'Biodegradable' plastic bags survive three years in soil and sea

Study found bags were still able to carry shopping despite environmental claims

Plastic bags that claim to be biodegradable were still intact and able to carry shopping three years after being exposed to the natural environment, a study has found.

The research for the first time tested compostable bags, two forms of biodegradable bag and conventional carrier bags after long-term exposure to the sea, air and earth. None of the bags decomposed fully in all environments.