SoE 2006 > Land > 4.7 Chemical contamination: food and produce

4.7 Chemical contamination: food and produce

National compliance with agreed food standards is high although chemical residues from pesticides above maximum residue limits are found in about 2.4% of targeted samples of NSW fresh fruit and vegetables. Dioxin levels in bottom-feeding fish and crustaceans in certain Sydney waterways can be traced back to leakage from historically contaminated land.

National compliance with agreed food residue standards is consistently very high. The complianace figures are slightly lower in NSW but are distorted by sampling methods which target produce with a history of residue presence. Incidents due to inappropriate management practices in the agricultural sector continue to cause occasional problems.

Surveys show that consumers' dietary exposure to food chemicals, including pesticides, is well below international and Australian reference standards.

NSW indicators

Introduction

Inappropriate or illegal chemicals used in farming and horticulture, and leakage from contaminated land can leave residues and contaminants in produce intended for human or animal consumption. Such residues include antibiotics, growth hormones, anthelmintics, fungicides, insecticides, herbicides and fumigants. Environmental contaminants include metals, mycotoxins and persistent organic pollutants (DAFF 2005).

Air pollution and poor quality irrigation water are also potential sources of contamination. Cadmium in agriculture is of particular concern. It can result from fertiliser and gypsum use and also from sewage sludge and manure (DPI 2005b) and may be mobilised as soils become more acidic.

Some chemicals, such as dioxins and heavy metals like lead and cadmium, are cumulative in organisms and ecosystems and may continue to affect produce for many years and some distance from the original source of application or leakage. For example dioxin residues found in bottom-feeding fish and crustaceans in Sydney Harbour (DPI 2006c) can be traced back to Homebush Bay industrial sites contaminated over the previous 100 years (see Water 5.7 and Land 4.6).

Chemical contamination can have serious impacts on human health and can also jeopardise domestic and foreign trade. Cadmium for example may cause kidney damage in humans (DPI 2005c). There is a nationally agreed set of standards for residues in food and produce based on Australian standard maximum residue limits (MRLs) and extraneous residue limits (DAFF 2005). There is usually a large safety margin between MRLs and the related health standards of acceptable daily intake levels.

Current status and trends

The Australian Total Diet Survey (FSANZ 2005), which publishes comprehensive data every two years, consistently shows that consumers' dietary exposure to a range of food chemicals, including pesticide residues, is well below Australian and international reference health standards and does not pose a human health and safety risk.

Samples of animal and plant food products in Australia, including meats, grains, honey and fish, are also regularly tested under the National Residue Survey program for the presence of chemical residues and environmental contaminants such as heavy metals. Chemical/commodity combinations for sampling are self-nominated by participating industries. Over the past decade, the results from this survey have consistently demonstrated very low levels of pesticides and contaminants in agricultural products. In the period 2004–05, the overall rate of compliance remained very high. Some 22,451 samples were analysed, of which 26 samples exceeded MRLs for Agvet-listed chemicals, while metals in excess of the agreed standards were detected in 20 samples (DAFF 2005).

In NSW, the Sydney Markets Fruit and Vegetable Monitoring Program (a joint Department of Primary Industries/ Sydney Market initiative) had data on 28 different types of pesticide residues in 48 different fruit and vegetables at Sydney Markets (Haymarket and Flemington) from 1989 to 2005. Out of 1497 samples collected between 2002 and 2005, each sample being a whole pack of produce such as a case of pears, approximately 80% contained no pesticide residues, while 36 samples (2.4%) exceeded the agreed MRLs. The percentage of residues exceeding maximum agreed levels tends to be higher than in other states. This discrepancy may be due to sampling procedures in NSW, which target produce types in which residues have been found, rather than selecting random samples. Produce from Flemington Market is also tested for cadmium. Only one of the 207 samples tested exceeded the maximum permitted concentration of 0.1 milligram per kilogram of fresh weight.

The CleanFresh project, established in 2005 to investigate pesticide residue in selected high-risk fruit and vegetables, has superceded the Sydney Markets program.

Large supermarket chains and some canning and packing industries conduct their own quality assurance programs for produce; however, data from these programs is not publicly available.

Response to the issue

There is a strong framework of intergovernmental and industry cooperation, including for setting MRLs and conducting regular compliance monitoring programs for most types of food and produce. Agencies are working together in 2006 to further strengthen the existing framework. The NSW Food Authority is responsible under the Food Act 2003 for food safety in the State, including policy on chemical residues and contaminants in food. Regulation of agricultural chemical usage under the Pesticides Act 1999 and Fertilisers Act 1985, and government policies relating to biosolids management, are playing an important role in minimising chemical residues and contaminants in food produce (EPA 2003). Food safety is reinforced through a network of local government environmental health programs that include both inspection and education.

The NSW Government has developed the Protection of the Environment Operations (Waste) Amendment Residue Wastes Regulation 2005 to protect agricultural land, agricultural produce and farmers from the actions of unscrupulous operators distributing harmful waste under the guise of 'fertiliser'. The Regulation aims to enhance the production of safe food and fibre products by prohibiting the application of potentially harmful industrial by-products and wastes to land for growing crops and other plants. The Government may grant exemptions from the prohibition where it can be shown that those wastes will not cause harm to agriculture, the environment or human health and will be of benefit.

The prohibition does not apply if the residue waste is lawfully sold as a soil improving agent (fertiliser or liming material) or trace element product within the meaning of the Fertilisers Act 1985, and it complies with the prescribed maximum contaminant levels.

The Government, in association with Flemington Market and some industries, also conducts trace-back programs to determine the reason for any exceedence of residue limits and take steps to prevent a recurrence. Selected vegetables and fruits are purchased at the Sydney markets for testing, enabling the source of any exceedences of residue limits to be identified, and feedback to be provided to growers and regulators. Within farming systems that use chemicals, an integrated pest management approach is being promoted.

Mandatory training programs in safe pesticide use and record keeping for all commercial and occupational users of pesticides (under the Pesticides Act), in conjunction with improved labelling by manufacturers and industry education programs, have worked to keep exceedence levels of pesticides in food at low levels. In addition, the utilisation of environmental management systems certified to the ISO 14001 standard has contributed to decreased exceedences as growers employ an internationally accepted strategic process for identifying and minimising potential environmental hazards.

The organic and biodynamic farming industry, which aims to produce goods without the use of manufactured chemicals, is growing in Australia at between 20% and 30% per annum (BFA 2005). The impact of this growth on overall residue levels is unclear.

Future directions

Consumer expectations for safe and wholesome food products are expected to increase adoption of industry based quality assurance programs delivering improved practices for pesticide use, residue minimisation and microbial contamination.

Introduction of food safety standards will further reduce opportunities for contamination of food as it moves along the supply chain. Increasing adoption of integrated pest and disease management programs, biological controls and new generation environmentally friendly pesticides offers additional opportunities to minimise contamination.

Comprehensive compliance monitoring is required for produce and food contamination problems to be detected and addressed early. Trace-back programs are an important part of the strategy.

The cooperative government agency review of the current framework will provide directions for future improvement. This work is to look at the benefits of more transparent monitoring and auditing of randomly selected samples which would provide a more accurate picture of chemical residues in a range of fresh produce.