Stress induced by heavy metals on breeding of magpie (Pica pica) from central Iran

Biomonitoring metals and metalloids in wild mammals: invasive versus non-invasive sampling

Heavy metal and metalloid pollution is a matter of concern in animal, human and environmental health (One Health) and also in wildlife conservation worldwide. Studying wild mammals in toxicology has been contributing significantly to our knowledge, namely to find out the most critical regions, to understand bioaccumulation and biomagnification phenomena or to evaluate their toxic effects. However, not all the animal tissues and organs provide the same information or should be interpreted in the same way. The best sample to use will depend on the objectives and conditions of the study. This review aims to compare invasive and non-invasive samples to biomonitor heavy metals, providing a brief resume of their advantages, limitations and examples of use. Further research, using a wider range of mammalian species, is required to establish what information can be obtained in biomonitoring studies that use non-invasive samples (such as hair, faeces and parasites) and/or invasive samples (such as blood, liver, kidney, bone and other organs).

Gamete quality in a multistressor environment

Over the past few decades, accumulated evidence confirms that the global environment conditions are changing rapidly. Urban industrialization, agriculture and globalization have generated water, air and soil pollution, giving rise to an environment with a growing number of stress factors, which has a serious impact on the fitness, reproduction and survival of living organisms. The issue raises considerable concern on biodiversity conservation, which is now at risk: it is estimated that a number of species will be extinct in the near future. Sexual reproduction is the process that allows the formation of a new individual and is underpinned by gamete quality defined as the ability of spermatozoa and oocytes to interact during fertilization leading to the creation and development of a normal embryo. This review aimed to provide the current state of knowledge regarding the impact of a broad spectrum of environmental stressors on diverse parameters used to estimate and evaluate gamete quality in humans and in canonical animal models used for experimental research. Effects of metals, biocides, herbicides, nanoparticles, plastics, temperature rise, ocean acidification, air pollution and lifestyle on the physiological parameters that underlie gamete fertilization competence are described supporting the concept that environmental stressors represent a serious hazard to gamete quality with reproductive disorders and living organism failure. Although clear evidence is still limited, gamete capacity to maintain and/or recover physiological conditions is recently demonstrated providing further clues about the plasticity of organisms and their tolerance to the pressures of pollution that may facilitate the reproduction and the persistence of species within the scenario of global change. Changes in the global environment must be urgently placed at the forefront of public attention, with a massive effort invested in further studies aimed towards implementing current knowledge and identifying new methodologies and markers to predict impairment of gamete quality.

Tissue distribution and oral exposure risk assessment of heavy metals in an urban bird: magpie from Central Iran

Direct ingestion of soil and/or soil attached to the food items is a potential rout for wildlife exposure to contaminants. In this study, bioaccumulation of five heavy metals (HMs) in internal tissues of an urban bird (Pica pica) collected from Aran-O-Bidgol City, Central Iran and their related soil were investigated. A total of 15 magpie specimens were collected in autumn 2013 and then their internal tissues were digested using a mixture of HNO₃ and H₂O₂, and finally, concentrations of HMs were detected by ICP-OES. In addition, in order to show level of HM exposure risk to magpie, an exposure risk assessment was modeled. Results indicated that HMs were accumulated as follows: liver > kidney > muscle. Zn and Cu were significantly higher in magpie's tissues collected from agricultural site; on the other hand, Pb and Cd were significantly higher in industrial site (p < 0.05). Level of Cd in male's livers (2.11 μg/g dw) was significantly higher than in females (1.85 μg/g dw) (p < 0.05). Levels of Cd, Pb, and Ni in liver, muscle, and kidney, respectively, were significantly higher in adults than in subadults (p < 0.05). Soil exposure doses of all HMs were lower than tolerable daily intake (Zn 4.35, Cu 1.34, Ni 5.65, Pb 0.35, and Cd 0.53). The calculated hazard quotations (HQs) for HMs were as follows: Pb > Zn > Cu > Ni > Cd and for all HMs were at no risk level (HQ < 1). The amounts of hazard index for three sites were as follows: urban (1.032) > agriculture (0.943) ≥ industry (0.941) and only for urban area was at low risk (1 < HQ < 2). It seemed that birds living in a safe environment and/or HM contaminations in soil separately had no negative effects on magpies. We can also suggest that low levels of HMs in magpie's tissues can be due to low levels of HMs in soil.