School custodians run an increased risk of developing asbestos-related diseases, the results of a groundbreaking medical study suggest.
The study, sponsored by the New York City Board of Education, was conducted by Irving J. Selikoff, one of the country’s leading researchers on the health effects of asbestos.
It found that 28 percent of the 660 custodians studied showed X-ray evidence of scarring of the lung tissue and surrounding areas. Among those who had been on the job 35 years or more, 39 percent showed such scarring.
According to Stephen Levin, Dr. Selikoff’s colleague at Mount Sinai Hospital in New York City, such scarring is evident on X-rays in “less than 1 percent” of the general population. It is believed to be caused by exposure to asbestos, he said, and is evidence of asbestosis, a lung disease caused by inhaling asbestos fibers.
The physician said that 53 percent of the custodians who had worked more than 35 years and whose only exposure to asbestos had been at school had chest X-rays that indicated some form of lung disease.
The study, whose findings were sent last week to the New York City board, is the first to examine whether school custodians are likely to develop asbestos-related diseases as a result of their occupational exposure to asbestos.
In a separate study that has yet to be published, a researcher at Massachusetts General Hospital in Boston found scarring in the lining of the lungs of 40 percent of the 121 school custodians examined.
Another study is investigating the instance of asbestos-related lung disease among school custodians in Los Angeles. And the EPA is funding a study that examines whether teachers are at any increased risk for such diseases.
Previous research in the field has established that the miners, millers, and manufacturers of asbestos, as well as those who have regularly used products with a high concentration of the mineral, such as insulators and shipyard workers, run a much greater risk of developing lung disease and cancer as a result of their exposure.
Robert Terte, a spokesman for the New York City Public Schools, said last week that he could not comment on the report until the board had received it.
Joseph Stigliano, chairman of the asbestos committee of Local 891 of the International Union of Operating Engineers, the union that represents the head school custodians included in the study, said he was “amazed” by the findings.
“Obviously,” he said, “we are going to be pushing the board to tighten up its safety standards.”
Mr. Stigliano indicated that after the union’s lawyers review the report, his group may consider suing asbestos manufacturers or the board to improve or better enforce existing safety codes.
Dr. Levin last week termed the high incidence of abnormal chest X-rays among the custodians significant. The scarring shown, he said, is evidence of asbestosis, an irreversible and progressively disabling disease marked by a shortness of breath, chest pain, and a dry, hacking cough.
The study “indicates pretty clearly that this is a problem for school custodians,” said Dr. Levin, medical director of the Mount Sinai-Irving J. Selikoff Occupational Health Clinical Center.
The study does not explore whether school custodians are more likely to develop asbestos-related cancers, he said. But other groups of workers that have been occupationally exposed to asbestos have a higher incidence of lung cancer and mesothelioma, a type of lung cancer caused by asbestos, he noted.
Dr. Levin said that school custodians are more likely to be exposed to asbestos than other school employees because of the nature of their work. He said before the risks of asbestos became well-known, school custodians were routinely disturbing asbestos-containing materials while on the job.
All of the custodians who agreed to be part of the study had worked for at least 15 years in New York City schools. Together, they represented about 85 percent of the district’s most veteran custodial workers, according to Dr. Levin.
He said only veteran workers were included in the study because evidence of asbestos-related disease is not usually apparent for at least 15 years after a person’s first exposure to the fiber.
The custodians took part in one-day medical screenings between 1985 and 1987, during which they were given a complete medical examination, a chest X-ray, and a breathing test, which also can indicate asbestosis.
The school workers were also questioned about their lifetime exposure to asbestos. A little more than a third of the group, or 247 workers, had only been exposed to asbestos at school, Dr. Levin said; the rest had been exposed in previous jobs.
According to the researcher, the report recommends that the custodians be put under medical surveillance because of their presumed greater likelihood of developing cancer. He said it also recommends that these workers avoid further exposure to asbestos at school.
Virtually all buildings, including schools, that were built through the early 1970’s contained asbestos. Federal and state laws that protect workers from asbestos exposure have been enacted since the late ‘70’s.
Despite such laws, Dr. Levin said, “it is still possible that custodians and other workers are exposed today in New York City schools.”
