Coastal and Freshwater news

Scientist Joel Bowater helps children at Nelson's Clifton Terrace School test different cleaning products
11 August 2013

Household cleaners under the microscope

What happens when our shampoos, antibacterial soaps and foaming face washes go down the drain?

That's exactly what a team of scientists is aiming to find out as part of an 18-month research project led by Cawthron Institute.

The 'Up-the-Pipe Solutions' project examines the potential environmental impact of active ingredients found in common household cleaning products and investigates less harmful alternatives.

Social scientists, toxicologists and chemists from Cawthron Institute and the Crown Research Institutes of ESR and SCION, along with iwi, school and community groups are all working on the project which started in June 2012 and is funded by the Ministry for the Environment's Waste Minimisation Fund. New Zealand company Ecostore is also supporting the research.

Lead researcher and environmental toxicologist, Dr Louis Tremblay, says the active ingredients flow out of homes through wastewater and can eventually enter the natural environment. The chemicals are also present in the nutrient rich sludge that remains after sewerage treatment so the sludge cannot be recycled and has to be added to landfill.

Involving communities

The scientists are using Kaikoura as a case study and working with local iwi group Te Runanga o Kaikoura Incorporated.

Dr Tremblay says Kaikoura was the perfect community to work with on the project because iwi, Council and the wider community are very supportive of the work. Local MP Colin King is also right behind the project, believing towns and cities need to effectively manage waste in all its forms and this project is a step to help make that possible.

Environmental effects

Dr Tremblay says active ingredients such as antibacterial agents found in a range of household products can influence the effectiveness of sewerage treatment plants as they rely on bacteria to do the work of breaking down the wastes.

One example is triclosan, which is commonly found in products like antibacterial liquid soaps and toothpaste. Triclosan can be a very effective weapon to control diseases but when used too much it can also lead to detrimental effects, such as the development of resistant microbes.

"When you consider most of these chemicals are used every day, in almost every house in every community - over time that amounts to a lot of chemicals that can potentially be released in our environment," Dr Tremblay says.

"On their own these might not be very toxic, but the risk is that they could have long-term implications that we don't yet know about - that's what we're trying to find out."

Understanding the impacts

Samples from septic tank sludge in Kaikoura are being tested to see what chemicals and active ingredients are present. The scientists want to find out exactly what effect these chemicals have on the environment, and then use that information to help consumers make better choices with products that could perform the same function but have fewer consequences downstream.

"As environmental scientists, too often we're the ambulance at the bottom of the cliff, cleaning up the messes. We want to shift from raising red flags to trying to be part of the solution through offering the community more sustainable choices."

Raising awareness

Dr Tremblay says the research is not about demonising particular products, but instead raising awareness about how as individuals we affect our environment.

"Our behavioural patterns and choices we make on a daily basis have consequences," Dr Tremblay says.

"It is easy to blame others for environmental damage, but if you gather all the cleaning products and body care products together in your home you'll see it's a surprising amount and, sooner or later, some of it reaches our natural environment."

Research components

The research includes two main components. The first is consumer research, community engagement and raising awareness of the issue through hui on marae around the country.

The community engagement process involved secondary school students who participated in various activities including making their own low cost cleaning and personal care products using a combination of ingredients that are known to have little effect or persistence in the environment, such as baking soda and white vinegar. The students competitively tested their recipes to determine for example, which worked best for cleaning a dirty cooking pan.

The second part of the project investigates a selection of ten chemicals found as the active ingredients in common household products, the risk they present to the environment and how long they persist in the natural environment. This is done through laboratory experiments using algae and fish embryo at the early developmental stage. The chemicals are tested individually as well as in mixtures – which are more commonly how they would be found in the natural environment.

"We've chosen compounds we use in large volumes every day but that we have relatively little information about how they act when released in the environment as a lot of them are replacements for other chemicals that have since been phased out. We need to increase our knowledge around the potential effects of these chemicals so we can develop better risk assessment."

The Up-the-Pipe research came out of another project by Cawthron, ESR and SCION, which looked at bio-solids - the remains that sink to the bottom after sewerage waste has been treated. These remains are nutrient rich and could be recycled as a useful fertiliser, however the researchers found they also contain many different micro-contaminants from everyday personal and domestic cleaning products. The contaminants mean the sludge cannot be recycled and instead has to be added to landfill.

"Ultimately, what we want to do is reduce the micro-contaminants in the waste," Dr Tremblay says.

Chemicals assessed in the Up the Pipe Solutions project:

  • Benzophenone - found in car wash, face hydration, conditioner 
  • Propylparaben -  a preservative and stain remover found in hair dye/skin care cream, baby lotion cream, moisturizer, shower gel, body lotion, pet care
  • 2-Phenoxyethanol -  found in shampoo, conditioner, moisturizer, hair colour, pet care (antibacterial)
  • 2-Phenylphenol - disinfectant (0.1%) 
  • Chloroxylenol - disinfectant
  • DEET - insect repellent (5 to 98%)
  • Octyl methoxycinnamate - found in sunblock (~8%)
  • 4-Methylbenzylidene camphor - found in sunblock (~3%)
  • Gemfibrozil - a lipid regulator drug to manage cholestorol levels
  • Diclofenac sodium salt - an anti-inflammatory drug found in most anti-inflammatory creams
  • Triclosan - an antibacterial agent found in toothpaste and almost all liquid cleaning products including hand soap
  • Bisphenol A - a plasticiser. Used in plastics and packaging

Please contact Louis Tremblay to find out more about this research.