Clearing up pollution can be a messy and expensive task, but around the world people are harnessing the power of plants to do the job for them.We hear how water hyacinths are going from hated weed to providing communities with a greener water filtration solution; how plants in the Niger Delta are helping rejuvenate land drenched in oil and devastated by fire and ask whether plants could be the future to more environmentally friendly mining.Presenter: Myra AnubiReporter: Georgina RannardReporter/producer: Lizzy McNeillProducer: Zoe GelberSeries producer: Tom CollsSound mix: Hal HainesEditor: Penny MurphyEmail: peoplefixingtheworld@bbc.co.ukImage: A water hyacinth (Getty Images)