How your washing machine could be damaging fertility

The mystery of how hormone-disrupting chemicals have come to be found in lakes and rivers has been solved, and the culprit is the washing machine.

Scientists have long puzzled as to how flame retardant compounds and chemicals used to make plastics bendy end up in the environment as factories are careful not to allow spillages.

The levels of phthalates and retardants in the natural world is worrying because there is increasing evidence that they damage fertility and could be the reason why male sperm counts have fallen dramatically since the 1940s.

Women with the highest concentrations of phthalates in their bodies are also more likely to suffer low libido and a study published this week by British researchers showed that the fertility of dogs has dropped since 1988,  because they share the same environment to humans.

Now researchers at the University of Toronto believe they have found the answer to how they chemicals are polluting the natural world.

It appears that human clothing can trap the chemicals in their fibres and come laundry day, they are released into water of the washing machine, before being swept away into the sewerage system.

Wastewater plants extract less than 20 per cent of the chemicals so most will find their way into rivers and lakes.

“These results have implications regarding the role of clothing conveying chemicals with indoor sources to the outdoor environment,” said lead author Dr Miriam Diamond, from the Department of Physical and Environmental Sciences at Toronto.

 “Clothing is unique in the indoor environment as it undergoes continual laundering.  These results support the hypothesis that clothing acts as an efficient conveyer of (chemicals) from indoors to outdoors through accumulation from air and then release during laundering.”

Phthalates are used in everything from synthetic fragrances to plastic food containers, vinyl flooring, insect repellent, shower curtains and even steering wheels and dashboards.

But they are not chemically bound to the plastics they are added to, so they are continuously released into the atmosphere. Bendy plastic tends to harden and become brittle over time and because the phthalates have leached out.

The study found that natural fibres were worse for trapping phthalates with cotton picking up nearly double the level of phalataes as polyester, 3475 ng/dm2 (billionth of a gram per 10cm squared) compared with 1950 ng/dm2 for the manmade fibre.

As well as fertility problems, studies in both animals and humans have also linked flame retardants to thyroid disorders, memory and learning problems, delayed mental and physical development, lower IQ, and advanced puberty. Phthalates have also been linked to diabetes.

Dr Michael Warhurst, Executive Director of CHEM Trust said phthalates could be found in household dust, which can also get on clothes.

"Most people don’t realise quite how many hazardous chemicals you can find in normal house dust.

"We can reduce part of our exposures to problem chemicals by keeping our homes clean, but ultimately we need to get these chemicals out of our lives by them being banned from products in the first place".

Health scares have led to some retardants like PBDEs being phased out in recent years but older products could still be coated in the chemicals. Many people keep sofas and beds for decades, while most offices did not replace chairs.

A new, triazine-based brominated flame retardant which has replaced polybrominated flame retardants is similar in structure to the PDBE’s and scientists have called for research into whether it is having the same health impact.

Two of the more commonly used flame retardants – tetrabromobisphenol A (TBBPA) and tetrachlorobisphenol A (TCBPA) are used on circuit boards and externally on plastic casings for electronics.  The University of Houston recently showed that they disrupted hormones and promoted obesity.

The team also believe that chemicals used in dry cleaning could also be left on clothes and transferred back into the environment.

The research was published in the American Chemical Society journal Environmental Science & Technology.