Assessment of heavy metal residues in Brazilian poultry and swine tissue

Abstract

Assessment of heavy metal residues in Brazilian poultry and swine tissue [ ABSTRACTThe aim of this study was to investigate the presence of arsenic, lead and cadmium residues in samples of liver, kidney and muscle of poultry and swine during the years from 2002 to 2008. A total of 1978 samples were analyzed: 1031 of poultry and 947 of swine from Brazilian slaughterhouses. The samples were analyzed at the National Agricultural Laboratory using the atomic absorption spectrometry technique. In poultry, the arsenic residues were detected in 53.6% of liver samples, although no results have exceeded the MRL. In kidneys, 39.7% of the samples showed measurable residues and there was no violation of the limits. Regarding lead, there were 5 contaminated liver samples and 24 contaminated kidney samples (1.5 and 3.6% respectively). In muscle tissue there was only one sample with residues. For cadmium, 3.8% of the samples were found below MRL. Cadmium residues were found in 110 kidney samples (16.3% of tested), but only one exceeded the legislation limits. In swine, arsenic residues were detected in 15.3% of liver samples, although no results exceeded the MRL. In kidneys, 14.2% of samples showed measurable residues. However, there was no violation of limits. Regarding lead levels, 7 liver samples and 18 kidney samples were contaminated (2.6 and 2.7% respectively). Cadmium was found below MRL in 14.9% of the analyzed samples. In kidneys, 448 samples (67.8% of the total tested) had cadmium residues and 4 samples exceeded the legislation limits. During the seven years of study (2002)(2003)(2004)(2005)(2006)(2007)(2008), only 5 (0.25%) out of 1978 tested samples violated the Brazilian law. However, even with low levels of violation, monitoring is essential, since the number of samples with residues was often greater than the number of violations, and in some cases, such as cadmium in the kidneys, the majority of samples contained quantifiable residues and with levels often near the limits. INTRODUCTIONAmong the obstacles currently faced by the Brazilian meat industry, one of the most concerning problems is, undoubtedly, the potential presence of residues in animal tissues, giving emphasis to toxic metals. Moreover, cadmium, arsenic and lead stand out as the main inorganic pollutants present in products of animal origin.The presence of heavy metals in tissues and products of animal origin might be a result of a natural occurrence of those elements in the soil, as well as harmful industrial activity, which causes environmental contamination. These substances have a diverse toxicity degree. Hence, the analysis of these residues is of vital importance, aiming to obtain information on the regional levels. Eventually, such data will allow the identification of areas of environmental pollution (WHO, 2007).Heavy metals constitute the greatest source of inorganic pollutant that affects soil and water, being introduced into the atmosphere mainly through fertilizers, pesticides, combustion of coal and oil, vehicular emissions, mining, fo...