Int. J. Environ. Res. Public Health 2009, 6 3128 the levels reported in this study do not represent a concern from a consumer safety point of view. The lack of a strong correlation between histopathological changes and the incidence of toxic elements found in this study might be explained as the result of synergism among toxic elements and other nephrotoxic compounds which enhance the toxicity of the individual toxins even at the relatively low mean concentrations observed in this study. Keywords: toxic elements; kidney; residue; pathomorphology; swine 1. Introduction Environmental pollution with toxic elements is a dangerous problem that is recognized worldwide. Toxic elements can be found in water, soil, air, plant and animal tissues as a result of both natural causes, industrial and agricultural practices [1]. Environmental concern pertaining to toxic elements relates to their toxicity, labile nature, bioaccumulation in organisms and ultimately to their effect on human beings [2]. One of the most important aspects of environmental pollution for humans is the intake of toxic elements in the diet [3]. Heavy metals are significantly toxic, due to their cumulative nature in the different body organs leading to unwanted effects [4,5]. Metals tend to bioaccumulate in the environment and biomagnify in food chains [6], their levels might reach toxic limits even when found in low concentrations in environmental samples. Since this should be limited to an unavoidable minimum, much attention is paid to the occurrence of these elements in food. Monitoring programmes are being carried out in many countries with the purpose of avoiding the distribution of foodstufs that could pose a risk to human health if consumed. The chemical interactions of toxic elements with proteins in living systems render essential reactions impotent [7]. Toxic elements can interfere with the functions of enzymes and are responsible for many diseases, especially cardiovascular, renal, nervous and even bone disorders [4,8–12]. Toxic elements are also implicated in several major human diseases including carcinogenesis-induced tumor promotion [13–17]. Some toxic elements are considered to be carcinogenic, mutagenic and teratogenic in experimental animals [18–19]. Toxic elements levels in animal tissues are organ specific. Meat and meat products form an important part of the human diet. Although the toxic elements content in muscle is generally low, offals, such as liver and kidney, often contain higher metal concentrations than most other foods [20–23]. In many European countries, internal organs (liver, kidneys, heart, and lungs) are sold and consumed as a valuable food source. Therefore, evaluating toxic metal levels in internal organs is important for safety and health purposes. The risks to health from certain elements in food can be assessed by comparing estimates of dietary exposures with the Provisional Tolerable Weekly Intakes (PTWIs) and Provisional Maximum Tolerable Daily Intakes (PMTDIs) recommended by the Joint Expert Committee on Food Additives (JECFA) of the Food and Agriculture Organization of the United Nations and the World Health Organization International Programme on Chemical Safety [24,25]. In order to ensure the safety of consumers in Serbia, the present study aims to conduct an exposure assessment of toxic elements (As, Cd, Hg and Pb) due to the consumption of pork meat by products in focusing on the presence of the toxic elements in the kidneys of healthy slaughtered swine.