Americans are less worried about a series of environmental problems than at any time in the past 20 years. That's the conclusion of a new Gallup poll released today. According to the poll, Americans are least concerned about global warming and most concerned about drinking water.

The poll, which was conducted by telephone in early March, shows for six of eight items the percentage of respondents who said they worry "a great deal" is the lowest point Gallup has ever measured. For all eight items, concern declined. The number of respondents who were worried about drinking water cleanliness fell from 59 to 50 percent during the past year. The number who were worried about climate declined from 33 to 28 percent.

Gallup attributes the decline to the fact that Americans "perceive environmental conditions in the United States to be improving," adding that the findings "also may reflect greater public concern about economic issues, which is usually associated with a drop in environmental concern."

Read more information about the Gallup poll's conclusions.