Coastal and Freshwater news

"Some of the things we do flush down the sink make their way through the sewage treatment plant and end up in the environment,” Dr Tremblay says (Photo: Tim Cuff)
18 November 2016

The trouble with toxins

Cawthron environmental toxicologist Dr Louis Tremblay mainly uses baking soda, vinegar and bar soap as cleaning products in his home. And though they’re cheap, it’s not out of thrift; their garishly coloured and heavily scented cousins are rich in chemicals that may be having a lasting impact on our environment.

Other common sources of contaminants include body washes containing plastic microbeads and antimicrobial soaps and cleaners. All add to the load that our environment and food chain absorb, along with pollutants like pharmaceuticals and pesticides. Antimicrobial agent triclosan has been found in biosolids, and contaminants such as the hormonal disruptor bisphenol-A (BPA), found in plastics, are commonly detected in water.

“So that means some of the things we do flush down the sink make their way through the sewage treatment plant and end up in the environment,” he says. “One of the things we are finding more and more is a chemical called galaxolide. It’s a musk put into products to give it a scent, and now we’re finding it in estuary sediments.”

That means it’s associated with stormwater - so when you wash your windshield using a standard windshield cleaner, you’re squirting chemicals all over the road that end up in the sea. “Not many people think of that.”

Listen to Dr Tremblay talk about his research on contaminants commonly found in household and personal care products.

But there is still a knowledge gap as to whether these chemicals can be considered a risk to us and to the environment, Dr Tremblay says. “We don’t have much data on a national level.”

However, there are moves to change this. In December, he will lead a Royal Society funded national workshop on the issue. It will involve participants from environmental and regulatory agencies, and members of central and local government who manage contaminants in our environment.

The aim of the workshop is to develop a national strategy document to manage emerging contaminants in New Zealand, including new ones and those that have been in our environment before but may not have been monitored.

“That will provide a roadmap of how we can use the resources we have in a more strategic way,” he says. “For example, we know triclosan is out there in the environment; the United States have now banned a whole range of similar chemicals in their products, so is this something we need to consider in New Zealand?

“This is a great opportunity to take a pragmatic approach to look at how we use chemicals to ensure that we get all the benefit with minimum impact on our environment,” he says. “Most of the time when a new problem occurs, regulatory actions are taken that can be reactive and lack cohesion. The approach we propose is take a step back and take a more holistic view initially when assessing the risks of chemicals we use daily so that we can achieve best outcomes for both the community and environment.”

Dr Tremblay says individual consumers also need to take responsibility for what they use at home.

“We are the ones using those products in the first place and the ones we choose for our daily activities can greatly influence the chemicals we flush and ultimately the pressure we place on our environment.”

Cawthron's community educator Cristina Armstrong helps raise awareness on this subject through school visits and workshops

Baking soda, vinegar, and plain bar soaps are “a really good way” to reduce pressure on our environment, he says. “All the products that are coloured and scented require a lot of chemicals, and if you look at the list of ingredients you’ll see a whole bunch of things that once flushed end up in the sewage and potentially the environment.

“We do have choices in the things we purchase and there are products that have been designed to be less harmful. It’s up to us to make the choices that will still be effective and meet our requirements but be more environmentally friendly.”


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

Click here to find out more about the impact of contaminants on the environment.