As Baby walks through the narrow, winding lanes of Alwar, a dusty, ancient town in the western Indian state of Rajasthan, passers-by swerve out of her path.
It is what the young woman is carrying that marks her out as someone to be avoided: her wide iron pan and large wire brush are the tools of the manual scavenger, who cleans away the human waste left in houses without flush toilets.
But even when her morning's work is done - gut-churning toil that earns her 75 rupees (nearly HK$14) for two hours' work - and she has scrubbed her entire body clean with soap, Baby is still treated as an untouchable, a member of a group at the bottom of the Hindu caste system.
Though India sought to abolish untouchability after independence, the practice continues. Alwar shopkeepers won't touch Baby; they drop what she buys onto her hand from a height. In many houses, she says, she would never be invited across the threshold.
Manual scavenging was banned in 1993 by a law that also forbids the building of toilets that do not flush. But in India, where many well-meaning laws are largely ignored, there are thought to be several hundred thousand manual scavengers still at work. A recent report by Delhi University found there were more than 1,000 in the capital alone.
They belong to a substrata at the bottom of the Dalit caste - formerly known as untouchables - called Valmiki. But while all manual scavengers are Valmikis, not all Valmikis are manual scavengers. Baby, for example, grew up in a family of Valmiki street sweepers. She did not realise that the women in the family she married into 10 years ago worked as manual scavengers until her mother-in-law told her she was retiring and it was Baby's turn to assume the family trade. She was handed a pan and a brush and given the addresses of several houses that were expecting her to clear away their 'night soil'.
'I was so shocked, the stench was so bad, but I was forced to do it,' said Baby, who left school at the age of eight and is not sure of how old she is now, but looks to be in her late 20s. 'I felt so ashamed and I told my mother-in-law I did not want to do it. She said: 'How will you survive?'' Baby's tiny wage is an important part of the family income: her husband, who works by day as a labourer and by night as a hotel cleaner, earns 2,200 rupees per month.
Not all the manual scavengers in Alwar are as wretched as Baby, however. In 2003, Bindeshwar Pathak, the founder of Sulabh,
an organisation that designs affordable flush toilets and retrains manual labourers for other jobs, visited Alwar. After meeting several of the town's manual scavengers, he opened a training centre where more than 50 women have learned skills from pickle-making to tailoring, that have allowed them to leave behind their old jobs.
In one room at the centre, Lalita Nanda makes wicks for oil lamps to be sold to Hindu temples. As she shovelled the handmade wicks into large bags, she said the priests who had ordered them did not, until recently, allow her and her colleagues into Alwar's temples.
Usha Chaumar, one of the first women Mr Pathak met in Alwar, said escaping manual scavenging and learning new skills had changed every aspect of her life.
She was especially proud of her new literacy. Like most scavengers, she could neither read nor write until the retraining centre opened.
'One day my daughter came home from school and said: 'Mummy, I got supplementary' [a retest, just above a fail mark]. And because I didn't know, I said 'Well done.' Now, I can help her with her homework,' Ms Chaumar said.
Manual labourers suffer from unusually high levels of respiratory illnesses, and diseases such as cholera. But Ms Chaumar's health has improved.
'I was ill all the time, and when I wasn't ill, I was weak. I'm fine now - I've completely changed.'
Many of the former scavengers who come to the centre say their idea of where they stood in society had been transformed.
'Earlier, I did not know how to talk to top [upper class] people,' said Lakshmi Nanda, who has become a part-time poet - writing about her old life - since she was taught to write.
'Now, I can make conversation. We are all in a better position to walk and talk with everyone else. Before, that was not even a dream.'
Such a positive turn, rare in Indian society, would not have been possible without the other plank of Sulabh's work: the development of cheap, sustainable toilets.
At Sulabh's headquarters in Delhi, Mr Pathak extolled the practicality of a simple Asian squat-toilet that also helps produce composted manure for use in a garden.
The organisation also extracts methane gas from the public toilet complex it has built in Delhi, running a generator and providing cooking gas.
Sulabh says it has built 1.2 million toilets throughout India and helped 60,000 scavengers find new work.
'The toilet is a tool of social change,' said Mr Pathak, who defies the stereotype of the scruffy Gandhian activist. He wears a starched white pajama suit with a smart jacket. His hair is dyed black like a politician's and he wears a gold ring on his index finger.
Born into a family of Brahmins - the highest caste - in a village in Bihar, Mr Pathak remembers, as a little boy, being intrigued by the notion that the ordinary looking woman who sold kitchen tools to his family could be untouchable.
'So I touched her, just to see,' he said. 'And my grandmother made me drink a mixture of cow urine, cow dung and Ganges water.' That is a 'purification' ritual for Brahmins.
Later, Mr Pathak joined a committee set up to celebrate Mahatma Gandhi's 1969 birth centenary.
He was struck by what Gandhi had said about scavengers: 'I may not be born again, but if it happens
I will like to be born into a family of scavengers, so that I may relieve them of the inhuman, unhealthy, and hateful practice of carrying night soil.'
Mr Pathak then went to live in a community of scavengers for three months. Two experiences made him decide to help them. The first was when he saw a newly married girl being forced by her mother-in-law to clean human waste by hand.
'I can't describe how awful her crying was,' he said. In the second, tragic instance, he saw a small boy being attacked by a bull. People rushed to save him, but when someone cried out the boy was from the Valmiki caste, they left him to die.
'These things still happen,' Mr Pathak said. 'But we have everything we need to change things. It is so, so simple, if people only have the will.'