ABSTRACT
Poly- and perfluoroalkyl substances (PFAS) are a large group of synthetic organofluorine compounds. Over 4700 PFAS compounds have been produced and used in our daily life since the 1940s. PFAS have received considerable interest because of their toxicity, environmental persistence, bioaccumulation and wide existence in the environment. Various treatment methods have been developed to overcome these issues. Thermal treatment such as combustion and pyrolysis/gasification have been employed to treat PFAS contaminated solids and soils. However, short-chain PFAS and/or volatile organic fluorine is produced and emitted via exhaust gas during the thermal treatment. Combustion can achieve complete mineralisation of PFAS at large scale operation using temperatures >1000 °C. Pyrolysis has been used in treatment of biosolids and has demonstrated that it could remove PFAS completely from the generated biochar by evaporation and degradation. Although pyrolysis partially degrades PFAS to short-chain fluorine containing organics in the syngas, it could not efficiently mineralise PFAS. Combustion of PFAS containing syngas at 1000 °C can achieve complete mineralisation of PFAS. Furthermore, the by-product of mineralisation, HF, should also be monitored due to its low regulated atmospheric discharge values. Alkali scrubbing is normally required to lower the HF concentration in the exhaust gas to acceptable discharge concentrations.
ABSTRACT
In 2020, decreased emergency department (ED) visits and hospitalization rates during the COVID-19 outbreak were reported. There is no data about cardiovascular emergencies and mortality for the whole COVID-19 year.This study aimed to compare the rates of cardiology ED visits, hospital admissions, and intrahospital mortality between the pre-COVID-19 and COVID-19 years in a single high-volume center.The retrospective observational cross-sectional study analyzed data on the number of ED visits, hospital admissions by different cardiovascular diagnoses, and outcomes.A total of 11744 patients visited the cardiology ED in the pre-COVID-19 year compared with 9145 in the COVID-19 year, indicating an overall decrease of 22.1% (P = 0.02) (IR 78.76 versus 61.33; incidence rate ratios (IRR) 1.28, P = 0.00), with an observed decrease of 25.5% in the number of hospitalizations (33.1% versus 31.6%, P = 0.02). A marked decrease in hospitalizations for cardiovascular emergencies was observed for hypertensive heart disease (-72.8%, P < 0.0001), acute coronary syndrome (-17.8%, P < 0.0001), myocardial and pericardial diseases and endocarditis (-61.2%, P = 0.00), and valvular heart disease (-70.8%, P < 0.0001). In the COVID-19 year, patients had increased need for mechanical ventilatory support (7% versus 6.3%, P = 0.03) with no overall difference in intrahospital mortality (IR 2.71 versus 2.78, IRR 0.98, 95% CI 0.82-1.16, P = 0.39).Decreased ED visits and hospitalizations not just in outbreaks but through the whole COVID-19 year highlight the risk of continuous delay of needed care for emergency life-threatening cardiovascular diseases. Urgent comprehensive strategies that will address patient- and system-related factors to decrease morbidity and mortality and prevent collateral damage of the pandemic are needed.
