Metal Pollution in Moscow's Road Dust: A Closer Look

In Moscow, scientists have been investigating the tiny particles of dust that float in the air, specifically those smaller than 1 micron, called PM1. This dust is found in traffic zones, residential parking areas, and parks. They discovered that the types of metals and metal-like substances, or MMs, in this dust can vary greatly depending on where it's collected. For instance, parks have different metal profiles compared to busy roads and courtyards. Compared to other cities, Moscow's PM1 dust has less of certain metals like arsenic and cadmium but more of others like copper and zinc. When compared to the Earth's upper crust, this dust is highly rich in metals like antimony, zinc, and cadmium. In residential areas with parking lots, where people come into contact with these metals frequently, the pollution levels are as high as on major roads. Scientists used special methods like correlation analysis and principal component analysis with multiple linear regression (APCA-MLR) to figure out where these metals were coming from. On busy roads, vehicle exhausts and other non-exhaust emissions contribute a lot to the metal content in PM1. Things like tire wear, road surface wear, and industrial emissions play a smaller role. However, in residential areas, the poor condition of roads and frequent construction lead to more dust from roads and soil, increasing the metal levels by up to 16%. In parks, the contribution from human activities drops by 20-48% due to more soil being stirred up. Understanding how these metals are distributed can help in creating better strategies for cleaning roads, which could in turn reduce health risks for the public.