What our wee reveals: Sydney is sad and London is party central.

Sydney, you have a problem – and your wee is telling the world about it.

Australian urine is being sent overseas for a massive international study of what our waste reveals about us. The European led study is getting into the sewers to find out what people are putting into their body.

This is what it may find according to results of some wee leakage into our harbour which have just been analysed.

– The top drug in Sydney systems is at least legal. It’s paracetamol (clearly the real estate prices of Sydney are giving everyone a headache).

– But the second and third most common drugs that showed up in Sydney’s wee were anti-depressants such as Prozac.

– Codeine came fourth.

– Strong narcotic pain killers came fifth and sixth.

Sydney Water says artificial sweeteners such as Acesulfame also show up.

The European project that Sydney has now joined has analysed wastewater in over 40 cities in 21 countries to explore the drug-taking habits of those who live in them.

London is party town. Its sewers have the highest level of cocaine in Europe. Every 1000 Londoners wee-d out 737mg of cocaine, and Friday and Saturdays saw the highest flush of the party drug.

Amsterdam wee is also high on cocaine, and levels continue to rise on Sundays when Londoners are in recovering mode.   Amsterdam also wins the title for the most cannabis in its toilets.

Finland is the least drug-fuelled city.

European researchers are also investigating urine to find out what rogue online pharmacies are selling. One study tracked the sewage load of an erectile dysfunction drug in three cities in the Netherlands.

The results of the international study will be available in six months.

The hints as to what it may find come from Sydney University researcher Gavin Birch who took samples from Sydney Harbour estuaries. He got the water analysed and revealed significant levels of strong pain killers and anti depressants.

"I was looking for sewage leaks in 30 sites adjacent to storm water outlets across the estuaries to Sydney harbour," Dr Birch told Debrief Daily. "The concentrations are minuscule - measured to one billionth of a gram".

So fear not for the fish. These concentrations are so low harbour dwellers will not be jumping out of the water with happiness or be off their gills with pain killers. Besides, now the sewage leaks can be traced and stopped.

Principle Public Health Advisor for Sydney Water Dr Pete Cox says he does a lot of analysis of waste, but is not looking for drug habits - just health dangers from sewage leaks. But he's interested in what the samples he sends to Europe will end up showing.

Dr Cox says contraceptives used to be the best marker to track leaks, but caffeine is now used more often because it's far more common.

And regarding the pill in pee. Do we need to worry about inter-sex fish who have lost their masculinity due to their guzzling of hormonal contraceptives?

Yes and no.

An American study found agricultural sources such as livestock waste, soy and dairy foods, and other pharmaceuticals are the main contributors to oestrogen in the water. The Environmental Science and Technology research found oral contraceptives account for just one per cent of the oestrogen found in our drinking water supply.

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