Source apportionment and deposition of dustfall-bound trace elements around Tabriz, Iran

Area of Science:

• Environmental Science
• Geochemistry
• Atmospheric Science

Background:

• Atmospheric dustfall (DF) poses environmental and health risks.
• Understanding DF composition and sources is crucial for urban air quality management.
• Previous studies in the region have not comprehensively analyzed DF's elemental composition and seasonal variations.

Purpose of the Study:

• To investigate the monthly and spatial variations of atmospheric dustfall (DF) and its elemental components.
• To identify the primary sources of DF in urban and suburban areas around Tabriz, Iran.
• To assess the influence of meteorological factors on DF levels.

Main Methods:

• Dustfall sampling using ASTM method D-1739 over 12 months (April 2017-March 2018).
• Analysis of elemental components in DF using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES).
• Calculation of Enrichment Factors (EF) to differentiate between natural and anthropogenic sources.

Main Results:

• DF levels ranged from 1.3 to 27.6 g/m².month, with higher levels in warmer seasons.
• DF showed a significant positive correlation with temperature, wind speed, and relative humidity.
• Iron (Fe) and Aluminum (Al) were the dominant elements, originating mainly from the Earth's crust. Trace elements like Hg, Pb, Cu, Sr, Mn, Co, Ni, and Cr showed high EF values, indicating significant anthropogenic contributions, particularly in colder seasons.

Conclusions:

• The Earth's crust is the primary source of atmospheric dustfall in the Tabriz region.
• Anthropogenic activities contribute substantially to the trace element content of DF.
• Meteorological conditions play a significant role in modulating DF levels and seasonal patterns.