``We found growth restrictions on roots of plants, the soft roots couldn't penetrate the layer of plastic,'' says Dhiren Pania, a former park official.

Once plastic carry bags enter the soil they stay there for eternity, forming an impermeable non-biodegradable layer that chokes the soil and prevents plants from growing. Roots of saplings that germinate in a layer of soil cannot enter the layer of plastic beneath, botanists say.

Saplings are unable to hold the soil firmly. ``In the first two rain showers, plants collapsed and had to be transplanted,'' Pania recalled.

Sensing a threat to their ongoing tree plantation and vermiculture drive, the army unit garrisoned in south Mumbai firstbanned plastic bags last month.

``Only two things in this universe are eternal -- the soul and plastic,'' Suyog Shet, an environmental engineer with the Brihanmumbai Municipal Corporation (BMC) illustrates the eternal qualities of the bag. ``Plastic bags cannot be acted upon by any micro-organism or bacteria in the soil.''

Shet explains how plastic bags prevent `leaching' or oozing of biodegraded material into the soil. A case in point being the thousands of floral offerings wrapped in plastic bags that are dumped by citizens into the sea, which BMC has tried hard to discourage.

Six months ago, Mahim nature park began receiving nearly four truckloads of vegetable garbage from municipal markets for use as manure. However, even here the garbage had been covered in plastic carry bags.

A few years ago, BMC tried hard to turn its garbage into manure. But even this novel attempt at composting garbage was wound up when it was found the plastic bags and glass shards in the trash were impossible to sortout.

And when they're not hampering garbage recycling and being washed ashore by the tonne on the city's beaches, the virtually indestructible plastic carry bags are also attacking fragile mangroves on the coastline.

Mangroves are vital. A repository of flora and fauna, they not only prevent soil erosion but support breeding of fish. The city has approximately 2,000 hectares of mangrove growth which environmentalists are working hard to preserve.

Sanjay Deshmukh, a botanist with Bombay Natural History Society (BNHS) who has studied mangroves recalls how he has seen thousands of seedlings covered with plastic bags. ``None of these mangrove seedlings have a chance of survival. The natural regeneration of mangroves which help in soil building towards the sea and prevention of erosion is severely hampered.''

As on land, plastic bags which can be seen flying as millions of little flags on mangroves, inhibit biodegradation. ``The plant and animal matter that normally decompose and provide food for othercreatures in mangrove areas are covered by plastic bags and prevented from decaying,'' says wildlife biologist Anand Pendharkar.

Ban plastic bags entirely:

Mehr JesiaI'm all for the idea of banning plastic bags entirely. In our country, we think of ideas every two minutes, but to see them implemented would be really something else. A few weeks ago, I heard all over the Lokhandwala Complex, where I live, how they are going to stop giving out plastic bags. But nothing has happened. So if something does happen, it would be great. Basically all you need a plastic bag for is to throw garbage. I'm sure there are other ways we can manage our garbage disposal -- after all, we did it before there were plastic bags, right? They should be used more for cleanliness than for convenience. I do think we can live without plastic bags, and very happily, at that.