BfR | Annual Report 2013
54
Heavy metals in offal of cattle and pigs
The liver and kidney of slaughtered animals contain a
higher concentration of heavy metals such as cadmium,
lead and mercury than is found in muscle meat. Although
livers and kidneys from cattle and pigs are eaten infre-
quently and in small quantities, it is still important to know
their heavy metal content for food safety purposes. As
there are currently only limited data available regarding
heavy metal contamination in older slaughtered animals,
the BfR carried out a pilot project in collaboration with
the German federal states and the Federal Office of Con-
sumer Protection and Food Safety. In this study, cattle and
pigs up to the age of two and older animals aged two and
above were examined. The aim was to find out whether a
higher concentration of heavy metals can be found in the
internal organs liver and kidneys of older animals.
The average content of lead, cadmium and mercury was
significantly higher in the organs of older slaughtered
animals than in the organs of younger pigs and cattle.
The maximum permissible levels in internal organs were
also exceeded more frequently in older animals than in
younger animals. While for lead 0.4 percent (%) of kid-
neys from older cattle exceeded the maximum levels, for
cadmium this was the case in 13 % of cattle kidneys and
8.9 % of pig kidneys. In contrast, the maximum cadmium
levels were exceeded in only 0.4 % of younger animals.
The maximum levels for mercury were exceeded in 18 %
of kidneys in older cattle and in 41 % of kidneys in older
pigs, whereas younger animals generally contained low-
er levels of mercury, with only 3 % measuring above the
maximum admissible level. In older animals, the levels of
the three heavy metals increased, with kidneys in par-
ticular exceeding the maximum levels.
Organs from animals which are over two years old can
generally be declared unfit for human consumption if the
animals come from regions contaminated by heavy met-
als. To find out whether heavy metal content in liver and
kidney differs from region to region, the BfR compared
their contamination in animals from three of the federal
states involved in the study. During the evaluation, new
statistical procedures were employed which also took
into account data below the limit of quantification and
the limit of detection. The results show that there are re-
gional differences concerning both average heavy metal
content and the number of times the maximum level was
exceeded. However, the data do not allow a uniform con-
clusion, suggesting that the federal states are too big
geographical entities for characterising different levels
of heavy metal contamination. The regions should be
differentiated into smaller administrative units for future
investigations.
What do these heavy metal levels mean for consumers?
An average consumption of liver and kidney from older
animals would result in a very low exposure correspond-
ing to less than 1 % of the tolerable weekly intake (TWI)
even if – as in this study – maximum levels of heavy metal
