Table Of ContentFOOD CONTAMINANTS
Sources and Surveillance
Food Contaminants
Sources and Surveillance
Edited by
Colin Creaser
University of East Anglia, Norwich
and
Rupert Purchase
British Industrial Biological Research Association, Carshalton,
Surrey
WOODHEAD
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First published by The Royal Society of Chemistry 1991
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Preface
This book contains contributions based on the proceedings of two symposia
on food contamination held in London in April 1989 and May 1990, both
of which were organized jointly by the Environment, Food Chemistry, and
Toxicology Groups of the Royal Society of Chemistry.
The aim of these meetings was to assess the extraneous chemical
contamination of food from two sources: firstly, food-chain contaminants -
the presence of plant toxicants or fungal metabolites in food, or the
contamination of food from environmental sources (airborne, aquatic, and
terrestrial); secondly, food-production contaminants - contaminants of
man-made origin brought about by a desire to facilitate food production
and distribution.
The surveillance of food contaminants through analytical and toxico-
logical investigations has stimulated public awareness, and in turn has led
to changes in the control of these substances by the legislators. Important
as these issues are, they should be placed in the broader context of food
hazards in general. A list of hazards associated with food drawn up by the
FDA in the United States, and reiterated by the late Professor Leon
Golberg, a pioneer of toxicology both in the UK and the USA (Chern.
Znd. (London), 1982, 354), is as follows (in decreasing order of import-
ance): food-borne disease of microbial origin, malnutrition, environmental
contaminants, toxic normal constituents of food, pesticide residues, and
food additives. It is through the vigilance of the agriculture and food
industries and legislative bodies that contamination problems of all these
types are comparatively rare.
The contributions in this volume concentrate on the contamination of
food by chemicals arising from environmental and food-production sources.
Chapter 1 is concerned with food-chain contaminants present in food as
natural components of the diet. This is followed by discussion of the
chlorinated dioxins and furans (Chapter 2), and polycyclic aromatic hydro-
carbons (Chapter 3). After an introduction to the control and surveillance
of food-production contaminants (Chapter 4), four areas of activity are
described: migration from food contact materials with particular reference
to plastics (Chapters 5 and 6), the regulatory control and analysis of
V
vi Preface
veterinary products (Chapters 7 and 8 respectively), the analysis of
pesticides in drinking water (Chapter 9), and finally the problem of food
taints (Chapter 10).
We thank our colleagues from the RSC subject groups for their
contribution to the organization of the two symposia which led to the
publication of this book: Dr. David Henshall, Dr. Robert Massey, Dr.
Martin Shepherd, and Dr. David Taylor.
Colin Creaser and Rupert Purchase
March 1991
Contents
Chapter 1 Natural Toxicants in Food
Jenny A. Lewis and G. Roger Fenwick 1
Chapter 2 Polychlorinated Dibenzo-p-dioxins, Polychlorinated
Dibenzofurans, and the Food Chain
James R. Startin 21
Chapter 3 Analysis and Occurrence of Polycyclic Aromatic
Hydrocarbons in Food
Keith D. Bartle 41
Chapter 4 Food Production Contaminants: Control and Surveillance
Jonathan R. Bell and David H. Watson 61
Chapter 5 Toxicology and Regulatory Control of Components of
Food Contact Plastics
Rupert Purchase 73
Chapter 6 Contaminants from Food Contact Materials:
Analytical Aspects
John Gilbert 85
Chapter 7 Use and Regulatory Control of Veterinary Drugs in
Food Production
Kevin N. Woodward 99
Chapter 8 Analysis of Veterinary Drug Residues in Edible
Animal Products
Martin J. Shepherd 109
Chapter 9 Analysis of Pesticides at Low Levels in Drinking Water
Keith M. Moore 177
Chapter 10 Unwanted Flavours in Food
J. David Henshall 191
Subject Index 20 1
vii
Contributors
Keith D. Bartle, School of Chemistry, University of Leeds, Leeh LS2 9JT,
UK
Jonathan R. Bell, Ministry of Agriculture, Fisheries and Food, 17 Smith
Square, London SWlP 3JR, UK
G. Roger Fenwick, AFRC Institute of Food Research, Colney Lane,
Norwich NR4 7UA, UK
John Gilbert, Ministry of Agriculture, Fisheries and Food, Food Science
Laboratory, Colney Lane, Norwich NR4 7UQ, UK
J. David Henshall, Campden Food and Drink Research Association,
Chipping Campden, Gloucestershire GL55 6LD, UK
Jenny A. Lewis, AFRC Institute of Food Research, Colney Lane, Norwich
NR4 7UA, UK
Keith M. Moore, Water Research Centre plc, ffenley Road, Medmenham,
Marlow, Buckinghamshire SL7 2HD, UK
Rupert Purchase, The British Industrial Biological Research Association,
Woodmansterne Road, Carshalton, Surrey SM5 4DS, UK
Martin J. Shepherd, Ministry of Agriculture, Fisheries and Food, Food
Science Laboratory, Colney Lane, Norwich NR4 7UQ, UK
James R. Startin, Ministry of Agriculture, Fisheries and Food, Food
Science Laboratory, Colney Lane, Norwich NR4 7UQ, UK
David H. Watson, Ministry of Agriculture, Fisheries and Food, 17 Smith
Square, London SWlP 3JR, UK
Kevin N. Woodward, Veterinary Medicines Directorate, Woodham Lane,
New Haw, Weybridge, Surrey KT1.5 3NB, UK
viii
CHAPTER 1
Natural Toxicants in Food
JENNY A. LEWIS AND G. ROGER FENWICK
1 Introduction
The maintenance of the safety of the food supply is an essential function of
the state. The food industry has a statutory obligation to provide safe,
wholesome food for its customers but it is the duty of government to
ensure that satisfactory methods and understanding exist to fulfil this
obligation. As has become all too apparent in the UK recently, when
agricultural products cannot be sold by virtue of the presence of recognized
hazards, producers lose income, trade is damaged, and consumers are
justifiably concerned. Public awareness of the importance of safe, highly
nutritious food has never been higher, and consumers are actively seeking
factual information and reassurance about the safety of their diets and of
the individual foods they consume. Such concern and interest is to be
welcomed, even at the expense of the sometimes ill-informed, and fre-
quently emotional, arguments which can develop as a consequence.
Much public concern has been focused on chemicals in the food chain,
be these agrochemicals, post-harvest dips or sprays, recognized and ap-
proved additives, environmental contaminants, or adulterants. There has,
in comparison, been much less attention paid to potentially harmful
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chemicals which occur naturally in our diet as a consequence of their
presence in plants used as foods and animal feeding stuffs. Such com-
pounds, usually termed natural toxicants, are the subject of this chapter.
Serious health problems due to natural toxicants are not new; indeed one
such episode is described in the Book of Numbers, Ch. 11, w. 31-33.
Another, admittedly extreme, example from history was the periodic
flare-up of ergotism. This occurred for over a thousand years and into the
present century, claiming many hundreds of thousands of victims. It is now
recognized that the causes of the epidemics were the naturally occurring
alkaloids produced by the rye fungus, Claviceps purpurea, and it is
interesting to note that the diminution of the problem was not a conse-
quence of any public or domestic health measures, but rather a change in
social and agricultural practice with the potato replacing rye as a staple of
the European diet.
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