Behind a tannery in the Hazaribag industrial district in Dhaka, these labourers use shovels and buckets to scoop boiled animal waste, byproducts of the leather -making process, into a slow-moving effluent that mixes with untreated dyes and chemicals before spilling directly into the Buriganga River. Lax environmental standards and lack of government enforcement make scenes like this common in the area.