The threat from asbestos exposure in the ship recycling industry goes far
beyond the realm of mesothelioma, raising the incidence rates for a wide
variety of cancers, according to a recent study examining the health history of
workers in Taiwan.
Although the relationship to mesothelioma is well documented, the latest
study also found an alarming rise in the incidence of esophageal, liver,
tracheal, bile duct and lung cancers for those exposed to asbestos on scrapped
ships.
Shipyards are dangerous places, and the shipbuilding industry is known as
a high-risk occupation because of the heavy reliance on asbestos products in
the past.
And while the use of asbestos in newer ships is significantly lower,
because less toxic materials replaced it, working with older ships remains
particularly dangerous if precautions are not taken consistently.
This study was one of the few that involved only
"shipbreaking," which is the dismantling of old ships for salvage or
scrap. It also examined cancers beyond mesothelioma, a cancer caused almost
exclusively by inhalation or ingestion of asbestos.
The study, published in the on-line medical journal PLOS One, was linked
to the Taiwan Cancer Registry and involved 4,227 workers from the 1985
Kaohsiung Shipbreaking Workers Union who belonged to the Labor Insurance
Program.
They were followed until 2008. There were 940 deaths and 436 cancer cases
reported. Their numbers were compared to a control group of 22,135 who worked
elsewhere.
Researchers from the National Health Research Institute and three
universities in Taiwan participated in the study.
Asbestos Leads to Many Cancers
"Shipbreaking workers had a significant percentage difference of
cancer in comparison with matched-cohort," the authors concluded.
"Overall, cancer also was seen in a dose-dependent relationship with
asbestos exposure."
The study revealed that shipbreakers had a 9.9 percent chance of a cancer
diagnosis, compared to 6.7 percent for those in the control group. They also
were diagnosed at a younger age, 54.5 years old, compared with 57 years for the
control group.
The high rates of cancer incidence beyond mesothelioma were startling.
Shipbreakers were 2.31 times more likely to be diagnosed with esophageal
cancer, 1.6 times more likely with liver and bile duct cancer and 3.08 times
more likely to get cancer of the lung, trachea or bronchus.
Previous studies from Finland and Norway included a 26 percent higher
risk of lung cancer for shipyard workers.
Taiwan Is Home to the Shipbreaking Industry
Taiwan played a particularly relevant role in the study because the small
Pacific island is home to the largest shipbreaking operation in the world.
The authors estimated that 65 percent of all ships worldwide are crushed
and recycled in Taiwan. It accounted for 67 million tons of recycled ship scrap
during one 10-year period.
Older ships often included asbestos materials from bow to stern.
Asbestos was coveted in shipbuilding for its ability to strengthen and
resist heat. It's why U.S. Navy veterans have been hit especially hard by
asbestos-related diseases like mesothelioma.
As many as 300 different parts containing asbestos were commonly used on
Navy ships built in the 20th century. Asbestos was used to insulate boilers and
pipes and virtually everything on a military ship. It would resist heat, fire
and corrosion.
The authors of the study called for "persistent monitoring," of
those in the shipbreaking industry, hoping it will detect any cancers in the
earliest stages when they can be treated more effectively.
Source: asbestos.com. 4 August 2015
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