[code_duck]

Hemp is a good alternative to cotton that has similar advantages - biodegradable, non-toxic, allows skin to breathe, but does not require input of toxic chemicals to produce.

One major drawback of synthetic fabrics that is recently coming to light is the tiny particles they constantly shed, which are too small to be filtered by most municipal water systems and are now found all over in lakes and rivers: https://www.theguardian.com/environment/2016/jun/20/microfib...

[Steve44]

The Patagonia website used to have a really goo presentation about the pollution caused by washing synthetic clothing but they seem to have redesigned their website very recently and it's not easy to get around.

Another major source of ocean plastic pollution is from car tyres. That 6mm of tread which disappears from your tyres is generally washed off the roads, through the drains and into the ocean.

> http://www.bbc.com/news/science-environment-39042655

> The report found between 15% and 31% of plastic pollution came from primary microplastics, of which the biggest contributors (almost two-thirds) were abrasion of synthetic textiles, while washing, and abrasion of tyres, while driving.

[Cthulhu_]

You'd think most countries would have good drainage by now, which includes filtering and reusing as much rain water as possible before dumping it back into the rivers / oceans / etc. I know in most towns over here, rain water goes through a different sewage system than sewage and isn't just discarded in the nearest river.

[code_duck]

Much infrastructure in the US is old and critically underfunded for maintenance, much less improvements, even when inadequate. Witness the drama over the collapsing Oroville dam in California, the collapsed bridge in Minneapolis, or more specifically, sewage overflows in Great Lake states.

I lived in Duluth, MN, and anytime there was significant rainfall, the sanitary sewer system would be overflowed by storm water, and dump thousands of gallons of untreated sewage directly into Lake Superior. http://www.duluthnewstribune.com/news/3772570-court-order-du...

It is a problem for the whole region: https://greatlakes.org/campaigns/sewage-overflows/

[Steve44]

It's to do with how fine these plastic particles are and the sheer volumes of waste which need filtering. They do remove a fair percentage but not all. [1]

Even in regular drains there will be a significant amount of contamination which would prevent the water from being used as-is; if you have a specific rainwater collection system that would work but is basically what our reservoirs are now.

[1] https://www.patagonia.com/blog//2017/02/an-update-on-microfi... "wastewater treatment plants filter a good amount of microfibers (65–92 percent) but still release a significant volume of waste into the environment"

[fwgwgwgch]

Talking of hemp, hemp "concrete" blocks are also considered good for buildings.

[scythe]

Hemp-lime aggregate is good insulation, but cement-fiber aggregates do not have the characteristic properties of more famous composite materials. Additionally, Portland cement is highly basic and tends to weaken wood, so the hemp is not really acting as a reinforcement in this case, but a filler which reduces density. Hempseed shells (the indigestible portion of hempseed) are often preferred here. See:

http://en.wikipedia.org/wiki/Fiber-reinforced_concrete

[Kalium]

You're right! It's ideal for suburbia or rural villages. So long as you don't need them to be higher that a story, hempcrete is great.