Too Many Doses of X-rays Can Make Film Sick

“Either we X-ray or you leave the airport.”

These words, feared by photographers, often are heard these days at London’s Heathrow Airport, one of the most security conscious in the world.

Steven Rothfeld, a Santa Monica-based free-lance travel photographer, has heard them twice in recent months. Los Angeles Times staff photographer Kirk McKoy received the same ultimatum while stopping over at Heathrow after a recent trip to Moscow.

“With a deadline to meet, a plane to catch and two months’ work in my camera bag,” Rothfeld said, “I swallowed hard and handed over the film in several sealed plastic bags. It went through without a problem.”

McKoy, on the other hand, was carrying his film in lead bags to protect it from X-ray damage and was delayed for 45 minutes.

“The lead bags showed up as black blobs on the screen, so inspection by hand was necessary,” McKoy said. “But I had 40 rolls still in factory packages. Every roll had to be opened before the inspectors would let me board.”

Naturally, professional photographers who travel a great deal have more to lose in terms of film ruined by X-rays, but even the amateur on vacation wants to be certain that his or her photographs are not at risk.

Do X-rays hurt film?

How can the traveler prevent that happening?

Are there countries where the problem is more serious than elsewhere?

Is there an international X-ray standard that must be met?

These and other questions were asked of several photographers, some of whom reported experiencing long delays and even missed flights because of film inspection procedures.

Yes, exposure to X-rays can harm film. Yes, there are ways of preventing that damage. Yes, some countries, most notably Third World nations, the Soviet Union, Hong Kong and Japan, use technology that can be more harmful than that used in the United States. And, no, there is no international standard that must be met.

The United States, however, does have a standard, one that precludes airport X-ray machines from harming film.

The Federal Aviation Administration (FAA) standard is one milli-Roentgen (mR) per exposure. At U.S. airports, X-ray machines should not exceed that amount.

However, this was not always the case. Jim Walsh, technical associate with Eastman Kodak in Rochester, N.Y., said he had heard in the past of 10mR and even 50mR devices.

“I’ve seen photographic results that indicate that kind of high exposure,” Walsh said. “I’ve seen camera parts clearly shadowed on film.”

Walsh said that one exposure at 34mR will result in noticeable damage to ASA 100 film.

But the possibility of damage also depends on the type of film.

“Basically, X-ray sensitivity hinges on film structure,” Walsh said. “If the film is fine-grain and has relatively low sensitivity to visible light, the sensitivity to X-ray is similar. But there are other confounding issues. And the increase in X-ray sensitivity does not parallel the increase in film speed.”

Fortunately, film’s sensitivity to X-rays rises slower than the rise in film speed. In other words, ASA 400 film (which is what most amateur photographers use) is not four times more sensitive than ASA 100.

Another factor to remember is that X-ray exposure is cumulative. The more times your film is exposed to X-rays, the more likely it will be damaged.

Kodak monitors X-ray sensitivity and assumes acceptable standards of five exposures. Anything more than that and there could be problems.

So what can you do to protect your vacation travel pictures?

In the United States it is generally possible to ask for and receive inspection by hand. You cannot count on the same cooperation overseas.

The only defensive strategy to follow is somewhat involved but, considering the time and money invested in travel, is worth the effort.

Before you leave home, remove all the packaging from the film. Take as many rolls as you think you might shoot, but also add a couple of high-speed rolls even though you may not use them. Put all the film in clear plastic bags.

Moderate amounts should be carried in your camera bag. Larger quantities can be packed in luggage, all in the same suitcase (thus simplifying inspection, if necessary), inside lead bags. Use the plastic bags, too, so you can quickly pull all the film out in one self-contained bundle when the black blobs appear on the X-ray screen.

Arrive at security well in advance of your flight. Take a moment to watch the lines and see which security personnel seem most relaxed and polite. When the crowd has thinned, politely tell the inspector that you have high-speed film, that you will be traveling on several flights and that you are concerned about cumulative X-ray doses. Sometimes, that is enough to get your film inspected by hand.

Never lose your patience. If your pleas fail, suggest that security run a roll or two through the X-ray to show them you have nothing to hide. Or, if you have a language problem, before you go to security contact a representative of the airline to translate your request.

Of course, one can always abandon film and shoot video instead. It is totally unaffected by X-ray.

One word of warning, though: Keep the video away from the magnetic metal detectors. They can scramble or even erase your vacation.