  Citation: Ajarem, J.S.; Hegazy, A.K.; Allam, G.A.; Allam, A.A.; Maodaa, S.N.; Mahmoud, A.M. Heavy Metal Accumulation, Tissue Injury, Oxidative Stress, and Inflammation in Dromedary Camels Living near Petroleum Industry Sites in Saudi Arabia. Animals 2022, 12, 707. https://doi.org/10.3390/ ani12060707 Academic Editor: Clive J. C. Phillips Received: 18 January 2022 Accepted: 9 March 2022 Published: 11 March 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). animals Article Heavy Metal Accumulation, Tissue Injury, Oxidative Stress, and Inflammation in Dromedary Camels Living near Petroleum Industry Sites in Saudi Arabia Jamaan S. Ajarem 1, *, Ahmad K. Hegazy 2,3 , Gamal A. Allam 4,5 , Ahmed A. Allam 1,5 , Saleh N. Maodaa 1 and Ayman M. Mahmoud 5,6, * 1 Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia; allam1081981@yahoo.com (A.A.A.); maodaa_28@yahoo.com (S.N.M.) 2 Department of Botany & Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia; akhegazy@yahoo.com 3 Department of Botany and Microbiology, Faculty of Science, Cairo University, Giza 12613, Egypt 4 Immunology Section, Department of Microbiology, College of Medicine, Taif University, Taif 21974, Saudi Arabia; gm_allam@yahoo.com 5 Zoology Department, Faculty of Science, Beni-Suef University, Beni-Suef 62514, Egypt 6 Department of Life Sciences, Faculty of Science and Engineering, Manchester Metropolitan University, Manchester M1 5GD, UK * Correspondence: jajarem@ksu.edu.sa (J.S.A.); ayman.mahmoud@science.bsu.edu.eg or a.mahmoud@mmu.ac.uk (A.M.M.) Simple Summary: The petroleum industry is a major source of energy and economic development but can pollute the environment and negatively impact animal and human health. Heavy metals are environmental pollutants and can reach the human body in direct and indirect ways. We investigated the levels of heavy metals in the soil and in the milk, blood, muscle, liver, and kidney of Arabian camels living near a petroleum industry site in the eastern region of Saudi Arabia. Our results revealed increased lead levels, cadmium, nickel, and vanadium in the soil and different tissues of camels. In addition, liver and kidney dysfunction, tissue damage, oxidative stress, inflammation, and apoptosis were reported. These findings may be of public interest and call attention to the assessment of the impact of the petroleum industry on the environment and the health of nearby communities. Abstract: The petroleum industry can impact the environment and human health. Heavy metals (HMs), including lead (Pb), cadmium (Cd), nickel (Ni), and vanadium (V), are toxic pollutants found in petroleum that can cause several severe diseases. This study investigated the impact of the oil industry on the Arabian camel (Camelus dromedarius) in the eastern region of Saudi Arabia, pointing to HMs accumulation, tissue injury, redox imbalance, inflammation, and apoptosis. Soil and camel samples (milk, blood, muscle, liver, and kidney) were collected from a site near an oil industry field and another two sites to analyze HMs. Pb, Cd, Ni, and V were increased in the soil and in the camel’s milk, blood, muscle, liver, and kidney at the polluted site. Serum aminotransferases, urea, and creatinine were elevated, and histopathological alterations were observed in the liver and kidney of camels at the oil industry site. Hepatic and renal lipid peroxidation, pro-inflammatory cytokines, Bax, and caspase-3 were increased, whereas cellular antioxidants and Bcl-2 declined in camels at the oil extraction site. In conclusion, the oil industry caused soil and tissue accumulation of HMs, liver and kidney injury, oxidative stress, and apoptosis in camels living close to the oil extraction site. These findings pinpoint the negative impact of the oil industry on the environment, animal, and human health. Keywords: oil industry; lead; cadmium; nickel; vanadium; ROS; inflammatory cytokines; apoptosis Animals 2022, 12, 707. https://doi.org/10.3390/ani12060707 https://www.mdpi.com/journal/animals