The Keep Australia Beautiful National Litter Index has revealed disposable nappies account for nearly half of miscellaneous rubbish.

Car parks and highways were the most common dumping grounds for dirty nappies in NSW, according to the findings.

The report comes after a reader expressed their disgust at this problem with a thumbs down recently.

“Thumbs down to the people in the van throwing out dirty nappies in Canal Street,” the reader said.

The report found used nappies comprised more than 10 of 21.6 litres/1000-square-metres of miscellaneous rubbish tossed in public places across the state.

Keep Australia Beautiful chief executive officer Peter McLean said it was a shocking example for parents to be setting their children.

“Presumably, many soiled nappies are thrown out of cars because, like cigarette butts, they smell,” Mr McLean said.

“Apart from being unhygenic, it is bad for the environment, with some disposable nappies taking up to 500 years to biodegrade.

“Parents are not considering the the fact that it will be their own children who will have to clean up environmental damage caused by dirty nappies left to rot along roadsides and in other public places.”

Nationally, the National Litter Index interim report revealed disposable nappies accounted for nearly 20 per cent of the 152 litres/1000-square-metres.

Dirty nappies were the third biggest problem after construction materials and tyres.

Mr McLean said while the number of dumped nappies was not as large as other litter items such as cigarette butts and fast food packaging, the issue was sizeable.

“Disposable nappies are not so absorbent that even small varieties swell to become relatively large and heavy,” he said.

“They take up more room in landfill which is why they are rapidly becoming an emerging litter trend when it comes to volume of waste.

Mr McLean urged mums and dads to do the right thing.

“We can only speculate that the nappies are discarded because they’re offensive, but surely it’s not too much to ask parents to travel with spare plastic bags which they can use to store the soiled nappy until they find a bin,” he said.

FAST FACTS

- Australians use about 5.6 miillion disposable nappies per day

- Two billion used disposable nappies go into landfill per year in Australia

- Scientists estimate disposable nappies can take up to 500 years to decompose

- In Australia, 95 per cent of parents use disposable nappies.