Background and Objective: The Sistan Basin is one of the world's primary dust sources due to the "120-day winds" and the desiccation of the Hamoun Wetlands. Atmospheric dust in this region carries toxic elements such as mercury (Hg) and arsenic (As). This study aimed to evaluate the impact of dust on the bioaccumulation of Hg and As in the hair of two native rodent species, the Indian Gerbil (Tatera indica) and the Persian Jird (Meriones persicus), as bioindicators of environmental pollution in the Sistan region.

Materials and Methods: Sampling was conducted in June and July 2025 across three sites with different land uses (agricultural, residential, and natural). A total of 27 individuals were captured. Hair samples underwent a three-step washing protocol to distinguish internal from external contamination and were analyzed using ICP-OES. Data analysis was performed using one-way ANOVA and independent t-tests in SPSS software.

Results: The results showed that the mean Hg concentration in the hair of M. persicus (1.76 µg/g) was significantly higher than in T. indica (0.96 µg/g) (p < 0.05). However, no significant difference in As concentration was observed between the two species. The highest concentrations of both elements were recorded at the site nearest to dust sources and agricultural lands (S1) (As: 4.18 µg/g and Hg: 2.5 µg/g), showing significant differences compared to other sites (p < 0.05). Furthermore, gender had no significant effect on the accumulation levels in either species.

Conclusion: The findings suggest that M. persicus, due to its omnivorous diet and higher soil contact, exhibits a greater potential for Hg accumulation. High As levels in areas near dust sources highlight the key role of dust storms and agricultural activities in transferring this element into the food chain. Since the observed concentrations in some sites are comparable to those in mining areas of Iran, continuous monitoring of regional wildlife is essential to prevent the transfer of pollutants to higher trophic levels.