Maryland health officials have decided to delay seeking regulations controlling use of rock containing asbestos fibres in roads, playgrounds and driveways around the state.
The move apparently reflects concern that the evidence is not strong enough to win the required legislative approval of emergency action.
Three weeks ago, officials said the high level of cancer-causing asbestos fibres in the widely-used rock taken from four quarries - including one near Rockville - constitutes an "imminent" health hazard.
Officials will seek substantially the same regulations as they originally requested, but in such a way that legislative approval will not be required. The new, non-emergency regulations, will require a much longer time to implement - perhaps three times as long as the original regulations which would have taken effect as early as Oct. 1. Public hearings will be required.
Sources involved in the issue said the decision was largely a tactical one, taken out of concern that the legislative committee would reject the regualtions.
The difficulty in convincing the legislative committee, officials believe, stems from the imprecise standards for determining what constitutes an asbestos hazard.
"We're not stepping back from our position," said a spokesman in Health Secretary Neil Solomon's office yesterday. "We still consider this a threat to public health."
The proposed regulations, which would have prohibited the use of serpentinite rock - which contains the absestos fibres - as a surfacing material unless it is sealed or covered drew strong protests from industries, such as the four Maryland quarries producing the rock, the National Crushed Stone Association and the Motor Truck Association.
"There is absolutely no evidence of an imminent hazard to public health." Robert G. Smith, a Baltimore attorney for the four quarries, wrote Solomon in a 14 page letter.
He also complained that tests in Montgomery County, where the Rocksville Crushed Stone quarry is located, showed asbestos fibre concentrations that were below levels "which can be predicted to cause any adverse health effects."
The entire Maryland delegation in Congress sent a letter to the acting regional administrator of the Envoirnmental Protection of Agency relaying the "concerns" of the National Crushed Stone Association about the proposed rules.
Among other things the congressional delegation's letter to Dr. Alvin R. Morris said that hears about health hazards associated with the use of crushed stone may have been "premature" because of limited testing.
Rep. Newton R. Steers, a Montgomery Country Republican, said that by signing the letter he was "in no way endorsing" the National Crushed Stone Association's position. The industry group has been lobbying against the regulations.
Steers said he backs restrictions on asbestos material based on the "best authorities presently available."
"They don't have to be based on precise measurement levels," he said. "Just set them on the safe side. This is cancer. It's a very, very dangerous problem."
Concern about the rock first surfaced last fall when Dr. Irving J. Selikoff, a leading asbestos experts, reported that asbestos concentrations near the Rocksville Crushed Stone quarry were 1,000 times greater than the average for 50 U.S. cities.
However, with the exception of exposure to industrial workers, little is known about what amount of asbestos concentration presents serious health hazards Scientists cannot agree just where to place the "danger threshold for inhalation of asbestos fibers.
Learning this at a National Bureau of Standards conference on asbestos last month, Maryland Assistant Health Secretary Benjamin D. White questioned the efficacy of seeking emergency standards, sources said.
"The problem is that the scientific community can't make up its mind," one health official said. "The problem is to get a doctor to stand up and declare it's an imminent threat."
By following the standard procedures, the health department believes it can build a sufficient case for the restrictive regulations on the grounds that the public must be protested from "potential" risks of acarcinogenic asbestos fibers, sources said.
Tests in Montgomery County showed asbestos levels which were 10 times greater than the amounts of asbestos found downwind from the spraying of asbestos on buildings, a practice now banned by the EPA.