The major deciding factor in our use of natural dyes is that no chemical pollutants are produced as a byproduct. The rivers of Kathmandu (Bagmati river shown above) are now so heavily polluted, not just from waste chemical dyes, but also human sewage and general garbage. Pictured below is a common scene of garbage in the street. At the time of taking the photograph, garbage collectors had been on a week's strike. A lot of infrastructure is required to start the slow process of cleaning, but it appears that the main hurdle is education and awareness. People in Kathmandu face many problems and challenges (made no easier by their ever failing government that is comprised of self serving politicians). I have faith that things will get better, but only after things get much worse.