Environmental observations of antibiotics and other pharmaceuticals have received attention as indicators of an urbanizing global water cycle. When connections between environment and development of antibiotic resistance (ABR) are considered, it is increasingly important to understand the life cycle of antibiotics. Here we examined the global occurrence of erythromycin (ERY) in: 1. wastewater effluent, inland waters, drinking water, groundwater, and estuarine and coastal systems; 2. sewage sludge, biosolids and sediments; and 3. tissues of aquatic organisms. We then performed probabilistic environmental hazard assessments to identify probabilities of exceeding the predicted no-effect concentration (PNEC) of 1.0 μg L−1 for promoting ABR, based on previous modeling of minimum inhibitory concentrations and minimal selective concentrations of ERY, and measured levels from different geographic regions. Marked differences were observed among geographic regions and matrices. For example, more information was available for water matrices (312 publications) than solids (97 publications). ERY has primarily been studied in Asia, North America and Europe with the majority of studies performed in China, USA, Spain and the United Kingdom. In surface waters 72.4% of the Asian studies have been performed in China, while 85.4% of the observations from North America were from the USA; Spain represented 41.9% of the European surface water studies. Remarkably, results from PEHAs indicated that the likelihood of exceeding the ERY PNEC for ABR in effluents was markedly high in Asia (33.3%) followed by Europe (20%) and North America (17.8%). Unfortunately, ERY occurrence data is comparatively limited in coastal and marine systems across large geographic regions including Southwest Asia, Eastern Europe, Africa, and Central and South America. Future studies are needed to understand risks of ERY and other antibiotics to human health and the environment, particularly in developing regions where waste management systems and treatment infrastructure are being implemented slower than access to and consumption of pharmaceuticals is occurring.

This study explored the long-run association among greenhouse gases (GHGs), financial development, forest area, improved sanitation, renewable energy, urbanization, and trade in 24 lower middle-income countries from Asia, Europe, Africa, and America (South and North) by using panel data from 1990 to 2015. Granger causality was tested by Toda and Yamamoto approach. The bi-directional causality was established among urbanization and GHGs (Asia), financial development and forest (Asia), energy use and renewable energy (Asia), renewable energy and forest (Asia), improved sanitation and forest (Asia, Africa, America), urbanization and forest (Asia), and improved sanitation and financial development (Europe). The GHG emission also shows one-way causality is running from financial development to GHG (America), energy to GHG (Asia), renewable energy to GHG (America), forest area to GHG (America), trade openness to GHG (Africa), urbanization to GHG (Europe), GHG to financial development (Europe), GHG to energy use (Europe, Africa, and America), and GHG to trade openness (Asia). On the basis of fully modified ordinary least square and generalized method of moment, the reciprocal relationship of GHGs was observed due to financial development in Asia and Africa; renewable energy in all panels; forest area in Asia, Europe, and America; improved sanitation in Asia, Africa, and America; trade openness in Africa; and urbanization in Europe and America. Policymakers should concentrate on these variables for the reduction in GHGs. The annual convergence towards long-run equilibrium was 50.5, 31.9, and 20.9% for America, Asia, and Africa, respectively.

This manuscript reported data for total suspended particulate matter (TSPM), particle-bound mercury (PBM), and total gaseous mercury (TGM) in Almadenejos, a rural zone of ancient Hg mining and metallurgical works. Concentrations of TSPM characterize the study site as being a rural area, with levels below 40 μg m⁻³ during most of the year and sporadic events involving dust intrusions from Africa. Mercury speciation of PM and nearby soils, which contain both cinnabar and organic Hg, confirms that the PM comes from local soil emissions involving the soils polluted by ancient metallurgical works. Conversely, PBM and TGM levels (average 1.8 ng m⁻³ and 88 ng m⁻³, respectively) define Almadenejos as a contaminated site similar to urban areas. A multiple linear regression analysis showed that evapotranspiration is the micrometeorological parameter that best explains the TSPM and PBM data, with the creation of a diurnal mixing layer being the main process involved in Hg emissions in the solid and gaseous states. Based on these findings, a micrometeorological-based model has been developed to acquire a complete set of daily PBM data and these were used to obtain dry deposition rates (317 μg m⁻² year⁻¹), which were seasonally distributed as 40% in summer, 33% in autumn, 16% in spring, and 11% in winter. In addition, an estimation of PBM emissions showed that 335 g year⁻¹ can be suspended in the Almadenejos environment. A large proportion of this PBM should be removed from the atmosphere through dry deposition in a continuous Hg exchange at the soil–atmosphere interface. Mercury fractionation (cinnabar and organic Hg) can increase the risk to the human population and nearby ecosystems of Almadenejos.

In order to assess the significance of PM in ambient air, it is necessary to evaluate their physical and chemical characteristics as well as identify their major emission sources. On a global scale, particulate matter in the atmosphere arises mainly from the combustion process of motorized vehicles, but natural sources are still considered as the major contributors. In Africa, PM emissions differ from those in developed countries; human activities such as biomass burning in households, poor household waste management, and the high number of diesel-powered vehicles are the predominant anthropogenic sources. Natural contributions are also observed. Saharan dust and savanna fires are the most common atmospheric natural sources of particulate matter. The present literature review gives an overview of the status of air quality in African cities and highlights the various sources of particulate matter emissions and local human activities specific to each African region. This could likely serve as a reference to evaluate the current air quality in this region and will be a useful tool in the future to develop pollution mitigation strategies at the source. Recommendations are proposed in the conclusion in order to reduce emissions from their sources, taking into account the low-income African countries.