The Hindu , Friday, April 11, 2008

Correspondent : Staff Correspondent

WASHINGTON: A rose smells as sweet by any other name but not in any other air, especially polluted air. A new study has found flowers are fast losing their fragrance, and the culprit is air pollution. Air pollution is also gradually eroding the quality of our life, besides undermining our health and well being, according to the study that found smoke from power plants and automobiles is destroying something as basic as fragrance of flowers and diminishing the ability of pollinating insects to follow scent trails to their source. This could explain why wild pollinators like bees that require nectar for food are declining worldwide. "The scent molecules produced by flowers in a less polluted environment, such as in the 1800s, could travel for roughly 1,000 to 1,200 metres; but in today's polluted environment downwind of major cites, they may travel only 200 to 300 metres," said Jose D. Fuentes of University of Virginia and a co-author of the study. "This makes it increasingly difficult for pollinators to locate the flowers." The result is a vicious cycle where pollinators struggle to find enough food to sustain their populations, and populations of flowering plants, in turn, do not get pollinated sufficiently to diversify. Findings of the study appear online in the latest edition of the journal Atmospheric Environment . Other studies and field experiences have shown that populations of bees and butterflies have declined greatly in recent years. The new study says air pollution, especially during peak summer, may be a factor. Scent molecules of flowers are volatile and quickly bond with pollutants like ozone, hydroxyl and nitrate radicals. Instead of travelling intact for long distances with the wind, the scents are chemically altered and the flowers, in a sense, no longer smell like flowers. This forces pollinators to search farther and longer and possibly to rely more on sight and less on smell.

SOURCE : The Hindu, Friday, April 11, 2008