If you were to throw, say, a banana skin out of your car while driving along the motorway, that would be a completely harmless action, due to the fact that it's part of a fruit—right? Actually, no. A banana skin can take up to two years to be naturally processed, and a third of drivers confess they litter while driving, that's a lot of thrown banana skin. An orange skin and a cigarette butt (烟蒂) have similar biodegrading (生物降解) time to that of a banana skin, but tin cans last up to 100 years; and plastic bottles last forever, as do glass bottles.
Despite the fact that longer-lasting materials will serve to damage the environment and its animals for longer, we can't measure the danger of a certain type of rubbish by its lifetime. For example, despite having a fairly short length of biodegrading time, more than 120 tons of cigarette-related litter is thrown in the UK every day.
It's not a cheap habit either: to keep our streets clean annually costs UK taxpayers £500 million, and when you include our green spaces, that goes up to £1 billion. So, it's not surprising that if caught throwing rubbish, you could face a £20,000 fine or even prison time and, if you threw something dangerous, the court could give you five years to serve. Regardless of how serious these punishments might seem, however, among the reported cases only 2,000 were found guilty out of 825,000, so we still have some way to go in making sure people obey the rules.