Household air pollution from cooking and risk of adverse health and birth outcomes in Bangladesh: a nationwide population-based study

Impact of Improved Biomass and Liquid Petroleum Gas Stoves on Birth Outcomes in Rural Nepal: Results of 2 Randomized Trials

Improved biomass stoves may not reduce indoor air pollution as much as is needed to have an impact on adverse birth outcomes.

Background:

Few randomized trials have assessed the impact of reducing household air pollution from biomass stoves on adverse birth outcomes in low-income countries.

Methods:

Two sequential trials were conducted in rural low-lying Nepal. Trial 1 was a cluster-randomized step-wedge trial comparing traditional biomass stoves and improved biomass stoves vented with a chimney. Trial 2 was a parallel household-randomized trial comparing vented biomass stoves and liquid petroleum gas (LPG) stoves with a year’s supply of gas. Kitchen particulate matter of 2.5 μm or less (PM_2.5) and carbon monoxide (CO) were assessed before and after stove installation. Prevalent and incident pregnancies were enrolled at baseline and throughout the trials. Birth anthropometry was compared across differing exposure times in pregnancy.

Results:

In trial 1, the mean 20-hour kitchen PM_2.5 concentration was reduced from 1380 µg/m³ to 936 µg/m³. Among infants born before the intervention, mean birth weight and gestational age were 2627 g (SD=443) and 38.8 weeks (SD=3.1), and 39% were low birth weight (LBW), 22% preterm, and 55% small for gestational age (SGA). Adverse birth outcomes were not significantly different with increasing exposure to improved stoves during pregnancy. In trial 2, the mean 20-hour PM_2.5 concentration was 885 µg/m³ in households with vented biomass and 442 µg/m³ in those with LPG stoves. Mean birth weight was 2780 g (SD=427) and 2742 g (SD=431), among households with vented and LPG stoves, respectively. Respective percentages for LBW, SGA, and preterm were 23%, 13%, and 42% in the vented stove group and not statistically different from 31%, 17%, and 42% in the LPG group.

Conclusions:

Improved biomass or LPG stoves did not reduce adverse birth outcomes. PM_2.5 and CO following improved stove installation remained well above the World Health Organization indoor air standard of 25 µg/m³ or intermediate air quality guideline of 37.5 µg/m³. Trials that lower indoor air pollution further are needed.

Cooking fuels use and carotid intima-media thickness during early pregnancy of women in Myanmar

BACKGROUND

Fuels burned in households for cooking cause indoor air pollution, exposing those who are cooking. Despite the mounting evidence of the effects of fuels use on health, few studies focus on the effect of cooking fuels have on carotid intima-media thickness (CIMT), a surrogate atherosclerosis biomarker in the early stages of pregnancy. This study aimed to examine the association between the use of cooking fuels and CIMT during early trimester of pregnancy among cooking women in Myanmar.

METHODOLOGY

In this cross-sectional study, a part of an ongoing birth cohort analysis, a total of 192 cooking pregnant women over 18 years with gestational weeks less than 18 were recruited from 15 rural health centers in Nay Pyi Taw from September to November 2019. Sociodemographic data, residential data, and fuels use data were collected with semi-structured questionnaires in face-to-face interviews. Anthropometric, hemodynamic, blood lipids, and ultrasound CIMT measurements were performed under standard protocols. Multiple linear regression was modeled to explore associations.

RESULTS

The study included 70 firewood fuel users, 26 charcoal fuel users, and 96 electricity fuel users. Following adjustments for potential confounding factors, firewood use was significantly associated with the increase of all CIMT analyzed. Importantly, a greater increase of mean CIMT of the right common carotid artery (RCCA; β = 0.033 mm; 95%CI: 0.006, 0.058; P<0.05) had significant association with charcoal use compared to firewood use (β = 0.029 mm; 95%CI: 0.010, 0.049; P<0.05).

CONCLUSIONS

Our findings demonstrate that the indoor use of cooking fuels that cause indoor air pollution, such as firewood and charcoal, is a considerable risk factor for human health and is associated with increased CIMT, wherein charcoal use contributes to more increase of mean CIMT of the RCCA. Measures to prevent health risks related to the use of such fuels should be instituted early on during pregnancy.

A prospective cohort study of in utero and early childhood arsenic exposure and infectious disease in 4- to 5-year-old Bangladeshi children

Previous research found that infants who were exposed to high levels of arsenic in utero had an increased risk of infectious disease in the first year of life. This prospective study examined the association between arsenic exposures during gestation, and respiratory, diarrheal, and febrile morbidity in children 4–5 years of age.

Cumulative Lifetime Burden of Cardiovascular Disease From Early Exposure to Air Pollution

The disease burden associated with air pollution continues to grow. The World Health Organization (WHO) estimates ≈7 million people worldwide die yearly from exposure to polluted air, half of which-3.3 million-are attributable to cardiovascular disease (CVD), greater than from major modifiable CVD risks including smoking, hypertension, hyperlipidemia, and diabetes mellitus. This serious and growing health threat is attributed to increasing urbanization of the world's populations with consequent exposure to polluted air. Especially vulnerable are the elderly, patients with pre-existing CVD, and children. The cumulative lifetime burden in children is particularly of concern because their rapidly developing cardiopulmonary systems are more susceptible to damage and they spend more time outdoors and therefore inhale more pollutants. World Health Organization estimates that 93% of the world's children aged <15 years-1.8 billion children-breathe air that puts their health and development at risk. Here, we present growing scientific evidence, including from our own group, that chronic exposure to air pollution early in life is directly linked to development of major CVD risks, including obesity, hypertension, and metabolic disorders. In this review, we surveyed the literature for current knowledge of how pollution exposure early in life adversely impacts cardiovascular phenotypes, and lay the foundation for early intervention and other strategies that can help prevent this damage. We also discuss the need for better guidelines and additional research to validate exposure metrics and interventions that will ultimately help healthcare providers reduce the growing burden of CVD from pollution.

Determinants of Acute Respiratory Infection Among Children in Ethiopia: A Multilevel Analysis from Ethiopian Demographic and Health Survey

Background

Acute respiratory infection (ARI) is one of the leading public health challenges among children in low- and middle-income countries. Child mortality due to ARI is disproportionately higher in African regions. In Ethiopia, an encouraging progress in the reduction of ARI was observed until 2010, however, since then the national prevalence is unchanged. There is limited information for the persistently higher prevalence of the infection. Therefore, the aim of this study was to determine regional variations and identify factors associated with the infection.

Methods

This study used data from the Ethiopian Demographic and Health Survey (EDHS) conducted in 2016. The analysis used information from 10,006 children. A two-level logistic regression analysis was used to consider the cluster random effect.

Results

Out of 10,006 children included, 15.9%, 8.9%, and 8.8% reported cough, short rapid breaths, and chest complaint respectively two weeks before the survey, making the overall prevalence of ARI 8.8%. Children aged six to 11 years (adjusted odds ratio (AOR)=1.466, 95%CI: 1.143-1.881), and 12 to 23 (AOR=1.390, 95%CI: 1.109-1.742), small birth size (AOR=1.387, 95%CI), and animal dung as cooking fuel (AOR=1.904, 95%CI: 1.152-3.146) are significantly associated with higher odds of ARI in the final multilevel modeling. The AOR (95%CI) for ARI for differing levels of altitude were: 1000 to 2000, 1.805 (1.403-2.483); 2000 to 3000, 1.882 (1.427-2.483); above 3000, 2.24 (1.023-4.907).

Conclusion

ARI is still a significant public health problem in Ethiopia among children underfive, with a huge variation in the burden across the regional states. Age of children, birth size, household cooking fuel, and altitude above sea level were important variables. Therefore, regional governments, health-care workers and concerned organizations should give emphasis to minimize ARI and the consequences associated with the disease.

Maternal cooking during pregnancy may increase hyperactive behaviors among children aged at around 3 years old

Cooking is one of the main sources of indoor air pollution in China. Given emerging evidence of a link between air pollutants and neurodevelopmental delays, we examined whether maternal experiences with cooking during gestation might increase their child's hyperactivity at 3 years of age. The participants involved 45 518 mothers of children who were newly enrolled at kindergarten in the Longhua District of Shenzhen from 2015 to 2017. The results show that maternal exposure to cooking fumes during pregnancy was related to an increased risk of their offspring having hyperactivity behaviors at the age of 3 years. Compared with pregnant mothers who never cooked, pregnant mothers who cooked sometimes, often, or always had children who showed a significantly higher hyperactivity risk. Households using cooking fuels such as coal, gas during the mothers' pregnancy, exhibited more hyperactivity behaviors in the young child when compared to those using electricity for cooking. In addition, poor ventilation during cooking, while mothers were pregnant, was found to be a significant risk factor for clinical levels of the offspring's hyperactive behaviors. Furthermore, the positive association with maternal cooking during pregnancy and their offsprings' hyperactivity was relatively consistent across strata defined by social class, education, and other covariates.

Cooking frequency and hypertension with gender as a modifier

Background

The effect of cooking frequency on hypertension is understudied. This study aimed to examine the effect of cooking on hypertension with a particular focus on gender differences.

Methods

The present study utilized cross-sectional data from China Kadoorie Biobank with a 512,891-population of China. Hypertension was identified by established diagnosis or by the 1999 WHO/ISH Guidelines for the Management of Hypertension on examination. Cooking frequency was obtained from a self-reported questionnaire and categorized as daily cooking, weekly or monthly cooking and never cooking. Multivariable logistic regression models were employed to examine the associations between cooking frequency and hypertension in men and women, respectively. Stratified analyses by demographic and socio-economic characteristics were conducted.

Results

Men who ever cooked had higher odds of hypertension compared with those who never cooked (weekly or monthly cooking adjusted odds ratio (AOR): 1.05, 95% CI: 1.02–1.07; Daily cooking AOR: 1.09, 95% CI: 1.06–1.11), while protective effects of cooking against hypertension were observed in women (weekly or monthly cooking AOR: 0.94, 95% CI: 0.89–0.99; daily cooking AOR: 0.96, 95% CI: 0.92–0.99). Socio-economic status including occupation, household income, education and region could further modify the effect of daily cooking on hypertension among men and women, respectively.

Conclusion

The present study highlighted the effect of cooking on hypertension. We found the opposite trends in men and women with regards to the association between cooking and hypertension. Factors relating to socio-economic status such as education, household income and occupation could further modify the gender-specific effects. Interventions to reduce hypertension should consider the gender differences in food choice and psycho-social stress related to cooking.

Association of biomass fuel smoke with respiratory symptoms among children under 5 years of age in urban areas: results from Bangladesh Urban Health Survey, 2013

BACKGROUND

Little is known regarding the effect of exposure to biomass fuel smoke inhalation on respiratory symptoms in the Bangladeshi population which is a major health hazard in most of the developing countries. This study aims to explore the association between respiratory symptoms and biomass fuel smoke exposure among children under 5 years of age.

METHODS

Data were extracted from the Bangladesh Urban Health Survey conducted in 2013. A total of 10,575 mothers with at least one surviving children were selected. Respiratory symptoms among children under 5 years of age were considered as the primary outcome. Sequential multiple logistic regression models were used to observe the association between respiratory symptoms and biomass fuel smoke exposure adjusting the effect of residential factors and mother and child characteristics.

RESULTS

Around 40% of the mothers exclusively used biomass fuel irrespective of the kitchen location and 54% of them were habituated in indoor cooking. The prevalence of respiratory symptoms of under-five children among in-house and outdoor biomass fuel users was 23.0% and 21.9%, respectively. Results of fitted multiple logistic regression models showed that the odds of having respiratory symptoms among children under 5 years of age were increased due to in-house biomass fuel use [OR = 1.18; 95% CI, 1.04-1.36] compared with the non-biomass user. An increased risk of respiratory symptoms was also significantly associated with mother's birth complication [OR = 1.51; 95% CI, 1.36-1.67], non-government organization (NGO) membership of mothers [OR = 1.32; 95% CI, 1.16-1.51], age of the child (6-23m) [OR = 1.29; 95% CI, 1.10-1.52], and nutritional status (stunting) [OR = 1.18; 95% CI, 1.06-1.31].

CONCLUSION

This study found the use of in-house biomass fuel as a significant risk factor associated with respiratory symptoms of children under 5 years of age. More longitudinal studies should be designed to establish a causal relationship between HAP (household air pollution) and respiratory symptoms among children with more direct measures of HAP and clinical procedure.

What Explains the Decline in Neonatal Mortality in India in the Last Three Decades? Evidence from Three Rounds of NFHS Surveys

Identifying the factors that have contributed to recent declines in neonatal mortality in India may help determine which policies and programs are most likely to facilitate further reductions. We use data from the 1992-93, 2005-06, and 2015-16 National Family Health Surveys (NFHS) to examine trends in neonatal mortality in India. We use multivariable decomposition to estimate the contribution of different factors to the change in neonatal mortality in India in the last three decades. When limited to most recent births in the 1-47 months preceding the surveys, 70 percent of the decline in neonatal mortality from 1992-2016 is due to changes in utilization of maternal- and child-care program factors and distribution of household, mother's, and child's characteristics. Improvement in "mother's schooling" and increase in utilization of "at least two tetanus toxoid injections" contributed the most followed by the increase in use of "at least three antenatal-care visits" and "clean fuel for cooking." The change in distribution of "birth order" also contributed significantly to the decline in neonatal mortality. Change in the benefits of "access to improved water," "delivery in a medical facility," and "mother's schooling" has led to a decline of 3 points, 2 points, and 1 point, respectively. More investments in maternal- and child-health programs (including family planning) and providing clean fuel for cooking are likely to pay higher dividends.

Trends and determinants of perinatal mortality in Bangladesh

BACKGROUND

Although the perinatal mortality rate (PNMR) has been reduced over time in Bangladesh, the rate is still very high. Only a few studies explored the determinants of high PNMR in Bangladesh, yet most of them were small-scale or conducted for stillbirths and early neonatal deaths separately. The objective of this study was to explore the trends in and determinants of perinatal deaths in Bangladesh which would be an advanced step in effective policies to tackle the issue.

METHODS

The data used for this study was extracted from four rounds of Bangladesh Demographic and Health Surveys (BDHSs) 2004, 2007, 2011 and 2014. We considered the outcome of the 26604 pregnancies reaching seven months of their gestation. The trends of perinatal mortality was assessed using the Cochran-Armitage test, while the logistic regression with generalized estimating equation (GEE) to account for the clustering effect was implemented to explore the association between perinatal mortality and its risk factors.

RESULTS

The PNMR was significantly reduced from 64 (95% CI: 57-73) to 41 (95% CI: 35-48) per 1000 pregnancies between 2004 and 2014 (stillbirths: 34 to 19 and early neonatal deaths: 30 to 22). After adjusting for potential covariates in the model, we found that administrative division, type of cooking fuel, child's gender, maternal occupation, body mass index, birth interval, history of miscarriage, previous deaths of children, total number of under 5 children, mode of delivery, type of delivery, access to participation in decision making, paternal education and occupation were significantly associated with perinatal deaths.

CONCLUSION

The study highlights the importance of strengthening proper postnatal care services in the healthcare facilities. Alongside this, effort should also be stressed to ensure proper pregnancy care and to improve the socio-economic condition of the households to address the issue.

Role of socioeconomic status and housing conditions in geriatric depression in rural China: a cross-sectional study

OBJECTIVES

The primary aim of this study was to describe the socioeconomic status (SES), housing conditions and depression of the elderly in rural China, as well as to examine the associations between depression and SES and housing conditions using the China Health and Retirement Longitudinal Study (CHARLS).

DESIGN

This is a cross-sectional study.

SETTING

A nationally representative sample of elderly in rural China.

PARTICIPANTS

A total of 4585 elderly adults in 2015 in rural China.

OUTCOME MEASURES

Prevalence and risk factors of depression among rural elderly.

RESULTS

Among the participants in this study, approximately 46.15% (2116/4585) reported depressive symptoms (10-item Center for Epidemiologic Studies Depression Scale [CESD-10] score >10) in rural China. The results revealed significant associations between higher scores on CESD-10 (indicating more symptoms of depression) and lowest personal annual income (OR=1.63, 95% CI 1.290 to 2.060), polluting cooking fuel (OR=1.16, 95% CI 1.018 to 1.321), toilet without seat (OR=1.273, 95% CI 1.056 to 1.535), as well as having no bath facility (OR=1.172, 95% CI 1.025 to 1.341) after adjustment for confounders.

CONCLUSION

Elderly in rural China experienced severe depressive symptoms. Lowest personal annual income, polluting cooking fuel, toilet without seat and having no bath facility were significantly associated with more depressive symptoms. Caution needs to be taken in generalising the findings of this study to the rest of the population in China since its highly selected sample.

Gender Differences in Geriatric Depressive Symptoms in Rural China: The Role of Physical Housing Environments and Living Arrangements

Physical housing environment and living arrangements are significant determinants of health, particularly in developing countries, although results are mixed. We conducted this study to examine the gender differences in geriatric depressive symptoms in rural China, and further explored the influence of housing environments and living arrangements on depressive symptoms. The data used for this study were from the third wave of the nationally representative China Health and Retirement Longitudinal Study (CHARLS) survey in 2015; a total of 2056 females and 2529 males were included in this study. According to the analysis findings, 46.15% of the respondents had depressive symptoms based on the CES-D, with a statistically significant gender difference of 54.32% in females and 39.50% in males. Logistic Regression findings identified that with regard to the items of physical housing environments, toilets without seats (OR = 1.349) and the unavailability of bathing facilities (OR = 1.469) were statistically associated with depressive symptoms among male participants, whereas for female participants the use of polluting fuels (OR = 1.248) and living arrangements (i.e., living with children, OR = 1.430) was statistically associated with depressive symptoms. Statistically significant gender differences were found for having shower or bath facilities and our findings underscored that physical housing environments and living arrangements were associated with depressive symptoms for both genders. Moreover, the study revealed that a slight gender difference exists in terms of geriatric depression in rural China. Females are more likely to become depressed than their male counterparts with the same characteristics.

Ambient air pollution and the risk of stillbirth: a population-based prospective birth cohort study in the coastal area of China

Accumulating evidence has shown that prenatal ambient air pollution exposure is associated with elevated stillbirth risk; however, the results are inconsistent. This population-based prospective cohort study aimed to explore the association between prenatal air pollution exposure and stillbirth rate in the coastal area in China. Data of air pollution and birth outcomes between January 1, 2015, and December 31, 2017, were collected. Among the 59,868 eligible births, there were 587 stillbirths and 59,281 live births. Although the air quality in this study was relatively better than most of the major cities in China, a positive association was still found between prenatal air pollution exposure and stillbirth rate. Every 10 μg/m³ increase of fine particulate matters (PM_2.5) in each trimester, as well as in the entire pregnancy, was associated with increased stillbirth rate (RR = 1.14, 1.11, 1.15, and 1.14 for the first, second, third trimester, and entire pregnancy, respectively). In addition, every 10 μg/m³ increase of PM₁₀ in the first trimester (RR = 1.09, 95% CI: 1.04-1.14), and 10 μg/m³ increase of O₃ in the first (RR = 1.05, 95% CI: 1.01-1.09) and third (RR = 1.04, 95% CI: 1.00-1.08) trimesters was also associated with increased stillbirth rate. The effects of PM_2.5 on stillbirth rate were found to be robust in the two-pollutant models. The findings of this study especially underscored the adverse effects of prenatal exposure of high levels of PM_2.5 on stillbirth. More studies are needed to verify our findings and further investigate the underlying mechanisms.

Prevalence and Risk Factors of Chronic Obstructive Pulmonary Disease in Bangladesh: A Systematic Review

Chronic obstructive pulmonary disease (COPD) is a leading cause of mortality and morbidity in low- and middle-income countries (LMICs) including Bangladesh. But no systematic review has been carried out in Bangladesh, which portraits the burden of COPD and its risk factors. Therefore, this systematic review was conducted to find out the prevalence and risk factors of COPD in Bangladesh. We searched PubMed, Google Scholar, Popline, and Banglajol from January 1, 1972 to April 30, 2017. We included studies that reported the prevalence and/or risk factors of COPD among Bangladeshi people. Two researchers independently searched and screened all the articles and extracted data from nine eligible studies. The whole process was verified by another researcher. Quality assessment was performed using a checklist adopted from published articles on quality assessment guidelines of observational studies. Discrepancies were resolved by consensus. Data analysis was done thematically. The pooled COPD prevalence among Bangladeshi adult was 12.5% (95% CI, 10.9-14.1) using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria and 11.9% (95% CI, 11.4-13.6) using the lower limit of the normality (LLN) criteria. The prevalence was higher among males, low socio-economic group, rural residents, and biomass fuel users. Tobacco consumption, exposure to biomass fuel, old age, and history of asthma were identified as major risk factors of COPD. COPD prevalence is high in Bangladesh. It is a timely need for the policy-makers and public health professionals to take pertinent steps for prevention and control of COPD in Bangladesh.

Impact of biomass fuel exposure from traditional stoves on lung functions in adult women of a rural Indian village

Introduction

Exposure to biomass fuel (BMF) from traditional cookstoves inflicts an enormous burden of morbidities in women across the developing world. This study aims to assess the lung function and its association with the indoor air pollutants generated using BMF.

Materials and Methods

This cross-sectional study including 310 women was conducted in a rural village of India. Households were divided into two groups based on the cooking fuel, the BMF group and the liquefied petroleum gas (LPG) group. Information on respiratory symptoms and socioeconomic status was obtained using a standard questionnaire. Indoor air concentration for PM₁₀and PM_2.5was measured during cooking hours. Pulmonary function tests (PFTs) were conducted for the women inhabitants.

Results

On comparing the two groups, the concentration of PM₁₀(890.26 ± 59.59 vs. 148.66 ± 31.97) μg/m³ and PM_2.5(728.90 ± 50.20 vs. 99.76 ± 41.80) μg/m³ (P < 0.01) were higher in the group using BMF. The respiratory symptoms such as wheezing, dyspnea, chronic cough, and nocturnal cough, were significantly more common in the group using BMF. A significant difference was seen in the lung function indices between the two groups. A significant negative correlation of respiratory indices with duration of exposure and the particulate matter (PM) values suggested a greater decline on lung function among women exposed to increased concentrations of PM. On comparing participants with normal and abnormal PFT, it was seen that the use of BMF (odds ratio [OR] 8.01; 95% confidence interval [CI] 4.80, 13.36, P < 0.001) and the duration of exposure to BMF (OR 1.16; 95% CI 1.13, 1.20., P < 0.001) increased the odds of having an abnormal PFT.

Conclusions

This study shows a high prevalence of respiratory symptoms and an abnormal pulmonary function in women exposed to BMF.

Urinary metals and metal mixtures in Bangladesh: Exploring environmental sources in the Health Effects of Arsenic Longitudinal Study (HEALS)

INTRODUCTION

Environmental exposure to toxic metals and metalloids is pervasive and occurs from multiple sources. The Health Effects of Arsenic Longitudinal Study (HEALS) is an ongoing prospective study predominantly focused on understanding health effects associated with arsenic exposure from drinking water. The goal of this project was to measure a suite of elements in urine to better understand potential exposure patterns and to identify common environmental sources of exposure among this semi-rural Bangladeshi population.

METHODS

In a random sample of 199 adult HEALS participants (50% female), the concentrations of 15 urinary elements (As, Ba, Cd, Co, Cs, Cu, Mn, Mo, Ni, Pb, Se, Sr, Tl, W, Zn) were assessed by Inductively-Coupled Plasma Mass Spectrometry (ICP-MS) to assess commonalities with sociodemographic characteristics and potential sources of exposure. We used principal component analysis (PCA) with varimax normalized rotations, and hierarchical cluster analysis (CA), using Ward's method with Euclidean distances, to evaluate these relationships.

RESULTS

PCA and CA showed similar patterns, suggesting 6 principal components (PC) and 5 clusters: 1)PC: Sr-Ni-Cs/ CA: Sr-Ni-Co; 2) Pb-Tl/Pb-Tl-Se-Cs; 3) As-Mo-W/As-Mo-W; 4) Ba-Mn/Ba-Mn; 5) Cu-Zn/Cu-Zn-Cd; and 6) Cd. There was a strong significant association between the As-Mo-W PC/cluster and water arsenic levels (p < 0.001) and between the Cd PC and betel nut use (p = 0.003). The Sr-Ni-Cs PC was not related to any of the socio-demographic characteristics investigated, including smoking status and occupation. The first PC, Sr-Ni-Cs, explained 21% of the variability; the third PC, As-Mo-W, explained 12.5% of the variability; and the sixth PC, Cd, explained 10% of the variability. Day laborers appeared to have the highest exposure.

CONCLUSIONS

Groundwater and betel nut use are likely important sources of metal and metalloid exposure in this population. These findings will guide future exposure assessment research in Bangladesh and future epidemiologic research investigating the degree to which metal mixtures play a role in disease development.

Association between prenatal exposure to cooking oil fumes and full-term low birth weight is mediated by placental weight

OBJECTIVE

Evidence regarding the association between prenatal exposure to cooking oil fumes (COF) and full-term low birth weight (FTLBW) is still controversial, and the mechanism remains unclear. This study thus aims to explore the association of prenatal COF exposure with off-spring FT-LBW as well as the mediating role of placenta in their association.

METHODS

A case-control study enrolling 266 pregnant women delivering FTLBW newborns (cases) and 1420 delivering normal birth weight (NBW) newborns (controls) was conducted. Information on prenatal COF exposure, socio-demographics, and obstetric conditions were collected at the Women's and Children's Hospitals of Shenzhen and Foshan in Guangdong, China. Linear and hierarchical logistic regression models were undertaken to explore the associations among COF exposure, placenta and birth weight, as well as the mediation effect of placental weight.

RESULTS

After controlling for potential confounders, prenatal COF exposure was significantly associated with the higher risk of FT-LBW (OR = 1.31, 95% CI= 1.06-1.63) and the lower placental weight (ß = -0.12, 95% CI= -0.23 ~ -0.005). Compared with mothers who never cooked, those cooking sometimes (OR= 2.99, 95% CI= 1.48-6.04) or often (OR= 3.41, 95% CI= 1.40-8.34) showed a higher risk of FT-LBW, and likewise, those cooking for less than half an hour (OR= 2.08, 95% CI= 1.14-3.79) or cooking between half to an hour (OR= 2.48, 95% CI= 1.44-4.29) were also more likely to exhibit FT-LBW. Different cooking methods including pan-frying (OR= 2.24, 95% CI= 1.30-3.85) or deep-frying (OR= 1.78, 95% CI= 1.12-2.85) during pregnancy were associated with increased FT-LBW risks as well. The further mediation analysis illustrated that placental weight mediated 15.96% (95% CI: 12.81~28.80%) and 15.90% (95% CI= 14.62%~16.66%) of the associations of cooking during pregnancy and frequency of prenatal COF exposure, respectively, with FT-LBW.

Lifetime socioeconomic status and early life microbial environments predict adult blood telomere length in the Philippines

OBJECTIVES

Psychosocial stress is postulated to hasten senescence in part by accelerating the shortening of telomere length (TL). One pathway through which this may happen is via increasing inflammation and innate immune system activation-a pathway which recent studies suggest acts more strongly for those who grew up in low microbial environments. Thus, we hypothesized that: (1) Psychosocial stress will be inversely associated with TL, (2) early life microbial environments will predict TL, and (3) microbial environments will moderate the association between psychosocial stress and TL.

METHODS

We utilized data from the Cebu Longitudinal Health and Nutrition Survey based in the Philippines (N = 1410). We determined early life microbial environments by season of birth and exposure to animal feces. Psychosocial stress measures included perceived stress in adulthood, lifetime socioeconomic status (SES), and parental instability in childhood. TL was measured in blood from young adults by qPCR.

RESULTS

Contrary to predictions, we found that higher SES was associated with shorter TL and no association of TL with the other stress variables. Individuals born in the higher microbial exposure season had shorter TL, but early life microbial environments did not moderate the association between psychosocial stress and TL.

CONCLUSIONS

The unexpected inverse association between SES and TL suggests that higher SES, while indexing lower psychosocial stress, may impact TL more strongly through nonstress factors in the Philippines, such as unhealthy behavior. The inverse association between microbial environments and TL is consistent with other evidence connecting early life infections to decreased life expectancies.

Mitigation of air pollution by greenness: A narrative review

Air pollution represents one of the world's most important environmental health risks, being associated with an increased rate of multiple diseases (mainly cardiopulmonary) and of premature deaths. A number of actions have been suggested and implemented to mitigate the deleterious health effects of air pollution. Accordingly, recent research has attempted to estimate the beneficial effect of exposure to greenness on human health. In this narrative review, we summarize and review the current literature on the favourable association between greenness and human health in both the outdoor and indoor environments. The potential mechanisms underlying this benefit will be also addressed.

Household air pollution from cooking fuel and respiratory health risks for children in Pakistan

Around 2.7 billion people in the world cook with polluting fuels, such as wood, crop residue, animal dung, charcoal, coal, and kerosene. Household air pollution from cooking with polluting fuels is recognized as a major risk factor for the disease burden. In this study, we examine the effect of using polluting fuels for cooking on the respiratory health of children in Pakistan. This study uses cross-sectional data from Pakistan Demographic and Health Survey 2012-13, with the sample size of 11,040 children under 5 years of age. Using logistic regression model, we control for factors such as averting activities, child characteristics, household characteristics, mother characteristics, and the unobserved factors using fixed effects. The results show that children in households using polluting fuels are 1.5 times more likely to have symptoms of acute respiratory infection (ARI) than children in households using cleaner fuels.

The associations between maternal lifestyles and antenatal stress and anxiety in Chinese pregnant women: A cross-sectional study

The study aimed to investigate the associations between maternal lifestyles and antenatal stress and anxiety. 1491 pregnant women were drawn from the Guangxi birth cohort study (GBCS). A base line questionnaire was used to collect demographic information and maternal lifestyles. The Pregnancy Stress Rating Scale (PSRS) and Self-Rating Anxiety Scale (SAS) were used to assess prenatal stress and anxiety, respectively. Regression analyses identified the relationship between maternal lifestyles and prenatal stress and anxiety: (1) Hours of phone use per day was positively correlated to prenatal stress and anxiety and increased with stress and anxiety levels (all P trend < 0.05). In addition, not having baby at home was positively correlated to prenatal stress. (2) Self-reported sleep quality was negative with prenatal stress and anxiety, and decreased with stress and anxiety levels (all P trend < 0.01). Moreover, not frequent cooking was negatively correlated to prenatal stress and having pets was negatively correlated to prenatal anxiety (P < 0.05). However, having pets was not correlated to prenatal stress (P > 0.05). Our results showed that adverse lifestyles increase the risk of antenatal stress and anxiety, a regular routine and a variety of enjoyable activities decreases the risk of prenatal stress and anxiety.

The Disease Burden of Indoor Air Pollution From Solid Fuel Use in China

Solid fuels, such as coal, straw, and firewood are wildly used for cooking and heating in China, with the negative side effects of indoor air pollution and residential health problems. This article investigates the current and historical trend of China’s disease burden caused by indoor air pollution (IAP) at the provincial level. The Global Burden Disease data set and national/provincial yearbooks are used. The results show the following: (1) In recent years, the burden of disease caused by IAP is decreasing; (2) in all health aspects, eastern coastal regions performed better than inland regions; (3) health risk is extremely severe in Henan, Sichuan, and Guizhou provinces; (4) IAP gives rise to serious diseases, including chronic obstructive respiratory diseases and cerebrovascular diseases. This article discusses the relevant causes and countermeasures.

Household environmental exposures during gestation and birth outcomes: A cross-sectional study in Shanghai, China

Several studies have reported that certain aspects of the household environments are associated with adverse birth outcomes, but associations have been inconsistent. Few of these studies have been conducted in China. During 2011-2012, we conducted a retrospective cross-sectional study and collected 13,335 parents-reported questionnaires for 4-6-year-olds children in Shanghai, China. We investigated associations of household environmental factors (environmental tobacco smoke (ETS), cooking fuel, dampness, pet-keeping, and home renovation) during gestation with preterm birth (PTB, gestational age<37weeks), low birth weight (LBW, birth weight<2500g), term low birth weight (T-LBW, LBW when the gestational age was ≥37weeks), and small for gestational age (SGA, birth weight<10th percentile of birth weight for gestational age). A total of 4.1% children were premature; 2.9% had LBW and 1.6% had T-LBW; 8.1% were SGA. In the multiple logistic regression analyses, home renovation during gestation was associated with PTB (adjusted odds ratio (OR), 95% confidence intervals (CI): 1.68, 1.11-2.54) and LBW (1.64, 0.99-2.72). Paternal smoking was associated with PTB (1.18, 0.98-1.43). No significant associations were found for SGA. Neither household dampness nor cooking fuel were significantly associated with birth outcomes. For boys, paternal smoking was associated with PTB (1.31, 1.02-1.69); home renovation during gestation was associated with PTB (2.14, 1.27-3.61) and LBW (2.19, 1.09-4.43). Among children whose mothers were ≥34-year-olds during gestation, paternal smoking (1.73, 1.04-2.76) and home renovation during gestation (1.80, 1.18-2.76) was associated with PTB. Our findings demonstrate that home renovation and ETS during gestation may be risk factors for adverse birth outcomes. Associations of these factors with adverse birth outcomes appear to be stronger in boys and among mothers older than 34years during gestation. Home renovation and ETS exposure should be avoided during gestation, especially for pregnancies with male fetuses and older pregnant women.

Effect of exclusive breastfeeding on selected adverse health and nutritional outcomes: a nationally representative study

BACKGROUND

Despite growing evidence in support of exclusive breastfeeding (EBF) among infants in the first 6 months of birth, the debate over the optimal duration of EBF continues. This study examines the effect of termination of EBF during the first 2, 4 and 6 months of birth on a set of adverse health and nutritional outcomes of infants.

METHODS

Three waves of Bangladesh Demographic and Health Survey data were analysed using multivariate regression. The adverse health outcomes were: an episode of diarrhea, fever or acute respiratory infection (ARI) during the 2 weeks prior to the survey. Nutritional outcomes were assessed by stunting (height-for-age), wasting (weight-for-height) and underweight (weight-for-age). Population attributable fraction was calculated to estimate percentages of these six outcomes that could have been prevented by supplying EBF.

RESULTS

Fifty-six percent of infants were exclusively breastfed during the first 6 months. Lack of EBF increased the odds of diarrhea, fever and ARI. Among the babies aged 6 months or less 27.37% of diarrhea, 13.24% of fever and 8.94% of ARI could have been prevented if EBF was not discontinued. If EBF was terminated during 0-2 months, 2-4 months the odds of becoming underweight were 2.16 and 2.01 times higher, respectively, than babies for whom EBF was not terminated.

CONCLUSION

Children who are not offered EBF up to 6 months of their birth may suffer from a range of infectious diseases and under-nutrition. Health promotion and other public health interventions should be enhanced to encourage EBF at least up to six-month of birth.

TRAIL REGISTRATION

Data of this study were collected following the guidelines of ICF International and Bangladesh Medical Research Council. The registration number of data collection is 132,989.0.000 and the data-request was registered on September 11, 2016.

Health Effects of Ambient Air Pollution in Developing Countries

The deleterious effects of ambient air pollution on human health have been consistently documented by many epidemiologic studies worldwide, and it has been calculated that globally at least seven million deaths are annually attributable to the effects of air pollution. The major air pollutants emitted into the atmosphere by a number of natural processes and human activities include nitrogen oxides, volatile organic compounds, and particulate matter. In addition to the poor ambient air quality, there is increasing evidence that indoor air pollution also poses a serious threat to human health, especially in low-income countries that still use biomass fuels as an energy resource. This review summarizes the current knowledge on ambient air pollution in financially deprived populations.