id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-331858-oz4mvyw8	Kifer, D.	Effects of environmental factors on severity and mortality of COVID-19	2020-07-14		.txt	text/plain	5518	303	47	Aiming to evaluate the association of humidity, and ambient temperature with the severity of the COVID-19 disease, we analysed individual-patient data for 6,914 patients with COVID-19 admitted to hospitals in Bergamo, Italy: Barcelona, Spain; Coburg, Germany; Helsinki, Finland; Milan, Italy; Nottingham, United Kingdom; Warsaw, Poland; Zagreb, Croatia and Zhejiang province, China since the beginning of the pandemics and compared it to environmental temperature and calculated indoor humidity. It is very difficult to prove causality in an observational study, in particular when many correlated factors are changed in the same time, but the observed decrease in COVID-19 severity with the end of winter fits very well with the known effects of outside temperature on indoor humidity and consequential restoration of mucosal barrier function, which is often impaired by dry air during the heating season 16 .	./cache/cord-331858-oz4mvyw8.txt	./txt/cord-331858-oz4mvyw8.txt