One in four asbestos-related cancer deaths likely go unreported
In the first attempt to determine the number of unreported mesothelioma cases worldwide, a team of researchers found that for every four to five known cases of the fatal disease, one case has been overlooked.
The findings, published in the latest issue of the National Institute of Health’s monthly journal, Environmental Health Perspectives, suggest that mesothelioma is much more prevalent than previously known, and that aggressive countermeasures will be needed to prevent and treat the disease in the future.
The study was conducted by researchers from the University of Occupational and Environmental Health in Japan who used reported data on mesothelioma rates and asbestos use in 56 countries. The researchers also calculated unreported mesothelioma cases in 33 countries that use asbestos, but for which no information on mesothelioma was available.
The data revealed that, from 1994 to 2008, mesothelioma killed 174,300 people in the 56 countries with reported data. The researchers estimate that another 38,900 died from the disease in the 33 countries without reported data during that same 15-year period.
“We estimate conservatively that, globally, one mesothelioma case has been overlooked for every four to five reported cases,” the researchers said. “Because our estimation is based on asbestos use until 1970, the many countries that increased asbestos use since then should anticipate a higher disease burden in the immediate decades ahead.”
The study noted that the estimated 213,200 deaths worldwide between 1994 and 2008 — more 14,000 a year — is larger than previous estimates for mesothelioma deaths in developed regions of the world, but smaller than previous estimates of global death.
But, despite the use of different research methods, the findings “are reasonably close to those of earlier reports,” the study said.
The study predicts that the rate of mesothelioma will continue to rise in the countries that produce and export asbestos. The health burden could be especially pronounced in countries such as Russia, Kazakhstan, China, India and Thailand, countries that are also thought to have the most unreported cases.
The shortage of data on mesothelioma frequency in some countries may reflect a lack of awareness, knowledge and resources, the study said. But it may also be because the information is being purposely withheld.
“It is also possible that, even if mesothelioma cases are diagnosed domestically, frequency numbers are not actively disclosed to the international community because of the increasing number of countries adopting bans on asbestos use on grounds of public health,” the study said.
Citing data collected by other sources, the researchers noted that, while more than 50 countries now ban asbestos, cumulative use has doubled since 1970, from 65 million tons in 1970 to 124 million tons. The 33 countries not reporting mesothelioma frequency have increased the use of asbestos by a factor of five.
As those countries struggle with what researchers predict will be “a very high burden of mesothelioma,” they would benefit from the experiences of countries that have long since recognized the dangers of continued asbestos use.
“Developed countries should share experience and technology to enable developing countries to promote accurate diagnosis, reporting, and management of [asbestos-related disease], including mesothelioma,” the study said. “Moreover, political will is essential to ensure that asbestos use ceases globally.”