contaminants in two populations of edible crab cancer pagurus: environmental and human health...

Contaminants in two populations of edible crab Cancer pagurus: environmental and human health implications

Bárbara TeixeiraAntónio MarquesMaria Luísa Carvalho

Sara Barrento

Paulo Vaz-PiresMaria Leonor Nunes

IPIMAR

WEFTA 2008 38th WEFTA Annual Meeting Florence, Italy. 17-19 September 2008

Sara Barrento : Contaminants in two populations of edible crab Cancer pagurus: environmental and human health implications WEFTA 2008 38th WEFTA Annual Meeting FLorence, Italy. 17-19 September 2008

Introduction Crustaceans Importance

Worldwide crustaceans are:

highly prized delicacies

highly profitable

Portugal:

8th biggest seafood consumer in the World

the live trade is of 3,000 tons (11 million euros)

crustaceans play a central role in gastronomy


Introduction

Crustaceans trade in Portugal

National production is insufficient importation

Portugal is the 13th biggest crustaceans importer countryCrustacean imports accounts for 88 % of the national trade


Introduction

Crustaceans trade in Portugal

Edible crab is the most popular crustacean species traded

live though there are no reports of national captures

Portuguese importations

1463

786

7

1

0 250 500 750 1000 1250 1500

UK

France

Spain

Ireland

Thousand tons

- Claw muscle, brown meat and gonads are delicacies - Males are more expensive


Introduction

Crustaceans and contaminants

Crustaceans are a good source of nutrients (amino acids, fatty acids and essential elements) and are very much publicized!

crustaceans, like seafood in general, can contribute to human exposure to chemical contaminants:

However...

AsCdHg Pb


Introduction

Crustaceans and contaminants

several studies reported the presence of contaminants in crustaceans

few combine the presence of contaminants in all edible tissues with risks to consumer, and none with edible crab

the accumulation of contaminants is affected by the habitat, tissue and sex


• Assess contaminants (As, Br, Sr, Cd, Hg and Pb) content in the edible tissues of two populations of Cancer pagurus

• Evaluate the environmental and human health implications

Aims


Muscle

Hepatopancreas

Gonads

Gills

Strategy

a) quantify and characterize the contents of:

AsBrSrCdHgPb

using EDXRF and FAAS techniques

Scotland

France

n = 20

n = 20


b) Compare the human intake of elements with:

Maximum Permissible Concentrations (MPC) set by the EC

Action Level (AL) set by the USFDA

Provisional Tolerable Daily Intakes (PTDI), 60 Kg adult, set by the (JECFA)

0.5

As PbCdHg

AL (ppm) – Crustacea

MPC (ppm) - crustaceans,

excluding brown meat of crab) (EC) No 1881/2006

PTDI (mg/day)

-

76

0.12

3

0.06

1.5

0.21

1

0.043

Strategy


Results Biological data

748 751

829977

0

200

400

600

800

1000

1200

F M F M

SC EC

8.5 11.9 9.810.4 10.2 9.2

10.3

77.5 76.5 77.8 72.3

16.30%

20%

40%

60%

80%

100%

F M F M

SC EC

Body weight 750-1000g

0%

20%

40%

60%

80%

100%

F M F M

SC EC

Shell

Gonads

Hepato

Muscle

have higher muscle meat yield

have higher gonads meat yield

Body weight (g) Yield (%)


Results and DiscussionArsenic dietary intake and health risks

010203040506070

SC EC SC EC SC EC SC EC

Muscle Hepato Gonads Gills

As

except in the gillsArsenic poses no risk to consumers

As

010203040506070



As

010203040506070



As

010203040506070



As

050

100150200250



Sr

F

M

EC have less As

[As]

ppm

None of the tissues exceeded the AL = 76 ppm

Though values exceeded PTDI (inorganic) = 0.12 mg

Only 1 % of seafood As is inorganic


Results and DiscussionBromine and strontium

0

100

200300

400

500



Br

but higher in the gills

higher [hepatopancreas]

Br

0

100

200300

400

500



Br

0

100

200300

400

500



Br

0

100

200300

400

500



Br

higher [hepatopancreas]

[Br]

ppm

050

100150200250



Sr

F

M

Sr

050

100150200250



Sr

050

100150200250



Sr

050

100150200250



Sr

050

100150200250



Sr

[Sr]

ppm


Results and DiscussionBromine and strontium

Bromine and Sr are typical in marine organisms

There is no information about Br essentiality or toxicity

However...

Sr might be important in bone metabolism

Still

There are no reccomendations


higher [hepatopancreas and muscle]

None of the tissues exceeded: MPC = 0.5 ppm AL = 1.0 ppm PTDI = 0.043 mg/d

Mercury poses no risk to consumers

Results and DiscussionMercury dietary intake and health risks

050

100150200250



Sr

F

M

EC have less Hg in all tissues

0.0

0.1

0.2

0.3



HgHg

[Hg]

ppm


• Pb in edible tissues was below DL (0.1 ppm)

0.00

0.10

0.20

0.30

0.40

SC EC

Gills

[Pb

] p

pm

050

100150200250



Sr

F

M

Lead poses no risk to consumers

Yet, in gills, male crabs had more Pb than females

EC > SCAL = 0.1 ppm

Results and DiscussionLead dietary intake and health risks


Cd

[Cd]

ppm

050

100150200250



Sr

F

M

Results and Discussion

Cadmium dietary intake and health risks

MPC = 0.5 ppm

AL = 3 ppm

Cd in the hepatopancreas is well above the MPC and the AL

The remaining tissues pose no risks to consumers


Results and DiscussionCadmium dietary intake and health risks (scenario I)

0.001-0.002 mg

1-2 mg

0.002-0.003 mg

Cadmium content

• Short-term exposure

Considering a meal of one edible crab (± 700 g):

100 g claw muscle

80 g hepatopancreas

10 g gonads

*PTDI = 0.06 mg/day

*NOAEL = 0.6 mg/day

Very high dose: risks for human health?Very high dose: risks for human health?



Cadmium dietary intake and health risks (scenario II)

•Long-term exposure (chronic)

1.6 g/d

1.3 g/d

0.16 g/d

g tissue/d [Cd/d]

0.03 g/d

0.04 mg/d

0.05 g/d

Limited risks for human health?Limited risks for human health?

Edible crab is not a major part of total diet

Considering a consumption of 6 crabs/persons/year

600 g claw muscle

480 g hepatopancreas

60 g gonads

g tissue/year

*PTDI = 0.06 mg/day

*NOAEL = 0.6 mg/day


Cadmium may accumulate in the human body and induce:

kidney dysfunction skeletal damage reproductive deficiencies cancer


Cadmium health risks

A diet low on protein, Zn, Ca, Cu, and Fe promote Cd absorption

On average, 5% of the Cd total oral intake is absorbed, but individual values range < 1% to > 20%

Adequate diet reduce Cd absorption and retention



Cadmium dietary intake and health risks

“the dose makes the poison”

80 g hepatopancreas *PTDI = 0.06 mg/d

*NOAEL = 0.6 mg/d

< 1095 g/year

< 3 g/day

[Cd] = 20 ppm

< 13 crabs/year

Still, and as a precautionary measure, hepatopancreas consumption should be avoided


Results and DiscussionEdible crab contaminant’s variability

• elemental composition of crabs differed according to capture origin and tissue

• The toxic elements’ composition depends on:

b) intake proportion

Physiology: age, sex, condition...

Bioavailability:

- season - location, - substrate, - depth, etc.

a) intake route

Seawater Food

• Gills are the main intake route for elements in seawater ( Br, Pb)

• Hepatopancreas is a detoxifying organ ( Cd, Sr, Hg)


Conclusions

The content of toxic elements in edible crab depends on location and tissues

Muscle and gonads are safe tissues in edible crab

Hepatopancreas has high Cd concentration and its consumption should be avoided

Br and Sr are abundant in edible crabs’ tissues and marine organisms in general; more studies are required to determine their degree of essentiality vs. toxicity to humans

HOWEVER...

More studies are needed to evaluate RfD in subcronical long-term and short-term exposure situations to Cd


Acknowledgements

Collective Research Project “CrustaSea: Development of best practice, grading and transportation technology in the crustacean fishery sector”, funded by the EC


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contaminants in two populations of edible crab cancer pagurus: environmental and human health...

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