Faisalabad, Pakistan - Mohammed Rafiq is a bus painter in Pakistan.

Like millions of his compatriots, Rafiq started work at the age of 12, missing out on education and exploited as a child labourer.

"We would put our heart into it," said Rafiq, recalling his early days as a bus painter.

"Nowadays the apprentices come and just see it as a day job," he sighs, sitting on a plastic chair on the muddy tarmac as Pakistan's now iconic colourful buses roll by.

He picked up painting quickly and gained notoriety for his skill, drawing beautiful scenes on the buses that would travel across the country.

"My work spread all over Pakistan. But we didn't get much money per bus."

The average daily wage for a bus painter today is around 600 rupees ($6).

Rafiq says he could barely survive, unable to secure a decent education for his children and struggling to pay the rent each month.

His passion for his work pulled him through.

"Everything was done by hand, by brush. It was beautiful. Now they use machine printed material, which is beautiful in its own way."

But more than 40 years of working without any safety equipment or precautions have taken their toll.

At 69 years old, Rafiq's lungs are now failing.

"This sickness is because of the paint, the chemicals, thinners, petrol fumes," he explains, gasping for breath.

Many of the men who worked alongside him also suffer in the same way. None are able to afford proper treatment.

Despite his passion for his work, Rafiq says he is not keen for others to follow in his footsteps.

"I don't want more people to do this job. I couldn't save any money in my life. I couldn't educate my children. Fate wasn't on my side."