After a four‐year period of new ownership and management, the Bing & Bing properties in Manhattan have changed hands again. The buyers are unidentified investors who apparently include members of the Bing family.

The Bing & Bing properties, long considered among the choicest specimens of prewar residential real estate in Manhattan, were acquired in 1973 by Sigmund Sommer, the builder. There are 37 properties, of which 33 are considered “luxury” buildings, largely on East Side sidestreets and avenues.

Last week title passed to buyers de scribed only as the investment clients of Arthur Richenthal. No sale price was reported, but there was a “substantial cash consideration above existing encumbrances,” as the title insurer, the City Title Insurance Company, put it.

For the tenants of the 2,500 apartments, the change means a return to management by Bing & Bing Inc., which ran the properties for many years before the sale. Although the concern bears the family name, it is no longer owned by the Bing family

It may also mean new investment to improve the buildings. Mr. Richenthal, though declining to identify his clients, said that the buildings were undergoing a physical examination by Bing & Bing to determine what must be done. Money will be budgeted as required to improve them over a period of time, he said.

So ends what can only be described as Mr. Sommer's unsuccessful fouryear experiment at managing, during a period of sharply rising operating costs, some of the finest and best prewar rental apartment buildings in Manhattan.

It was a tenure marked by tenant complaints and lawsuits, not an accustomed circumstance in the first‐class residential properties that Bing & Bing buildings symbolized. At one time the company had more than 10,000 tenants in office, apartment and hotel properties. In its days as a construction organization, it built not only apartment houses but also hotels, including the Drake, Dorset, Taft, Alden and St. George.

When the Sommer organization took over, it was also involved in completing and renting two major luxury apartment projects in a tough rental market —the Sovereign at 425 East 58th Street and North Shore Towers in Queens, on a portion of the old Glen Oaks Country Club.

The Bing interests—Dr. Peter Bing, Anna Bing and Matthew Kanin—gave Mr. Sommer a $38.4 million “blanket” mortgage on the apartment properties as part of the 555.8 million sale in 1973. There was no information on whether the mortgage was in default. The “encumbrances” paid off in the sale were said to include a $2.6 million Citibank mortgage and unpaid taxes.

Most of the Bing & Bing apartments are rent stabilized. Mr. Sommer bought them at a time when many investors thought that vacancy decontrol would gradually lift the value of choice residential real estate or that a conversion to cooperative ownership might be possible. Instead, vacancy decontrol was ended by the Legislature, although the first rental after a controlled apartment becomes vacant is allowed at market level, as the apartment moves into the stabilization system. Cooperative conversion has drastically subsided since passage of the Goodman‐Dearie law.

Bing & Bing was founded in 1960 by Alexander M. Bing and Leo Bing. Alexander M. Bing's son, Alexander S. Bing, retired as president in 1955, and a year later the company was reorganized. It remained in the ownership and management business, but did no more construction.

The current president is Mortimer Grunauer and the executive vice president is Gonzaga Woods. After the sale to Mr. Sommer Bing & Bing continued to manage the Hotel Dorset and several smaller properties.

Mr. Sommer could not be reached for comment on the transaction. His office said he would be out of town for a week.

The addresses of the properties follow:

WASHINGTON, April 30 — John W. Gardner said today that while he was Secretary of Health, Education and Welfare he was never given the results of a Government‐financed study in 1965 showing a high rate of leukemia deaths among people exposed to low‐level radiation during nuclear weapons tests in Nevada in the 1950's. He attributed the omission to a “conscious act of negligence.”

The Teukemia study, headed by Edward S. Weiss, who was then in charge of the United States Public Health Service's radiologial health division, was never published and came to the attention of the public only this year through a request made under the Freedom of Information Act.

Mr. Gardner, who founded Common Cause, the public lobby, after leaving the Government, said in an interview that “something of that relevance” should not have been withheld from him. He said he did not know who might have been responsible for the failure or how it might have occurred.

Documents released recently from H.E.W. indicate that Mr. Gardner and Douglass Cater, President Johnson's special assistant for health, knew leukemia research was being conducted. However, both mid in interviews that they could not recall receiving the results of the study; and there was no indication in the documents that they pursued the results.

Thousands of documents on the health studies of people who lived near the test site have been released recently and are likely to play a large role in future Congressional hearings. Among them are papers showing that in 1965 some officials in the White House and H.E.W. knew the results of Dr. Weiss's leukemia study as well as its companion report on thyroid disease among children in Utah. Mr. Gardner said he knew of the thyroid study, and the documents show that he urged its release.

President Carter has ordered that both the thyroid study and leukemia research be reopened and investigated thoroughly.

Although the studies did not conclude that there was a direct link between radiation exposure and leukemia or thyroid diseases, the documents show that Government officials in 1965 were so concerned that they held numerous highlevel conferences on how to present some of the information to the public in a manner that would not alarm people but at the same time would protect the officials from charges of withholding pertinent data.

The documents show that Government officials worried about the legal responsibility for injuries or deaths that might be linked to the Nevada tests. There were detailed analyses of what were viewed.

particularly by experts at the Atomic Energy Commission, as scientific errors in the studies. There were also debates about the impact of the data on peaceful application of nuclear energy.

In recent years, as the body of scientific knowledge about radiation exposure has grown, hundreds of people living near the test site and former soldiers who participated In the tests have filed claims against the Government for deaths or disease contend resulted from the However, there is still sharp controversy in the community over the exact nature of the effects that the fallout might have produced. In 1965 dozens of top Government offi

cials were involved in planning a response for public to the leukemia and thyroid studies. After two months of. meetings, a press release was issued giving the results of the thyroid study and announcing that tests would be conducted. All references to the leukemia study were edited out of the final press release. One of the studies showed “exces

sive” rate of leukemia deaths in Utah's Washington and Iron counties, which are adjacent to Nevada, between 1950 and 1965. people died of leukemia, compared to 19 that would have been expected according to national averages. The other study found 70 children in County had nodules, six of whom were recommended for immediate medical attention. Among other things, thyroid nodules could lead to benign or malignant tumors. “What would be the Federal Govern

any possibly due to radiation, which might be discovered” in further studies of the thyroid an official in the White House science adviser's office, Peter Bing, wanted to know in September 1965. The question apparently of such urgency that next day Mr. conferred with lawyers from H.E.W., officials from the Energy Commission, an Assistant Surgeon General and radiological health experts. According the documents, they discussed both the leukemia and thyroid studies and how to draft a press release on these studies.

Associated Press