Impact of the COVID-19 pandemic on coastal environment: positive or negative? A 1-year study on litter in Caspian coasts

Litter is one of the major environmental problems. These wastes cause adverse health, environmental, and even economic effects. One of the consequences of the COVID-19 pandemic is the impact on litter composition and density due to its changes in lifestyle and consumption patterns. In this study, the effect of the COVID-19 pandemic on the composition and density of litter on the ten southern beaches of the Caspian Sea in Iran in 1 year was investigated. The results showed that the density of the litters was in the range of 36.5–306 items/m(2). The highest and lowest proportions of the COVID-related litters on the locations studied were 2.54 and 5.95%, respectively. The indexes in the areas studied showed that the COVID-19 pandemic has reduced the density of the litter in 90% of the beaches studied by changing the style of citizens, but the emergence of new dumping related to COVID-19 has increased the potential for health and environmental hazards caused by litters. The effects of the COVID-related litters increased the clean environment index by 5 to 12% on the beaches. This study shows that the impact of social phenomena such as a pandemic on litter and its results can be used for the better management of municipal solid wastes, including litter in similar situations in the future.