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The Definitive Guide to the Dirty Dozen


The Dirty Dozen and the Clean Fifteen are lists updated annually and produced by the Environmental Working Group (EWG).  The EWG are an American environmental research and advocacy organisation who conduct original research in order to inspire people, businesses and governments to take action to protect human health and the environment. Their mission is to create a healthier and cleaner environment for “the next generation and beyond”.

The Dirty Dozen contains the top 12 fruits and veggies that contain the highest pesticide residue levels and are recommended to buy organic.  The Clean Fifteen, on the other hand, contains the fruits and veggies that have the lowest levels of pesticide residues and are less likely to test positive for multiple pesticides.  If you want to maximise your grocery shopping budget, these lists are essential tools for deciding when it is worth spending more for organic produce.

As from 2012, the EWG began calling the list the Dirty Dozen Plus in order to call attention to hot peppers, kale and collard greens - vegetables that did not qualify for the Dirty Dozen but are of special concern because samples tested positive for organophosphate and organochlorine pesticides that are exceptionally toxic to the nervous system.

 THE DIRTY DOZEN (always buy organic)

  1. Apples
  2. Peaches
  3. Nectarines
  4. Strawberries
  5. Grapes
  6. Celery
  7. Spinach
  8. Capsicum
  9. Cucumbers
  10. Cherry Tomatoes
  11. Snap Peas
  12. Potatoes


  • Hot peppers
  • Kale/collard greens


THE CLEAN FIFTEEN (OK to buy conventional)

  1. Avocados
  2. Pineapples
  3. Sweetcorn
  4. Cabbage
  5. Sweet peas (frozen)
  6. Onions
  7. Asparagus
  8. Mangos
  9. Papaya
  10. Kiwi
  11. Eggplant
  12. Grapefruit
  13. Cantaloupe (rock melon)
  14. Cauliflower
  15. Sweet Potatoes

Don’t think, though, that the above lists don’t refer to produce here as most supermarkets in New Zealand are inundated with non-organic produce from overseas, including the United States.  New Zealand farmers are also just as guilty of using pesticides as any other farmer from around the world.

So how does New Zealand fare in comparison to overseas?  The following information is provided by the Soil and Health Association of New Zealand:

 New Zealand’s Dirty Dozen (in order)

  1. Celery
  2. Peaches (fresh/canned)
  3. Apricots (fresh/canned)
  4. Butter/cream/cheese
  5. Wheat: bread, all products
  6. Apples
  7. Plums
  8. Mandarins
  9. Raspberries
  10. Oranges
  11. Strawberries
  12. Grapes/raisins/sultanas

What do these pesticides do to us?

Studies have shown that exposure to organophosphate and organochlorine pesticides may result in numerous health problems including diabetes, attention deficit disorders, prostate cancer, fertility problems, thyroid disorders and obesity.  The most vulnerable are foetuses and children.

An organophosphate pesticide, chlorpyrifos, is used on a range of fruit, vegetables and grain in New Zealand.  It has been found in celery, peaches, apricots, apples, pears, mandarins, oranges, raisins, sultanas, grapes, tomatoes and bread, amongst others.

A 2007 study (1) linked chlorpyrifos with delays in learning rates, reduced physical coordination and behavioural problems in children, especially ADHD.  In 2010, another study (2) found that organophosphate exposure was also associated with an increased risk of Alzheimer's Disease.

Chlorpyrifos was banned in the US in 2000 for home and garden use as it is highly toxic to both humans and wildlife, particularly bees.

In Conclusion

Food in New Zealand isn't cheap.  I used to buy all my organic veggies, etc from an organic store.  Now I'm a solo mum on one income I am buying my fruit and vegetables from the local market where I can buy organic produce a little cheaper than in the stores, but mainly non-organic, spray-free produce which is cheaper again.  

So what if you feel you can’t, or don't want to, buy any organic produce.  As the EWG says, "The health benefits of a diet rich in fruits and vegetables outweigh the risks of pesticide exposure."  Much better to have an apple, albeit doused in pesticides, than a doughnut.  But the 'Dirty Dozen' are foods to think twice about, regardless of their country of origin.

Until next time…


(1)   Study Links Organophosphate Insecticide Used on Corn With ADHD. Beyond Pesticides. 5 January 2007.

(2)   Hayden, K.; Norton, M.; Darcey, D.; Ostbye, T.; Zandi, P.; Breitner, J., et al. (2010). "Occupational exposure to pesticides increases the risk of incident AD: the Cache County study". Neurology 74 (19): 1524–1530.  

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