Search

Background: The high under-five mortality rate (U5MR) in Africa is a significant public health concern. Previous studies have found that satellite retrieved light at night (LAN) data with long-term and global coverage can be used as a proxy for socio-economic development and urbanization. Currently, few studies on the effects of LAN on child mortality have been conducted in Africa, a region with varying levels of urbanization between countries. Objective: To quantify the correlation between risk of child mortality and LAN as an indicator of urbanization and economic development in Africa. Methods: Using data from the Demographic and Health Survey (DHS) database conducted in 15 African countries out of 46 countries from 2005 to 2013, this study estimated LAN levels for children based on their year of birth and residential addresses. This study used Cox proportional hazards models to assess the association between LAN and the risk of child mortality in Africa. Results: The mean U5MR was 95 per 1,000 livebirths among the 15 African countries during 2005–2013. After adjusting for covariates, each 10-unit increment in LAN was associated with a 5.3% reduction in the risk of U5MR. The effect estimates were more pronounced in areas with lower LAN. Conclusion: In Africa, the risk of U5MR decreased with increasing LAN, especially in areas with lower LAN. The results suggest that the development of urbanization and socio-economic conditions may be beneficial to child health, especially in regions with low LAN. The use of LAN as a proxy may offer an intriguing approach for identifying areas requiring targeted development in urbanization and socio-economic conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Evidence is scarce on PM 2.5 exposure and birth outcome in African countries. • Use of Satellite-derived PM 2.5 estimates and the Demographic Health and Surveys data. • PM 2.5 exposure was significantly associated with preterm birth (8%) and low birth weight (28%) • Associations were modified by region, and maternal, infant, household characteristics. Fine particulate matter (PM 2.5) exposure has been reported to adversely affect birth outcomes, but the evidence is limited, particularly in low- and middle-income countries (LMICs). We assessed the associations between maternal PM 2.5 exposure and low birth weight (LBW) and preterm birth (PTB) in Africa. We used standard Demographic and Health Surveys (DHS) data (2005–2015) from 15 countries in Africa to conduct a cross-sectional study. The study population was composed of 131,594 births with detailed information on maternal and household variables. LBW was defined as a birth weight of < 2500 g after 37 weeks, and PTB was defined as live birth occurring before 37 weeks of gestation. Average exposure to PM 2.5 during pregnancy was estimated using satellite-based models. Multivariable logistic regression models were constructed, and analyses of data by region (Western, Eastern, Central, and Southern Africa) and data stratified by potential effect modifiers were conducted. A total of 13,214 (10%) LBW and 4,377 (3.3%) PTB cases were identified. An interquartile range (IQR) (33.9 μg/m3) increase in PM 2.5 during pregnancy was associated with increased odds of LBW and PTB, with odds ratios (ORs) of 1.28 (95% CI: 1.23, 1.34) and 1.08 (95% CI: 1.01, 1.16), respectively. Region-specific analyses revealed significant associations between PM 2.5 and LBW in all regions, and significant associations between PM 2.5 and PTB in Western and Southern Africa. Subgroup analyses revealed that the association between PM 2.5 and LBW was present in all subgroups, and stronger associations were observed in female infants, while the association between PM 2.5 and PTB was larger in subgroups of older individuals living in urban areas. This multicountry study in Africa demonstrated significant associations between maternal exposure to PM 2.5 and higher odds of LBW and PTB. Our findings may facilitate air quality control strategies that address adverse birth outcomes in LMICs. [ABSTRACT FROM AUTHOR]

• Limited evidence on the PM 2.5 constituents - infant mortality association in developing countries. • A multi-country cross-sectional study based on the Demographic and Health Surveys in Africa. • PM 2.5 was associated with increased infant mortality across 15 countries in Africa. • PM 2.5 carbonaceous fractions and sulfate play a major important role in infant mortality. Few studies have investigated the association between exposure to fine particulate matter (PM 2.5) and infant mortality in developing countries, especially for the health effects of specific PM 2.5 constituents. We aimed to examine the association of long-term exposure to specific PM 2.5 constituents with infant mortality in 15 African countries from 2005 to 2015. Based on the Demographic and Health Surveys (DHS) dataset, we included birth history records from 15 countries in Africa and conducted a multicountry cross-sectional study to examine the associations between specific PM 2.5 constituents and infant mortality. We estimated annual residential exposure using satellite-derived PM 2.5 for mass and a chemical transport model (GEOS-Chem) for its six constituents, including organic matter (OM), black carbon (BC), sulfate (SO 4 2−), nitrate (NO 3 −), ammonium (NH 4 +), and soil dust (DUST). Multivariable logistic regression analysis was employed by fitting single-constituent models, the constituent-PM 2.5 models, and the constituent-residual models. We also conducted stratified analyses by potential effect modifiers and examined the specific associations for each country. We found positive and significant associations between PM 2.5 total mass and most of its constituents with infant mortality. In the single-constituent model, for an IQR increase in pollutant concentrations, the odds ratio (OR) of infant mortality was 1.03 (95 %CI; 1.01, 1.06) for PM 2.5 total mass, and was 1.04 (95 %CI: 1.02, 1.06), 1.04 (95 %CI: 1.02, 1.05), 1.02 (95 %CI: 1.00, 1.03), 1.04 (1.01, 1.06) for BC, OM, SO 4 2−, and DUST, respectively. The associations of BC, OM, and SO 4 2− remained significant in the other two models. We observed larger estimates in subgroups with older maternal age, living in urban areas, using unclean cooking energy, and with access to piped water. The associations varied among countries, and by different constituents. The carbonaceous fractions and sulfate play a major important role among PM 2.5 constituents on infant mortality. Our findings have certain policy implications for implementing effective measures for targeted reduction in specific sources (fossil fuel combustion and biomass burning) of PM 2.5 constituents against the risk of infant mortality. [ABSTRACT FROM AUTHOR]