Wageh S. Darwish, Abd-El Salam E. Hafez, Aya A. Khairy


Environmental pollution by heavy metals is a major problem worldwide. Domesticated animals such as cattle and camel share the same environmental conditions like human and they are exposed to heavy metals via different sources. Therefore, these animals are considered as ideal bio-indicators for human exposure to heavy metals. Heavy metals accumulate in the different tissues of the animals. Estimation of toxic metal residues such as arsenic (As), mercury (Hg), lead (Pb) and cadmium (Cd) in the animal edible tissues had been extensively studied. However, estimation of such toxicants in the non-edible animal byproducts had received little attention. Additionally, non-edible animal byproducts are frequently used in many industries such as animal feed additives  and leather fabrication. Therefore, this study was undertaken to estimate the residual concentrations of As, Hg, Pb and Cd in the hair, hides and bones of cattle and camel slaughtered at Zagazig, Abo-Hammad and Belbies cities, Sharkia Governorate, Egypt. Metal-metal correlations were additionally calculated. The achieved results indicated exposure of cattle and camel to high levels of heavy metals, particularly lead and arsenic. Camel had higher concentrations (mg/kg ww) of arsenic compared with cattle particularly in hair (38.57 ± 8.77 and 22.48 ± 1.91 in camel and cattle, respectively). Bone had the highest load of the measured metals among examined samples. For instances, in camel, elemental concentrations (mg/kg ww) in bone were 34.53 ± 6.16 (As), 3.41 ± 0.56 (Hg), 2.76 ± 0.36 (Pb) and 0.11 ± 0.01 (Cd). Samples collected from Zagazig city were highly contaminated compared with other locations. Significant positive correlations were observed between lead - mercury, lead - cadmium and arsenic- mercury (r <0.0001 in each). Contaminated non-edible animal byproducts should be hygienically disposed and avoid its introduction to downstream industries. It is highly recommended to control environmental pollution with heavy metals in Egypt.

Key words: bone; domesticated animals; hair; heavy metals; hide

Full Text:



(1) Cheng S. Heavy metal pollution in China: origin, pattern and control. Environ Sci Pollut Res Int 2003; 10: 192–8.

(2) Järup L. Hazards of heavy metal contamination. Br Med Bull 2003; 68: 167–82.

(3) Sanders T, Liu Y, Buchner V, Tchounwou PB. Neurotoxic Effects and Biomarkers of Lead Exposure: A Review. Rev Environ Health 2009; 24: 15–45.

(4) Tondel M, Rahman M, Magnuson A, Chowdhury IA, Faruquee MH, et al. The relationship of arsenic levels in drinking water and the prevalence rate of skin lesions in Bangladesh. Environ Health Perspect 1999; 10: 727–9.

(5) Graeme KA, Pollack CV Jr. Heavy metal toxicity, Part I: arsenic and mercury. J Emerg Med 1998; 16: 45–56.

(6) Alao BO, Falowo AB, Chulayo A, Muchenje V. The Potential of Animal By-Products in Food Systems: Production, Prospects and Challenges. Sustainability 2017; 9:1089.

(7) Darwish WS, Hussein MA, El-Desoky KI, Ikenaka Y, Nakayama S, et al. Incidence and public health risk assessment of toxic metal residues (cadmium and lead) in Egyptian cattle and sheep meats. Int Food Res J 2015; 22: 1719–26.

(8) Yamada M, Tohno S, Tohno Y, Minami T, Ichii M, Okazaki Y. Accumulation of mercury in excavated bones of two natives in Japan. Sci Total Environ. 1995; 162(2-3): 253–6.

(9) Alqadami AA, Khan MA, Otero M, Siddiqui MR, Jeon B et al. A magnetic nanocomposite produced from camel bones for an efficient adsorption of toxic metals from water. J Cleaner Prod 2018; 178: 293–304.

(10) Soliman MK. Functional anatomical adaptations of dromedary (Camelus Dromedaries) and ecological evolutionary impacts in KSA. International Conference on Plant, Marine and Environmental Sciences (PMES-2015) Kuala Lumpur (Malaysia). 2015.

(11) Yáñez J, Fierro V, Mansilla H, Figueroa L, Cornejo L et al. Arsenic speciation in human hair: a new perspective for epidemiological assessment in chronic arsenicism. J Environ Monit 2005; 7: 1335–41.

(12) Rogowska KA, Monkiewicz J, Grosicki A. Lead, cadmium, arsenic, copper, and zinc contents in the hair of cattle living in the area contaminated by a copper smelter in 2006 – 2008. Bull Vet Inst Pulawy 2009; 53:703–6.

(13) Rana T, Bera AK, Das S, Bhattacharya D, Pan D et al. Subclinical arsenicosis in cattle in arsenic endemic area of West Bengal, India. Toxicol Ind Health 2014; 30: 328–35.

(14) Giżejewska A, Szkoda J, Nawrocka A, Żmudzki J, Giżejewski Z. Can red deer antlers be used as an indicator of environmental and edible tissues' trace element contamination. Environ Sci Pollut Res Int 2017; 24: 11630–8.

(15) Lee JI, Jung WY, Lee G, Kim MS, Kim YS et al. Heavy metal concentrations in hair of newly imported China-origin rhesus macaques (Macaca mulatta). Lab Anim Res 2012; 28: 151–4.

(16) Nuttall KL. Interpreting hair mercury levels in individual patients. Ann Clin Lab Sci 2006; 36(3): 248–61.

(17) Rashed MN, Soltan ME. Animal hair as biological indicator for heavy metal pollution in urban and rural areas. Environ Monit Assess 2005; 110: 41–53.

(18) Markowitz ME, Shen XM. Assessment of bone lead during pregnancy: a pilot study. Environ Res 2001; 85: 83–9.

(19) Keil DE, Berger-Ritchie J, McMillin GA. Testing for toxic elements: A focus on arsenic, cadmium, lead, and mercury. Lab Medicine 2011; 42: 735–42.

(20) Goyer RA. Toxic and essential metal interactions. Annu Rev Nutr 1997; 17: 37–50.

Shabbaj II, Alghamdi MA, Shamy M, Hassan SK, Alsharif MM, et al. Risk assessment and implication of human exposure to road dust heavy metals in Jeddah, Saudi Arabia. Int J Environ Res Public Health 2017; 15: 36.

(21) Shabbaj II, Alghamdi MA, Shamy M, Hassan SK, Alsharif MM, et al. Risk assessment and implication of human exposure to road dust heavy metals in Jeddah, Saudi Arabia. Int J Environ Res Public Health 2017; 15: 36.



  • There are currently no refbacks.