April 26, 2006

Health and Safety

Wanted: workers exposed to asbestos

Mesothelioma most fatal to construction workers

PETER KENTER

correspondent

TORONTO

Medical researchers are looking for workers to take part in a study into mesothelioma, the occupational illness most likely to kill construction workers.

Mesothelioma, primarily caused by exposure to asbestos fibres, isn’t lung cancer or asbestosis, which are conditions affecting the lungs themselves, says Dr. Michael R. Johnston, Division of Thoracic Surgery, Department of Surgical Onncology at Princess Margaret Hospital.

The condition is a cancer affecting the pleura, a thin lining of the chest wall outside the lungs. Of 400 cases of mesothelioma diagnosed in Ontario each year, about 80 per cent are directly attributable to asbestos exposure — though the numbers may be as high as 95 per cent, says Johnston.

Dr. Michael Johnston

Most cases are concentrated in people involved in the construction trades, where asbestos had been used as a common construction material.

“Those numbers are still increasing each year, because of the long latency period of the disease,” says Johnston. “In the 1950s, ‘60s and ‘70s, asbestos was the miracle product used as anything from play dough to insulation. It can take anywhere from 20 to 50 years to develop to a point where a patient has symptoms.

“People developing symptoms today may have had exposure in the 1970s, so we may see a levelling off of cases in about 10 years.”

WSIB statistics show that, in the past 10 years, 135 deaths in the construction industry were caused by mesothelioma, as compared to 69 for lung cancer and 10 for asbestosis.

Johnston’s study is part of a three-pronged approach that will attempt to: identify workers who may have mesothelioma with early detection through CAT scans; provide aggressive treatment through chemotherapy, surgery and radiation; and conduct further research into why asbestos exposure initiates the formation of tumours in the chest cavity.

One of the goals of the program is to purchase a mobile-screening facility that would screen workers on-site.

The cost of a single bus equipped with a CAT scanner: $2 million.

“We’ll have to look at private donations to fund such an initiative as this,” says Johnston.

Currently, workers from Sarnia — an area where a disproportionate number of workers with mesothelioma are located—are transported to Toronto by bus.

Johnston spoke at the annual general meeting of the Construction Safety Association of Ontario (CSAO), held in Mississauga on Monday. New CSAO president Neil McCormick has identified an increased awareness of occupational disease as one of the priorities for his term of office.

Workers who have been exposed to asbestos at least 20 years ago, and those who have been told that chest X-rays reveal pleural plaques can take part in the study by contacting Brenda O’Sullivan, Co-ordinator of the Mesothelioma Early Detection Study at Princess Margaret Hospital at 416-340-5686.

Print | Email | Comment