A systematic review of the risk management frameworks for potentially toxic chemical elements.

In the last 50 years, various frameworks have been used to control and manage potentially toxic chemical risks; however, these chemicals continue to negatively impact environmental and human health. This work was intended to provide a systematic review of the literature on essential aspects of current risk management frameworks for potentially toxic chemicals. The frameworks were reviewed using Organisation for Economic Co-operation and Development (OECD) principles that focus on elements, successes, shortcomings, similarities, and dissimilarities premised on the experiences of many countries. Keywords such as heavy metals, health risk, industrial chemicals, potentially toxic elements, chemical pollutants, and risk management framework were utilised to search the literature from databases and other sources. Ten risk framework documents selected from an initial yield of 1349 using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow processes met the inclusion criteria. The key elements of risk frameworks that were identified included the risk assessment paradigm, iteration, tiered approach, weight of evidence, uncertainty analysis, and multi-criteria decision analysis among others. Notable gaps in risk frameworks that required improvements to effectively manage health risks posed by potentially toxic chemicals were identified. While existing risk frameworks have made significant contributions to human health and environmental protection, new and comprehensive frameworks are needed to address the novel and dynamic risks posed by toxic industrial chemicals. Also, there is a need to promote the use of risk management frameworks in developing countries through technology transfer and the provision of financial assistance to improve environmental and public health protection from toxic chemicals.

Extracts Obtained from Pterocarpus angolensis DC and Ziziphus mucronata Exhibit Antiplasmodial Activity and Inhibit Heat Shock Protein 70 (Hsp70) Function.

Malaria parasites are increasingly becoming resistant to currently used antimalarial therapies, therefore there is an urgent need to expand the arsenal of alternative antimalarial drugs. In addition, it is also important to identify novel antimalarial drug targets. In the current study, extracts of two plants, Pterocarpus angolensis and Ziziphus mucronata were obtained and their antimalarial functions were investigated. Furthermore, we explored the capability of the extracts to inhibit Plasmodium falciparum heat shock protein 70 (Hsp70) function. Heat shock protein 70 (Hsp70) are molecular chaperones whose function is to facilitate protein folding. Plasmodium falciparum the main agent of malaria, expresses two cytosol-localized Hsp70s: PfHsp70-1 and PfHsp70-z. The PfHsp70-z has been reported to be essential for parasite survival, while inhibition of PfHsp70-1 function leads to parasite death. Hence both PfHsp70-1 and PfHsp70-z are potential antimalarial drug targets. Extracts of P. angolensis and Z. mucronata inhibited the basal ATPase and chaperone functions of the two parasite Hsp70s. Furthermore, fractions of P. angolensis and Z. mucronata inhibited P. falciparum 3D7 parasite growth in vitro. The extracts obtained in the current study exhibited antiplasmodial activity as they killed P. falciparum parasites maintained in vitro. In addition, the findings further suggest that some of the compounds in P. angolensis and Z. mucronata may target parasite Hsp70 function.

The African Wastewater Resistome: Identifying Knowledge Gaps to Inform Future Research Directions.

Antimicrobial resistance (AMR) is a growing global public health threat. Furthermore, wastewater is increasingly recognized as a significant environmental reservoir for AMR. Wastewater is a complex mixture of organic and inorganic compounds, including antibiotics and other antimicrobial agents, discharged from hospitals, pharmaceutical industries, and households. Therefore, wastewater treatment plants (WWTPs) are critical components of urban infrastructure that play a vital role in protecting public health and the environment. However, they can also be a source of AMR. WWTPs serve as a point of convergence for antibiotics and resistant bacteria from various sources, creating an environment that favours the selection and spread of AMR. The effluent from WWTPs can also contaminate surface freshwater and groundwater resources, which can subsequently spread resistant bacteria to the wider environment. In Africa, the prevalence of AMR in wastewater is of particular concern due to the inadequate sanitation and wastewater treatment facilities, coupled with the overuse and misuse of antibiotics in healthcare and agriculture. Therefore, the present review evaluated studies that reported on wastewater in Africa between 2012 and 2022 to identify knowledge gaps and propose future perspectives, informing the use of wastewater-based epidemiology as a proxy for determining the resistome circulating within the continent. The study found that although wastewater resistome studies have increased over time in Africa, this is not the case in every country, with most studies conducted in South Africa. Furthermore, the study identified, among others, methodology and reporting gaps, driven by a lack of skills. Finally, the review suggests solutions including standardisation of protocols in wastewater resistome works and an urgent need to build genomic skills within the continent to handle the big data generated from these studies.

Health risk management framework for heavy metals and cyanide in Kwekwe city of Zimbabwe: a mixed-method study protocol.

BACKGROUND: According to WHO, in 2015, over 35% of ischaemic heart disease, the leading cause of death and disability worldwide, and about 42% of strokes, the second largest contributor to global mortality, could have been prevented by reducing or removing exposure to chemical pollutants. Heavy metal and cyanide pollution are prevalent in developing countries, especially in sub-Saharan Africa where the effects of industrial pollutants are more severe, partly due to poor regulation. In Zimbabwe, the mining industry alone contributed to 25% of occupational conditions and injuries in 2020. Therefore, to mitigate these problems, this study seeks to develop a health risk management framework for heavy metals and cyanide pollution in the industrial city of Kwekwe. METHODS: The convergent parallel mixed-method study design will be utilised. Qualitative and quantitative data will be collected, analysed, and merged in order to inform the development of the risk framework. An analytical cross-sectional survey would be used to determine levels of heavy metals in surface water, soil, and vegetables. Free cyanide will be determined in surface water samples only. The phenomenological qualitative inquiry will be used to investigate health events and risks associated with potentially toxic pollutants (heavy metals and cyanide) to describe or interpret participants' lived experiences. The qualitative and quantitative results will be used to develop and validate the framework to manage identified health risks. For data analysis, statistical analysis will be used in the quantitative study, while thematic analysis will be used in the qualitative study. The study was approved by the University of Venda Ethics Committee (Registration Number FHS/22/PH/05/2306) and the Medical Research Council of Zimbabwe (Approval Number MRCZ/A/2944). All ethical principles will be adhered to throughout the study in accordance with the Helsinki Declaration. DISCUSSION: While existing risk management frameworks have significantly contributed to human and environmental health protection, novel and comprehensive frameworks need to be developed to counter the ever-dynamic and evolving risks associated with chemical pollutants. If the management framework is successfully developed, it could offer an opportunity for the prevention and control of potentially toxic elements.

In Zimbabwe, just like most developing countries, the problem of environmental pollution continues to threaten and endanger public health. Current pollution management measures seem insufficient in combating the problem to the extent that communities living in or near industrial areas continue to suffer from associated acute and chronic health conditions. Kwekwe city is an industrial and mining area with several abandoned and active mines and processing plants. Artisanal mining is widespread in the area, and many parts of the city's landscape are littered with open mining pits, dumps, and abandoned tailings. Most of these facilities are potential sources of heavy metals and cyanide and pose risks to human health. This study, therefore, seeks to develop a health risk management framework to address problems, which are associated with anthropogenic pollutants such as heavy metals and cyanide. The study will be conducted in two phases, that is, the first phase would involve the collection and analysis of empirical data from environmental samples, residents, and key stakeholders on heavy metal and cyanide pollution and associated health risks. The second phase would utilise findings from the first phase to develop a regulatory framework and to manage identified health risks. The developed framework would be validated through stakeholder and expert participation. The developed health risk management framework could be useful in the prevention and control environmental contamination, hence assisting to improve non-communicable diseases' outcomes in Kwekwe city.

Enteropathogenic Escherichia coli Infection Induces Diarrhea, Intestinal Damage, Metabolic Alterations, and Increased Intestinal Permeability in a Murine Model.

Enteropathogenic E. coli (EPEC) are recognized as one of the leading bacterial causes of infantile diarrhea worldwide. Weaned C57BL/6 mice pretreated with antibiotics were challenged orally with wild-type EPEC or escN mutant (lacking type 3 secretion system) to determine colonization, inflammatory responses and clinical outcomes during infection. Antibiotic disruption of intestinal microbiota enabled efficient colonization by wild-type EPEC resulting in growth impairment and diarrhea. Increase in inflammatory biomarkers, chemokines, cellular recruitment and pro-inflammatory cytokines were observed in intestinal tissues. Metabolomic changes were also observed in EPEC infected mice with changes in tricarboxylic acid (TCA) cycle intermediates, increased creatine excretion and shifts in gut microbial metabolite levels. In addition, by 7 days after infection, although weights were recovering, EPEC-infected mice had increased intestinal permeability and decreased colonic claudin-1 levels. The escN mutant colonized the mice with no weight loss or increased inflammatory biomarkers, showing the importance of the T3SS in EPEC virulence in this model. In conclusion, a murine infection model treated with antibiotics has been developed to mimic clinical outcomes seen in children with EPEC infection and to examine potential roles of selected virulence traits. This model can help in further understanding mechanisms involved in the pathogenesis of EPEC infections and potential outcomes and thus assist in the development of potential preventive or therapeutic interventions.

The Impact of Human Activities on Microbial Quality of Rivers in the Vhembe District, South Africa.

BACKGROUND: Water quality testing is dictated by microbial agents found at the time of sampling in reference to their acceptable risk levels. Human activities might contaminate valuable water resources and add to the microbial load present in water bodies. Therefore, the effects of human activities on the microbial quality of rivers collected from twelve catchments in the Vhembe District in South Africa were investigated, with samples analyzed for total coliform (TC) and Eschericha coli (E. coli) contents. METHODS: Physical parameters and various human activities were recorded for each sampling site. The Quanti-Tray(®) method was adopted for the assessment of TC and E. coli contents in the rivers over a two-year period. A multiplex polymerase chain (PCR) method was used to characterize the strains of E. coli found. RESULTS: The microbial quality of the rivers was poor with both TC and E. coli contents found to be over acceptable limits set by the South African Department of Water and Sanitation (DWS). No significant difference (p > 0.05) was detected between TC and E. coli risks in dry and wet seasons. All six pathogenic E. coli strains were identified and Enteroaggregative E. coli (EAEC), atypical Enteropathogenic E. coli (a-EPEC) and Enterotoxigenic E. coli (ETEC) were the most prevalent E. coli strains detected (respectively, 87%, 86% and 83%). CONCLUSIONS: The study indicated that contamination in the majority of sampling sites, due to human activities such as car wash, animal grazing and farming, poses health risks to communities using the rivers for various domestic chores. It is therefore recommended that more education by the respective departments is done to avert pollution of rivers and prevent health risks to the communities in the Vhembe District.

Tuberculosis Treatment Outcome and Drug Resistance in Lambaréné, Gabon: A Prospective Cohort Study.

Despite overall global progress in tuberculosis (TB) control, TB remains one of the deadliest communicable diseases. This study prospectively assessed TB epidemiology in Lambaréné, Gabon, a Central African country ranking 10th in terms of TB incidence rate in the 2014 World Health Organization TB report. In Lambaréné, between 2012 and 2014, 201 adult and pediatric TB patients were enrolled and followed up; 66% had bacteriologically confirmed TB and 95% had pulmonary TB. The human immunodeficiency virus (HIV) coinfection rate was 42% in adults and 16% in children. Mycobacterium tuberculosis and Mycobacterium africanum were identified in 82% and 16% of 108 culture-confirmed TB cases, respectively. Isoniazid (INH) and streptomycin yielded the highest resistance rates (13% and 12%, respectively). The multidrug resistant TB (MDR-TB) rate was 4/91 (4%) and 4/13 (31%) in new and retreatment TB cases, respectively. Treatment success was achieved in 53% of patients. In TB/HIV coinfected patients, mortality rate was 25%. In this setting, TB epidemiology is characterized by a high rate of TB/HIV coinfection and low treatment success rates. MDR-TB is a major public health concern; the need to step-up in-country diagnostic capacity for culture and drug susceptibility testing as well as access to second-line TB drugs urgently requires action.