As this video touched the subject of my previous post I couldn't resist posting it here, basically it is just a video showing that our laundry pollutes the water. Found the video here.
To lessen the pollution from your laundry you can firstly avoid buying clothes from material that contains chemicals from colouring etc. Secondly, buy an eco-friendly detergent or use soap nuts. I haven't tried soap nuts myself yet, but I'm curious to try. Soap nuts come from trees in India and Nepal and naturally will produce a soap-like content when rubbed in water. So you just put a few of them into the washing machine with your laundry and no need to use softener eihter. They are completly frangrance free so if you want your clothes to have a a nice smell you can add for example a few drops of lavender oil.
There have been some tests though showing that the nuts don't really work (link in Swedish) and that the clothes were even cleaner after just washing them in water. So perhaps there is acctually no need for any detergent unless the clothes have stains? (link in Swedish again) However, I think that there are so many people happy with the use of these soap nuts that I don't think it really matters, it's not like the nuts will make your clothes dirtier at least.
Main point is not to use any detergent with strong chemicals, try to fill up the whole machine when you do laundry and use a program that uses as little energy as possible.