Do you know there could be chemicals in your clothes, food packaging and even your make-up which can take hundreds or even thousands of years to break down?

They’re called PFAS - or “forever chemicals” - and they are everywhere. They're in our drinking water, at harmful levels in some areas, and they’re inside our bodies, our brains and our blood. They’ve been found on the top of Mount Everest, too.

BBC climate and science reporter Esme Stallard explains what these chemicals are and how they get into our bodies. Stephanie Metzger from the Royal Society of Chemistry in the UK tells us the effect they can have on our health. And podcast host Robin Laird tells us what she does to try to avoid PFAS.

France has just brought in a ban on cosmetics and clothing that contain these chemicals - they can’t be produced, imported or sold there now. We hear about the steps some countries are taking to try to limit their use. Gittemarie Johansen, a Danish environmental and sustainability advocate, gives us her view on what governments and manufacturers should do.

Instagram: @bbcwhatintheworld Email: whatintheworld@bbc.co.uk WhatsApp: +44 330 12 33 22 6 Presenter: Iqra Farooq Producers: Chelsea Coates and Julia Ross-Roy Video Journalist: Baldeep Chahal Editor: Verity Wilde