- Nylon, acrylic and especially polyester clothing release lots of microplastics during laundry. For polyester a study found between 6 and 17,7 million microfibers per 5kg wash
- Microplastics are now ubiquitous; they are found in various foods and in 83% of drinking water samples around the world, including both tap and bottled water
- We don't know the exact effects of microplastics on human or animal health, but the results of preliminary research are rather negative; human immune cells die after trying to absorb microplastics and micro-lungs stop growing when exposed to nylon fibers
I found more information about this, and since there hasn't been a single answer so far I'm going to self-answer my question based on what I found.
Microplastics are spreading
There are several aspects that make this a rather worrying problem. First of all recent research found that clothing gives off much more particles in a washing machine than previously thought. The 2011 paper written by Mark Browne mentioned over 1900 fibers per garment, but new research has found that
a typical 5 kg wash load of polyester fabrics could release an impressive number of microfibres, in the range of 6,000,000 - 17,700,000 ... depending on the type of detergent used.
As far as I've read there still is no direct evidence linking microfibers found in oceans to clothing but we do know that microfibers make up 85% of all man-made materials found in various ocean water samples (see Mark Brown's 2011 paper mentioned earlier). Also the types and amount of fibers found on shores matches those used in the clothing industry.
Second, we know from past research that plastic particles in (sea)water absorb other toxins present in the water. We also know microplastics are eaten by marine animals, thus introducing toxic pollutants into the food chain.
Third, waste water treatment plants lets microfibers through and microplastics are now found in 83% of drinking water samples around the world, including both tap and bottled water. Besides water, microplastics have also been found in fish, honey, beer and salt
Plastic particles have spread around the entire globe and are now also found in remote places such as the North Pole
Research on the health effects of microplastics in animal or human bodies has only just begun:
The WHO recently released a report saying that
Based on the limited evidence available, chemicals and microbial pathogens associated with microplastics in drinking-water pose a low concern for human health. Although there is insufficient information to draw firm conclusions on the toxicity of nanoparticles, no reliable information suggests it is a concern.
However, the preliminary results of a large Dutch study are very negative:
Source: original news article in Dutch
and translated to English by Google
Although research is still in progress, an EU-sponsored research project called MERMAIDS mentions several solutions to at least reduce the problem:
Furthermore the Ocean Clean Wash Charter mentions a few potential future solutions:
- Develop washing machine filters that catch the microfibers
- Develop synthetic fabrics or that don't give off microfibers
- Develop impregnation that prevents the release of microfibers.
Of course you could also try to avoid buying polyester, acrylic and nylon clothing until a good permanent solution has been found and implemented.