The U.S. Food and Drug Administration is going to start testing milk this year for residues of antibiotics and other drugs used by dairy farmers to fight infections in cows.

But don't expect the new program to end arguments about whether or not the American milk supply is completely safe. There's room for wondering if enough tests are made by the FDA. And critics claim some drug residues can subject consumers to potential risk from cancer.While it is legal to administer the drugs to animals, it is illegal to sell milk that contains residues of most of the medications. In other words, farmers must wait until the drugs are out of the animals' systems before sending the milk to market.

The FDA plans random testing at 250 of the nation's biggest milk processing plants. Each week five plants will be tested. At that rate, each plant would be tested only once a year.

Scripps Howard News Service quotes Rep. Ted Weiss, D-N.Y., a leading proponent of testing, as calling the FDA's plan "a paltry effort" that "will tell the public virtually nothing about the true extent of animal drug residues in milk."

This situation ought to bother the dairy industry as much as it does critics like Rep. Weiss. The testing of milk is much better than it used to be. And the FDA isn't the only body that tests milk. But as new drugs are developed for use by dairymen, there's more for testers to check on. It would be devastating for the industry to have a problem with drug residues. Dairymen should join the public in pressing the FDA to do a more thorough job with the agency's latest testing program.