Assessment of heavy metal residues in Brazilian poultry and swine tissue

The 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 (2002-2008), 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.