Monday, June 25, 2012

Grave risk of silica.

Study Exposes Grave Health Risks of Silica

A study conducted in China has recently unearthed some new findings that could be very important to the prevention of future respiratory problems. The study, which was conducted by Chinese scientists over many years, followed and examined a large group of Chinese mine workers that were exposed to a compound called silica. Silica is a substance that is present in both sand and rock, and can be extremely harmful if inhaled. It is perfectly harmless if contained within the rock or the sand, but when rocks and sand are drilled or broken, fine silica dust particles then escape. These are easily inhaled and then lodge themselves deep within the lungs. This leads to all kinds of problems, such as scarring and respiratory issues and even death.

The problems experienced by the Chinese workers - who were working in places such as mines, pottery factories and gem stone factories - had a sinister outlook. The study found that the workers were not only experiencing problems with breathing, but as a result were also at a greater risk of contracting very serious heart problems, infectious diseases and even cancer.

Significant findings

The study is of particular significance due to its sheer size. The scientists monitored the health of 74,040 mine and pottery workers in China, and over a period of 33 years. They then compared the health of these workers to that of people who were not exposed to silica.

One of the leading researchers on the study, Professor Weihong Chen at the School of Public Health, Huazhong University of Science and Technology in Wuhan, Hubei province, acknowledged the new significance of the findings: "In addition to a higher risk of respiratory disease, we see a heightened risk of cardiovascular disease in exposed workers," she said. "This is a new discovery."

The findings of the study are likely to change the focus of health concerns for those conducting jobs with a high exposure to silica and other harmful dust particles; not only for those in mining jobs but also those conducting regular activities such as joinery, glass engraving or sanding. "Before we were mostly concerned about respiratory diseases," Professor Weihong Chen explained. "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."

Large scale

The results of the Chinese study are not only significant in terms of focus and direction of health care issues for these workers, but also in terms of the scale of the risk being posed. The study found that workers exposed to silica were a massive seven times more likely to develop harmful infectious diseases, five times more likely to develop serious respiratory tuberculosis, and around twice as likely to develop some form of cardiovascular illness than those people that worked in clean environments with little exposure to silica. Also among the findings of the study was that those working in environments such as pottery factories or mining wells were almost twice as likely to develop nose or throat cancers.

This study should set off warning bells for industries such as mining, pottery and stone farming, not just in China, but throughout the rest of the world. China is one of the many countries that has a strong industrial dependency, with around 23 million workers exposed to silica through their jobs. Although the United States has nowhere near this number (we currently have around 1.7 million people in these trades), we still have a huge number of people to think about.


One form of harmful respiratory disease is a condition called silicosis that, as its name suggests, is caused by silica. In China, around 24,000 workers die from this disease every year as a result of silica getting into their lungs and staying there. The silica causes so much inflammation, scarring and pain that people with the disease die young - commonly in their forties. This is a huge proportion and a grave cause for concern.

It is hoped that the publication of this study and its findings will lead to increased awareness of the dangers of exposure to silica and will prompt companies to do all they can to decrease the risk of harm to their workers. Professor Chen has made the following recommendations for organisations.

"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. Factories can use stronger ventilators, and more effective masks for workers will reduce silica exposure."

Members of the general public should also take this study as a warning of the dangers of dust compounds such as silica. It is always dangerous to expose your lungs to overly dusty environments. Wearing masks in these circumstances will go some way to protecting your lungs against harmful long term damage.

The ground-breaking study was published this week in the Public Library of Science journal PLoS Medicine.