Call center workers in India are having nervous breakdowns after being abused by fed-up Australians – but they aren’t getting much sympathy.

Half a million people are employed in India’s fast-growing call-center industry, famous for maddening calls at dinner time in Australia.

For some of the workers, abuse and overnight working hours are contributing to stress, sleeping disorders, fatigue and migraines.

A survey of Mumbai call centers found most call-center workers suffer from burn-out stress syndrome.

The abuse included racial taunts, the Global South Research Group survey found.

"Racial abuse by foreign customers is a job hazard that most employees have to deal with," a report on the survey says.

"The US and Australia are the worst abusers," said Vino Shetty, from his Young Professionals Collective office in Mumbai.

"Australian accents – especially in working-class areas – are very difficult to understand.

"The Australians then get frustrated because they are not being understood and when they realise the call is from India their anger gets worse.

"They can feel that jobs are being taken away from Australians and if they recently have been out of a job themselves, the abuse escalates," he said.

But Queensland Consumers’ Association spokeswoman Cherie Dalley said Australians were reacting to phone calls because they were at "ridiculous" times.

"Australians are tired of having their privacy interrupted by people trying to sell them things they didn’t want in the first place," she said.

James Organ, director of Australian research organisation, said "lots of poor innocent Indian workers" were abused regularly by Australians.

"Some companies are regretting outsourcing this business to India because of the damage it does to their products’ reputation," he said.

"Its a cultural thing – the moment an Australian suspects the call is coming from India they can get uptight.

"Yet in the UK, where they are used to interacting with Indian people, there’s not so much negative reaction."

Mr Organ’s group estimates Indian call centers account for 50 million calls to Australian homes each year – one fifth of the total telemarketing calls made. "Everyone has a story of how they were called by someone in Mumbai," he said.

Outsourcing of telemarketing and other business began about seven years ago when companies found it was cheaper to hire people in India, the Philippines and Malaysia to sell mobile phone plans, financial services, insurance and credit cards.