Water

Water is massively overused within the textile industry due to the massive amount of wastage with cotton farming using the most water out of any fabric.
Approximately 10,000 litres of water is used in the production of only ONE pair of denim jeans. In China polluted water causes 75% of diseases from which over 100,000 die annually.
But the textile industry isn't the only place to focus the blame. Us as consumers can play our part through the amount of washing we do especially at high temperatures. Drying also is a massive contributor.