and multi yanina saving up to buy a professional weighing scale and eventually a truck of their own. then they plan to employ dozens more waste collectors. to make and keep a clean place to live. now and so this week's doing your bit it's hard to imagine an infrastructure project anywhere in the world doesn't use concrete well producing cement for the concrete produces a lot of c o 2 emissions well a group of german scientists and the african partners in nigeria want to make a difference they want to make concrete production more sustainable they've made on all spending discovery take a look at this. africa's building sector is booming the continent uses as much concrete for construction as europe does but making the cement that binds it produces a lot of carbon dioxide up to 10 percent of the world's c o 2 emissions. scientists from germany and nigeria are studying alternatives there are experimenting with remains of local plants such as kosov appeals that have been incinerated at certain temperatures. from the ash that we collect we develop cement like products they could be used i