In the outskirts of Kolkata, India, fertilizer factories can be spotted on the roadside. Scrap leather is placed by labourers in an oven to be burnt in order to recover a solid collagenic material containing high nitrogen levels, which can be employed for the production of nitrogenous fertilizers used by farmers to boost yields of staples such as rice and wheat. The burning of leather trimmings causes harmful smoke and it has a major negative impact on the health of the people working at the factories.
