TABLE 6.

Effect of SO₂ on COVID‐19 cases and mortality

Author	Country	Period	Analysis method	Quantified results
Liu et al 2	9 countries	21 Jan to 20 May 2020	Discontinuous linear regression	SO2 increased the propagation speed of COVID‐19 infection, which is significant in Korea and China, respectively.
Jiang et al 46	Wuhan, China	25 Jan to 7 Apr 2020	The Pearson's and Poisson's regression models	SO2 was inversely associated with COVID‐19 deaths.
Wang et al 47	337 prefecture‐level cities in China	NA	Spearman's rank correlation analysis and multiple linear regression	SO2 was positively correlated with newly confirmed cases.
Zhu et al 49	120 cities, China	23 Jan to 29 Feb 2020	Generalized additive model	10 μg/m3 increase of SO2 was associated with a 7.79% decrease (95% CI: −14.57 to −1.01) in COVID‐19 confirmed cases.
Landoni et al 63	33 European countries	NA	Pearson's correlation analysis	SO2 was positively correlated with positive COVID‐19 cases and deaths.
Jiang et al 64	Wuhan, Xiaogan and Huanggang, China	25 Jan to 29 Feb 2020	Multivariate Poisson's regression	SO2 was not correlated with daily COVID‐19 incidence.

This article is being made freely available through PubMed Central as part of the COVID-19 public health emergency response. It can be used for unrestricted research re-use and analysis in any form or by any means with acknowledgement of the original source, for the duration of the public health emergency.