| HONG KONG, April 19
HONG KONG, April 19 Chinese workers who are
exposed to silica dust in mines, and pottery and gemstone
factories suffer not only from respiratory illnesses, but are at
higher risk of contracting heart and infectious diseases and
cancer, researchers in China have found.
Silica is a compound found in sand and rock. When rocks are
drilled or broken, fine silica dust particles are produced that
lodge deep in the lungs and can lead to scarring, severe
respiratory problems and death.
Researchers monitoring the health of 74,040 mine and pottery
workers over an average of 33 years found that they suffered a
far higher risk of contracting a range of diseases compared with
people who were not exposed.
"In addition to a higher risk of respiratory disease, we see
a heightened risk of cardiovascular disease in exposed workers.
This is a new discovery," said Professor Weihong Chen at the
School of Public Health, Huazhong University of Science and
Technology in Wuhan, Hubei province.
"Before we were mostly concerned about respiratory diseases
... as to whether it raises the risk of cancer, we can give a
definite answer: We see a heightened risk of lung cancer in
workers exposed to silica."
Compared with people operating in cleaner environments,
workers exposed to silica were nearly seven times more likely to
contract infectious diseases, nearly five times more susceptible
to respiratory tuberculosis and nearly twice as vulnerable to
cardiovascular disease, Chen and colleagues said in a paper
published this week in the Public Library of Science journal
Exposed workers who have spent at least a year in either
metal mines or pottery factories were found to be nearly twice
as susceptible to cancers of the nose and throat.
More than 23 million workers in China and more than 10
million in India are exposed to silica dust. This occupational
health hazard is also present in the developed world, with 1.7
million people in the United States and 3 million in Europe
According to the World Health Organisation, more than 24,000
workers in China die each year from silicosis - a disease caused
by silica penetrating deep into the lungs, causing inflammation
and scarring. Many victims die relatively young, in their
mid-40s, according to social workers.
Medical research has also estimated that one in two former
gold miners has silicosis in South Africa, where gold mines
employed as many as 500,000 people in the 1980s.
Chen said she hoped the study would help lead to work place
"We recommend that worksites control levels of such
pollutants; it's a public health problem. Through changes in the
work environment, we can reduce the risk of disease and (early)
death," she said. "Factories can use stronger ventilators, and
more effective masks for workers will reduce silica exposure."
The full paper is available at: here%3Adoi%2F10.1371%2Fjournal.pmed.1001206
(Editing by Chris Lewis)