A systematic review of pharmaceutical and personal care products as emerging contaminants in waters: The panorama of West Africa.

Pharmaceutical and Personal Care Products (PPCPs) are widely used to prevent or treat human and animal diseases, thereby improving the quality of daily life. Poor management of post-consumer products is recognized worldwide, as they negatively affect the ecosystems where they are discharged. The first action to prevent negative impacts is the state of knowledge regarding their occurrence. This paper critically reports the panorama of West Africa in terms of PPCPs occurrence in different water sources. To achieve this objective, a systematic review was conducted on PPCPs in West Africa following the PRISMA guidelines. Databases, including African Journals Online, PubMed, Google Scholar, Scopus, and Dimensions, were used for this search. Thirty-five articles, representing 58 % of West African countries, were selected according to the inclusion and exclusion criteria. Of these articles, one included data from multiple West African countries, while the remaining 34 exclusively focused on Benin, Cameroon, Ghana, and Nigeria. The results revealed a variety of PPCPs investigated, about 27 groups and 112 compounds, with greater emphasis on antibiotics, analgesics and PSHXEs. HPLC was the predominant analytical method used, resulting in total concentrations of PPCPs in the range of 200,000 to 3,200,000 ng/L in drinking water, 12 to 700,000 ng/L in groundwater, 0.42 to 107,800,000 ng/L in surface water, 8.5 to 121,310,000 ng/L in wastewater, and 440 to 421,700 ng/L in tap water. Ghana, Nigeria and Cameroon reported the highest number of PPCPs investigated and consequently the highest concentration of cases. These compounds present a high potential ecological risk, with >50 % exceeding the risk quotient limit. Therefore, West Africa as a community needs integrated approaches and strategies to monitor water, especially transboundary resources. This review is timely and provides pertinent information to policymakers and researchers on PPCPs in water.

Impact of climate change on future precipitation amounts, seasonal distribution, and streamflow in the Omo-Gibe basin, Ethiopia.

This study projected the impact of climate change on the amount of precipitation, seasonal distribution, and streamflow of the Omo-gibe basin, Ethiopia. Projections of climate change using the results of high-resolution multimodal ensembles from fifteen regional climate models (RCMs) of the Coordinated Regional Climate Reduction Experiment (CORDEX)-Africa were statistically downscaled and bias-adjusted using a quantile mapping approach. Precipitation and temperature were projected under RCP 8.5 and RCP 4.5 emission scenarios. Climate and streamflow projections from a mean ensemble of RCMs in the near future (2025-2050), medium future (2051-2075), and far future (2076-2100) were compared to the reference (1989-2019). Mann-Kendall (MK) trend testing was used to determine if a change is statistically significant and to detect trends in temperature, precipitation, and streamflow. The Soil and Water Assessment Tool (SWAT) hydrological model was used to project the impact of climate change on the streamflow. According to RCP4.5 and RCP8.5, the emission scenarios predicted significant positive (rising) temperature, but significant negative (decreasing) precipitation and streamflow. The average temperature projected increases range from 2.40-3.34 °C under the RCP 4.5 emission scenarios and 2.6-4.54 °C under the RCP 8.5 emission scenarios. Annual average precipitation projected decreases range between 10.77-13.11% under the RCP 4.5 emission scenario, while the RCP 8.5 emission scenarios decrease range between 11.10-13.86% in the rainy summer season (June-August) and the irregular rain season (March-May). Projected annual average streamflow decrease range between 7.08-10.99% under the RCP 4.5 emission scenarios and 10.98-12.88% under the RCP 8.5 emission scenarios. Results on projected temperature increases and reductions in precipitation and streamflow will help to develop effective adaptation measures to reduce the ongoing impacts of climate change and draw up long-term water resource management plans in the river basin. Both the results and the multidisciplinary approach will be vital to irrigation and hydropower project planners.

Pathogen and heavy metal contamination in urban agroecosystems of northern Ghana: Influence of biochar application and wastewater irrigation.

The benefit of biochar as a soil fertility enhancer is well known and has been broadly investigated. Equally, many tropical and subtropical countries use wastewater for irrigation in urban agriculture. To assess the related health risks, we determined pathogen and heavy metal fate associated with biochar application and wastewater irrigation in the urban agriculture of northern Ghana. Rice (Oryza L.) husk biochar (20 t ha-1 ), N-P-K 15-15-15 fertilizer (212.5 kg ha-1 ), and their combinations were evaluated in a field-based experiment. Untreated wastewater and tap water served as irrigation water. Red amaranth (Amaranthus cruentus L.) was used as a test crop and was grown in wet (WS) and dry (DS) cropping seasons. Irrigation water, soil, and vegetables were analyzed for heavy metals, Escherichia coli, fecal coliform, helminth eggs, and Salmonella spp. Unlike the pathogens, analyzed heavy metals from irrigation water and soil were below the FAO/WHO permissible standard for agricultural activities. Wastewater irrigation caused E. coli concentrations ranging from 0.5 to 0.6 (WS) and from 0.7 to 0.8 (DS) log10 colony forming units per gram fresh weight (CFU gFW -1 ) on vegetables and from 1.7 to 2.1 (WS) and from 0.6 to 1.0 (DS) log10 CFU per gram dry weight (gDW -1 ) in soil. Average log10 CFU gFW -1 rates of 6.19 and 3.44 fecal coliform were found on vegetables, whereas in soil, 4.26 and 4.58 log10 CFU gDW -1 were observed in WS and DS, respectively. Helminth egg populations were high in wastewater and were transferred to the crops and soil. Biochar did not affect bacteria contamination. Pathogen contamination on vegetables and in soil were directly linked to the irrigation water, with minimal or no difference observed from biochar application.