Food Protection Trends - January/February 2018 - 25

and McPherson (7) and Scanes and Roach (25) were based
on sampling of wild oysters, rather than oysters obtained
directly from commercial harvest areas.
The majority of heavy metal results reported in this study
were comparable to results in historical reports of heavy
metals in NSW shellfish. Variations in metal concentrations
to those reported in the study of Gifford et al. (13) may
be due to the smaller sample size and/or different species
(Pinctada imbricata, pearl oyster). The mean concentration
of Cu during the current study was higher than that recorded
by NSW Health (21), but similar to the concentration
reported Mackay et al. (17). The difference may be due to
the large variety of mollusc species sampled by NSW Health
(21) (Sydney rock oysters, pipis, squid, octopus, cuttlefish
and calamari) compared to Mackay et al. (17) and this study,
which focused primarily on oysters. Nielsen and Nathan (18)
found that C. gigas had a greater tendency to accumulate Cu
than other molluscs. The triennial data in the current study
found the lowest concentrations of Cu (< 1 mg kg-1) in cockle
and mussel samples.
CONCLUSIONS
Shellfish have long been used as biological indicators
of contamination (23), and their ability to accumulate
potential contaminants can give an indication of the

overall health of a water body. This study provides a longterm assessment of potential metal contaminants over a
fifteen-year period. The concentrations of heavy metals in
shellfish farmed along the NSW coast were generally low.
All samples tested in the current study were found to be
compliant with the FSC, with maximum concentrations
of inorganic As, Cd, Pb and Hg being less than the MLs
specified for bivalve molluscs. The dietary assessments
for Cu, Se and Zn demonstrated that these elements did
not represent a food safety risk. Further investigation into
concentrations of these elements pre- and post-depuration
may explain the elevated results observed in certain harvest
areas. Ongoing monitoring is necessary to ensure that
shellfish consumers are protected from any changing trends
in potential chemical contaminants.
ACKNOWLEDGMENTS
The authors thank local program coordinators from
NSW shellfish harvest areas for their assistance with
sample collection, acknowledge Amanda Cassidy (NSW
Food Authority) for helping with sample preparation, and
thank Alison Imlay (NSW Food Authority) for important
feedback on the revised manuscript. The authors appreciate
the constructive comments of three anonymous reviewers.

REFERENCES
1. Agency for Toxic Substances and Disease
Registry. 2003. Public health statement for
selenium. Available at https://www.atsdr.cdc.
gov/phs/phs.asp?id=151&tid=28. Accessed
16 May 2017.
2. Anonymous, 2015. Preliminary dietary
exposure assessment - commercial oysters
- Tilligerry Creek and Fullerton Cove,
Williamtown NSW. Available at http://www.
epa. nsw.gov.au/resources/epa/152670preliminary-assessment-commercialoysters-211015.pdf. Accessed 16 May 2017.
3. Australian Bureau of Statistics. 2016.
Australian demographic statistics, Sep 2016.
Available at http://www.abs.gov.au/ausstats/
abs@.nsf/mf/3101.0. Accessed 16 May 2017.
4. Australian Shellfish Quality Assurance
Advisory Committee. 2016. The
Australian Shellfish Quality Assurance
Program Operations manual. Available
at http://safefish.com.au/wp-content/
uploads/2016/07/Australian-ShellfishQuality-Assurance-Program-OperationsManual-2016.pdf. Accessed 16 May 2017.
5. Batley, G. E., M. S. Scammell, and C. I.
Brockbank. 1992. The impact of the banning
of tributyltin-based antifouling paints on the
Sydney rock oyster, Saccostrea commercialis.
Sci. Total Environ. 122:301-314.
6. Birch, G. F. 1996. Sediment-bound metallic
contaminants in Sydney's estuaries and
adjacent offshore, Australia. Estuar. Coast.
Shelf Sci. 42:31-44.

7. Brown, K. R., and R. G. McPherson.
1992. Concentrations of copper, zinc and
lead in the Sydney rock oyster, Saccostrea
commercialis (Iredale and Roughley) from the
Georges River, New South Wales Sci. Total
Environ. 126:27-33.

13. Gifford, S., H. Dunstan, W. O'Connor, and
G. R. Macfarlane. 2005. Quantification of in
situ nutrient and heavy metal remediation by
a small pearl oyster (Pinctada imbricata) farm
at Port Stephens, Australia. Marine Poll. Bull.
50:417-422.

8. Duffus, J. H. 2002. "Heavy metals" a
meaningless term? (IUPAC Technical
Report). Pure App. Chem. 74:793-807.

14. Hardiman, S., and B. Pearson. 1995. Heavy
metals, TBT and DDT in the Sydney rock
oyster (Saccostrea commercialis) sampled
from the Hawkesbury River estuary, NSW,
Australia. Marine Poll. Bull. 30:563-567.

9. European Food Safety Authority. 2015. Panel
on dietetic products, nutrition and allergies:
scientific opinion on dietary reference values
for copper. EFSA Journal. 13:4253.
10. Food Standards Australia New
Zealand. 2011. 23rd Australian total
diet survey. Available at http://www.
foodstandards.gov.au/publications/
Pages/23rdaustraliantotald5367.aspx.
Accessed 16 May 2017.
11. Food Standards Australia New Zealand.
2011. Mercury in fish. Available at http://
www.foodstandards.gov.au/consumer/
chemicals/mercury/Pages/default.aspx.
Accessed 16 May 2017.
12. Food Standards Australia New Zealand.
2016. Australia New Zealand Food
Standards Code. Available at http://www.
foodstandards.gov.au/code/Pages/default.
aspx. Accessed 16 May 2017.

15. Järup, L. 2003. Hazards of heavy metal
contamination. Br. Med. Bull. 68:167-182.
16. Joint Expert Committee on Food Additives.
2012. Joint FAO/WHO expert meeting on
dietary exposure assessment methodologies
for residues of veterinary drugs: final report
including report of stakeholder meeting.
Available at http://www.fao. org/fileadmin/
user_ upload/agns/pdf/jecfa/Dietary_
Exposure_Assessment_ Methodologies_
for_Residues_of_Veterinary_Drugs.pdf.
Accessed 16 May 2017.
17. Mackay, N. J., R. J. Williams, J. L. Kacprzac,
M. N. Kazacos, A. J. Collins, and E. H. Auty.
1975. Heavy metals in cultivated oysters
(Crassostrea commercialis = Saccostrea
cucullata) from estuaries of New South Wales.
Mar. Freshwater Res. 26:31-46.
18. Nielsen, S. A., and A. Nathan. 1975. Heavy
metal levels in New Zealand molluscs. New
Zeal. J. Mar. Fresh. 9:467-481.

January/February Food Protection Trends

https://www.atsdr.cdc.gov/phs/phs.asp?id=151&tid=28 https://www.atsdr.cdc.gov/phs/phs.asp?id=151&tid=28 http://www.epa.nsw.gov.au/resources/epa/152670-preliminary-assessment-commercial-oysters-211015.pdf http://www.epa.nsw.gov.au/resources/epa/152670-preliminary-assessment-commercial-oysters-211015.pdf http://www.epa.nsw.gov.au/resources/epa/152670-preliminary-assessment-commercial-oysters-211015.pdf http://www.abs.gov.au/ausstats/abs@.nsf/mf/3101.0 http://www.abs.gov.au/ausstats/abs@.nsf/mf/3101.0 http://www.foodstandards.gov.au/publications/Pages/23rdaustraliantotald5367.aspx http://www.foodstandards.gov.au/publications/Pages/23rdaustraliantotald5367.aspx http://www.fao.org/fileadmin/user_upload/agns/pdf/jecfa/Dietary_Exposure_Assessment_Methodologies_for_Residues_of_Veterinary_Drugs.pdf http://www.fao.org/fileadmin/user_upload/agns/pdf/jecfa/Dietary_Exposure_Assessment_Methodologies_for_Residues_of_Veterinary_Drugs.pdf http://safefish.com.au/wp-content/uploads/2016/07/Australian-Shellfish-Quality-Assurance-Program-Operations-Manual-2016.pdf http://www.foodstandards.gov.au/consumer/chemicals/mercury/Pages/default.aspx http://safefish.com.au/wp-content/uploads/2016/07/Australian-Shellfish-Quality-Assurance-Program-Operations-Manual-2016.pdf http://www.foodstandards.gov.au/consumer/chemicals/mercury/Pages/default.aspx http://safefish.com.au/wp-content/uploads/2016/07/Australian-Shellfish-Quality-Assurance-Program-Operations-Manual-2016.pdf http://www.foodstandards.gov.au/code/Pages/default.aspx http://www.foodstandards.gov.au/code/Pages/default.aspx http://www.foodstandards.gov.au/code/Pages/default.aspx

Table of Contents for the Digital Edition of Food Protection Trends - January/February 2018