WASHINGTON -- A new survey finds most American adults strongly support environmental protection but are overwhelmingly wrong about how waste is handled and what really causes most pollution.

In many cases, Americans still tend to believe that corporations and institutions are responsible for most environmental problems when the blame lies more on the practices of individual consumers and households.Although most adults express a willingness to take steps to help protect the environment, "myths are a powerful force in our environmental thinking," said Kevin Coyle, president of the National Environmental Education and Training Foundation, which sponsored the survey of 2,000 people conducted by the polling firm of Roper Starch Worldwide.

"This dependence on mythology threatens to block progress on important environmental initiatives."

Of 10 multiple-choice questions that contained a true answer, a mythical answer and two plausible but incorrect answers, people taking the survey got an average of just 2.2 correct -- worse than the 2.5 they'd have scored just by random picks.

Among the most common enviro-myths:

-- Spray cans contain ozone-depleting chlorofluorocarbons (CFCs). They haven't since 1978, but 32 percent said they did. Only 35 percent knew that the only remaining source of CFCs are air conditioners and refrigerators.

-- Oil pollution comes mainly from tanker leaks, offshore drilling or coastal refineries. Only 16 percent correctly said the major source of oil spills are do-it-yourself oil changes and improper disposal of waste oil down drains.

-- Most electricity comes from power plants that don't release any emissions to the air -- like hydroelectric dams. Only 27 percent knew that burning oil, coal and wood accounts for 70 percent of the nation's electricity.

-- The major cause of wildlife entanglement are discarded plastic six-pack rings. Only 10 percent correctly said that fishing lines abandoned by anglers are the leading cause of entrapment.

-- Disposable diapers are responsible for clogging landfills. Just 23 percent said correctly that office paper and cardboard packaging are the leading culprits.

-- Factories are the leading cause of water pollution. While this was once true, only 22 percent knew that runoff from farm fields, lawns, roads and parking lots is now the major water quality problem faced by the nation.

Coyle said the myths are likely embedded in part because consumer campaigns and media reports have focused on specific problems that have now largely been solved.

"An oil spill from a tanker has a much bigger visual impact than an oil spill under your lawnmower," he said. "It's a lot easier to say that the problem is upstream."

The survey found that 71 percent of respondents believed that environmental protection should take precedence over economic development if a reasonable compromise is impossible -- more than at any time in seven years that the survey question has been posed.

And as many 85 percent said they frequently take steps in their daily lives to protect the environment by turning off lights and appliances, with 65 percent saying they recycle.