There’s something pretty magical about citrus season in Queensland.

Big bowls of mandarins on the bench. Fresh lemon squeezed over dinner. Ruby grapefruit at breakfast. Kids smashing through oranges faster than you can buy them.

But here’s the part most people don’t realise…

Conventional citrus is one of the more heavily treated crops in modern agriculture, particularly after harvest.

And because citrus tends to become an everyday food during winter, it’s one of the fruits worth paying closer attention to.

Because when you understand how your food is grown - and what can happen to it after harvest - you get to make more informed choices for your family, your health, and the kind of farming system you want to support.

Why Citrus Gets Sprayed So Often

Citrus trees are vulnerable to all sorts of pests and fungal diseases. Fruit fly, citrus gall wasp, mould, scale insects, fungal spots… growers are constantly managing pressure from insects and spoilage.

And unfortunately, supermarkets don’t exactly reward “real-looking” fruit.

They want citrus that’s shiny, blemish-free, uniform, and capable of surviving long transport and storage times without going mouldy.

That pressure often leads to repeated fungicide and pesticide applications throughout the growing season, plus chemical treatments after harvest to stop fruit rotting on shelves.

Two of the most common post-harvest fungicides used on conventional citrus are Imazalil and Thiabendazole.

The Fungicides Most People Have Never Heard Of

Imazalil

Imazalil is commonly used on citrus after harvest to prevent mould during storage and transport.

The concern with imazalil isn’t usually one orange. It’s the idea of repeated, low-level exposure over time, especially when citrus is something your family eats every day during winter.

Research has linked imazalil exposure in animal studies to effects on the liver and thyroid, and the US EPA has classified it as “likely to be carcinogenic to humans” based on animal data.

More recently, scientists have also started looking at what it may do to the gut microbiome.

Animal studies have shown imazalil exposure can disrupt beneficial gut bacteria, contribute to gut inflammation, and alter metabolism in mice and zebrafish.

Now, that doesn’t mean eating one conventional mandarin is suddenly catastrophic.

But it does raise important questions about what repeated exposure to synthetic fungicides may be doing to our bodies over time, especially when modern research is increasingly showing how important the gut microbiome is for immunity, digestion, inflammation, mood, and overall health.

Thiabendazole

Thiabendazole is another fungicide commonly used post-harvest on citrus to help prevent mould and extend shelf life.

The gut microbiome research around thiabendazole isn’t as strong or specific as it is for imazalil, but studies have still linked exposure to oxidative stress, inflammation, developmental toxicity, and cellular damage markers in animal models.

There’s also emerging concern around the combined effects of multiple fungicide residues together, because in the real world, chemicals are rarely encountered one at a time.

“But We Don’t Eat The Peel…”

This is probably the biggest misconception around citrus.

Yes, peeling helps reduce exposure. But pesticide residues can still transfer from the skin onto your hands, knives, chopping boards, and the fruit itself during peeling and slicing.

And honestly… a lot of us do eat the peel in some form.

Think:

• Lemon zest in baking
• Citrus slices in drinks
• Orange peel in marmalade
• Cocktails and garnishes
• Teas and infusions

Kids are also some of the biggest citrus eaters around… especially mandarins during winter.

So when something becomes a regular daily food, reducing unnecessary chemical exposure starts to feel pretty reasonable.

Why The Gut Microbiome Matters

The gut microbiome is basically an entire ecosystem living inside your body.

These trillions of bacteria help to regulate digestion, immunity, nutrient absorption, inflammation, hormones, and even mental health.

And while science is still evolving in this area, researchers are increasingly investigating how repeated exposure to pesticides and fungicides may affect that delicate ecosystem.

It actually makes a lot of sense when you think about it…

Many pesticides and fungicides are specifically designed to disrupt biological processes in living organisms. So researchers are asking: what happens when tiny amounts of those compounds are consumed repeatedly over years?

We don’t have all the answers yet. But there’s enough emerging evidence around chemicals like imazalil that many people are choosing to reduce exposure where they reasonably can.

Not perfectly. Just intentionally.

Why Organic & Spray-Free Citrus Matters

Choosing organic or genuinely spray-free citrus helps reduce exposure to synthetic pesticides, herbicides, fungicides, and post-harvest chemical treatments.

But that’s only part of the story.

Supporting growers who farm this way also means supporting:

• Healthier soils
• More biodiversity on farms
• Cleaner waterways
• Farming systems that work with nature rather than against it
• Farmers who prioritise long-term soil and ecosystem health

And then there’s the obvious part…

Good citrus just tastes better.

Sweeter mandarins. More fragrant lemons. Juicier oranges. Grapefruit that actually tastes vibrant instead of watery and sad.

That’s the thing about food grown with care. You can usually tell.

Why We Care So Much About It

At Joy Wholefoods, citrus season is one of our favourite times of year. But we’re incredibly picky about where it comes from.

We prioritise organic and spray-free growers because we believe everyday foods matter most.

You don’t need to eat perfectly. You don’t need to panic about every ingredient. But if there are simple swaps that can reduce your chemical exposure while supporting good local farmers at the same time… that feels like a pretty good place to start.

Especially when the food tastes better too.

Small Changes Matter

If switching everything to organic feels financially overwhelming, citrus is actually a really great place to start prioritising.

Especially for:

• Kids’ lunchbox fruit
• Lemons you juice regularly
• Citrus you zest or use whole
• Winter immune-support staples

Sometimes better food isn’t about perfection.

It’s just about making a few more intentional choices where you can.

And citrus season is a pretty delicious place to begin. 🍊

References

• Australian Pesticides and Veterinary Medicines Authority (APVMA)
  APVMA
• Food Standards Australia New Zealand — Pesticide Residues
  FSANZ Pesticide Residues
• NSW Department of Primary Industries — Post-harvest fungicides for citrus
  NSW DPI Citrus Resources
• US EPA — Imazalil Risk Assessment US EPA Imazalil Assessment
• Jin et al. (2016) — Oral imazalil exposure induces gut microbiota dysbiosis and colonic inflammation in mice.  PubMed Study – Imazalil & Gut Microbiota
  Tisza et al. (2025) — Possible genotoxic effects of post-harvest fungicides applied on citrus peels NIH PMC – Citrus Fungicide Study
• Matsuzaki et al. — Pesticide exposure and the microbiota-gut-brain axis  NIH PMC – Pesticides & Gut Microbiome_)
• Duffy, B. & Lee, P. — Post-Harvest Fungicides for Citrus (Australian citrus industry resource) Citrus Australia – Post-Harvest Fungicides for Citrus