# Morphometric Characteristics of Rat Testes Tissue After Exposure to Dust–Salt Aerosols of the Aral Sea

## TL;DR

Exposure to dust-salt aerosols from the Aral Sea harms rat testes, potentially affecting human fertility in the region.

## Contribution

This study reveals the harmful effects of Aral Sea dust-salt aerosols on rat testicular structure.

## Key findings

- Inhalation of dust-salt aerosols reduces seminiferous tubule thickness and diameter in rats.
- Exposure leads to fewer hormone-producing and supporting cells in rat testes.
- Prolonged exposure causes depletion of the spermatogenic layer and Leydig cell reduction.

## Abstract

The significant shrinkage of the Aral Sea, located in Central Asia, is one of the major anthropogenic environmental disasters of recent decades. The exposure of the seabed has led to the formation of the Aralkum Desert, created by human activities. This artificial desert is a source of frequent and prolonged dust–salt storms in the surrounding regions. In our experiment, we simulated the conditions of a dust–salt storm to determine how this natural phenomenon affects the structure of the testes in laboratory animals. We found that inhalation exposure to dust–salt aerosols leads to a decrease in the thickness and diameter of the seminiferous tubules, a reduction in the number of hormone-producing and supporting cells, and disruptions in germ cell differentiation in the testes of rats. It is possible that similar disruptions may also occur in men living in areas affected by dust storms, negatively impacting their reproductive health. Therefore, the findings of this study can be used to develop measures aimed at improving the demographic situation in the Aral Sea region of Kazakhstan.

The long-term reduction of the Aral Sea area has led to an ecological catastrophe and a deterioration in the health of the population. The progressing demographic crisis necessitates research on factors that negatively impact the fertility of the population in the Aral region. To investigate the influence of Aral Sea dust–salt aerosols on rat testicular tissues, we exposed male rats to the inhalation of dust–salt aerosols for 7, 24, 30, 48 and 72 days. The results of the morphometric analysis of the rat testes tissues indicate that aerosols containing salts from the Aral Sea have a detrimental effect on the seminiferous epithelium, causing a depletion of the spermatogenic layer and reduction of seminiferous tubules lumen. The morphological signs of testicular damage in the experimental animal groups included low cellularity of seminiferous tubules, vacuolization of Sertoli cells, and a decrease in the number of Leydig cells in the interstitium. The smallest thickness of the spermatogenic layer and the lowest number of Leydig cells were observed in rats after the longest inhalation exposure to the dust–salt aerosols.