Peter Cressey

Environmental Science & Research | ESR · Department of Environmental Health

Recent epidemiological studies have reported associations between colorectal cancer incidence and nitrates in drinking-water, but not from the diet. The toxicokinetics of nitrates were reviewed and exposure data from New Zealand were analysed. Dietary (including drinking-water) exposure of New Zealanders to nitrates was found to be very similar to...

Fish (n = 281) of six species, caught in New Zealand waters, were analysed for total mercury (t-Hg), methylmercury (MeHg) and the long-chain polyunsaturated fatty acids, eicosapentanoic acid (EPA) and docosahexaenoic acid (DHA). Mean t-Hg and MeHg concentrations for the six species were in the range 0.06–0.53 mg/kg and 0.06–0.46 mg/kg, respectively...

Rome, 19-23 November 2018, Food Safety and Quality Series, 9

Objectives: To estimate the proportions of human cases of nine specific microbial diseases in New Zealand that were due to transmission by food and the proportion of the foodborne burden that was due to transmission by some specific foods. Materials and Methods: Subjective probability distributions were elicited from 10 food safety experts using a...

Risk assessments for pesticide and veterinary drug residues in food are performed respectively by the Joint FAO/WHO Expert Meeting on Pesticide Residues (JMPR) and the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The models used by the two Committees to assess chronic dietary exposure are based on different data and assumptions which m...

Potential toxicity of cyanogenic glycosides arises from enzymatic degradation to produce hydrogen cyanide. Information on the metabolism of cyanogenic glycosides is available from in vitro, animal and human studies. In the absence of β-glucosidase enzymes from the source plant material, two processes appear to contribute to the production of cyanid...

Microbial contamination of fresh produce (fresh fruits and vegetables) poses serious public health concerns worldwide. This study was conducted as a comprehensive analysis of biological hazards in the global fresh produce chain. Data about produce-related outbreaks and illness were collected from the annual reports and databases of foodborne outbre...

Sterigmatocystin is a toxic fungal secondary metabolite (mycotoxin) that has been reliably reported to be produced by many phylogenetically and phenotypically different fungal genera, including more than two dozen species each of Aspergillus and Emercella and one or more species of Bipolaris, Botryotrichum, Chaetomium (Botryotrichum, Humicola), Moe...

Polychlorinated biphenyls (PCBs) are chemically stable aromatic chlorinated hydrocarbons. They were first produced commercially around 1930 and for the next 5 decades found a wide range of industrial applications as a result of their physicochemical properties of low electrical conductance, fire resistance, resistance to thermal breakdown and chemi...

From the New Zealand perspective. Available on the MPI website.

Available on the NZ MPI website. The risk profile is written from the NZ perspective.

Available of the NZ MPI website

Avialable on the NZ MPI website.

Risk profile written from the New Zealand perspective. Available form the NZ MPI website.

Risk profile from the NZ perspective, available on the MPI website

The impact of caffeine from energy drinks occurs against a background exposure from naturally occurring caffeine (coffee, tea, cocoa and foods containing these ingredients) and caffeinated beverages (kola type soft drinks). Background caffeine exposure, excluding energy drinks, was assessed for six New Zealand population groups aged 15 years and ov...

Aflatoxin concentration data for a range of foods available in New Zealand (maize products, nuts and nut products, dried fruits and spices) were combined with dietary recall food consumption information from New Zealand national nutrition surveys to derive exposure estimates for a range of age-gender groups. Mean exposure estimates for total aflato...

Two distinct immunologically-mediated diseases, Coeliac disease and wheat allergy, are associated with ingestion of proteins from wheat and some related cereals. Both conditions are usually managed by adherence to a gluten-free (GE) diet. Two methods for detecting gluten protein were compared: enzyme-linked immunosorbent assay (ELISA) and liquid ch...

Cyanogenic glycosides occur in a wide range of plant species. The potential toxicity of cyanogenic glycosides arises from enzymatic degradation to produce hydrogen cyanide, which may result in acute cyanide poisoning and has also been implicated in the aetiology of several chronic diseases. One hundred retail foods were sampled and analysed for the...

The potential effects of four interventions to improve iodine intakes of six New Zealand population groups are assessed. A model was developed to estimate iodine intake when (i) bread is manufactured with or without iodized salt, (ii) recommended foods are consumed to augment iodine intake, (iii) iodine supplementation as recommended for pregnant w...

A survey of the fluoride content of infant and toddler formulae available on the New Zealand market was conducted. Results were used to estimate the dietary fluoride intake for a fully formula-fed infant. Infant and toddler formulae were prepared according to manufacturers' instructions with fluoride-free water and analyzed for fluoride by a modifi...

Existing fluoride concentration and consumption data were used to estimate fluoride intakes from the diet and toothpaste use, for New Zealand subpopulations, to identify any population groups at risk of high-fluoride intake. For each sub-population, two separate dietary intake estimates were made--one based on a non-fluoridated water supply (fluori...

Priority setting for food safety management at a national level requires risks to be ranked according to defined criteria. In this study, two approaches (disability-adjusted life years (DALYs) and cost of illness (COI)) were used to generate estimates of the burden of disease for certain potentially foodborne diseases (campylobacteriosis, salmonell...

A study was carried out to determine the prevalence and concentrations of pesticide residues in conventionally grown and organic produce (bananas, broccoli, grapes, lettuce, potatoes, tomatoes, wine). Sampling was stratified, with organic produce being over-sampled, when available. All food samples were analysed, as received, by a multi-residue pes...

Thirty foods assessed as being the likely major contributors to dietary preservative exposure were purchased, prepared as normally consumed and analyzed for sulfite, sorbate and benzoate. The majority of preservative concentrations (>98%) were within maximum permitted levels (MPLs) specified in the Australia New Zealand Food Standards Code. Mean po...

In 2002 New Zealand and Australia initiated a joint food regulatory approach, codified in the Australia New Zealand Food Standards Code. Prior to drafting of the joint Code a series of risk assessments were carried out by Food Standards Australia New Zealand (FSANZ; then Australia New Zealand Food Authority). This included a review of the maximum p...

Exposure to excess nitrite is a potential health risk for humans. One hundred meat and processed foods and 100 vegetable samples purchased from New Zealand retail outlets were prepared as for consumption and analysed for nitrite and nitrate concentration using a standard, validated methodology. Nitrate concentrations ranged from less than the limit...

We have measured the glycine betaine, proline betaine, trigonelline and dimethylsulphoniopropionate (DMSP) content of 74 predominantly processed foods. Combining these data with a previous survey (predominantly commodity based) and using data from the New Zealand National Nutrition Survey, the betaine intake in the average New Zealand diet has been...

This is a qualitative risk assessment.

Pesticide residues in various foods were assessed for the relative risk to the consumer. The analysis took into account criteria such as a pesticide's toxicity, usage, frequency of occurrence in foods, frequency of Maximum Residue Level (MRL) exceedances, and the overall risks of specific pesticide/food combinations. Examination of the top ten rank...

Published on the MPI website: http://www.foodsafety.govt.nz/elibrary/industry/Risk_Profile_Vibrio-Science_Research.pdf

Continuing evidence of the feminising effects of xenoestrogens on a range of wildlife species increases the need to assess the human health risk of these estrogen mimics. We have estimated the exposure of New Zealand males, females and young men to a range of naturally occurring and synthetic xenoestrogens found in food. Only estrogenic compounds t...

A survey of the pesticide content of 25 commercially available infant formulae and 30 weaning foods available in New Zealand was undertaken in 1996. It included a representative mixture of imported and New Zealand manufactured infant foods. Three different pesticide screening techniques were used: a high-sensitivity organochlorine screen was carrie...

New Zealand provides a naturally low-iodine environment. Estimates of New Zealanders’ iodine intakes suggest that intakes have decreased steadily during the 1980s and 1990s. This evidence combined with the reported decrease in the use of iodophors in the dairy industry prompted a review of the iodine content of New Zealand dairy products. Sixteen m...

Occurrence of pre-harvest wheat-bug damage to New Zealand wheats is documented. There have been five major outbreaks of damage since the problem was first reported in 1936 until the present time. In the worst outbreak (1970) about 10 000 tonnes of wheat was damaged. North Canterbury is the region most consistently affected and years in which seriou...

Insects of the species Nysius huttoni, Calocoris norvegicus, and Sidnia kinbergi were caged separately on plots of ‘Rongotea’ wheat at the watery ripe stage of grain development. S. kinbergi did not attack the grain in any detectable way. C. norvegicus attacked the grain producing pale circular marks on 40 – 45 grains per thousand. However, this at...

Reversed-phase high-performance liquid chromatography (RP-HPLC) was used to separate storage proteins (B and C hordeins) extracted from 22 New Zealand-grown barley cultivars. Fourteen of these could be uniquely identified by the hordein pattern revealed by RP-HPLC. Single seed analysis revealed two major biotypes for each of ‘Ark Royal’, ‘Kym’, and...

Lines of three varieties of New Zealand wheat (cv. Aotea, Oroua and Kopara) damaged by wheat-bug were investigated. Hydrolysis of gluten proteins was shown to be of the endo- rather than the exo-proteolytic type. Electrophoresis revealed that the bug protease had a high specificity for the high molecular weight (HMW) glutenin subunits. An autolytic...

Some properties of a glutenin hydrolysing enzyme present in bug ( Nysius huttoni ) damaged wheat ( Triticum aestivum ) were examined using a modified SDS sedimentation test reported previously. The enzyme appears to be a water‐soluble alkaline protease with an activity optimum at pH 9.0. It is relatively heat stable, but the temperature optimum for...

Hexaploid derivatives of wild emmer wheat (Triticum dicoccoides Koern.) were examined by electrophoresis for high molecular weight (HMW) glutenin subunits and for gliadin composition from 10 days after anthesis to full maturity. Two established bread wheats were included in the investigation for comparison. No outstanding or consistent differences...

Hexaploid derivatives of wild emmer wheat (Triticum dicoccoides Koern.) developed at the Volcani Research Center, Israel, were grown at Lincoln, New Zealand and tested for a number of milling and baking quality parameters and for gliadin and high molecular weight (HMW) glutenin protein composition. The average protein content of most of the derivat...

The reactions of two fulvic acid samples with Cu2+ and Cd2+ have been studied by potentiometric titration (pH and ion selective electrode). The metal-uptake curves for samples initially rendered ‘metal-free’ by a precipitation-solvent extraction technique resemble those for citric and malic acids at soil pH (4–6.5). The presence of aliphatic and ar...