The first COVID-19 case in Turkey was reported on March 10, 2020, by the Ministry of Health of the Republic of Turkey. Due to the increasing number of cases, a curfew was declared on weekends as of 11-12 April 2020. Although curfews were only implemented on public holidays and weekends, there were reductions in industrial, traffic, and human activities. The restrictions and curfews implemented to prevent the spread of the COVID-19 pandemic are a unique opportunity to understand the effects of anthropogenic sources on water quality. In this study, it was aimed to determine the temporal variations of the concentration of seven heavy metals (HMs) (Fe, Mn, Cu, Al, Cr, Ni, and Zn) in surface waters before and during the COVID-19 lockdown period, and their carcinogenic and non-carcinogenic risks that may occur through digestion and dermal absorption. Surface water samples were taken from 14 different sampling points within the borders of Bursa (Turkey). HM concentrations except Ni increased at rates ranging from 7.92% to 83.33% during the COVID-19 lockdown period compared to before the COVID-19 lockdown period. The heavy metal pollution index and heavy metal evaluation index increased during the COVID-19 lockdown period compared to before the COVID-19 lockdown period. Also, according to the results regarding the carcinogenic risk that may occur via digestion and dermal absorption, serious risks were determined for adults and children in both periods. Generally, similar correlation coefficients were obtained in both sampling periods, and it was concluded that HMs were affected by similar sources.