Industrialised and developing countries are under threat from asbestos dangers
Despite increasingly strict exposure standards, which have contributed to a fall in asbestos-related pulmonary fibroses, and a cessation of production or prohibitions on use in several countries, there is an alarming increase in asbestos-related cancers, delegates at the annual congress of the European Respiratory Society (ERS) heard.
At the meeting in Berlin on 24 September delegates were told that it is impossible to ignore the global problem caused by the mineral, with an alarming increase in asbestos-related cancers only partly due to the effects of exposure manifesting themselves years or decades after the event. Millions of people continue to suffer daily exposure, largely in the poorer countries, said Antti Tossavainen of the Finnish Institute of Occupationnal Health, with global asbestos production topping two million tonnes in 2000.
Three countries are responsible for the great majority of asbestos production, the largest producer being Russia with 700,000 tonnes, followed by China with 450,000 tonnes, and Canada, with 335,000. The latter exports almost all of its asbestos and appealed against a French ban on the substance earlier this year (see related story). The specialists participating in the congress emphasised that, in the countries that had taken draconian measures, experience showed that the full scope of the damage inflicted by asbestos only became evident long after the exposure took place, while the transition and developing countries are storing up a bleak future for themselves.
“We know that occupational asbestos exposure in Western Europe, North America, Japan and Australia was at its peak in the 1970s,” Tossavainen said. “Now, recent estimates indicate that 30,000 new asbestos-related cancers continue to be diagnosed there every year. They include some 10,000 mesotheliomas and approximately 20,000 cases of lung cancer.”
The Congress heard that while the introduction of increasingly strict limits for exposure had produced a reduction in the diseases known as asbestosis, namely disabling pulmonary fibroses linked to very high asbestos exposure, cases of other asbestos-linked pathologies, particularly cancers of the pleura, known as mesotheliomas, are continually rising. “The epidemiological outlook is clear: there will be a steady rise in the frequency of asbestos-linked cancers until at least 2010 or 2020 because they take years to manifest themselves,” said Marc Letourneux, of University Medical Center Côte de Nacre in Caen, France. He said that the mesothelioma rates are expected to rise in France by as much as 25% every three years, with some 150 fatalities every year between 2010 and 2020, almost twice the rate of 1996-1997. The figures are particularly worrying as research by Brussels’ University of Erasmus shown at the same Congress discussed that any level of exposure can increase the risk of developing a cancer of the lungs.
Another study by the Erasmus Hospital showed that of 160 autopsies performed between 1998 and 2000, pleural plaques, indicating a thickening of the pleura, were found in 14% of subjects and concentrations of over 1,000 asbestos bodies per gramme of dry lung tissue were found in 13% of subjects, meaning that, at present, almost one person in seven bears the scars of asbestos exposure.
The specialists concluded that there is no answer at present as to whether hospitals should screen systematically for the signs of past exposure in all patients who have had contact with asbestos, as it is possible for a bronchopulmonary cancer to appear, develop and evolve during the period between two scans.
The UK’s National Society for Clean Air recently published a leaflet on the safe handling of asbestos in the work-place (see related story).