mortality cases associated with HAP could be avoidable in the four South Asian countries studied.

CONCLUSIONS

Elimination of exposure to use of cooking fuel in the household targeting valuable intervention strategies (such as cooking in separate kitchen, improved cook stoves) could reduce substantially under-five mortality in South Asian countries.

Cooking fuel and risk of under-five mortality in 23 Sub-Saharan African countries: a population-based study

Relationship between cooking fuel and under-five mortality has not been adequately established in Sub-Saharan Africa (SSA). We therefore investigated the association between cooking fuel and risk of under-five mortality in SSA, and further investigated its interaction with smoking. Using the most recent Demographic Health Survey data of 23 SSA countries (n = 783,691), Cox proportional hazard was employed to determine the association between cooking fuel and risk of under-five deaths. The adjusted hazard ratios were 1.21 (95 % CI, 1.10-1.34) and 1.20 (95 % CI, 1.08-1.32) for charcoal and biomass cooking fuel, respectively, compared to clean fuels. There was no positive interaction between biomass cooking fuel and smoking. Use of charcoal and biomass were associated with the risk of under-five mortality in SSA. Disseminating public health information on health risks of cooking fuel and development of relevant public health policies are likely to have a positive impact on a child's survival.

Household air pollution from various types of rural kitchens and its exposure assessment

Exposure to household air pollutants has become a leading environmental health risk in developing countries. Considering this, real-time temporal variation in fine particulate matter (PM_2.5) and carbon monoxide (CO) concentrations were measured in various types of rural household kitchens. Observed average concentrations of PM_2.5, CO, percent relative humidity (%RH) and temperature (T) in five different kitchen types were 549.6μg/m³, 4.2ppm, 70.2% and 20°C respectively. Highest CO and PM_2.5 concentration were found in household performing cooking in indoor kitchens (CO: 9.3ppm; PM_2.5: 696.5μg/m³) followed by outdoor kitchens (CO: 5.8ppm; PM_2.5: 539.5μg/m³). The concentration of PM_2.5 and CO varied according to the fuel type and highest concentration was observed in kitchens using cowdung cakes followed by agricultural residue>firewood>biogas>Liquefied Petroleum Gas (LPG). Results revealed that the pollutants concentration varied with kitchen type, fuel type and the location of kitchen. An exposure index was developed to calculate the exposure of cook, non-cook and children below 5years. Analysis of exposure index values shows that cooks, who use solid biomass fuel (SBF) in indoor kitchen, are four times more exposed to the harmful pollutants than the cooks using clean fuel. Further, using indoor PM_2.5 concentrations, hazard quotient was calculated based on evaluation of intake concentration and toxicological risk, which also shows that SBF users have higher health risks (hazard quotient>1) than the clean fuel (LPG) users.

Use of Cooking Fuels and Cataract in a Population-Based Study: The India Eye Disease Study

BACKGROUND

Biomass cooking fuels are commonly used in Indian households, especially by the poorest socioeconomic groups. Cataract is highly prevalent in India and the major cause of vision loss. The evidence on biomass fuels and cataract is limited.

OBJECTIVES

To examine the association of biomass cooking fuels with cataract and type of cataract.

METHODS

We conducted a population-based study in north and south India using randomly sampled clusters to identify people ≥ 60 years old. Participants were interviewed and asked about cooking fuel use, socioeconomic and lifestyle factors and attended hospital for digital lens imaging (graded using the Lens Opacity Classification System III), anthropometry, and blood collection. Years of use of biomass fuels were estimated and transformed to a standardized normal distribution.

RESULTS

Of the 7,518 people sampled, 94% were interviewed and 83% of these attended the hospital. Sex modified the association between years of biomass fuel use and cataract; the adjusted odds ratio (OR) for a 1-SD increase in years of biomass fuel use and nuclear cataract was 1.04 (95% CI: 0.88, 1.23) for men and 1.28 (95% CI: 1.10, 1.48) for women, p interaction = 0.07. Kerosene use was low (10%). Among women, kerosene use was associated with nuclear (OR = 1.76, 95% CI: 1.04, 2.97) and posterior subcapsular cataract (OR = 1.71, 95% CI: 1.10, 2.64). There was no association among men.

CONCLUSIONS

Our results provide robust evidence for the association of biomass fuels with cataract for women but not for men. Our finding for kerosene and cataract among women is novel and requires confirmation in other studies. Citation: Ravilla TD, Gupta S, Ravindran RD, Vashist P, Krishnan T, Maraini G, Chakravarthy U, Fletcher AE. 2016. Use of cooking fuels and cataract in a population-based study: the India Eye Disease Study. Environ Health Perspect 124:1857-1862; http://dx.doi.org/10.1289/EHP193.

Household air pollution and under-five mortality in India (1992-2006)

BACKGROUND

Household air pollution (HAP) - predominantly from cooking fuel is a major public health hazard and one of the leading causes of respiratory illness and deaths among children under-five years in India. This study investigates the association between HAP from cooking fuel and under-five mortality using India's National Family and Health Survey (NFHS) datasets over the period 1992-2006 (total of 166,382 children), and the extent to which the association differed by environmental and behavioral factors affecting level of exposure.

METHODS

The association between HAP and under-five mortality of three age-groups (neonatal age between 0-28 days, post-neonatal age between 1-11 months and children aged between 12-59 months) was examined using multi-level logistic regression models.

RESULTS

HAP was associated with mortality among children aged under-five (OR = 1.30, 95%CI = 1.18-1.43, P < 0.001) and was more strongly associated in sub-group analyses of post-neonatal mortality (OR = 1.42, 95%CI = 1.19-1.71, P < 0.001) and child mortality (OR = 1.42, 95%CI = 1.05-1.91, P = 0.021) than neonatal mortality (OR = 1.23, 95%CI = 1.09-1.39, P = 0.001). The association was stronger for households in rural areas and for households without a separate kitchen using polluting fuel, and in women who had never breastfed for all age-groups.

CONCLUSION

Use of cooking fuel in the household is associated with increased risk of mortality in children aged under-five years. Factors relating to access to clean fuels, improvements in infrastructure and household design and behavioral factors are discussed, and can result in further declines in under-five mortality in India.

Respiratory symptoms, lung function decrement and chronic obstructive pulmonary disease in pre-menopausal Indian women exposed to biomass smoke

BACKGROUND

The impact of chronic exposure to smoke from biomass burning on respiratory health has been examined.

METHODS

Six-hundred and eighty-one non-smoking women (median age 35 years) from eastern India who cook exclusively with biomass (wood, dung and crop residues) and 438 age-matched women from similar neighborhood who cook with liquefied petroleum gas (LPG) were examined. Pulmonary function test was done by spirometry. The concentrations of particulate matter having diameter of < 10 µm (PM10) and < 2.5 µm (PM2.5) in indoor air was measured by real-time aerosol monitor.

RESULTS

Compared with LPG users, biomass users had greater prevalence of upper (50.9 versus 28.5%) and lower respiratory symptoms (71.8 versus 30.8%) and dyspnea (58.4 versus 19.9%). They showed reduction in all parameters measured by spirometer especially in mid-expiratory volume. PM10 and PM2.5 concentration in biomass using kitchen were 2-3-times more than LPG-using kitchen, and the decline in spirometry values was positively associated PM10 and PM2.5 levels in indoor air after controlling education, family income and kitchen location as potential confounders. Overall, 29.7% of biomass users and 16.4% of LPG users had deficient lung function, and restrictive type of deficiency was predominant. Chronic obstructive pulmonary disease (COPD) was diagnosed in 4.6% of biomass and 0.9% of LPG users. Women who predominantly used dung cake and did not possess separate kitchen had poorer lung function.

CONCLUSION

Cumulative exposure to biomass smoke causes lung function decrement and facilitates COPD development even in non-smoking and relatively young pre-menopausal women.

Establishing integrated rural-urban cohorts to assess air pollution-related health effects in pregnant women, children and adults in Southern India: an overview of objectives, design and methods in the Tamil Nadu Air Pollution and Health Effects (TAPHE) study

INTRODUCTION

In rapidly developing countries such as India, the ubiquity of air pollution sources in urban and rural communities often results in ambient and household exposures significantly in excess of health-based air quality guidelines. Few efforts, however, have been directed at establishing quantitative exposure-response relationships in such settings. We describe study protocols for The Tamil Nadu Air Pollution and Health Effects (TAPHE) study, which aims to examine the association between fine particulate matter (PM2.5) exposures and select maternal, child and adult health outcomes in integrated rural-urban cohorts.

METHODS AND ANALYSES

The TAPHE study is organised into five component studies with participants drawn from a pregnant mother-child cohort and an adult cohort (n=1200 participants in each cohort). Exposures are assessed through serial measurements of 24-48 h PM2.5 area concentrations in household microenvironments together with ambient measurements and time-activity recalls, allowing exposure reconstructions. Generalised additive models will be developed to examine the association between PM2.5 exposures, maternal (birth weight), child (acute respiratory infections) and adult (chronic respiratory symptoms and lung function) health outcomes while adjusting for multiple covariates. In addition, exposure models are being developed to predict PM2.5 exposures in relation to household and community level variables as well as to explore inter-relationships between household concentrations of PM2.5 and air toxics. Finally, a bio-repository of peripheral and cord blood samples is being created to explore the role of gene-environment interactions in follow-up studies.

ETHICS AND DISSEMINATION

The study protocols have been approved by the Institutional Ethics Committee of Sri Ramachandra University, the host institution for the investigators in this study. Study results will be widely disseminated through peer-reviewed publications and scientific presentations. In addition, policy-relevant recommendations are also being planned to inform ongoing national air quality action plans concerning ambient and household air pollution.

Understanding Air Pollution and Cardiovascular Diseases: Is It Preventable?

Fine particulate matter (<2.5 µm, PM_2.5) air pollution is a leading risk factor for morbidity and mortality worldwide. The largest portion of adverse health effects is from cardiovascular diseases. In North America, PM_2.5 concentrations have shown a steady decline over the past several decades; however, the opposite trend has occurred throughout much of the developing world whereby daily concentrations commonly reach extraordinarily high levels. While air quality regulations can reduce air pollution at a societal level, what individuals can do to reduce their personal exposures remains an active field of investigation. Here, we review the emerging evidence that several interventions (e.g., air filters) and/or behavioral changes can lower PM pollution exposure and as such, may be capable of mitigating the ensuing adverse cardiovascular health consequences. Air pollution remains a worldwide epidemic and a multi-tiered prevention strategy is required in order to optimally protect global public health.

Association between household air pollution sand neonatal mortality: an analysis of Annual Health Survey results, India

BACKGROUND

In India, household air pollution (HAP) is one of the leading risk factors contributing to the national burden of disease. Estimates indicate that 7.6% of all deaths in children aged under 5 years in the country can be attributed to HAP. This analysis attempts to establish the association between HAP and neonatal mortality rate (NMR).

METHODS

Secondary data from the Annual Health Survey, conducted in 284 districts of nine large states covering 1 404 337 live births, were analysed. The survey was carried out from July 2010 to March 2011 (reference period: January 2007 to December 2009). The primary outcome was NMR. The key exposure was the use of firewood/crop residues/cow dung as fuel. The covariates were: sociodemographic factors (place of residence, literacy status of mothers, proportion of women aged less than 18 years who were married, wealth index); health-system factors (three or more antenatal care visits made during pregnancy; institutional deliveries; proportion of neonates with a stay in the institution for less than 24 h; percentage of neonates who received a check-up within 24 h of birth); and behavioural factors (initiation of breast feeding within 1 h). Descriptive analysis, with district as the unit of analysis, was performed for rural and urban areas. Bivariate and multivariable linear regression analysis was carried out to investigate the association between HAP and NMR.

RESULTS

The mean rural NMR was 42.4/1000 live births (standard deviation [SD] = 11.4/1000) and urban NMR was 33.1/1000 live births (SD=12.6/1000). The proportion of households with HAP was 92.2% in rural areas, compared to 40.8% in urban areas, and the difference was statistically significant (P < 0.001). HAP was found to be strongly associated with NMR after adjustment (β = 0.22; 95% confidence interval [CI] = 0.09 to 0.35) for urban and rural areas combined. For rural areas separately, the association was significant (β = 0.30; 95% CI = 0.13 to 0.45) after adjustment. In univariable analysis, the analysis showed a significant association in urban areas (β = 0.23; 95% CI = 0.12 to 2.34) but failed to demonstrate an association in multivariable analysis (β = 0.001; 95% CI = -0.15 to 0.15).

CONCLUSION

Secondary data from district level indicate that HAP is associated with NMR in rural areas, but not in urban areas in India.

The effect of solid fuel use on childhood mortality in Nigeria: evidence from the 2013 cross-sectional household survey

BACKGROUND

In Nigeria, approximately 69% of households use solid fuels as their primary source of domestic energy for cooking. These fuels produce high levels of indoor air pollution. This study aimed to determine whether Nigerian children residing in households using solid fuels at <5 years of age were at higher risk of death.

METHODS

The 2013 Nigeria Demographic and Health Survey data were analysed in Cox regression analyses to examine the effects of solid fuel use on deaths of children aged 0-28 days (neonatal), 1-11 months (post-neonatal), and 12-59 months (child).

RESULTS

The results indicated that approximately 0.8% of neonatal deaths, 42.9% of post-neonatal deaths, and 36.3% of child deaths could be attributed to use of solid fuels. The multivariable analyses found that use of solid fuel was associated with post-neonatal mortality (hazard ratio [HR] =1.92, 95% confidence interval [CI]: 1.42-2.58) and child mortality (HR = 1.63, CI: 1.09-2.42), but was not associated with neonatal mortality (HR = 1.01, CI: 0.73-1.26). Living in rural areas and poor households were associated with an increased risk of death during the three mortality periods.

CONCLUSION

Living in a rural area and poor households were strongly associated with an increased risk of a child > 1 to < 60 months dying due to use of solid fuels. The health effects of household use of solid fuels are a major public health threat that requires increased research and policy development efforts. Research should focus on populations in rural areas and low socioeconomic households so that child survival in Nigeria can be improved.

Biomass fuel use and the exposure of children to particulate air pollution in southern Nepal

The exposure of children to air pollution in low resource settings is believed to be high because of the common use of biomass fuels for cooking. We used microenvironment sampling to estimate the respirable fraction of air pollution (particles with median diameter less than 4 μm) to which 7-9 year old children in southern Nepal were exposed. Sampling was conducted for a total 2649 h in 55 households, 8 schools and 8 outdoor locations of rural Dhanusha. We conducted gravimetric and photometric sampling in a subsample of the children in our study in the locations in which they usually resided (bedroom/living room, kitchen, veranda, in school and outdoors), repeated three times over one year. Using time activity information, a 24-hour time weighted average was modeled for all the children in the study. Approximately two-thirds of homes used biomass fuels, with the remainder mostly using gas. The exposure of children to air pollution was very high. The 24-hour time weighted average over the whole year was 168 μg/m(3). The non-kitchen related samples tended to show approximately double the concentration in winter than spring/autumn, and four times that of the monsoon season. There was no difference between the exposure of boys and girls. Air pollution in rural households was much higher than the World Health Organization and the National Ambient Air Quality Standards for Nepal recommendations for particulate exposure.

Assessment of cardiovascular disease risk in South asian populations

Although South Asian populations have high cardiovascular disease (CVD) burden in the world, their patterns of individual CVD risk factors have not been fully studied. None of the available algorithms/scores to assess CVD risk have originated from these populations. To explore the relevance of CVD risk scores for these populations, literature search and qualitative synthesis of available evidence were performed. South Asians usually have higher levels of both “classical” and nontraditional CVD risk factors and experience these at a younger age. There are marked variations in risk profiles between South Asian populations. More than 100 risk algorithms are currently available, with varying risk factors. However, no available algorithm has included all important risk factors that underlie CVD in these populations. The future challenge is either to appropriately calibrate current risk algorithms or ideally to develop new risk algorithms that include variables that provide an accurate estimate of CVD risk.

State and national household concentrations of PM2.5 from solid cookfuel use: results from measurements and modeling in India for estimation of the global burden of disease

BACKGROUND

Previous global burden of disease (GBD) estimates for household air pollution (HAP) from solid cookfuel use were based on categorical indicators of exposure. Recent progress in GBD methodologies that use integrated-exposure-response (IER) curves for combustion particles required the development of models to quantitatively estimate average HAP levels experienced by large populations. Such models can also serve to inform public health intervention efforts. Thus, we developed a model to estimate national household concentrations of PM2.5 from solid cookfuel use in India, together with estimates for 29 states.

METHODS

We monitored 24-hr household concentrations of PM2.5, in 617 rural households from 4 states in India on a cross-sectional basis between November 2004 and March 2005. We then, developed log-linear regression models that predict household concentrations as a function of multiple, independent household level variables available in national household surveys and generated national / state estimates using The Indian National Family and Health Survey (NFHS 2005).

RESULTS

The measured mean 24-hr concentration of PM2.5 in solid cookfuel using households ranged from 163 μg/m3 (95% CI: 143,183; median 106; IQR: 191) in the living area to 609 μg/m3 (95% CI: 547,671; median: 472; IQR: 734) in the kitchen area. Fuel type, kitchen type, ventilation, geographical location and cooking duration were found to be significant predictors of PM2.5 concentrations in the household model. k-fold cross validation showed a fair degree of correlation (r = 0.56) between modeled and measured values. Extrapolation of the household results by state to all solid cookfuel-using households in India, covered by NFHS 2005, resulted in a modeled estimate of 450 μg/m3 (95% CI: 318,640) and 113 μg/m3 (95% CI: 102,127) , for national average 24-hr PM2.5 concentrations in the kitchen and living areas respectively.

CONCLUSIONS

The model affords substantial improvement over commonly used exposure indicators such as "percent solid cookfuel use" in HAP disease burden assessments, by providing some of the first estimates of national average HAP levels experienced in India. Model estimates also add considerable strength of evidence for framing and implementation of intervention efforts at the state and national levels.

Indoor air pollution and respiratory health of children in the developing world

Indoor air pollution (IAP) is a key contributor to the global burden of disease mainly in developing countries. The use of solid fuel for cooking and heating is the main source of IAP in developing countries, accounting for an estimated 3.5 million deaths and 4.5% of Disability-Adjusted Life Years in 2010. Other sources of IAP include indoor smoking, infiltration of pollutants from outdoor sources and substances emitted from an array of human utilities and biological materials. Children are among the most vulnerable groups for adverse effects of IAP. The respiratory system is a primary target of air pollutants resulting in a wide range of acute and chronic effects. The spectrum of respiratory adverse effects ranges from mild subclinical changes and mild symptoms to life threatening conditions and even death. However, IAP is a modifiable risk factor having potential mitigating interventions. Possible interventions range from simple behavior change to structural changes and from shifting of unclean cooking fuel to clean cooking fuel. Shifting from use of solid fuel to clean fuel invariably reduces household air pollution in developing countries, but such a change is challenging. This review aims to summarize the available information on IAP exposure during childhood and its effects on respiratory health in developing countries. It specifically discusses the common sources of IAP, susceptibility of children to air pollution, mechanisms of action, common respiratory conditions, preventive and mitigating strategies.

Longitudinal relationship between personal CO and personal PM2.5 among women cooking with woodfired cookstoves in Guatemala

Household air pollution (HAP) due to solid fuel use is a major public health threat in low-income countries. Most health effects are thought to be related to exposure to the fine particulate matter (PM) component of HAP, but it is currently impractical to measure personal exposure to PM in large studies. Carbon monoxide (CO) has been shown in cross-sectional analyses to be a reliable surrogate for particles<2.5 µm in diameter (PM_2.5) in kitchens where wood-burning cookfires are a dominant source, but it is unknown whether a similar PM_2.5-CO relationship exists for personal exposures longitudinally. We repeatedly measured (216 measures, 116 women) 24-hour personal PM_2.5 (median [IQR] = 0.11 [0.05, 0.21] mg/m³) and CO (median [IQR] = 1.18 [0.50, 2.37] mg/m³) among women cooking over open woodfires or chimney woodstoves in Guatemala. Pollution measures were natural-log transformed for analyses. In linear mixed effects models with random subject intercepts, we found that personal CO explained 78% of between-subject variance in personal PM_2.5. We did not see a difference in slope by stove type. This work provides evidence that in settings where there is a dominant source of biomass combustion, repeated measures of personal CO can be used as a reliable surrogate for an individual's PM_2.5 exposure. This finding has important implications for the feasibility of reliably estimating long-term (months to years) PM_2.5 exposure in large-scale epidemiological and intervention studies of HAP.

Household fuels, low birth weight, and neonatal death in India: the separate impacts of biomass, kerosene, and coal

We examined the impact of maternal use of different household cooking fuels in India on low birth weight (LBW<2500g), and neonatal mortality (death within 28 days of birth). Using cross-sectional data from India's National Family Health Survey (NFHS-3), we separately analyzed the prevalence of these two outcomes in households utilizing three types of high-pollution fuels for cooking - biomass, coal, and kerosene - using low-pollution fuels (gas and biogas) as the comparison "control" group. Taking socioeconomic and child-specific factors into account, we employed logistic regression to examine the impact of fuel use on fetal and infant health. The results indicate that household use of high-pollution fuels is significantly associated with increased odds of LBW and neonatal death. Compared to households using cleaner fuels (in which the mean birth weight is 2901g), the primary use of coal, kerosene, and biomass fuels is associated with significant decreases in mean birth weight (of -110g for coal, -107g for kerosene, and -78g for biomass). Kerosene and biomass fuel use are also associated with increased risk of LBW (p<0.05). Results suggest that increased risk of neonatal death is strongly associated with household use of coal (OR 18.54; 95% CI: 6.31-54.45), and perhaps with kerosene (OR 2.30; 95% CI: 0.95-5.55). Biomass is associated with increased risk of neonatal death among infants born to women with no more than primary education (OR 7.56; 95% CI: 2.40-23.80). These results are consistent with a growing literature showing health impacts of household air pollution from these fuels.

Household air pollution is a major avoidable risk factor for cardiorespiratory disease

Household air pollution (HAP) from biomass fuels, coal, and kerosene burned in open fires, primitive stoves, and lamps causes at least 2 million deaths per year. Many of these deaths occur in children <5 years of age with pneumonia and in women with COPD, lung cancer, and cardiovascular disease. HAP is inextricably linked to poverty, with activities to obtain fuel consuming a large proportion of the time and financial resources of poor households. Thus, fewer resources used in this way means less is available for basic needs like food, education, and health care. The burden of work and the exposure to smoke, particularly during cooking, are predominantly borne by women and children. Although historically HAP has not received sufficient attention from the scientific, medical, public health, development, and policy-making communities, the tide has clearly changed with the broad-based support and launch of the Global Alliance for Clean Cookstoves in 2010. There is now considerable reason for optimism that this substantial cause of cardiorespiratory morbidity and mortality will be addressed comprehensively and definitively. Drawing on our experience from four continents, we provide background information on the problem of HAP, health impacts of HAP, opportunities for research, and the current best solutions.

Cooking practices, air quality, and the acceptability of advanced cookstoves in Haryana, India: an exploratory study to inform large-scale interventions

Background

In India, approximately 66% of households rely on dung or woody biomass as fuels for cooking. These fuels are burned under inefficient conditions, leading to household air pollution (HAP) and exposure to smoke containing toxic substances. Large-scale intervention efforts need to be informed by careful piloting to address multiple methodological and sociocultural issues. This exploratory study provides preliminary data for such an exercise from Palwal District, Haryana, India.

Methods

Traditional cooking practices were assessed through semi-structured interviews in participating households. Philips and Oorja, two brands of commercially available advanced cookstoves with small blowers to improve combustion, were deployed in these households. Concentrations of particulate matter (PM) with a diameter <2.5 μm (PM_2.5) and carbon monoxide (CO) related to traditional stove use were measured using real-time and integrated personal, microenvironmental samplers for optimizing protocols to evaluate exposure reduction. Qualitative data on acceptability of advanced stoves and objective measures of stove usage were also collected.

Results

Twenty-eight of the thirty-two participating households had outdoor primary cooking spaces. Twenty households had liquefied petroleum gas (LPG) but preferred traditional stoves as the cost of LPG was higher and because meals cooked on traditional stoves were perceived to taste better. Kitchen area concentrations and kitchen personal concentrations assessed during cooking events were very high, with respective mean PM_2.5 concentrations of 468 and 718 µg/m³. Twenty-four hour outdoor concentrations averaged 400 µg/m³. Twenty-four hour personal CO concentrations ranged between 0.82 and 5.27 ppm. The Philips stove was used more often and for more hours than the Oorja.

Conclusions

The high PM and CO concentrations reinforce the need for interventions that reduce HAP exposure in the aforementioned community. Of the two stoves tested, participants expressed satisfaction with the Philips brand as it met the local criteria for usability. Further understanding of how the introduction of an advanced stove influences patterns of household energy use is needed. The preliminary data provided here would be useful for designing feasibility and/or pilot studies aimed at intervention efforts locally and nationally.