A total diet survey of pesticide residues and contaminants
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The Australia New Zealand Food Authority (ANZFA) became Food Standards Australia New Zealand (FSANZ) on 1 July, 2002. Food Standards Australia New Zealand is a bi-national statutory authority that develops food standards for composition, labelling and contaminants, including microbiological limits, that apply to all foods produced or imported for sale in Australia and New Zealand.
The primary role of Food Standards Australia New Zealand, in collaboration with others, is to protect the health and safety of Australians and New Zealanders through the maintenance of a safe food supply. Monitoring the food supply for pesticide residues, contaminants and other substances  is conducted in both Australia and New Zealand. In Australia, this monitoring was conducted by ANZFA (and now by FSANZ) and in New Zealand, by the Ministry of Health (and from 1 July 2002, by the New Zealand Food Safety Authority (NZFSA)).
FSANZ monitors the food supply to ensure that existing food regulatory measures provide adequate protection of consumer health and safety. The Australian Total Diet Survey (ATDS) is part of that monitoring. It was previously named the Australian Market Basket Survey (AMBS). A total diet survey is also conducted in New Zealand and the New Zealand Ministry of Health have been responsible for administering that survey. Future surveys in New Zealand will be administered by the NZFSA.
The purpose of the ATDS is to estimate the level of dietary exposure of the Australian population to a range of pesticide residues, contaminants and other substances that can be found in the food supply. Dietary exposure is the intake of pesticide residues, contaminants and other substances from foods consumed. In the ATDS, dietary exposure is estimated by determining the level of the substance in foods by direct analysis, and then multiplying this by the amount of food consumed, as determined in a separate study. In order to achieve more accurate dietary exposure estimates, the foods examined in the ATDS were prepared to a ‘table ready’ state before they were analysed. As a consequence, both raw and cooked foods were examined.
ANZFA coordinated the survey while the States and Northern Territory purchased and prepared the food samples. The Australian Government Analytical Laboratories (AGAL) carried out all analyses.
Sixty-five types of foods representative of the Australian diet were tested for pesticide residues, contaminants and other substances from foods sampled during July and November 2000 and February and April 2001. These food types incorporate foods central to the Australian diet (core foods), foods that might be expected to show regional variation of residue, contaminant or other substance levels (regional foods), and foods that are available nationwide and are not expected to show regional variation (national foods). These food types were sampled in each of the States and the Northern Territory and some were sampled at four different times throughout the year.
All foods were screened for pesticide residues, including chlorinated organic pesticides, organophosphorus pesticides, synthetic pyrethroids, carbamates and fungicides; as well as antimony, arsenic, cadmium, copper, lead, mercury, selenium, tin and zinc. Breads, biscuits, rice, oats, processed wheat bran, breakfast cereals (including infant cereal), instant coffee, peanut butter, almonds and milk chocolate were tested for aflatoxins (B1, B2, G1 and G2) and ochratoxin A. A range of meats, dairy products, eggs, offal meat and infant formula were tested for inhibitory substances (penicillin G, streptomycin and oxytetracycline).
Dietary exposures to pesticide residues, contaminants and other substances were estimated for six age–gender groups. These age-gender groups were infants (9 months), toddlers (2 years), girls (12 years), boys (12 years), adult females (25-34 years), and adult males (25-34 years). Each food in the survey was chemically analysed to measure the levels of pesticide residues, contaminants and other substances. Representative age-gender groups were selected and individual diets for these groups were examined, based on food consumption data from the 1995 National Nutrition Survey (NNS). Dietary exposure to each pesticide residue and metal  was estimated using the food consumption data and the level of substance present in each food.
The estimated dietary exposure to each chemical from the Australian diet was compared to Australian health standards (Commonwealth Department of Health and Ageing, December 2001). In those cases where there were no Australian health standards, international health standards were used.
The key results from the survey are:
• The estimated dietary exposures to antimony, arsenic, cadmium, lead, mercury, copper, selenium, zinc and tin were within acceptable health standards. Analytical techniques with a lower limit of reporting for antimony and mercury were instituted for this survey and as a result a more refined dietary exposure estimate for these contaminants was achieved than in the 19th survey.
• Aflatoxins (B1, B2, G1 and G2) and ochratoxin A were not found in any food tested, namely: breads, biscuits, rice, oats, processed wheat bran, breakfast cereals (including infant cereal), instant coffee, peanut butter, almonds and milk chocolate.
• A range of meats, dairy products, eggs, offal meat and infant formula were tested for inhibitory substances (penicillin G, streptomycin and oxytetracycline). These substances were not detected in any of these foods.
• The estimated dietary exposures to pesticide residues were all within acceptable health standards.
In conclusion, the 20th ATDS, conducted between July 2000 and April 2001, confirms the overall safety of the Australian food supply and demonstrates that pesticide residues, metals, and selected antibiotics, aflatoxins and ochratoxins are either absent or present in low amounts.
It is recommended that:
• method development be undertaken to achieve lower LORs for antimony, arsenic, cadmium, lead and mercury. This would allow a more accurate and refined estimate of dietary exposure to be presented in future total diet surveys;
• in future surveys, tin analyses be focussed on canned foods;
• analyses of antimony, arsenic, cadmium, copper, lead, mercury, selenium and zinc, continue to be undertaken in future surveys so that dietary exposure assessments can be undertaken for these substances;
• future surveys should continue to monitor aflatoxins and ochratoxins but this should be targeted to specific foods where these toxins are more likely to be found;
• pesticide residues should continue to be monitored to determine dietary exposure to pesticide residues. Over a number of surveys, a large amount of data relating to pesticide residues has been collected, with the estimated dietary exposures to pesticide residues being well below that of the respective health standards (ADIs). As a consequence, it is recommended that monitoring of pesticide residues be undertaken at a lower frequency in future surveys;
• monitoring of pesticide residues in future total diet surveys should focus on those chemicals for which there are no recent data and should not be limited to those chemicals registered for use in Australia.
 The term “other substances” refers to aflatoxins B1, B2, G1 and G2, and ochratoxin A.
 The term “metals” has been used to encompass antimony, arsenic, cadmium, copper, lead, mercury, tin and zinc. Both arsenic and antimony are metalloids and selenium is a non-metal (Bentor 1996-2000) but are grouped with metals for simplicity.
Part A | Part B | Part C | Supplementary Information