Association between COVID-19 and Heavy Metal Pollution in Iraqi Cities Determined from Hierarchical Prediction

This study assesses the relationship between coronavirus (COVID-19) and the spread of various heavy metal contaminants across Iraq. The study collects all confirmed, recovered, and death cases of the COVID-19 virus at its onset in Iraq until May 2, 2020, com-paring Iraq with the top three infected countries in the world (the United States Spain, and Italy). In addition, numerous heavy metal contamination in different Iraqi cities have been summarized and associated with the allowable upper and lower worldwide standard limits. Furthermore, the study introduces a hierarchical predictive approach for the relationship between confirmed infected cases and deaths due to the COVID-19 virus and heavy metal contamination in various Iraqi cities. It is concluded that all the studied Iraqi cities have heavy metal contamination for different chemical elements exceeding the allowable standard limits. Extreme con-tents of copper, nickel, lead, and zinc are concentrated in Al-Qadisiyah, Al-Sulaimaniyah, Erbil, and Baghdad with limits of 160 mu g/g, 240.9 mu g/g, 378 mu g/g, and 1,080 mu g/g, respectively. Based on the hierarchical pre-diction approach, a linear positive relationship between both confirmed cases and deaths due to COVID-19 with different heavy metal contamination was obtained with a maximum coefficient of determination (R-2) of 0.97.