Detection of Chemical Hazards 477the United Nations Environment Programme
as those persistent chemical substances that
can accumulate in foods and cause adverse
effects to consumers. Most of the organo-
chlorine pesticides were banned during the
1970s and 1980s, but they are persistent and
stable and may remain in the environment
for many years, constituting a risk of long -
term exposure (Moats 1994 ). These sub-
stances tend to be accumulated in the fatty
tissue of living organisms. Current maximum
residue limits in the EU for the organochlo-
ride pesticides that can be present in animal
products are within 0.02 and 1 mg/kg of fat,
while in the United States they are estab-
lished between 0.1 and 7 mg/kg fat (Iamiceli
et al. 2009 ).
The contaminants described above, as
well as polychlorinated biphenyls (PCBs) (a
family of 209 compounds that were used in
lubricating oils and heat exchange fl uids),
mycotoxins produced by molds and marine
toxins, and heavy metals, among others, can
be present in feeds used for farm animals.
The reasons for such contamination are
varied: use of contaminated ingredients, lack
of control of the ingredients, inadequate
processing, growth of molds in feed grains
and meals, etc. (Croubels et al. 2004 ).
Environmental contaminants are rather dif-
fi cult to control, even though they can exert
potential toxicity in the product (Heggum
2004 ). There are recent reviews on the
methods of analysis for the detection and
identifi cation of persistent organic pollutants
in meat (Iamiceli et al. 2009 ) and polychlo-
rinated byphenils in meat products (Garc í a -
Regueiro and Castellari 2009 ).References
Armenteros , M. , M. Heinonen , V. Ollilainen , F. Toldr á ,
and M. Est é vez. 2009. Analysis of protein carbonyls
in meat products by using the DNPH method, fl uores-
cence spectroscopy and liquid chromatography -
electrospray ionisation - mass spectrometry (LC - ESI -
MS). Meat Science 83 : 104 – 112.residue test samples (Croubels et al. 2004 ).
The FDA Center for Veterinary Medicine
issues the analytical criteria. The control of
residues of these substances in meats exported
to the European Union was further assured
by an Additional Testing Program designed
by the USDA (Croubels et al. 2004 ).
The detection of these substances is quite
complex due to the large number of samples
and the low levels of the substances to be
detected. The control is usually based on
screening tests like ELISA test kits, anti-
body - based automatic techniques, or chro-
matographic techniques (Reig and Toldr á
2008 ). In the case of antibiotics, microbio-
logical tests such as the European Four Plate
Test can be used. Screening tests are useful
because they are rapid, but they are unable to
confi rm the results because they can only
give qualitative or semiquantitative data. The
next step for suspicious samples (suspected
of being noncompliant) is a confi rmatory
analysis through gas or high performance
liquid chromatography coupled with mass
spectrometry or other sophisticated method-
ologies for accurate identifi cation and
con fi rmation of the substance (Toldr á and
Reig 2006 ). The description of methods of
analysis for the detection and identifi cation
of growth promoters and veterinary drug
residues in meat and meat products has
been recently reviewed (Reig and Toldr á
2009b, c ).
Environmental Contaminants
There are a wide variety of environmental
contaminants. The main concern is that they
may be present in the feeds consumed by
farm animals and thus contaminate the result-
ing meats. Some well - known contaminants
are dioxins, organophosphorous, and organo-
chlorine pesticides. These contaminants are
quite extensive worldwide, making their
control very diffi cult. The term “ persistent
organic pollutants ” (POPs) was defi ned by