Dow Chemical Co. yesterday released results of medical tests tht indicate sterility in workers exposed to the pesticide DBCP was confined to one of the three plants where the company produced the chemical.

The tests company spokesman said, do not contradict earlier findings that 37 workers exposed ot DBCP at a Dow plant in Magnolia, Ark, developed sterility problems.

But, spokesman said, they do raise two possibilities either the company had poorer controls on the handling of the presticide at its Magnolia or that sterility may ne reversible in time.

"There's no question that we had a very, very serious problem at the Magnolia plant," company spokesman james Hansen said. "These tests don't change anything about that problem. We still don't know what happened in Magnolia.

Dow recalled all outstanding stocks of the liquid pesticide dibromochloropropane, or DBCP, in August after 60 cases of sterility among male workers were found in Magnolia and at an Occidental Chemical Co. plant in Lathrop. Calif.

The new tests were conducted in Midland, Mich., where Dow produced DBCP for 18 years. The Company said it found that 249 workers exposed to the pesticide from one to 15 years appeared no less fertile than other males tested.

Two-thirds in each group had mormal sperm counts, while 6.8 per cent of the DBCP workers and 6.5 per cent of the 77-membre control group had what are considered low sperm counts.

"We're obviously delighted with the findings," said Hansen. "They substantiated what I've been saying all along, There's one helluva lot of kids in Midland and they had to come from somewhere."

A chemical soil fumigant sold under the trade names of Fumazone or Nemagon, DCBP is used to kill parasite worms that feed on root crops. It has been produced in the United States by Dow and Shell Chemical companies.

Research conducted 20 years ago by the two companies indicated taht DBCP caused serility and cancer in animals. But it wasn't until September that the federal government took steps to restrict its use.

Dow moved its main DBCp activities from Midland to Magnolia two years ago. Spokesmen earlier announced that no cases of sterility were found in a third company plant at Pittsburg, Calif., where the presticide was processed.

Dr.Estill Blair, company director of health and environment, said officials have been unable to pinpoint why DBCP workers in Magnolia and Lathrop became serile and those at the two other locations tested did not.

However, he noted that the Midland plant is a major Dow facility, employing more than 12,000 people. It has a longhistory of dealing with dangerour chemicals, he said.

"The other thing that may be operating here is that there may be reversal over a period of time," he added.

Dow workers in Pittsburg, Calif., and Midland have not come in contact with the chemical during the last two years.