Endosulfan Residues in Fruit and Vegetables - April-June 1998

April - June 1998

OBJECTIVE

To monitor the levels of Endosulfan pesticide residues in fruit and vegetables sold in the ACT market.

To determine whether the samples comply with the Food Standards Code permissible residue pesticide levels.

Background

Pesticide residues in fruit and vegetables have been previously monitored by this Service. The latest survey was conducted in early 1997. Previous surveys have found that approximately half of the samples tested contained at least one pesticide residue and that the most commonly encountered residue was Endosulfan.

In response to a review of pesticide residue testing, it was agreed that emphasis should be changed from general screening to more targeted testing. So, in accordance with this policy direction, pesticide residue testing will become focused on either a particular pesticide in various foods, or a group of pesticides commonly used on certain produce.

Endosulfan residue has been one of the most commonly encountered pesticides in fruit and vegetables testing conducted to date. It has widespread application as demonstrated by Schedule 1, Standard A14 of permitted Maximum Residue Limits (MRLs) in the Food Standards Code (Ref_1). See below.

Endosulfan

 

FOOD

MRL (mg/kg)

Carrot

0.2

Cattle (edible offal)

0.2

Cattle meat (in the fat)

0.2

Cereal grains

0.2

Common bean (dry)

1

Cotton seed oil (crude)

0.5

Eggs

0.05

Fruiting vegetables, other than cucurbits

2

Fruit

2

Goat (edible offal)

0.2

Goat meat (in the fat)

0.2

Lupins (dry)

1

Milks (in the fat)

0.5

Mung bean (dry)

1

Oilseed

1

Onion, bulb

0.2

Peanut

1

Potato

0.2

Poultry (edible offal)

0.2

Poultry meat, (in the fat)

0.2

Rice

0.1

Sheep (edible offal)

0.2

Sheep meat (in the fat)

0.2

Soya bean (dry)

1

Sweet corn (corn-on-the-cob)

0.2

Sweet potato

0.2

Tea (green, black)

30

Tree nuts

0.2

Vegetables [except carrot; common bean (dry); lupins (dry); mung bean (dry); onion, bulb; potato; soya bean (dry); sweet corn (corn-on-the-cob); sweet potato]

2

 

Endosulfan is classified as an organochlorine pesticide, but unlike its earlier predecessors, it is not highly persistent in the environment. For most fruit and vegetables, 50 % of residues are lost within 3-7 days. In animals, Endosulfan is metabolised and excreted in the urine and does not accumulate in the milk, fat or muscle (Ref_2). Its purpose is to control a wide range of insect pests including thrips and aphids. Because of its relatively low cost and broad application, it is widely used by many producers for pest control.

Although previous surveys have found that its compliance is generally good, there have been some rare exceedences in green leafy vegetables. In order to demonstrate continuing compliance regular monitoring is required. Consequently this sampling survey was scheduled for the end of the active growing season and was particularly targeted at green leafy vegetables.

Regular monitoring of residue pesticide levels is also undertaken by the Australian New Zealand Food Authority (ANZFA) though their Market Basket Survey program. For further information about the Market Basket Survey, ANZFA may be contacted on 02 6271 2222.

SURVEY

70 samples of various fruit and vegetables were collected throughout Canberra between April and June 1998. Table_1 indicates the variety and numbers of samples collected for analysis. As indicated in the Schedule above, the Endosulfan MRL for fruit is 2.0 mg/kg and for the vegetables sampled in this survey, the MRL of 2.0 mg/kg applies, with the exception of carrots which is 0.2 mg/kg.

Table_1

 

Food Commodity

Examples

Sample Number
Berry fruit grape, strawberry

4

Brassica cauliflower, broccoli

brussel sprouts

8

Cucurbit cucumbers, zucchini

5

Fruiting vegetable capsicum, tomato, choko, egg plant, rock melon

10

Green and leafy vegetable lettuce, spinach, boy choy, silver beet, celery, snow peas, green beans, fennel

23

Pome fruit apples, pears

9

Carrot carrot

2

(sub)Tropical fruit nashi pears, kiwi fruit, banana, pineapple, custard apple, avocado

10

 

RESULTS

Testing again demonstrated the widespread occurrence of Endosulfan pesticide residues. 51 of the 70 samples (73 %) showed residues of Endosulfan in one or more of its forms (either a or b isomers or the major active metabolite Endosulfan sulfate). Graph_1 shows the proportion of samples with the relative concentration of Endosulfan detected (expressed as a % of MRL).

In the majority of samples, the concentration was found to be less than 0.2 mg/kg. The highest level found occurred in a green bean sample which had a result of 1.12 mg/kg.

Graph_1

 

graph indicates None of the samples failed the required MRL

None of the samples failed the required MRL as indicated in the above graph. The graph does show a large portion of samples fall in the 0.1 - 10 % MRL category, with only one sample exceeding 50 % of the MRL.

DISCUSSION

The survey results are very reassuring as none of the samples failed the required MRL. Although wide spread in the samples tested, the concentrations detected tended to be below 10 % of the MRL and no samples were identified above 60 % of the MRL. This should place continuing confidence in the supply of safe, fresh fruit and vegetables in the Canberra market with relation to Endosulfan pesticide residue levels.

CONCLUSION

Endosulfan pesticide residues in fresh fruit and vegetables are at safe levels and well within the required MRL.

RECOMMENDATIONS

Refer to recommendations document.

BIBLIOGRAPHY

Australia and New Zealand Food Authority, Food Standards Code, incorporating amendments up to and including Amendment 38, April 1998.

Kidd and James, The Agrochemical Handbook, The Royal Society of Chemistry, 3rd Edition, 1991.

ACKNOWLEDGMENTS

Sampling Officers: Andrew Rigg

Sample analysis: Andrew Rigg

Report: Simon Christen