General news

Dr Louis Tremblay is leading a two day workshop on emerging organic contaminants. Photo: Tim Cuff
1 December 2016

What we flush and drain can cause strain

Instead of cooking with baking soda and vinegar, scientists advocate that we use them as cleaning products to reduce the pressure on our environment.

Cawthron environmental toxicologist, Dr Louis Tremblay, wants us to think about what we put down our plugholes and toilets. He says that “household chemicals, fragrances, and medicines play a beneficial role in maintaining our lifestyles and reducing the risk of diseases.

Unfortunately, sometimes these same chemicals can be harmful when they are disposed of, or flushed down the sink, and end up in the environment”.

A workshop to manage the risk of emerging organic contaminants (EOCs) is being led by Dr Tremblay 1-2 December. It is funded by the Royal Society and involves participants from environmental and regulatory agencies all over New Zealand, the USA, Europe and Australia.

International research shows that EOCs are released to the environment wherever humans live and they have a detrimental impact on natural ecosystems and water quality. For example, research has found that when fish are exposed to the anti-depressant, Prozac, they experience altered behaviour patterns. Other pollutants can mimic the hormone estrogen and disrupt fish physiology.

Although there isn’t much data about EOCs at national level, regulators are increasingly concerned about their risks and the knowledge gaps that prevent impact assessment. EOCs are seldom regulated as their effects can be subtle and expressed over a long period.

New Zealand needs to develop the capability to identify and manage the threats posed by the high-risk chemicals to keep us safe. Emerging organic contaminants can potentially pose health and environmental hazards.


Listen to Jesse Mulligan and Dr Tremblay talk about "What we flush" on RadioNZ

Scientists and representatives from Regional Councils, MfE, MPI, EPA, DoC, and industry will develop a document to manage emerging contaminants in New Zealand. This will provide a road-map of how we can use resources in a more strategic way to better manage chemicals and engage Maori and the wider community to promote changes in national policy.

"The workshop is a great opportunity to take a pragmatic approach to look at how we use chemicals to ensure that we get all the benefits with minimum impact on our environment,” says Dr Tremblay. “We know these chemicals are out there and we need to have a debate about their pros and cons. We need to weigh up the benefit of using chemicals to enhance our quality of life, against their impact on the environment when released”.

Dr Tremblay’s aim is to lessen the risk that EOCs pose to unique ecosystems and taonga species. Better awareness will help people make good choices with their product purchase and thus protect precious water resources. People can also put pressure on companies to make more sustainable products. He maintains that individual consumers need to take responsibility for what they use at home.

“We are the ones using those products in the first place – thousands of chemicals in every household. The ones we choose for daily activities can greatly influence what we flush and ultimately stress we place on our environment.

If we have unused medicines, it is tempting to put them down the drain. They then get into our streams, rivers and lakes. This is because antibiotics, hormones, contraceptives and steroids are not always removed completely at waste water treatment plants.

Continued exposure to low level pharmaceuticals in our water systems may alter the behaviour and physiology of aquatic organisms who call it home”.

Dr Tremblay says that coloured or scented cleaning products require numerous chemicals and once flushed, potentially end up in the environment. Baking soda, vinegar, and plain bar soaps are ‘a really good way’ to reduce this pressure.


Listen to Dr Tremblay talk about the "Up the Pipe" project

For more information on the workshop, please contact Dr Tremblay.