The comparative toxicity of biobased, modified biobased, biodegradable, and petrochemical-based microplastics on the brackish water flea Diaphanosoma celebensis.

The escalating production and improper disposal of petrochemical-based plastics have led to a global pollution issue with microplastics (MPs), which pose a significant ecological threat. Biobased and biodegradable plastics are believed to mitigate plastic pollution. However, their environmental fate and toxicity remain poorly understood. This study compares the in vivo effects of different types of MPs, poly(butylene adipate-co-terephthalate) as a biodegradable plastic, polylactic acid (PLA) as a biobased plastic, ß-cyclodextrin-grafted PLA as a modified biobased plastic, and low density polyethylene as the reference petrochemical-based plastic, on the key aquatic primary consumer Diaphanosoma celebensis. Exposure to MPs resulted in significant reproductive decline, with comparable effects observed irrespective of MP type or concentration. Exposure to MPs induced distinct responses in redox stress, with transcriptional profiling revealing differential gene expression patterns that indicate varied cellular responses to different types of MPs. ATP-binding cassette transporter activity assays demonstrated altered efflux activity, mainly in response to modified biobased and biodegradable MPs. Overall, this study highlights the comparable in vivo and in vitro effects of biobased, biodegradable, and petrochemical-based MPs on aquatic primary consumers, highlighting their potential ecological implications.

Toxicity of methylmercury in aquatic organisms and interaction with environmental factors and coexisting pollutants: A review.

Mercury is a hazardous heavy metal that is distributed worldwide in aquatic ecosystems. Methylmercury (MeHg) poses significant toxicity risks to aquatic organisms, primarily through bioaccumulation and biomagnification, due to its strong affinity for protein thiol groups, which results in negative effects even at low concentrations. MeHg exposure can cause various physiological changes, oxidative stress, neurotoxicity, metabolic disorders, genetic damage, and immunotoxicity. To assess the risks of MeHg contamination in actual aquatic ecosystems, it is important to understand how MeHg interacts with environmental factors such as temperature, pH, dissolved organic matter, salinity, and other pollutants such as microplastics and organic compounds. Complex environmental conditions can cause potential toxicity, such as synergistic, antagonistic, and unchanged effects, of MeHg in aquatic organisms. This review focuses on demonstrating the toxic effects of single MeHg exposure and the interactive relationships between MeHg and surrounding environmental factors or pollutants on aquatic organisms. Our review also recommends further research on biological and molecular responses in aquatic organisms to better understand the potential toxicity of combinational exposure.

Physiological and molecular responses of the copepods Acartia clausi and Acartia tonsa to nickel nanoparticles and nickel chloride.

Nickel compounds in dissolved form or as nanoparticles may affect planktonic invertebrates in marine ecosystems. Here, we assessed the physiological (naupliar mortality, egg production, egg hatching success) and molecular (quantitative gene expression) responses of the crustacean copepods Acartia clausi (indigenous Mediterranean species) and Acartia tonsa (model organism in ecotoxicology), to nickel nanoparticles (NiNPs) and nickel chloride (NiCl2), over time. We also measured NPs size and the temporal release of Ni ions in aqueous solution, through dynamic light scattering (DLS) and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. Nauplii of A. clausi were highly vulnerable to NiCl2 in the 48 h acute test, with an EC50 in the range of Ni concentrations measured in polluted waters. Females of both species exhibited a decreased egg production and hatching success after the 4-day exposure to NiNPs. Molecular responses in A. clausi incubated in NiNPs and NiCl2 showed a stronger up- or down-regulation, compared to A. tonsa, of genes associated with detoxification (phospholipid-hydroperoxide glutathione peroxidase, glutathione-S-transferase sigma), oxidative stress (superoxide dismutase), nervous system functioning (acetylcholinesterase), and oogenesis (vitellogenin). In conclusion, new information was here obtained on the effects of different forms of nickel on physiological and molecular responses of A. clausi, that could help to identify biomarker genes of exposure to be used as early-warning indicators. Our results also highlighted the need of employing indigenous copepod species to better evaluate the ecotoxicological impact of pollutants in different geographical area.

Predictive factors of mortality in patients admitted to the emergency department for SARS-Cov2 pneumonia.

INTRODUCTION: The overcrowding of intensive care units during the corona virus pandemic increased the number of patients managed in the emergency department (ED). The detection timely of the predictive factors of mortality and bad outcomes improve the triage of those patients. AIM: To define the predictive factors of mortality at 30 days among patients admitted on ED for covid-19 pneumonia. METHODS: This was a prospective, monocentric, observational study for 6 months. Patients over the age of 16 years admitted on the ED for hypoxemic pneumonia due to confirmed SARS-COV 2 infection by real-time reverse-transcription polymerase chain reaction (rRT-PCR) were included. Multivariate logistic regression was performed to investigate the predictive factors of mortality at 30 days. RESULTS: 463 patients were included. Mean age was 65±14 years, Sex-ratio=1.1. Main comorbidities were hypertension (49%) and diabetes (38%). Mortality rate was 33%. Patients who died were older (70±13 vs. 61±14;p<0.001), and had more comorbidities: hypertension (57% vs. 43%, p=0.018), chronic heart failure (8% vs. 3%, p=0.017), and coronary artery disease (12% vs. 6%, p=0.030). By multivariable analysis, factors independently associated with 30-day mortality were age ≥65 years aOR: 6.9, 95%CI 1.09-44.01;p=0.04) SpO2<80% (aOR: 26.6, 95%CI 3.5-197.53;p=0.001) and percentage of lung changes on CT scan>70% (aOR: 5.6% 95%CI .01-31.29;p=0.04). CONCLUSION: Mortality rate was high among patients admitted in the ED for covid-19 pneumonia. The identification of predictive factors of mortality would allow better patient management.