Second quarter results released in December 2024
The New Zealand Total Diet Study (NZTDS) aims to evaluate the risk to New Zealanders from exposure to certain chemicals, such as agricultural chemicals, contaminants, and nutrients in a range of foods most commonly eaten in a typical diet.
The food, prepared as it would be consumed (for example, bananas are peeled and meat is cooked), is then tested for the presence and levels of the chemicals, an estimate of exposure for certain population groups is determined, and the risk is estimated through comparison against health-based guidance values.
The second quarter of the 2024 NZTDS included sampling and testing of 43 'regional' foods and ingredients, bought from Auckland, Palmerston North, Christchurch, and Dunedin food retailers from July to September 2024.
We tested the composite samples for a range of agricultural chemicals, contaminants (including packaging chemicals) and nutrients.
More information on the methodology can be found in the final project outline.
2024 New Zealand Total Diet Study (Infants and Toddlers) final project outline [PDF, 2.6 MB]
What we found
We conducted a total of 51,423 chemical tests analysing 362 chemicals in a total of 731 foods and ingredients.
A general element screen was done on all foods and ingredients, including for aluminium, antimony, arsenic (total), cadmium, iodine, iron, lead, mercury, selenium, sodium, thallium, and zinc. Foods and ingredients were selected for specific agricultural chemical and contaminant (including packaging chemicals) testing.
Of the 48,064 agricultural chemical tests conducted, 99.6% had levels below the limit of quantification (LOQ). Of the very small number of detections above the LOQ, none were of a food safety concern.
Of the heavy metal contaminants (arsenic [inorganic and total], cadmium, lead and mercury [total]), all were within regulatory standards and none exceeded historical normal ranges.
None of the bought foods tested contained the chemicals related to food packaging: bisphenols, per- and polyfluoroalkyl substances (PFAS), or the mycotoxin deoxynivalenol (DON).
Phthalates were found in less than 1% of the foods tested, and the concentrations found were significantly lower than from a previous survey.
Nutrient results were within levels that we would expect and are in line with previous NZTDS findings.
Detailed results by chemical groupings
- Agricultural chemicals 1 [XLSX, 2 MB]
Includes: a multi-residue screen covering a wide range of insecticides, fungicides, herbicides, and chemical groups such as organophosphates, organochlorines, triazoles, and neonicotinoids. - Agricultural chemicals 2 [XLSX, 235 KB]
Includes: a targeted multi-residue screen covering dithiocarbamate fungicides screen (expressed as CS2) and phenoxy, and aromatic acid herbicides. - Contaminants [XLSX, 370 KB]
Includes: aluminium, antimony, arsenic (total), arsenic (inorganic), bisphenols, cadmium, DON, lead, mercury (total), nitrates and nitrites, PFAS, phthalates, thallium, and tin. - Nutrients [XLSX, 139 KB]
Includes: Iodine, iron, selenium, sodium, and zinc.
Third quarter sampling began in October 2024
The third quarter sampling round started on 7 October and finished on 13 December 2024. Similar to the first quarter, we collected 73 national foods from the Auckland region. Testing is still underway.
Four quarters of sampling and testing are expected to be completed by May 2025. The full report, including the full dietary exposure assessment, will be published mid-2026.
