Ecotoxicity of commonly used oilfield-based emulsifiers on Guinean Tilapia (Tilapia guineensis) using histopathology and behavioral alterations as protocol.

This study examined the histological aberrations in the gill and liver tissues and behavioural changes of Tilapia guineensis fingerlings exposed to lethal concentrations of used Oilfield-based emulsifiers for 96 h. Various concentrations of the surfactants were tested, ranging from 0.0 to 15.0 ml/L. The behaviour of the fish was observed throughout the experiment, and the results showed that increasing concentrations of the surfactants led to progressively abnormal behaviour, including hyperventilation and altered opercular beat frequency. These behavioural changes indicated respiratory distress and neurotoxic effects. Histological analysis revealed structural aberrations in the gill and liver tissues, with higher concentrations causing more severe damage, such as lesions, necrosis, inflammation, and cellular degeneration. This implies that surfactants released even at low concentrations are capable of inducing changes in the tissues of aquatic organisms. These findings highlight the toxic effects of the surfactants on fish health and provide biomarkers of toxicity. Future research should focus on understanding the specific mechanisms and long-term consequences of surfactant toxicity on fish genetic composition, populations, and ecosystems to implement effective conservation measures.

Evaluation of human health and ecological risk of heavy metals in water, sediment and shellfishes in typical artisanal oil mining areas of Nigeria.

Heavy metal contamination in water and sediment is a serious concern in nations that depend heavily on natural resources such as Nigeria. In most coastal communities around oil mining areas in Nigeria, drinking water quality, staple food, and livelihoods are primarily dependent on ecological systems and marine resources (e.g., fish). Thus, humans and other receptors are exposed to heavy metal risks through ingestion and dermal contact. This research evaluated the potential ecological risks of heavy metals including Cadmium (Cd), Chromium (Cr), Nickel (Ni), and Lead (Pb) in water, sediments, and shellfishes (Callinectes amnicola, Uca tangeri, Tympanotonus fuscatus, Peneaus monodon) along the Opuroama Creek in Niger Delta, Nigeria. The concentrations of heavy metals were measured in three stations using the Atomic Absorption Spectrophotometer and their relative ecological (geo-accumulation index and contamination factor) and human health risk (hazard index and hazard quotient) analysed. The toxicity response indices of the heavy metals indicate that the sediments pose significant ecological risk particularly with Cd. None of the three exposure pathways to heavy metals in the shellfish muscles and age groups pose a non-carcinogenic risk. Total Cancer Risk values for Cd and Cr exceeded the acceptable range (10-6 to 10-4) established by USEPA in children and adults, raising concerns of potential cancer risks following exposure to these metals in the area. This established a significant possibility of heavy metal risks to public health and marine organisms. The study recommends conducting in-depth health analysis and reducing oil spills while providing sustainable livelihoods to the local population.

Pollution and Potential Ecological Risk Evaluation Associated with Toxic Metals in an Impacted Mangrove Swamp in Niger Delta, Nigeria.

Anthropogenic activities along coastal areas have contributed to the unwarranted discharge of toxic metals into mangrove swamps, posing risks to marine deposits and ecological environments. In this research, we studied the Isaka−Bundu tidal swamp area in the Niger Delta, which is an impacted mangrove creek located along the Bonny river, exposed to pollution pressures. The ecological risks (Er) of toxic metals in the sediments and water of the Isaka−Bundu tidal mangrove swamp followed a decreasing order (Cu > Zn > Cd > Cu > Pb > As), according to our results, while the potential ecological risk index (PERI) of the toxic metals in the sediments and water of the Isaka−Bundu tidal mangrove swamp can be said to have a very high ecological risk (PERI ≥ 600). The sediment pollution load index (PLI) was higher than 1 in all three analyzed stations, suggesting extremely toxic pollution. The enrichment evaluation shows that the studied stations have a moderate potential ecological risk of Cd, with the enrichment value for Pb showing low potential ecological risk. Our study shows that the Isaka−Bundu tidal mangrove swamp has a significant level of toxic metal pollution, which is evidence of the illegal activities performed in the Niger Delta.

The burden of nosocomial covid-19: results from the Wales multi-centre retrospective observational study of 2518 hospitalised adults.

ObjectivesTo define the burden of nosocomial (hospital-acquired) novel pandemic coronavirus (covid-19) infection among adults hospitalised across Wales. DesignRetrospective observational study of adult patients with polymerase chain reaction (PCR)-confirmed SARS-CoV-2 infection between 1st March - 1st July 2020 with a recorded hospital admission within the subsequent 31 days. Outcomes were collected up to 20th November using a standardised online data collection tool. SettingService evaluation performed across 18 secondary or tertiary care hospitals. Participants4112 admissions with a positive SARS-CoV-2 PCR result between 1st March to 1st July 2020 were screened. Anonymised data from 2518 participants were returned, representing over 60% of adults hospitalised across the nation of Wales. Main outcome measuresThe prevalence and outcomes (death, discharge) for nosocomial covid-19, assessed across of a range of possible case definitions. ResultsInpatient mortality rates for nosocomial covid-19 ranged from 38% to 42% and remained consistently higher than participants with community-acquired infection (31% to 35%) across a range of case definitions. Participants with nosocomial-acquired infection were an older, frailer, and multi-morbid population than those with community-acquired infection. Based on the Public Health Wales case definition, 50% of participants had been admitted for 30 days prior to diagnostic testing. ConclusionsThis represents the largest assessment of clinical outcomes for patients with nosocomial covid-19 in the UK to date. These findings suggest that inpatient mortality rates from nosocomial-infection are likely higher than previously reported, emphasizing the importance of infection control measures, and supports prioritisation of vaccination for covid-19 negative admissions and trials of post-exposure prophylaxis in inpatient cohorts. Trial registrationThis project was approved and sponsored by the Welsh Government, as part of a national audit and quality improvement scheme for patients hospitalised covid-19 across Wales. Key MessagesO_ST_ABSWhat is already known on this topicC_ST_ABSWe searched PubMed and ISI Web of Science up until 31-December-2020 for studies reporting on patient outcomes following hospital-acquired infection due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We identified a range of case-definitions for hospital-acquired infection, based on timing of diagnostic testing 5 to 15 days following admission. The largest and only multi-centre study concluded individuals with nosocomial infection are at a lower risk of death from SARS-CoV-2 than those infected in the community, however, was performed early in the pandemic and utilised a conservative definition of nosocomial infection. What this study addsOur multi-centre observational study represents the largest assessment of clinical outcomes for patients with nosocomial covid-19 in the UK to date, and suggests the burden of nosocomial SARS-CoV-2 infection has been underestimated. Nosocomial-infection occurred in older, frailer, and multi-morbid individuals, and was consistently associated with greater inpatient mortality than amongst those who were infected in the community across a spectrum of case-definitions. Our findings support implementation of enhanced infection control measures to reduce this burden during future waves, especially given the recent emergence of novel viral variants with enhanced transmissibility. Furthermore, roughly half of the patients meeting the Public Health Wales definition of definite nosocomial SARS-CoV-2 infection had been admitted for 30 days prior to diagnosis, highlighting a potential window of opportunity for inpatient pre-exposure and/or post-exposure prophylaxis.