This paper describes a study that was aimed at optimizing the pelletization of fecal sludge-based fertilizers for agricultural use. The process developed is easy to implement and increases the marketability of the products while also addressing a serious health and environmental challenge. The study took place during the period 2011-2012 in Ghana. The fecal sludge, rich in nutrients and organic matter, was dried and used to produce five different fertilizers (i.e., four formulations of compost and one with gamma irradiated material). Each material was then pelletized using locally constructed machinery. Key operating parameters, such as moisture content (10-55% in mass), binder type (clay or starch) and concentration (0-10% in mass), were varied and their impacts on the characteristics of pellets (e.g., amount of fine materials generated, length distribution or stability of pellets, and pellet disintegration rate) were also followed. Given the low analyzing capabilities of developing countries, some simple analytical methods were developed and used to compare pellets produced under different conditions. The results confirmed that the addition of 3% of pregelatinized starch is recommended during pelletization of fecal sludge-based fertilizers. Applicable moisture contents were also identified per fertilizer type, and were found to comprise between 21 and 43%.

Little is known about the occurrence of emerging pollutants (EPs) in waters in the Middle East and North Africa (MENA) region despite the extensive use of low-quality water there. Available data dealing with the sources, occurrence and removal of EPs within the MENA region in different categories of water is collected, presented and analyzed in this literature review. According to the collected database, the occurrence and removal efficiency of EPs in the water matrix in the MENA region is available, respectively, for 13 and six countries of the 18 in total; no available data is registered for the rest. Altogether, 290 EPs have been observed in different water matrices across the MENA countries, stemming mainly from industrial effluents, agricultural practices, and discharge or reuse of treated wastewater (TWW). Pharmaceutical compounds figure among the most frequently reported compounds in wastewater, TWW, surface water, and drinking water. Nevertheless, pesticides are the most frequently detected pollutants in groundwater. Worryingly, 57 cases of EPs have been reported in different fresh and drinking waters, exceeding World Health Organization (WHO) and European Commission (EC) thresholds. Overall, pharmaceuticals, organic compounds, and pesticides are the most concerning EP groups. The review revealed the ineffectiveness of treatment processes used in the region to remove EPs. Negative removals of some EPs such as carbamazepine, erythromycin, and sulfamethoxazole were recorded, suggesting their possible accumulation or release during treatment. This underlines the need to set in place and strengthen control measures, treatment procedures, standards, and policies for such pollutants in the region.

peer reviewed | Recently, the World Health Organization’s International Association for Research on Cancer classified outdoor air pollution as carcinogenic to humans and puts air pollution in the same category as tobacco smoke, UV radiation, and plutonium. The ambient air is polluted by emissions from motor vehicles, industrial processes, power generation, household combustion of solid fuel, and other sources. Dust storms lead to particulate levels that exceed internationally recommended levels, especially near the Sahara. However, this source of air pollution appears to be under-studied, particularly in the literature devoted to human health impacts in West Africa. More than 50 % of the total dust emitted into the atmosphere comes from the Sahara. These aerosols contribute to increase the concentrations of particles smaller than 10 μm (PM10), which are breathable particles. This study is the first designed to assess the real impact of Saharan dust on air quality and respiratory health of children in a region of West Africa. Dust events having affected the Northern Benin during the dry seasons between 2003 and 2007 were determined. The analyzed health data are the monthly rates of acute lower respiratory infections (ALRI). Over the entire study period, 61 days of dust events were observed in the region. They recorded on average a daily PM10 concentration of 1017 μg m−3, more than 18 times higher than that calculated on all days without dust events. The study also highlighted a mean increase of 12.5 % of ALRI rates during the months recording dust events. The use of daily health data should help to refine these initial results in the future.

Water quality has recently emerged as one of the utmost severe ecological problems being faced by the developing countries all over the world, and Bangladesh is no exception. Both surface and groundwater sources contain different contaminants, which lead to numerous deaths due to water-borne diseases, particularly among children. This study presents one of the most comprehensive reviews on the current status of water quality in Bangladesh with a special emphasis on both conventional pollutants and emerging contaminants. Data show that urban rivers in Bangladesh are in a critical condition, especially Korotoa, Teesta, Rupsha, Pashur, and Padma. The Buriganga River and few locations in the Turag, Balu, Sitalakhya, and Karnaphuli rivers have dissolvable oxygen (DO) levels of almost zero. Many waterways contain traces of NO3, NO2, and PO4-3 pollutants. The majority of the rivers in Bangladesh also have Zn, Cu, Fe, Pb, Cd, Ni, Mn, As, and Cr concentrations that exceed the WHO permissible limits for safe drinking water, while their metal concentrations exceed the safety threshold for irrigation. Mercury poses the greatest hazard with 90.91% of the samples falling into the highest risk category. Mercury is followed by zinc 57.53% and copper 29.16% in terms of the dangers they pose to public health and the ecosystem. Results show that a considerable percentage of the population is at risk, being exposed to contaminated water. Despite hundreds of cryptosporidiosis cases reported, fecal contamination, i.e., Cryptosporidium, is totally ignored and need serious considerations to be regularly monitored in source water.

Reuse of sewage sludge is a general trend and land application is an essential way to reuse sludge. The outbreak of coronavirus disease has raised concerns about human pathogens and their serious threat to public health. The risk of pathogenic bacterial contamination from land application of municipal sludge has not been well assessed. The purpose of this study was to investigate the presence of pathogenic bacteria in municipal sewage sludge and to examine the survival potential of certain multidrug-resistant enteroaggregative Escherichia coli (EAEC) strain isolated from sewage sludge during heat treatment. The sewage sludge produced in the two wastewater treatment plants contained pathogenic bacteria such as pathogenic E. coli, Shigella flexneri, and Citrobacter freundii. The environmental strain of EAEC isolated from the sludge was resistant to eight types of antibiotics. It could also enter the dormant state after 4.5 h of treatment at 55 °C and regrow at 37 °C, while maintaining its antibiotic resistance. Our results indicate that the dormancy of EAEC might be why it is heat-resistant and could not be killed completely during the sludge heat treatment process. Owing to the regrowth of the dormant pathogenic bacteria, it is risky to apply the sludge to land even if the sludge is heat-treated, and there is also a risk of spreading antibiotic resistance.

Previous studies have indicated that outdoor light at night (LAN) is associated with a higher prevalence of overweight or obesity in adults. However, the association of LAN levels with overweight or obesity in children is still unknown. This study utilized data from the Seven Northeastern Cities study, which included 47,990 school-aged children and adolescents (ages 6–18 years). Outdoor LAN levels were measured using satellite imaging data. Weight and height were used to calculate age-sex-specific body mass index (BMI) Z-scores based on the World Health Organization (WHO) growth standards. Overweight status and obesity were defined using the Chinese standard. Information regarding socioeconomic status, sleep-related characteristics, and obesogenic factors were obtained using a questionnaire. A generalized linear mixed model examined the associations of outdoor LAN levels (in quartiles) with the outcomes of interest. Compared to children in the lowest quartile of outdoor LAN levels, children exposed to higher outdoor LAN levels had larger BMI Z-scores and higher odds of being overweight (including obesity) or obese, with the largest estimates in the third quartile [BMI Z-score: β = 0.26, 95% CI: 0.18–0.33; overweight (including obesity): OR = 1.40, 95% CI: 1.25–1.56; obesity: OR = 1.46, 95% CI: 1.29–1.65]. There was a significant sex difference (Pᵢₙₜₑᵣₐcₜᵢₒₙ<0.001) in the association of outdoor LAN levels with BMI Z-scores, and the association was stronger in males. Results remained robust following multiple sensitivity analyses and the adjustment of sleep-related characteristics, obesogenic factors, and environmental exposures. Our findings suggest that higher outdoor LAN levels are associated with larger BMI Z-scores and greater odds of overweight (including obesity) and obesity in school-aged children and adolescents. Further, the association between outdoor LAN levels and BMI Z-scores is stronger in males. Future studies with exposure assessments that consider both outdoor and indoor LAN exposures are needed.

Heavy metal toxicity has become an impediment to agricultural productivity, which presents major human health concerns in terms of food safety. Among them, arsenic (As) a non-essential heavy metal has gained worldwide attention because of its noxious effects on agriculture and public health. The increasing rate of global warming and anthropogenic activities have promptly exacerbated As levels in the agricultural soil, thereby causing adverse effects to crop genetic and phenotypic traits and rendering them vulnerable to other stresses. Conventional breeding and transgenic approaches have been widely adapted for producing heavy metal resilient crops; however, they are time-consuming and labor-intensive. Hence, finding new mitigation strategies for As toxicity would be a game-changer for sustainable agriculture. One such promising approach is harnessing plant microbiome in the era of ‘omics’ which is gaining prominence in recent years. The use of plant microbiome and their cocktails to combat As metal toxicity has gained widespread attention, because of their ability to metabolize toxic elements and offer an array of perquisites to host plants such as increased nutrient availability, stress resilience, soil fertility, and yield. A comprehensive understanding of below-ground plant-microbiome interactions and their underlying molecular mechanisms in exhibiting resilience towards As toxicity will help in identifying elite microbial communities for As mitigation. In this review, we have discussed the effect of As, their accumulation, transportation, signaling, and detoxification in plants. We have also discussed the role of the plant microbiome in mitigating As toxicity which has become an intriguing research frontier in phytoremediation. This review also provides insights on the advancements in constructing the beneficial synthetic microbial communities (SynComs) using microbiome engineering that will facilitate the development of the most advanced As remedial tool kit in sustainable agriculture.