Big-budget special effects and disposable sets help make Hollywood one of California's top air polluters, pumping out 127,000 tonnes of ozone and diesel emissions a year, a study found.

The film and television industry produced more air pollution than four other industries that were studied, according to a report released Tuesday by the University of California in Los Angeles Institute of the Environment.

"People talk of 'the industry,' but we don't think of them as an industry," said Institute head Mary Nichols.

"We think of the creative side, the movie, the people, the actors — we don't think of what it takes to produce the product."

The institute found that the industry emits 127,000 tonnes of ozone and diesel particulate pollutant emissions from idling trucks, generators, special-effect fires and earthquakes, and the demolition of sets with dynamite and other methods.

Beats aerospace, apparel industries

Hollywood produced more pollution than four other industries: aerospace manufacturing, apparel, hotels and semiconductor manufacturing, the study found.

Only the petroleum industry likely tops it in emissions, though the study did not have comparable data to prove this claim.

The report said the use of dozens of contractors with inconsistent practices make the industry difficult to regulate.

Hollywood studios representatives, however, said they are doing a better job of eliminating waste than the study implies, and point to a recent industry study which looked at solid waste recycling.

Cutting down on waste, industry says

The Alliance of Motion Picture and Television Producers study, released in April, said 64 per cent of waste from studio sets — about 21,770 tonnes — was diverted from going to landfills in 2005.

A spokeswoman for Participant Productions, which worked to offset carbon emissions on the sets of Syriana and An Inconvenient Truth, said she was surprised by the study.

"I think the industry as a whole does look at itself," she said. "The studios have done a lot in terms of waste reduction. I think that energy is the new thing the industry is looking at and what impact they have."

The study also noted a few examples where the industry offset emissions. The production teams for the The Matrix Reloaded and The Matrix Revolutions arranged for 97.5 per cent of materials to be recycled, for example.

With files from the Associated Press