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%.

This study determined the contamination levels of oil and grease (O/G) across nine (9) galamsey operations under different environmental media (background soil, surface drainage, slurry/sludge and galamsey wastes) in three galamsey hotspot assemblies (Tarkwa Nsuaem, Amenfi East and Prestea Huni Valley) within the Western region of Ghana. Triplicate samples each of the four environmental media for the nine galamsey types (Washing Board, Washing Plant, Anwona, Dig and Wash, Dredging, Underground Abandoned Shaft, Underground Sample Pit, Chamfi and Mill House) were collected and analysed using n-hexane extractable materials in acidic medium by extraction and gravimetry to determine O/G concentrations. From the comparison of mean ranked concentration of O/G, using Kruskal-Wallis Test, the observed differences in the ranking was significant across all four media. The O/G concentrations for Anwona, Chamfi, Mill House, Washing Board and Washing Plant galamsey recorded exceedances when compared to the Ghana EPA Effluent Guideline Value of 100 mg/L for water and The New Dutch Lists’ Target and Intervention Value of 50 mg/kg and 500 mg/kg for solid/semi-solid materials. Consistently and for all environmental media types, the levels of O/G across the galamsey types were in the descending order of: Washing Board, Chamfi, Anwona, Mill House, Washing Plant, Underground Sample Pit, River Dredging, Dig and Wash, Underground Abandoned Shaft and Control Sample (non-galamseyed areas). In general, the surface drainage medium was predominantly found to be the most impacted upon medium from hydrocarbons by seven of the nine galamsey operations (Washing Board, Anwona, Chamfi, Mill House, Dredging, Dig and Wash and Underground Sample Pit). This was followed by slurry/sludge, background soil and waste media in that order. Expectedly, there were no exceedances for the Reference or Control Samples (non-galamseyed areas).

The use of mercury in small-scale gold mining is globally the largest anthropogenic source of mercury in the environment. In countries like Ghana, where small-scale gold mining is a highly important economic sector, the activity is also expected to cause local pollution. This study is based on a hypothesis that the mining activity in Ghana is causing more widespread soil pollution also outside active mining sites, and that the main part of regional differences in soil concentrations of mercury might come from pollution. Little systematic and dependable data has been collected to assess the extent of mercury contamination of soils in areas outside active mining areas. The regional aspect of mercury pollution from mining has not been studied in Ghana or other countries with a large small-scale gold mining sector. Systematic collection of soil samples on a 25 × 25 km² net covering the entire country was carried out to ensure the representativeness of data and to allow calculation of spatial trends. The soil concentrations found in one-third of the country, where most intensive mining takes place, are three times higher than concentrations in the rest of the country. This difference cannot be explained by sources of natural variation in mercury concentrations but can be explained by decades of atmospheric deposition. It is therefore likely that the mining activity has caused a more widespread increase in soil concentrations, also outside active mining sites. The mercury concentrations found are on average 0.024 mg kg⁻¹, which is low compared to published studies from other countries and regions and estimated world averages. All measured concentrations are well below soil quality criteria for human health. The build-up of soil concentrations in the mining area is still problematic because mercury is a hazardous substance in the environment.

This work aims to study the pseudo-total content, geochemical fractions, and species of arsenic (As) in the bulk soil and in the coarse and fine particles of top soil and soil profiles collected from active and abandoned gold mine spoils in Ghana. The human health risk for adults (male and female) and children has been assessed. To achieve our aims, we collected 51 samples, characterized them, determined the total As content, and sequentially extracted the geochemical fractions of As including water-soluble and un-specifically bound As (FI); specific-sorbed/exchangeable As (FII); poorly (FIII)- and well-crystalline (IV) Fe oxide; and residual/sulphide fraction (FV). In selected samples, As species were determined using synchrotron-based X-ray absorption near edge structure (XANES). Pseudo-total As contents varied from 1807 to 8400 mg kg⁻¹, with the extremes occurring at the abandoned mine spoil. Arsenic was almost 10-fold higher in the fine particles (<0.63 μm) than in the coarse particles. Arsenic was mainly associated with FIII and FV, indicating that the distribution of As in these spoils is governed by their contents of amorphous Fe oxides, sulphides and As bearing minerals. The XANES results indicated that scorodite (FeAsSO₄ = 65–76%) and arsenopyrite (FeAsS = 24–35%) are the two major As-containing minerals in the spoils. The potential mobility (PMF = ∑FI-FIV) of As in the fine particles of the top soil was higher (48–61%) than in the coarse particles (25–44%). The mobile fraction (MF) (FI+FII) and PMF of As in the coarse particles of the profiles increased with depth while it decreased in the fine particles. The median hazard index values indicated an elevated human health risk, especially for children. The high contamination degree and potential mobility of As at the studied mine spoils indicate high potential risk for human and environmental health.

Studies of polycyclic aromatic hydrocarbons (PAHs) and its metabolites in PM10, soils, rat livers and cattle urine in Kumasi, Ghana, revealed high concentrations and cancer potency. In addition, WHO and IARC have reported an increase in cancer incidence and respiratory diseases in Ghana. Human urine were therefore collected from urban and control sites to: assess the health effects associated with PAHs exposure using malondialdehyde (MDA) and 8-hydroxy-2-deoxyguanosine (8-OHdG); identify any association between OH-PAHs, MDA, 8-OHdG with age and sex; and determine the relationship between PAHs exposure and occurrence of respiratory diseases. From the results, urinary concentrations of the sum of OH-PAHs (∑OHPAHs) were significantly higher from urban sites compared to the control site. Geometric mean concentrations adjusted by specific gravity, GMSG, indicated 2-OHNaphthalene (2-OHNap) (6.01 ± 4.21 ng/mL) as the most abundant OH-PAH, and exposure could be through the use of naphthalene-containing-mothballs in drinking water purification, insect repellent, freshener in clothes and/or “treatment of various ailments”. The study revealed that exposure to naphthalene significantly increases the occurrence of persistent cough (OR = 2.68, CI: 1.43–5.05), persistent headache (OR = 1.82, CI: 1.02–3.26), tachycardia (OR = 3.36, CI: 1.39–8.10) and dyspnea (OR = 3.07, CI: 1.27–7.43) in Kumasi residents. Highest level of urinary 2-OHNap (224 ng/mL) was detected in a female, who reported symptoms of persistent cough, headache, tachycardia, nasal congestion and inflammation, all of which are symptoms of naphthalene exposure according to USEPA. The ∑OHPAHs, 2-OHNap, 2-3-OHFluorenes, and -OHPhenanthrenes showed a significantly positive correlation with MDA and 4-OHPhenanthrene with 8-OHdG, indicating possible lipid peroxidation/cell damage or degenerative disease in some participants. MDA and 8-OHdG were highest in age group 21–60. The present study showed a significant sex difference with higher levels of urinary OH-PAHs in females than males.

A total of 549 samples of rice, maize, wheat, sorghum and millet were obtained from markets in Ghana, the EU, US and Asia. Analysis of the samples, originating from 21 countries in 5 continents, helped to establish global mean trace element concentrations in grains; thus placing the Ghanaian data within a global context. Ghanaian rice was generally low in potentially toxic elements, but high in essential nutrient elements. Arsenic concentrations in rice from US (0.22 mg/kg) and Thailand (0.15 mg/kg) were higher than in Ghanaian rice (0.11 mg/kg). Percentage inorganic arsenic content of the latter (83%) was, however, higher than for US (42%) and Thai rice (67%). Total arsenic concentration in Ghanaian maize, sorghum and millet samples (0.01 mg/kg) was an order of magnitude lower than in Ghanaian rice, indicating that a shift from rice-centric to multigrain diets could help reduce health risks posed by dietary exposure to inorganic As.

In the present study, the daily dose in terms of particle surface area received by citizens living in different low- and middle-income countries, characterized by different lifestyles, habits, and climates, was evaluated. The level of exposure to submicron particles and the dose received by the populations of Accra (Ghana), Cairo (Egypt), Florianopolis (Brazil), and Nur-Sultan (Kazakhstan) were analyzed. A direct exposure assessment approach was adopted to measure the submicron particle concentration levels of volunteers at a personal scale during their daily activities. Non-smoking adult volunteers performing non-industrial jobs were considered. Exposure data were combined with time-activity pattern data (characteristic of each population) and the inhalation rates to estimate the daily dose in terms of particle surface area.The received dose of the populations under investigation varied from 450 mm² (Florianopolis, Brazil) to 1300 mm² (Cairo, Egypt). This work highlights the different contributions of the microenvironments to the daily dose with respect to high-income western populations. It was evident that the contribution of the Cooking & Eating microenvironment to the total exposure (which was previously proven to be one of the main exposure routes for western populations) was only 8%–14% for low- and middle-income populations. In contrast, significant contributions were estimated for Outdoor day and Transport microenvironments (up to 20% for Cairo, Egypt) and the Sleeping & Resting microenvironment (up to 28% for Accra, Ghana), highlighting the effects of different site-specific lifestyles (e.g. time-activity patterns), habits, socioeconomic conditions, climates, and outdoor air quality.

To evaluate BPA's potential risk to health, it is important to know human daily intake. This study describes a simple but effective method to estimate the levels of human BPA intake among four different populations based on urinary concentration data. Nationally, of the 30 countries examined, the top ten countries for adult intake were Italy, Sweden, Denmark, France, Cyprus, Australia, Israel, Ghana, Jamaica, and Belgium. When the urinary excretion sample size was large enough and over 1000, it was found that the national estimated BPA daily intakes in the child group among countries, showed a good linear relationship with those of their corresponding adult group. Except the infant group with limited data, the global estimated BPA daily intakes for children and pregnant women were 2 and 1.4 times that of the adult group. Although the national and global estimated BPA daily intakes were generally below the temporary tolerable daily intake (tTDI) recommended by the European Food Safety Authority (EFSA), but some normal individuals' daily intakes exceeded the tTDI.

Previous studies of polycyclic aromatic hydrocarbons (PAHs) in particulate matter, soils and livers of wild rats indicated that the city centre of Kumasi, Ghana has been severely polluted with high cancer potency. Cattle urine were therefore collected from Kumasi (urban) and Offinso (rural), Ghana: to determine concentrations of urinary PAH metabolites (OH-PAHs); and find their association with sex; and to estimate exposure of cattle to PAHs from the different sites. From the results, geometric mean concentrations (adjusted by specific gravity), GMSG, showed that 2-OHNaphthalene (2-OHNap) was the most abundant OH-PAH in cattle urine from all study sites, and naphthalene-containing-mothballs might have contributed significantly to the levels. There was no significant difference between urinary OH-PAHs concentrations in cattle from urban and rural sites except for 2-OHPhe and 4-OHPhe, and similar to urban areas, rural sites could also be polluted with PAHs. GMSG of 2-OHNap in cattle urine in Kokote (21.9 ± 6.51 ng/mL; a rural area), was significantly higher compared to the other sites followed by Oforikrom (4.15 ± 4.37 ng/mL; urban). The GMSG concentration (ng/mL) of the sum of OH-PAHs decreased in the order, Kokote (44.7) > Oforikrom (7.87) > Saboa (6.98) > Santasi (6.68) > and Twumasen Estate (5.23). The high concentrations of urinary 2-OHNap, 2-3-OHFlu, 2-OHPhe, 3-OHPhe and 4-OHPhe in Kokote indicated high PAHs exposure to cattle in this area or different/specific source of PAHs exposure. GMSG of 2-OHNap was significantly higher in male cattle compared to females while 1-9-OHPhe was significantly higher in females.

Open burning of electronic waste (e-waste) releases various metals and organohalogen compounds in the environment. Here we investigated the interplay of metals (Cu, Pb, Zn, Fe, Co, and Sr) and bromine (Br) in the formation of dioxin-related compounds (DRCs), including polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs), as well as non-regulated DRCs such as polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) and their monobrominated PCDD/Fs in soils sampled from open burning e-waste sites at Agbogbloshie in Accra, Ghana. The predominant DRCs were PBDFs, PCDFs, PCDDs, and DL-PCBs. Statistical analyzes, X-ray absorption spectroscopy, and the PCDF/PCDD ratio suggested possible formation paths of PCDD/Fs and DL-PCBs by catalytic behaviors of copper chlorides (CuCl, CuCl2, and Cu2(OH)3Cl) and thermal breakdown of polyvinyl chloride. Predominant formation of brominated furans may be derived from electron transfer from intermediates of PBDE to copper, Cu(II) → Cu(I). Lead chloride also contributed to generate DRCs and may become highly bioaccessible through the open burning of e-waste. The main zinc species (ZnCl2 and ZnS) suggested a possible relationship to generate DRCs and specific zinc source such as tire burning. Cu, Pb, Zn, and Br contained in various e-wastes, wires/cables, plastics, and tires strongly influenced generation of many DRCs.