The Olympics shine a light on many things. Sporting prowess and the host city's attractions get well-deserved attention. They also illuminate darker elements such as the sponsors' ethical records. Dow Chemical's connection with the Bhopal tragedy may have garnered the most headlines, but it is far from the only harsh Olympic truth. The Independent's investigation into sweatshop conditions in some factories making kit for Team GB highlights the dirty secrets of the industry. Our athletes aren't the only ones whose clothes are made in misery.

In the past few years, I have met staff across the retail industry. Behind closed doors, they admit the same thing: their supply chains hide shocking secrets. The problem is clear. The women – and it is mostly women – who make our clothes are paid a pittance. They are often bullied and forced to work unpaid overtime. Sexual harassment is not unusual. Workers who try to unionise are generally sacked. The experiences of the women interviewed by The Independent are so common as to be clichéd, but no less shocking for being predictable.

Campaign groups have been drawing attention to the problem for years. Companies and shoppers alike have heard it all before. Television shows or articles create a splash and clean up a factory or two, but for the vast majority of workers, life continues unchanged. So if everyone knows the problem, why hasn't it been fixed? Retailers like to say it's because things are too complicated. Countries are too poor. Factory owners are too corrupt. Supply chains are too complex. These points are true, but they are not the real truth, which is that some clothing companies care about profits, not people. If they really wanted to ensure workers received decent pay and humane treatment, they could do it.

The effort to make 2012 the most sustainable Games in history stumbled straight into the clothing industry's dirty laundry. The London Organising Committee of the Olympic Games (Locog) has a sustainable sourcing code. But a code is only the first step. Unless decent pay and conditions are written into contracts, codes tend to present aspirations rather than drive changes in reality. Locog also has a complaints mechanism. That is genuinely a big step forward, but it isn't going to do much good for most workers. By its nature it assumes things are generally fine with just the odd problem. But things in the clothing industry are not fine.

Locog's contracts are all signed now so it's too late to insist that workers get a living wage. But it could invest a lot more in helping them safely to access its complaints mechanism. More investigations such as that in Indonesia are also an important way to help. But these approaches can solve problems only one factory at a time. Systemic change requires real commitment from the industry itself.

Meredith Alexander was a member of the Commission for a Sustainable London. She resigned in January over Dow Chemical's Olympic sponsorship.