Estimation of pollution impacts on health is critical for guiding policy to improve health outcomes. Estimation is challenging, however, because economic activity can worsen pollution but also independently improve health outcomes, confounding pollution–health estimates. We leverage variation in exposure to local particulate matter of diameter <2.5 μm (PM_2.5) across Sub-Saharan Africa driven by distant dust export from the Sahara, a source uncorrelated with local economic activity. Combining data on a million births with local-level estimates of aerosol particulate matter, we find that an increase of 10 μg m^–3 in local annual mean PM_2.5 concentrations causes a 24% increase in infant mortality across our sample (95% confidence interval: 10–35%), similar to estimates from wealthier countries. We show that future climate change driven changes in Saharan rainfall—a control on dust export—could generate large child health impacts, and that seemingly exotic proposals to pump and apply groundwater to Saharan locations to reduce dust emission could be cost competitive with leading child health interventions.

Poor air quality is thought to be an important mortality risk factor globally1,2,3, but there is little direct evidence from the developing world on how mortality risk varies with changing exposure to ambient particulate matter. Current global estimates apply exposure–response relationships that have been derived mostly from wealthy, mid-latitude countries to spatial population data4, and these estimates remain unvalidated across large portions of the globe. Here we combine household survey-based information on the location and timing of nearly 1 million births across sub-Saharan Africa with satellite-based estimates5 of exposure to ambient respirable particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5) to estimate the impact of air quality on mortality rates among infants in Africa. We find that a 10 μg m−3 increase in PM2.5 concentration is associated with a 9% (95% confidence interval, 4–14%) rise in infant mortality across the dataset. This effect has not declined over the last 15 years and does not diminish with higher levels of household wealth. Our estimates suggest that PM2.5 concentrations above minimum exposure levels were responsible for 22% (95% confidence interval, 9–35%) of infant deaths in our 30 study countries and led to 449,000 (95% confidence interval, 194,000–709,000) additional deaths of infants in 2015, an estimate that is more than three times higher than existing estimates that attribute death of infants to poor air quality for these countries2,6. Upward revision of disease-burden estimates in the studied countries in Africa alone would result in a doubling of current estimates of global deaths of infants that are associated with air pollution, and modest reductions in African PM2.5 exposures are predicted to have health benefits to infants that are larger than most known health interventions.

Women empowerment (WE) is increasingly viewed as an important strategy to reduce maternal and child undernutrition,^1–3 which continues to be a major health burden in low- and middle-income countries causing 3.5 million preventable maternal and child deaths, 35% of the disease burden in children younger than 5 years, and 11% of total global disability-adjusted life years.^4,5Global data show that one of the worst affected regions is sub-Saharan Africa (SSA), where about 20% of children are malnourished.^6,7 Benin is no exception, as the prevalence of stunting, wasting, and underweight was 37%, 5%, and 17%, respectively, among children aged 6 to 59 months in the 2006 Benin Demographic and Health Survey (DHS),⁸ while 9% of women had chronic energy deficiency in the 2012 DHS.⁹ Greater rates were observed in rural areas where stunting was found in 40% of children, underweight in 19%, and wasting in 5%, while 10% of women had chronic energy deficiency.^8,9 Additionally, Beninese women and children have a limited dietary diversity score (DDS), with diets predominately composed of starchy staples with little or no animal products and few fresh fruits and vegetables.^10,11 Government, United Nation agencies, and nongovernmental organizations in Benin recognize that the state of maternal and child undernutrition requires multiple types of interventions.¹²

However, women’s low empowerment status in Benin can hinder the improvement in women’s and children’s undernutrition. Indeed, although females accounted for 47% of the economically active population in 2014,¹³ social and civil legislation is strongly influenced by tradition and customs, as women continue to be required to seek their husband’s authorization in certain areas such as family planning or health services.¹⁴ Rural women provided labor to the families’ commercial plots, were responsible for household food production and processing, and also had to work in the cooperative structures set up by the state in addition to their household tasks.¹⁴ In a more recent study of productivity differences by gender in central Benin, researchers noted that female rice farmers are particularly discriminated against with regard to access to land and equipment, resulting in significant negative impacts on their productivity and income.¹⁵ As in other areas of West Africa, women also have the responsibility of caring for children and preparing food for the household,¹⁶ but they may be vulnerable to food insecurity owing to unequal intrahousehold food distribution and their willingness to forego meals in favor of children during times of scarcity.¹⁷ Finally, no study to date has examined links between women’s empowerment and nutrition in Benin.

In addition, the evidence backing the effect of women’s empowerment on maternal and child undernutrition is inconsistent.¹⁸ Using the Women’s Empowerment in Agriculture Index (WEAI), Malapit et al¹⁹ reported positive and significant association between women’s group (WG) membership, control over income, overall empowerment, and women’s health (as measured by body mass index [BMI] and DDS) in Nepal. However, in Ghana, women’s aggregate empowerment and participation in credit decisions were positively correlated with women’s DDS, but not BMI.²⁰ Mixed findings were also observed between women’s empowerment and child anthropometry. Moestue et al²¹ found a positive association between maternal involvement in social groups and length-for-age z score of 1-year-old children, but De Silva and Harpham²²showed a negative association in 6- to 18-month-old children. Shroff et al²³ found positive association between decision-making and child weight-for-age z score (WAZ), but Begum and Sen’s²⁴ analysis of Bangladesh DHS data did not reveal any significant associations. Therefore, information about which domains of WE are associated with nutritional status is limited,²⁰ and this lack of knowledge constrains the set of policy options that can be used to empower women and improve nutrition.

In addition to a limited set of studies in SSA, examinations of the effects of WE on nutrition outcomes are constrained due to interstudy differences in population characteristics, settings, or methods/conceptualizations of WE.^25–27 For example, despite recognition of the complex, multidimensional, and culturally defined nature and influence of empowerment on nutrition,^20,26,28,29 only a few studies considered the multidimensional structure of empowerment domains in Africa or examined the varied relationships between each measure of WE and maternal and child nutrition status.^30,31 Furthermore, in 2012, the International Food Policy Research Institute developed WEAI constructed from 5 prespecified domains of empowerment,³²which may not be equally relevant in all areas. In contrast, in 2015, the United Nations adopted the Sustainable Development Goals (SDG), but the specific indicators for the SDG empowerment targets are largely equality metrics.³³ To address the need for multidimensional and contextual examinations of WE and its influence on maternal and child health outcomes, we draw from the concepts put forward in the WEAI and the SDGs but took an approach more along the lines of the World Bank which gathers indicators, both equity and empowerment related, that can be used in contextually appropriate ways.³⁴ The aims of this study were therefore to first explore the structure and domains of WE in Kalalé district of northern Benin and then to examine the effects of these constructs on nutritional status of women and their children in the region.

Objective: To identify the magnitude of anaemia and deficiencies of Fe (ID) and vitamin A (VAD) and their associated factors among rural women and children.

Design: Cross-sectional, comprising a household, health and nutrition survey and determination of Hb, biochemical (serum concentrations of ferritin, retinol, C-reactive protein and α1-acid glycoprotein) and anthropometric parameters. Multivariate logistic regression examined associations of various factors with anaemia and micronutrient deficiencies.

Setting: Kalalé district, northern Benin. Subjects: Mother–child pairs (n 767): non-pregnant women of reproductive age (15–49 years) and children 6–59 months old.

Results: In women, the overall prevalence of anaemia, ID, Fe-deficiency anaemia (IDA) and VAD was 47·7, 18·3, 11·3 and 17·7%, respectively. A similar pattern for anaemia (82·4 %), ID (23·6%) and IDA (21·2%) was observed among children, while VAD was greater at 33·6%. Greater risk of anaemia, ID and VAD was found for low maternal education, maternal farming activity, maternal health status, low food diversity, lack of fruits and vegetables consumption, low protein foods consumption, high infection, anthropometric deficits, large family size, poor sanitary conditions and low socio-economic status. Strong differences were also observed by ethnicity, women’s group participation and source of information. Finally, age had a significant effect in children, with those aged 6–23 months having the highest risk for anaemia and those aged 12–23 months at risk for ID and IDA.

Conclusions: Anaemia, ID and VAD were high among rural women and their children in northern Benin, although ID accounted for a small proportion of anaemia. Multicentre studies in various parts of the country are needed to substantiate the present results, so that appropriate and beneficial strategies for micronutrient supplementation and interventions to improve food diversity and quality can be planned.

The ongoing decline in under-5 mortality ranks among the most significant public and population health successes of the past 30 years. Deaths of children under the age of 5 years have fallen from nearly 13 million per year in 1990 to less than 6 million per year in 2015, even as the world's under-5 population grew by nearly 100 million children. However, the amount of variability underlying this broad global progress is substantial. On a regional level, east Asia and the Pacific have surpassed the Millennium Development Goal target of a two-thirds reduction in under-5 mortality rate between 1990 and 2015, whereas sub-Saharan Africa has had only a 24% decline over the same period. Large differences in progress are also evident within sub-Saharan Africa, where mortality rates have declined by more than 70% from 1990 to 2015 in some countries and increased in others; in 2015, the mortality rate in some countries was more than three times that in others.

What explains this remarkable variation in progress against under-5 mortality? Answering this question requires understanding of where the main sources of variation in mortality lie. One view that is implicit in the way that mortality rates are tracked and targeted is that national policies and conditions drive first-order changes in under-5 mortality. This country-level focus is justified by research that emphasises the role of institutional factors in explaining variation in mortality—factors such as universal health coverage, women's education, and the effectiveness of national health systems. It is argued that these factors, which vary measurably at the country level, fundamentally shape the ability of individuals and communities to affect more proximate causes of child death such as malaria and diarrhoeal disease.

An alternate view has focused on exploring the importance of subnational variation in the distribution of disease. In the USA, studies on the geographical distribution of health care and mortality have been influential for targeting of resources and policy design. Similar studies in developing regions have shown the substantial variability in the distribution and changes of important health outcomes such HIV, malaria, and schistosomiasis—information that can then be used to improve the targeting of interventions. Nevertheless, the relative contribution of within-country and between-country differences in explaining under-5 mortality remains unknown. Improved understanding of the relative contribution of national and sub-national factors could provide insight into the drivers of mortality levels and declines in mortality, as well as improve the targeting of interventions to the areas where they are most needed.