American actor and singer Zac Efron highlights the huge issue of London’s plastic waste problem as part of a new series on Netflix airing in the UK from 10 July. Efron visited a key plastic waste hotspot at the scenic Concrete Barges, Rainham, an area of Essex saltmarsh where tonnes of lightweight plastic waste from the capital accumulates, forming huge plastic carpets.Thousands of single-use bottles, cotton buds and food containers wash up on the strandline at high tide, and local…