The content of heavy metals in the dust aerosol of southern and central parts of Tajikistan

The article provides statistical parameters for the concentrations of heavy metals of first, second and fourth hazard classes in dust samples. The highest content of lead was found in the spring of 2014, arsenic - in the summer of 2010, zinc - in the fall of 2013 in Ayvadzh. Correlation analysis of concentrations of some heavy metals has been carried out. The correlation between the concentrations of many heavy metals is small. A significant positive correlation was found between the concentrations in atmospheric aerosol samples from the southern and central parts of Tajikistan. The average concentration of nickel has been defined in 2011 and 2019, and the maximum concentration of lead in 2013 and 2014. In 2015, the concentrations of cobalt and arsenic, as well as nickel and lead, are almost the same. During the entire observation period, the iron oxide concentration is several times higher than the concentration of titanium dioxide. The average zinc content is maximum in 2007-2009, 2011 and 2013. In 2010, the average concentration of copper was the highest in the aerosol. In 2014, 2015, 2019, the concentrations of all elements were close. The maximum average concentration of manganese dioxide was observed in 2007, the minimum average content in 2019. From 2008 to 2015, the average concentration of manganese dioxide remained almost unchanged. Reverse trajectories of the air mass flow were constructed according to the model for the transfer of pollutants. (author)