Histological study of testis and epididymis under the influence of high levels of arsenic (As) and lead (Pb) in sheep blood serum

Contamination of heavy-metals in roadside grazes is a major threat to livestock especially in places that are experiencing a high level of traffic and whose pollution-control strategies are weak. This paper was designed to determine the effects of lead (Pb) and arsenic (As) in grazing in rams along the Sulaymaniyah-Diyala highway in the Kurdistan Region of Iraq. Twenty of them were found more than 500m away along the highway road side and the other twenty grazed close to the road verge. Blood Pb/As were measured and thus utilized to separate the animals into low-level, high-Pb and high-As categories. Histological examination of the testis and epididymis samples was done to assess the effects of metals. It was found that animals in the low-level group had normal tubular structure and adequate sperm count.lead-exposed rams showed mild-to-moderate degeneration of seminiferous tissue and decreased sperm density. As-affected rams showed the most severe lesions, including marked germ-cell depletion, interstitial fibrosis, and pronounced epididymal dysfunction, indicating a higher reprotoxic potential for As compared to Pb. Johnsen’s scoring confirmed a significant reduction in spermatogenesis in Pb- and As-exposed groups. This study offers the first regional evidence that highway exposure increases Pb and As to levels sufficient to cause detectable reproductive damage in rams. Results indicate the need for surveillance metal contamination in pasture areas to safeguard fertility.