Featured Research

from universities, journals, and other organizations

Emphysema Severity Directly Linked To Coal Dust Exposure

Date:
July 24, 2009
Source:
American Thoracic Society
Summary:
Coal dust exposure is directly linked to severity of emphysema in smokers and nonsmokers alike, according to new research.

Coal dust exposure is directly linked to severity of emphysema in smokers and nonsmokers alike, according to new research from the National Institute for Occupational Safety and Health (NIOSH).

"In this study we have shown that coal mine dust exposure is a significant predictor of emphysema severity," said Eileen Kuempel, Ph.D., a senior scientist at NIOSH and lead author of the study.

The findings, which were reported in the August 1 issue of the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine (AJRCCM), highlight a health problem related to a growing industry. In the past 25 years, coal production has nearly doubled worldwide.

Dr. Kuempel and colleagues compared lung autopsy results from 722 individuals, including 616 coal miners from West Virginia and 106 non-miners from West Virginia and Vermont. Those from West Virginia were collected from consecutive autopsies from 1957 and 1973 at the Beckley Southern Appalachian Regional Hospital as part of a black lung study. Those from Vermont were taken from consecutive autopsies performed at the University of Vermont between 1972 and 1978. Age at death, race, miner/non-miner status and smoking history were established where possible, and individual exposure to coal dust was estimated using work history data and job-specific dust exposure estimates.

Pathologists Francis Green, M.D., and Val Vallyathan, Ph.D., two of the coauthors on this study, examined sections of the lungs to determine the presence and extent of emphysema. A smaller subset of the study group had their lung tissue analyzed for dust content. Emphysema was graded for type and severity.

The researchers found that cumulative exposure to respirable coal mine dust was a highly significant predictor of emphysema severity after accounting for cigarette smoking, age at death, and race. Miners tended to be older at death than non-miners due to a higher proportion of accidental or other sudden deaths among the non-miners. Miners also smoked less on average, though differences were nonsignificant. However, emphysema in miners was significantly more severe than in non-miners among both smokers and never-smokers. Unsurprisingly, emphysema was also more severe among smokers than never smokers in both miners and non-miners. Coal mine dust exposure and cigarette smoking had similar, additive effects on emphysema severity in this study.

The lung tissue analysis corroborated these findings; the greater the concentration of coal dust in the lungs, the more severe the emphysema.

While the data were collected on miners who worked in the mines before the enforcement of the federal standard limiting legal coal dust concentrations to 2mg/m3 imposed in 1972, the study does have immediate relevance to current occupational safety standards. Even at the current federal standard, a full working lifetime's exposure would produce a cumulative exposure similar to the levels found in the autopsied miners.

"Based on our findings, exposure to respirable coal mine dust for a full working lifetime at the current 2 mg/m3 standard would increase the emphysema severity index by 99 points on average. This provides additional evidence of the need to reduce dust exposures to 1 mg/m3 or less as NIOSH has recommended." said Dr. Kuempel. "Furthermore, miners in developing countries may be faced with exposure levels in excess of those reported here. Thus, the effects of dust that we report are relevant to current conditions in many countries, including the U.S."

A 99-point increase on the 1000-point emphysema severity index scale is equivalent to an approximately 10 percent increase in diseased lung tissue. Previous studies have shown that a 99-point increase in emphysema severity could mean the difference between "normal" and "abnormal" lung function or the worsening of existing lung function.

Coal mine dust exposure is now generally accepted as a cause of COPD, but this study will provide the basis for improved recognition of dust-induced COPD, its relationship to cigarette smoking, and may enhance efforts at prevention, diagnosis and medical management of occupational dust-related lung diseases, according to Dr. Kuempel.

"Coal employs over 7 million people worldwide, 90 percent of whom are in developing countries. Coal production has almost doubled in the past 25 years," notes Benoit Nemery, M.D., Ph.D., in an editorial in the same issue of the AJRCCM. "The environmental and climatic impacts of burning coal are, quite rightly, a source of concern. However, the direct consequences of extracting coal on the health of millions of coal miners must be an equal concern."

"Improving disease surveillance and awareness among healthcare professionals about the occupational components of COPD including emphysema can increase the effective detection and management of these diseases," said Dr. Kuempel.


Story Source:

The above story is based on materials provided by American Thoracic Society. Note: Materials may be edited for content and length.


Cite This Page:

American Thoracic Society. "Emphysema Severity Directly Linked To Coal Dust Exposure." ScienceDaily. ScienceDaily, 24 July 2009. <www.sciencedaily.com/releases/2009/07/090723175438.htm>.
American Thoracic Society. (2009, July 24). Emphysema Severity Directly Linked To Coal Dust Exposure. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2009/07/090723175438.htm
American Thoracic Society. "Emphysema Severity Directly Linked To Coal Dust Exposure." ScienceDaily. www.sciencedaily.com/releases/2009/07/090723175438.htm (accessed October 22, 2014).

Share This



More Health & Medicine News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Working Mother (Oct. 22, 2014) Is your child ready? Video provided by Working Mother
Powered by NewsLook.com
U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

Newsy (Oct. 22, 2014) Now that the U.S. is restricting travel from West Africa, some are dropping questions about a travel ban and instead asking about visa bans. Video provided by Newsy
Powered by NewsLook.com
US to Track Everyone Coming from Ebola Nations

US to Track Everyone Coming from Ebola Nations

AP (Oct. 22, 2014) Stepping up their vigilance against Ebola, federal authorities said Wednesday that everyone traveling into the US from Ebola-stricken nations will be monitored for symptoms for 21 days. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Doctors Help Paralysed Man Walk Again, Patient in Disbelief

Doctors Help Paralysed Man Walk Again, Patient in Disbelief

AFP (Oct. 22, 2014) Polish doctors describe how they helped a paralysed man walk again, with the patient in disbelief at the return of sensation to his legs. Duration: 1:04 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins