sentence1: Cairo is now home to some 15 million people - a burgeoning population that produces approximately 10,000 tonnes of rubbish per day, putting an enormous strain on public services. In the past 10 years, the government has tried hard to encourage private investment in the refuse sector, but some estimate 4,000 tonnes of waste is left behind every day, festering in the heat as it waits for someone to clear it up. It is often the people in the poorest neighbourhoods that are worst affected. But in some areas they are fighting back. In Shubra, one of the northern districts of the city, the residents have taken to the streets armed with dustpans and brushes to clean up public areas which have been used as public dumps.