Advances in Understanding Environmental Risks of Red Mud After the Ajka Spill, Hungary

In the 5 years since the 2010 Ajka red mud spill (Hungary), there have been 46 scientific studies assessing the key risks and impacts associated with the largest single release of bauxite-processing residue (red mud) to the environment. These studies have provided insight into the main environmental concerns, as well as the effectiveness of remedial efforts that can inform future management of red mud elsewhere. The key immediate risks after the spill were associated with the highly caustic nature of the red mud slurry and fine particle size, which once desiccated, could generate fugitive dust. Studies on affected populations showed no major hazards identified beyond caustic exposure, while red mud dust risks were considered equal to or lesser than those provided by urban dusts of similar particle size distribution. The longer-term environmental risks were related to the saline nature of the spill material (salinization of inundated soils) and the release and the potential cycling of oxyanion-forming metals and metalloids (e.g., Al, As, Cr, Mo, and V) in the soil–water environment. Of these, those that are soluble at high pH, inefficiently removed from solution during dilution and likely to be exchangeable at ambient pH are of chief concern (e.g., Mo and V). Various ecotoxicological studies have identified negative impacts of red mud-amended soils and sediments at high volumes (typically [5 %) on different test organisms, with some evidence of molecularlevel impacts at high dose (e.g., genotoxic effects on plants and mice). These data provide a valuable database to inform future toxicological studies for red mud. However, extensive management efforts in the aftermath of the spill greatly limited these exposure risks through leachate neutralization and red mud recovery from the affected land. Monitoring of affected soils, stream sediments, waters and aquatic biota (fungi, invertebrates and fish) have all shown a very rapid recovery toward prespill conditions. The accident also prompted research that has also highlighted potential benefits of red mud use for critical raw material recovery (e.g., Ga, Co, V, rare earths, inform), carbon sequestration, biofuel crop production, and use as a soil ameliorant

P444 COVID-19 risk factors, infection course and vaccination among patients with inflammatory bowel disease based on a Hungarian cohort

Abstract Background Inflammatory bowel disease potentially elevates the risk of infections, furthermore, disease activity and medical treatment(s) can increase the risk as well. However, both international data and recent studies do not confirm these preliminary conceptions regarding the SARS-CoV-2 infection. In addition, a number of studies have reported that less antibodies are produced against the virus in IBD patients. In January, 2021, the vaccination campaign has begun in Hungary as well, however, questions have been raised about the effectiveness and safety of the vaccine. Methods In this multicentre study, we assessed the prevalence and risk factors of COVID-19 infection, the willingness to receive COVID-19 vaccine and the efficacy of vaccination among IBD patients receiving biological therapy, based on a cross-sectional questionnaire-based study. To assess safety and antibody response to COVID-19 vaccines, we conducted a prospective study in the same Hungarian IBD centers. IgG antibody was quantified to SARS-CoV-2 spike protein and nucleocapsid, 1 week before and after the first vaccine and, 4 and, 8 weeks after the second vaccinane, respectively. Results 472 patients were enrolled in the first part of our study. SARS-CoV-2 infection was confirmed in, 16.9% of patients. Wearing gloves and masks were found to be effective in preventing infection (p=0.02; p=0.005), avoidance of communal areas had no effect on infection rates. Male sex increased the risk (p=0.008) of viral infection. Based on subjective complaints, UC patients had a worse disease course (p=0.002). Biological therapies did not increase the risk of infections. Patients vaccinated with mRNA vaccine had a significantly higher spike protein antibody titer one month after the second vaccination (p=0.004) compared to other vaccine types (Sinopharm©, Sputnik V©, Astra Zeneca©). Seropositivity was detected in, 98% of patients. Sinopharm© vaccination triggered the lowest number of side effect (p&amp;lt;0.001). SARS-CoV-2 infection induced relapses more frequently than vaccinations. Conclusion Face mask was the most effective preventive tool. The risk of infection was not increased by biological therapy, therefore therapy discontinuation is not justified. Almost every vaccinated patient developed seropositivity two month after vaccination independently from the type of the vaccine, however, spike protein antibody was significantly higher following mRNA vaccinations. </jats:sec