Dried Blood Spot Biomarkers of Oxidative Stress and Inflammation Associated with Blood Pressure in Rural Senegalese Women with Incident Hypertension.

Blood biomarkers of oxidative stress and inflammation have been associated with increased risk of hypertension development; yet their application in sub-Saharan Africa has been limited due to the lack of blood collection facilities. In this study, we evaluated the usefulness of dried blood spots (DBS), a more feasible alternative to venous blood, in rural sub-Saharan residents. We recruited 342 women with incident hypertension from rural Senegal, and measured C-reactive protein (CRP) and malondialdehyde (MDA) in DBS and concurrent blood pressure (BP) at baseline and 1-year follow-up. Associations of DBS biomarkers with current levels of and 1-year changes in BP were examined after adjusting for demographic, medical, and socioeconomic covariates. DBS concentrations of MDA were significantly associated with concurrent systolic BP (SBP) (p < 0.05), while DBS baseline concentrations of CRP were associated with longitudinal changes in SBP between baseline and follow-up. Compared to participants with baseline CRP < 1 mg/L, those with CRP of 1-3 mg/L and 3-10 mg/L had 2.11 mmHg (95%CI: -2.79 to 7.02 mmHg) and 4.68 mmHg (95%CI: 0.01 to 9.36 mmHg) increases in SBP at follow-up, respectively. The results support the use of DBS biomarkers for hypertension prevention and control, especially in settings with limited clinical resources.

Malondialdehyde in dried blood spots: a biomarker of systemic lipid peroxidation linked to cardiopulmonary symptoms and risk factors.

BACKGROUND: There are few oxidative biomarkers that can be used in resource-limited settings (e.g., rural Africa) where blood collection facilities are lacking. This study aims to evaluate the potential of malondialdehyde (MDA) in dried blood spots (DBS) as a useful biomarker to monitor cardiopulmonary health. METHODS: We first conducted a cross-validation comparison of matched capillary DBS, plasma, and whole venous blood collected from nine healthy volunteers for the measurement of total MDA (free + conjugated) and C-reactive protein (CRP), a well-established biomarker of systemic inflammation. Then a field study was conducted in a rural Senegal with a population of 441 women routinely exposed to severe household air pollution, examining associations of MDA and CRP levels in 882 DBS with self-reported cardiopulmonary symptoms. RESULTS: In the cross-validation study, CRP levels were strongly correlated across DBS, plasma, and whole blood. MDA levels were correlated between DBS and whole blood and were 1-2 orders of magnitude lower in plasma, suggesting that DBS MDA may reflect total oxidation levels in intracellular and extracellular compartments. In the field study, we observed significantly higher MDA levels in women with secondhand smoke exposure. An interquartile range increase in MDA concentration was associated with 27.0% (95% CI: 3.1-56.5%) and 21.1% (95% CI: -3.5% to 52.0%) increases in the incidence of chest tightness and breath difficulty, respectively. In contrast, CRP levels were not associated with worse outcomes or risk factors. CONCLUSIONS: These results support the use of DBS as a convenient alternative to venous blood when MDA is measured as a biomarker for cardiopulmonary health risk.

Biomonitoring of metals and trace elements in urine of central Ethiopian populations.

Biomonitoring of chemical concentrations in humans is important for detecting, monitoring, and addressing a wide range of health threats. However, it is virtually absent across many African nations, including Ethiopia. This study aims to determine urinary concentrations for metals and trace elements in populations living in the central Ethiopian Rift Valley. The region is unindustralized, rural, and characterized by unique geologic rifting and volcanic activities that have produced vast pyroclastic materials, forming its aquifer and fertile agricultural soils. Millions of people in the region rely on wells for drinking water and are engaged in cereal-based subsistence agriculture. We enrolled a total of 386 residents aged 10-50 years old (201 females and 185 males). The levels of 23 elements except F─ were quantified in water and urine samples by ICP-MS. Mean concentrations of B, F─, Ca, and Mg were measured in mg/L levels, while concentrations of Mo, Zn, Sr, Rb, and Li ranged between 100 and 700 µg/L. Mean concentrations between 5 and 15 µg/L were found for Ni, Cu, and Mn, while Ag, Be, Cd, Co, Pb, Sb, Th, TI, and U were all below 5 µg/L. Arsenic and Al had mean concentrations between 30 and 50 µg/L. Mean urinary concentrations of Ca, Cu, Mg, Pb, Sr, and Zn were significantly higher in males than females, whereas Co and Mn were higher in females. Finally, younger individuals (10-30 years) had significantly higher mean concentrations of B, Cd, Co, Mg, Mo, and Pb than those between 31 and 50 years, whereas only Ca was higher in the older age group. The concentration ranges of B, Mo, Mn, TI, Li, Zn, and in particular F─ (0.44-44.6 mg/L) and As (2.2-164 µg/L) in urine were higher than the reference ranges reported in healthy unexposed North American and European populations, while those for the remaining 16 elements were comparable to published reference ranges from such settings. The established concentration ranges are important to monitor future changes in exposure, and risk factors for disease, that might stem from the economic growth and industrialization that is currently underway in the region.

Access to environmental health assets across wealth strata: Evidence from 41 low- and middle-income countries.

INTRODUCTION: Low levels of household access to basic environmental health assets (EHAs)-including technologies such as clean cookstoves and bed nets or infrastructure such as piped water and electricity-in low- and middle-income countries (LMICs) are known to contribute significantly to the global burden of disease. This low access persists despite decades of promotion of many low-cost, life-saving technologies, and is particularly pronounced among poor households. This study aims to characterize variation in access to EHAs among LMIC households as a function of wealth, as defined by ownership of various assets. METHODS: Demographic and Health Survey (DHS) data from 41 low- and middle-income countries were used to assess household-level access to the following EHAs: 1) improved water supply; 2) piped water supply; 3) improved sanitation; 4) modern cooking fuels; 5) electricity; and 6) bed nets. For comparison, we included access to mobile phones, which is considered a highly successful technology in terms of its penetration into poor households within LMICs. Ownership levels were compared across country-specific wealth quintiles constructed from household assets using bivariate analysis and multivariable linear regression models. RESULTS: Access to EHAs was low among the households in the bottom three quintiles of wealth. Access to piped water, modern cooking fuels, electricity and improved sanitation, for example, were all below 50% for households in the bottom three wealth quintiles. Access to certain EHAs such as improved water supply and bed nets increased only slowly with concomitant increases in wealth, while gaps in access to other EHAs varied to a greater degree by wealth quintile. For example, disparities in access between the richest and poorest quintiles were greatest for electricity and improved sanitation. Rural households in all wealth quintiles had much lower levels of access to EHAs, except for bed nets, relative to urban households. CONCLUSIONS: The findings of this study provide a basis for understanding how EHAs are distributed among poor households in LMICs, elucidate where inequalities in access are particularly pronounced, and point to a need for strategies that better reach the poor, if the global environmental burden of disease is to be reduced.

Piloting improved cookstoves in India.

Despite the potential of improved cookstoves to reduce the adverse environmental and health impacts of solid fuel use, their adoption and use remains low. Social marketing-with its focus on the marketing mix of promotion, product, price, and place-offers a useful way to understand household behaviors and design campaigns to change biomass fuel use. We report on a series of pilots across 3 Indian states that use different combinations of the marketing mix. We find sales varying from 0% to 60%. Behavior change promotion that combined door-to-door personalized demonstrations with information pamphlets was effective. When given a choice amongst products, households strongly preferred an electric stove over improved biomass-burning options. Among different stove attributes, reduced cooking time was considered most valuable by those adopting a new stove. Households clearly identified price as a significant barrier to adoption, while provision of discounts (e.g., rebates given if households used the stove) or payments in installments were related to higher purchase. Place-based factors such as remoteness and nongovernmental organization operations significantly affected the ability to supply and convince households to buy and use improved cookstoves. Collectively, these pilots point to the importance of continued and extensive testing of messages, pricing models, and different stove types before scale-up. Thus, we caution that a one-size-fits-all approach will not boost improved cookstove adoption.

Why "improved" water sources are not always safe.

Existing and proposed metrics for household drinking-water services are intended to measure the availability, safety and accessibility of water sources. However, these attributes can be highly variable over time and space and this variation complicates the task of creating and implementing simple and scalable metrics. In this paper, we highlight those factors - especially those that relate to so-called improved water sources - that contribute to variability in water safety but may not be generally recognized as important by non-experts. Problems in the provision of water in adequate quantities and of adequate quality - interrelated problems that are often influenced by human behaviour - may contribute to an increased risk of poor health. Such risk may be masked by global water metrics that indicate that we are on the way to meeting the world's drinking-water needs. Given the complexity of the topic and current knowledge gaps, international metrics for access to drinking water should be interpreted with great caution. We need further targeted research on the health impacts associated with improvements in drinking-water supplies.

Les indicateurs existants et proposés pour la distribution de l'eau potable des ménages visent à mesurer la disponibilité, la salubrité et l'accessibilité des sources d'eau. Cependant, ces caractéristiques peuvent être très variables dans le temps et l'espace, et ces variations compliquent la tâche de création et de mise en œuvre d'indicateurs simples et extensibles. Dans le présent article, nous mettons l'accent sur ces facteurs ­ en particulier, sur ceux qui concernent les sources d'eau soi-disant améliorées ­ qui contribuent à la variabilité de la salubrité de l'eau, mais qui peuvent ne pas être perçus généralement comme importants par les non-spécialistes. Les problèmes d'approvisionnement en eau, en quantité suffisante et en qualité satisfaisante ­ ces problèmes interdépendants sont souvent influencés par le comportement des hommes ­ peuvent contribuer à un risque accru d'être en mauvaise santé. Ce risque peut être masqué par les indicateurs globaux de l'eau qui indiquent que nous sommes en bonne voie de répondre aux besoins en eau potable de la planète. Compte tenu de la complexité du sujet et des lacunes des connaissances actuelles, les indicateurs internationaux pour l'accès à l'eau portable doivent être interprétés avec une grande prudence. Nous avons besoin de recherches ciblées et plus approfondies sur les effets sanitaires des améliorations dans le domaine de l'approvisionnement en eau potable.

Las mediciones existentes y propuestas para los servicios de agua potable de los hogares pretenden considerar la disponibilidad, seguridad y accesibilidad de las fuentes de agua. No obstante, estas características pueden variar mucho a lo largo del tiempo y del espacio, lo que complica la tarea de crear y poner en práctica mediciones sencillas y ampliables. En este documento destacamos los factores, en particular los relacionados con las llamadas fuentes de agua mejoradas, que contribuyen a la variabilidad de la seguridad del agua pero que, por lo general, los legos no identifican como importantes. Los problemas en el suministro de agua en cantidad y calidad suficientes, problemas interrelacionados en los que el comportamiento humano influye a menudo, pueden contribuir a un mayor riesgo de problemas sanitarios. Ese riesgo puede quedar oculto por mediciones de agua globales que indican que vamos camino de satisfacer las necesidades de agua potable en el mundo. Dada la complejidad del tema y las lagunas de conocimiento actuales, las mediciones internacionales sobre el acceso al agua potable deberían interpretarse con mucha cautela. Necesitamos más investigaciones específicas sobre el impacto sanitario asociado a las mejoras de los suministros de agua potable.

The long-term dynamics of mortality benefits from improved water and sanitation in less developed countries.

The problem of inadequate access to water, sanitation and hygiene (WASH) in less-developed nations has received much attention over the last several decades (most recently in the Millennium Development Goals), largely because diseases associated with such conditions contribute substantially to mortality in poor countries. We present country-level projections for WASH coverage and for WASH-related mortality in developing regions over a long time horizon (1975-2050) and provide dynamic estimates of the economic value of potential reductions in this WASH-related mortality, which go beyond the static results found in previous work. Over the historical period leading up to the present, our analysis shows steady and substantial improvements in WASH coverage and declining mortality rates across many developing regions, namely East Asia and the Pacific, Latin America and the Caribbean, Eastern Europe and the Middle East. The economic value of potential health gains from eliminating mortality attributable to poor water and sanitation has decreased substantially, and in the future will therefore be modest in these regions. Where WASH-related deaths remain high (in parts of South Asia and much of Sub-Saharan Africa), if current trends continue, it will be several decades before economic development and investments in improved water and sanitation will result in the capture of these economic benefits. The fact that health losses will likely remain high in these two regions over the medium term suggests that accelerated efforts are needed to improve access to water and sanitation, though the costs and benefits of such efforts in specific locations should be carefully assessed.

Benefits and costs of improved cookstoves: assessing the implications of variability in health, forest and climate impacts.

Current attention to improved cook stoves (ICS) focuses on the "triple benefits" they provide, in improved health and time savings for households, in preservation of forests and associated ecosystem services, and in reducing emissions that contribute to global climate change. Despite the purported economic benefits of such technologies, however, progress in achieving large-scale adoption and use has been remarkably slow. This paper uses Monte Carlo simulation analysis to evaluate the claim that households will always reap positive and large benefits from the use of such technologies. Our analysis allows for better understanding of the variability in economic costs and benefits of ICS use in developing countries, which depend on unknown combinations of numerous uncertain parameters. The model results suggest that the private net benefits of ICS will sometimes be negative, and in many instances highly so. Moreover, carbon financing and social subsidies may help enhance incentives to adopt, but will not always be appropriate. The costs and benefits of these technologies are most affected by their relative fuel costs, time and fuel use efficiencies, the incidence and cost-of-illness of acute respiratory illness, and the cost of household cooking time. Combining these results with the fact that households often find these technologies to be inconvenient or culturally inappropriate leads us to understand why uptake has been disappointing. Given the current attention to the scale up of ICS, this analysis is timely and important for highlighting some of the challenges for global efforts to promote ICS.