It may not be a pleasant job but in Dhaka, Bangladesh, the thriving meat and bone meal industry is a lifeline for many workers.

Every day in factories around the city workers labour to convert waste animal carcasses, bones and entrails into usable materials.

The most common product is Meat and Bone Meal (MBM), which is used as a high-protein animal feed.

Since the 2001, following the BSE (Mad Cow Disease) crisis, the use of MBM as animal feed has been forbidden in Europe, but no such measures are in place in Bangladesh.

Here, as in many other countries across the world, including Argentina, Australia, Brazil, Uruguay, and New Zealand, the rendering industry is an important player in the country's economy - employing thousands of people.

Much of the work, from scraping animal hides to cooking the meat and bone meal, is all done by hand.

The rendering factories in Dhaka produce a variety of different products, including purified lard, fertiliser and Meat and Bone Meal (MBM) from animal carcasses and abattoir waste.

Hypo Fide International, owned by Kholilur Rahman, is one of the biggest producers of MBM in the city.

Though the factory specialises in the production of high-protein animal feed from animal remnants it also has a large area dedicated to the sorting of fish produce.

Daily, barrels of fish remnants (heads, entrails etc.) arrive at the factory and require washing before all of the scales are removed and dried. These are then sold as feed for fish harvests in Thailand and Japan.

There are also daily deliveries of blood, carcasses and bones from Dhaka's butchers and abattoirs. These are ground down into small fragments before being cooked in large containers.

Rahman pays 15000 takas (£150) per month for the carcasses and other abattoir wastes that are sold in Dhaka's 36 markets.

Once all the ingredients are added together, the preparation time of the animal feed is between three and six hours.

The act of cooking the MBM is done by hand, as are almost all of the other processes in the factory.

Furthermore, due to limited resources, there is an emphasis on recycling in the industry, meaning nothing is wasted.

The grease from the cooking process is collected by workers, placed into moulds and dried under the sun to be sold to solvent manufacturers. The fuel used to heat the containers is plastic waste from neighbouring factories.

Unsurprisingly, the industry is a large contributor to Bangladesh's serious pollution problem.

The Hypo Fide International factory is situated in the Hazaribagh district of Dhaka, which is one of the most polluted areas in the world.

With the industrial fumes, polluted water supplies and the vast amount of waste that comes from more affluent parts of the city, it is more of a dumping ground than an inhabitable area.

People who work in the factory and others like it suffer many health problems, including, ulcers, jaundice and skin maladies; 80% of them will die before reaching the age of 50.

Nonetheless, the rendering industry remains on the rise in Bangladesh due to worldwide demand for high-protein produce.

MUST CREDIT PHOTOS BY: Sipa Press / Rex Features