Surprise! Hollywood's a major air polluter.

What creates more air pollution than the apparel, hotel, or aerospace industries in southern California? Hollywood, says a new report.

Although it's widely known for a 'green' image, the film and TV production industry in California is actually a significant contributor to America's dirtiest skies, sending 140,000 metric tons of ozone and diesel particulates into the air each year.

The good news: Hollywood is getting better despite all those exploding buildings and car crashes.

Those are the conclusions of the UCLA Institute of the Environment's ninth annual Southern California Environmental Report Card.

"There is lots of good stuff going on in Hollywood on this issue, but we found there is much room for improvement," says Mary Nichols, director of the UCLA Institute, in a Monitor interview. "We don't mean to be dropping a bombshell on the industry ... but we found the structure of the industry and the competitiveness doesn't favor making ideas like these universal. There are so many companies that are constantly forming and reforming that it's not easy to develop regulations that work. We need to highlight the good practices to get the overall industry to voluntarily adopt them."

Many in Hollywood aren't happy.

"The UCLA study purports to discuss film and television industry practices but was prepared without consultation with the MPAA or the Alliance of Motion Picture and Television Producers, the major trade industries for the entertainment industry," says Kori Bernards, vice president of communications for the Motion Picture Association of America (MPAA). "And the methodology raises some real questions. Specifically, data being referenced is from 1997 and there are no regulatory bodies sited for authority, which if asked, would tell you the industry gets high marks."

But the study's findings have been welcomed by some in the industry, including John Hughes. He owns the Hollywood computer-generated imagery studio "Rhythm & Hues," which has produced a host of movies, including Oscar-winning "Babe" in 1995 and "Chronicles of Narnia" in 2005.

His firm does not participate in the outdoor, live-action productions that generate the lion's share of airborne pollutants here. But his hundreds of computers require both electricity and air conditioning that do. He says he is considering alternatives, including solar panels and high-tech processors that remove heat from the computers and lower power consumption.

More formal scrutiny, combined with voluntary efforts to reduce pollution industrywide, could go a long way toward instituting a set of standards and practices that does not yet exist, he says.

"It's a good idea to see a report like this and be graded for how we affect the environment," says Mr. Hughes, "because in being graded, we would begin to develop alternatives for better ways to do what we do. It makes you investigate what you do to see if you can improve."

Such individual initiative was singled out in the report as just the kind of innovation that's needed for film and TV production, which employs 252,000 people in the greater Los Angeles area and generates $29 billion in annual revenue.

The study cited several other productions for being environmentally friendly.

•Makers of the 2004 film, "The Day After Tomorrow," paid $200,000 for the planting of trees to offset the carbon dioxide emissions caused by vehicles, generators, and other machinery used in that production.

•Producers of the 2003 film "The Matrix Reloaded" and "The Matrix Revolutions" arranged for more than 97 percent of set material to be recycled – including some 11,000 tons of concrete, structural steel, and lumber.

•Producers with the TV sitcom "According to Jim," eliminated the use of paper in scriptwriting and editing by using small personal computers, "saving time as well as trees," the report said.

State film officials, too, have been quick to point out that every industry in California, including the motion picture/TV industry, is already heavily regulated to curb environmental pollutants.

"California is one of America's most-regulated states when it comes to business and the environment," says Amy Lemisch, director of the California Film Commission, noting that the UCLA report gave the industry an "A" for recycling and the reuse of sets.

"It is true there are so many independent productions that it is hard to make them uniform – but what I see is an industry that is compliant ... as soon as new technologies become available, they are among the first to jump on board."