Professor Ivan Png rightly pointed out that charging for plastic bags may have unintended consequences for public health and estate cleaning (Charging for plastic bags may have unintended costs; Oct 6).

However, he failed to amplify how bad it could be for high-rise building dwellers, especially those living on the lower floors.

In the past, before the anti-littering campaign took off, people who received a summons purposely littered to get back at the system.

When the anti-smoking campaign first started, there were reports of people who wilfully threw lit cigarette butts from high-rise buildings.

With the move to charge for plastic bags, I foresee that people will deliberately "bomb" the rubbish chutes with loads of leftover food.

They will have no inclination to put the unwanted food in plastic bags as it would cost them money.

Even if it is not done in revenge, the messy spills and the stench will be terrible for residents.

Cleaners may not be able to cope either.

It will be a nightmare. But I know that the Government will go ahead because we have always done the right thing, no matter how difficult.

To lessen the backlash, perhaps supermarkets can consider giving away "plastic bag rebate vouchers".

The amount must not be negligible, so that it may prompt the public against the rampant discarding of food waste.

Phillip Tan Fong Lip