Food and Nutrition Sciences, 2013, 4, 10-13
http://dx.doi.org/10.4236/fns.2013.47A002 Published Online July 2013 (http://www.scirp.org/journal/fns)
Risk Assessment for Metals and PAHs by Mediterranean
Seafood
Chiara Copat1, Gea Oliveri Conti1*, Carlo Signorelli2, Sandra Marmiroli3, Salvatore Sciacca1,
Marco Vinceti4, Margherita Ferrante1
1Department G.F. Ingrassia-Hygiene and Public Health, University of Catania, Catania, Italy; 2Department of Public Health, Univer-
sity of Parma, Parma, Italy; 3Department of Surgery, Medicine, Odontoiatrics and Morphological Sciences, University of Modena
and Reggio Emilia, Modena, Italy; 4Department of Diagnostic and Clinical Medicine and of Public Health, University of Modena and
Reggio Emilia, Modena, Italy.
Received March 18th, 2013; revised April 19th, 2013; accepted April 29th, 2013
Copyright © 2013 Chiara Copat et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
Fish is a very important food because of its high nutritional value. Fish consumption is largely recommended in all
countries, so quality and safety of seafood are becoming of great concern. Especially in Mediterranean Sea, where many
pollutants, as metals and Polycyclic Aromatic Hydrocarbons (PAHs), are often relieved also in high concentrations,
seafood safety has to be checked by a methodologically rigorous risk assessment. So we propose in this paper a stages-
risk assessment methodology to estimate the seafood potential risk for human health and point-out critical topics in or-
der to support fish advisories.
Keywords: Risk Assessment; Seafood Safety; Contamination; Sea Environment; Metals; Polycyclic Aromatic
Hydrocarbons
1. Introduction
Fish is a very important food because its high nutritional
value [1-3] and his consumption is largely recommended
in all countries [4,5]. Thus, safety of seafood is becoming
of great concern, to better characterize balance between
benefits and risks due to ingestion of chemical contami-
nants [6].
Toxic chemicals released to the environment from
point sources such as industrial and municipal discharges
and from nonpoint sources such as agricultural runoff
and atmospheric deposition have contaminated surface
waters and their sediments across [7].
Many chemical pollutants are concentrated in fish and
shellfish by accumulating in fatty tissues or selectively
binding to fish muscle tissue (the fillet) in relation to
waterborne and dietary exposure [8-11]. Even extremely
low concentrations of bioaccumulative pollutants de-
tected in water or bottom sediments may result in marine
plants [12], fish or shellfish tissue concentrations high
enough to pose health risks to fish consumers. Lipophilic
contaminants, particularly certain organochlorine com-
pounds, tend to accumulate in the fatty tissues of fish.
Consequently, fish species with a higher fat content, such
as carp, bluefish, some species of salmon, and catfish,
may pose greater risks from some contaminants than
leaner fish such as bass, sunfish, and yellow perch. Al-
though exposure to some contaminants may be reduced
by removing the fat, skin, and viscera before the fish is
eaten, other contaminants, such as methylmercury, are
accumulated in the muscle tissue of the fillet and there-
fore cannot be removed by trimming. In addition, some
fish are consumed whole or are used whole in the prepa-
ration of fish stock for soups and other foods. Under
these conditions, the entire body burden of bioaccumula-
tive contaminants contained in the fish would be ingested
by the consumer [13].
Mediterranean Sea has limited water exchange with the
open seas, and many pollutants, such as metals and poly-
cyclic aromatic hydrocarbons (PAHs), are often relieved
also in high concentrations for the combined effect of an-
thropic and natural origin, the last caused by submarine
volcanic emission characteristic of the area [14,15].
Thus, this sea is thus sensitive to the build-up of pol-
lutants that may cause a progressive degradation of the
*Corresponding author.

Risk Assessment for Metals and PAHs by Mediterranean Seafood 11
marine ecosystem [16,17] and seafood safety has to be
checked by a methodologically rigorous risk assessment.
So we propose in this paper a stages-risk assessment
methodology to estimate the potential and real risk for
human health derived from seafood consumption in order
to support fish advisories.
2. Materials and Methods
For risk assessment to estimate the potential and real risk
for human health derived from seafood consumption first
of all, it must been identify specific chronic and acute
health effects of the metals and PAHs chosen for the risk
assessment, proceeding with performing the extraction of
the selected contaminants from fish and shellfish tissues.
To date, according with the most appropriate tech-
nique in use, metals analysis must be carried on by ICP-
MS technique coupled with an LC pump for the element
speciation, and for PAHs by HPLC-UV/FL or GC-MS.
Samples must be processed together with a certified ref-
erence material to validate the analysis. Alternatively, it
should be spiked real samples to check the recovery for
each contaminant.
Furthermore, after dosage of pollutants, evaluates means
(ẍ) of metals (mg/Kg w.w.) and PAHs (µg/Kg w.w.),
standard deviation (SD) and analysis of variance with al-
most the minimum level of significance fixed at p < 0.05.
For the risk assessment it must be applied Environ-
mental Protection Agency methodology [16-19] settled
to standardize advisory consumption recommendations
for minimizing the risk of both cancer and non-cancer
endpoints due to the consumption of fish.
For the potential risk assessment, all consumption rate
and risk factors should be calculated assumed for adults
an ingestion rate of 227 g (meal size) and a body weight
(BW) of 70 Kg [19], and for child of six years old a in-
gestion rate of 114 g and a BW of 16 Kg [20].
For the real risk assessment, a validate questionnaires
should be provided to local population to obtain real data
on the seafood consumption frequency, the ingestion rate
(substitutive of the assumed meal size), the body weight
and the age classes.
Additionally, based on the US-EPA guidance [21], we
assume that the ingestion dose is equal to the adsorbed
contaminant dose and that cooking has no effect on the
contaminants [22].
For a preliminary investigation, the estimated daily in-
take (EDI) according to the equation reported in previous
reports [8,9] should be calculated:

EDIIR CBW
where IR is the ingestion rate daily or meal size, C is the
metal concentratio (mg/kg w.w.); BW is the body weight.
All consumption rates after calculation can be com-
pared with daily and weekly tolerable intake (TI) levels
suggested by the World Health Organization for specific
contaminants. If no speciation was carried out Food and
Drug Administration (FDA) gives values in % for inor-
ganic and organic forms of metals.
According to the guideline of the United State Envi-
ronmental Protection Agency [21] and based on the US-
EPA guidance [16], it is possible proceeding to calculate
other risk factors.
Target Hazard Quotient (THQ), indicate the ratio be-
tween exposure and the reference dose, and calculations
have to be made using the standard assumption for an
integrate US-EPA risk analysis.

 
THQEFEDIR CRfDoBWAT 
EF is the exposure frequency (350 days/year for people
that eat fish 7 times a week); ED is the exposure duration
(adults, 70 years; child, 6 years); IR is the food ingestion
rate; C is the metal concentration in fish (µg/g, wet
weight); RfDo is the oral reference dose (µg/g/day); BW
is the body weight; AT is the averaging time (it is equal
to EF × ED). If THQ risk is above 1, value considered by
the US-EPA, it is assumed as an acceptable risk for
chronic systemic effects.
Then Incremental lifetime cancer risk (ILCR) for es-
timate the potential carcinogen risk associated with ex-
posure at measured dose of pollutant must be obtained by
using the Cancer Slope Factor (CSF) or Unit Risk in the
following equation [18]:

 
I
LCREFEDIR C CSFBWAT 
where CSF is the daily dose (µg/g/day) set by US-EPA
only for inorganic As. If ILCR risk is above the 10−5 val-
ue considered by the US-EPA, it is assumed as an accept-
able risk for cancer and the risk assessment should either
be refined and/or risk management measures should be
taken.
As suggested by US-EPA, the allowable number of
fish meals of a specific meal size that may be consumed
oven a given period of time should be also evaluated.
For carcinogenic effects, US-EPA provides the equa-
tion to calculate maximum allowable fish consumption
rate (CRmwc) meals/week expected to generate a risk no
greater than the maximum acceptable individual lifetime
risk (ARL), considered to be 1 in 100,000 for almost
studies.
Firstly it must be calculated the allowable daily con-
sumption (CRdc) of contaminated fish, that represents
the amount of fish (in kilograms) expected to generate a
risk no greater than the maximum ARL used.
A
RL BW
CRdc CSF Cm


To calculate weekly fish meal consumption limits, the
previous equation is modified as follows:

Risk Assessment for Metals and PAHs by Mediterranean Seafood 12
CRdc Tap
CRmwc MS


where MS is the daily ingestion rate or meal size and Tap
is the time averaging period (7 days/week).
For non-carcinogenic effects, the maximum allowable
fish consumption rate (CRmmr) meals/week that would
not be expected to cause adverse non-carcinogenic health
effects, is also provided by US-EPA.
Firstly it must be calculated the maximum lifetime
daily consumption rate (CRdr) (in kilograms of fish) that
would not be expected to cause adverse non-carcinogenic
health effects
RfDo BW
CRdr Cm


Then, the CRdr equation is modified as the previous
for the calculations of consumption rate meal/week
(CRmwr).
3. Discussion and Conclusions
Supporting a unique guide for the risk assessment result-
ing from consumption of contaminated seafood is basilar
for a common risk prevention and management plan.
Toxicity of some metals and PAHs is known, but, to
date, there isn’t regulatory limit for all hazard substance
in food. For example, the European Regulation 1881/
2006 [23] sets a threshold only for Cd, Pb, Hg, and benzo
(A) pyrene, but the World Health Organizations, the En-
vironmental Protection Agency and others international
organizations have suggested tolerable ingestion rates
such as tolerable intake, reference dose and cancer slope
factor applicable to a large numbers of pollutants. The
Evaluations of the Joint FAO/WHO Expert Committee
on Food Additives (JECFA) online database and the
EPA’s Integrate Risk Information System (IRIS) provide
the above mentioned doses. For a comprehensive risk
assessment of fish intake, also other elements such as the
metalloid selenium, which is of both nutritional and toxi-
cological interest and whose safe range of intake has still
not been clearly defined [24], should be considered.
Most RfDo are based on chronic exposure studies. Be-
cause the contaminant concentrations required to produce
chronic health effects are generally lower than those
causing acute health effects, the use of chronic RfDo in
developing consumption limits is expected to also protect
consumers against acute health effects. CSFs are instead
based on carcinogenic exposure studies.
Regarding consumption limits for PAHs, EPA’s Inte-
grated Risk Information System (IRIS) provides informa-
tion on a cancer slope factor only for benzo (A) pyrene,
which is considered as probable human carcinogen
(group B2) based on sufficient evidence of carcinogenic-
ity in animals. Furthermore, EPA considers that total
PAHs have the same cancer slope factor as BaP.
Among metals, only as have a settled CSF. Although
the role of As is not clear, it has been proposed that the
As mediated intracellular biosynthesis of reactive oxygen
species (ROS) such as free radicals (particularly H2O2),
may be implied in the carcinogenic process induced by
As via DNA damage [25,26]. Many studies support the
correlation between inorganic as exposure and cancer in
the skin, lung, bladder or kidney [25-30].
For a valid risk assessment is very important to obtain
more laboratory results, such as in vivo exposure to pol-
lutants and environmental monitoring, in quality to ob-
tain further data and applied validate risk factors equa-
tions to a larger number of contaminants.
Thus, this investigated issue should be studied further
in the future, to get missing data on cancer slope factor as
well as on reference doses and a better comprehension of
seafood safety.
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