Opening the Arctic National Wildlife Refuge to drilling would result in only 46,300 jobs, far fewer than the hundreds of thousands of jobs cited by some unions, according to a study released by environmental groups. The study, by Dean Baker of the Center for Economic and Policy Research, found numerous faults in an outdated 1990 study that was used by the Teamsters and the oil industry to claim that 750,000 jobs would be created by the drilling. The Teamsters, who helped President Bush win House approval for his plan to open the refuge last month, stood by the 1990 study this weekend. But the United Auto Workers and the Service Employees International Union have come out against the drilling plan in recent days. On Sunday, Sen. John Kerry (D-Mass.) repeated his pledge to filibuster a bill supporting drilling, if necessary.