|In Ekaterinburg, scientists made more than 60 mud samples. |
Photo credit: Ilya Safarov
Scientists at Ural Federal University and the Institute of Industrial Ecology Ural Branch of the Russian Academy of Sciences, together with their colleagues from Southern Federal University, Egypt and Saudi Arabia, have studied the concentration of potentially harmful substances in surface sediments in Ekaterinburg and identified possible sources of pollution. The research contributes to the development and adoption of standards for the content of harmful substances in mud. The results of the research, funded by the Russian Science Foundation (Project №18-77-10024), are described in the journal Chemosphere.
Over several seasons, scientists took more than 60 mud samples collected at the same sites: first, in green areas with flower beds and lawns, second, from roads and, third, from neighborhoods, parking lots and sidewalks in residential areas of the 1.5 million metropolises. Dirt samples were dried under laboratory conditions for several weeks and then passed through a 1-mm sieve. The resulting dust was analyzed.
"In samples from all surveyed areas the highest concentrations of iron and manganese are found, as they are contained in rocks and soils, on which Yekaterinburg is located. Dust from green areas, in addition, has high concentrations of zinc and lead, in samples from roads - cobalt, nickel, tin and antimony, dust from yard passages, parking lots and sidewalks is full of zinc and copper," says Andrian Seleznev, Associate Professor of Department of Health and Safety at UrFU, Senior Scientist of Industrial Ecology Ural Branch of the Russian Academy of Sciences.
In the dust from green areas and roads, there is a correlation between the presence of not only zinc and lead, but also cobalt and nickel. In samples from neighborhoods, the same correlation can also be seen between tin and antimony.
"This suggests that these elements come from the same source at the same time. Cobalt and nickel come from rocks and soils, as well as from emissions from motor vehicles and industry, from corrosion of metal materials, from the destruction of household waste, including plastics, electronics, paints and pigments. The origin of zinc, lead, copper, tin and antimony is most likely explained not only by exhaust emissions and metal erosion, but also by the wear of brake pads and tires, spills of motor oils and lubricants, degradation of road surfaces and asphalt," comments Andrian Seleznev.
The specialists of the Ural Federal University and the Institute of Industrial Ecology Ural Branch of the Russian Academy of Sciences have been using dirt and dust samples as types of urban surface deposits to determine concentrations of potentially harmful substances for 15 years. This technology is distinguished by the ease of sampling, and the material is a good indicator of urban pollution. This is evidenced by the fact that the results of the described studies are consistent with the data obtained at the Ural Federal University and Institute of Industrial Ecology Ural Branch of the Russian Academy of Sciences in 2014 with the analysis of atmospheric precipitation in puddles of Ekaterinburg.
"The problem is that there are no standards for the content of harmful substances in dirt in our country. It's possible to bring responsibility for pollution of soil, water, atmosphere, to force to fix the consequences and sources of pollution, but the dirt remains "nobody's business". Our long-term research aims to substantiate the need to develop and adopt such standards," emphasizes Andrian Seleznev.
Potentially harmful elements are considered one of the most dangerous pollutants posing a health threat to urban populations. People can be exposed to potentially harmful elements in dust through inhalation and, to a lesser extent, through direct skin-to-skin contact. The most dangerous route of exposure is through ingestion, with food intake. The degree of potentially harmful elements exposure also depends on the age of the person: children are especially sensitive to the negative impact of environmental pollution.
For example, continuous inhalation of iron oxide vapor causes serious eye and lung disease. Lead carries the risk of cancer, even with short-term exposure to high concentrations, and also causes developmental and neurological disorders. Cobalt, in addition to asthma, which can lead to permanent disability and death, causes hair loss and dermatitis. Nickel is also a carcinogenic agent and causes skin and cardiovascular disease, lung fibrosis and respiratory cancer with prolonged exposure.
Source/Credit: Ural Federal University