It's hard to be a parent on the mainland these days, with children's safety threatened everywhere. The risks have ranged from melamine-tainted baby formula to poorly built schools - blamed for the deaths of more than 5,000 children in the Sichuan earthquake of 2008 - and the callous attitude of fellow citizens, with 18 people ignoring a toddler who was run down in Foshan in October. Last month, 19 children from a kindergarten in Gansu's Zhengning county died on their way to class when the nine-seater van they were travelling in - packed with 62 children - slammed head-on into a coal truck. Overloaded school buses are not only a problem in poor rural areas. They are common in Pearl River Delta boom towns, with hundreds of thousands of children of poor migrant workers taking them every day. A day after the crash, Guangzhou traffic police announced they had impounded two overloaded buses from schools for migrant workers' children. One, a 26-seater, had 43 children crammed on board, and the other, with 19 seats, was carrying 27 children. Neither was licensed to operate as a school bus and they lacked necessary safety equipment such as seatbelts and signs warning other drivers to watch out for students. Police say they punished and fined the operators of more than 1,100 school buses in October and November, many for overloading. In Dongguan , traffic police stopped a 50-seat school bus carrying 75 migrant workers' children a few days after the Gansu crash. Some were sharing seats and many were standing in the aisle. 'We have to take the overloaded school buses even though we're afraid of possible accidents,' one boy told the Dongguan Daily. 'We don't have any other way to get to school.' While the children of permanent residents usually enrol in public schools close to home, or have relatives who can take them to class, the children of some 30 million migrant workers in Guangdong - often rejected by the public system - are forced to study in substandard private schools far from home that do not receive government support. Principals of schools for migrant workers' children complain about the financial difficulties they face and say they cannot afford to ensure every child has their own seat on buses to and from school. 'We charge students 70 yuan (HK$85) for the school bus every month, but that's only 70 per cent of what it costs,' one Dongguan principal said. 'Migrant parents can't afford more but the school would lose 150,000 yuan if the buses aren't overload - we don't have a choice.' Guo Kaizhi, the principal of Guangzhou's Haizhu school for migrant workers' children, said it could not afford its own buses and had to rent private buses and drivers at 500 yuan a day. 'The school spends about 264,000 yuan to rent six school buses every semester, but receives only 225,000 yuan in bus fees from 250 students, charging them 900 yuan each,' Guo said. 'We still run up a deficit even though we charge the highest bus fees in the district, because the government has declined to provide funding and we can't transfer the cost to parents.' Guo Bin, who works for a Beijing-based non-government organisation dedicated to improving the welfare of migrant workers' children, said more than 90 per cent of school buses used by the children were overloaded, according to a survey it conducted in 2009. 'The safety hazard of school buses has been a problem ever since we started to pay attention to migrant children's education in 2004,' he told the Beijing Times. 'Beijing's school buses for migrant children are very similar to those in rural areas in central and western China. Parents can't afford safe buses, schools are forced to use broken buses and drivers are temporary workers - there's danger all down the line.' Professor Chu Zhaohui, from the National Institute for Educational Research, says the authorities should make sure that every child is protected. Proper public funding for school buses and quality education for migrant workers' children is an investment in the country's future. Every child deserves a seat. 90% The proportion of school buses carrying children of migrant workers that were overloaded, according to an NGO survey in 2009