Pesticide residues in conventionally grown and organic New Zealand produce.

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 pesticide residue screen. Residues were found in 130 of 307 conventionally grown food samples (42%) and in nine of 41 organic food samples (22%), including six of eleven (55%) organic tomato samples. Only four organic samples (9.8%) contained multiple residues, while 24% of conventionally grown food samples contained multiple residues. Nine conventionally grown food samples (2.6%) contained pesticide residues that exceeded the maximum residue limit (MRL). Where direct comparisons were possible between conventionally grown and organic produce, the mean concentration of residues was usually lower in the organic produce, but was generally higher than would be expected from spray drift or other adventitious sources. While the presence of these residues does not represent a significant risk to human health, their presence is inconsistent with consumer expectations for organic produce.

Pesticide content of infant formulae and weaning foods available in New Zealand.

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 carried out on all infant formulae, while a multiresidue screen (organochlorine and organophosphorus pesticides, synthetic pyrethroids, carbamate pesticides, fungicides and herbicides), and a specific screen for dithiocarbamate fungicides were both carried out on all weaning foods and on soy-based infant formulae. All results are expressed on a ready-to-feed basis. Extremely low levels of residues of three organochlorine compounds (p,p'-DDE, p,p'-DDT and dieldrin) were detected in infant formulae samples. Residues of p,p'-DDE were found in seven of 20 milk-based infant formulae at concentrations ranging from 0.03 to 0.5 microgram kg(-1). Residues of p,p'-DDT were found in one imported milk-based infant formula at 0.7 microgram kg(-1), and dieldrin residues were detected in four of five soy-based infant formulae at concentrations ranging from 0.05 to 0.08 microgram kg(-1). The multiresidue pesticide screen detected low levels of residues of two organophosphorus pesticides; azinphos-methyl in one soy-based infant formula at a level of 22 microgram kg(-1) and pirimiphos-methyl in two cereal-based weaning foods at concentrations of 5 and 14 microgram kg(-1). None of the other approximately 140 pesticides (including fungicides and herbicides) included in the multiresidue screen were detected in any weaning foods or soy-based infant formulae, at a detection limit of 10 microgram kg(-1). No residues of dithiocarbamate fungicides were detected in any product analysed, at a detection limit of 100 microgram kg(-1).