Four coal slag samples from commercial suppliers were tested for fibrogenicity in male Sprague-Dawley-rats. The geometric mean diameters for Slag-I, Slag-II, Slag-III, Slag-IV, and Minusil (a positive control) were 0.47, 0.62, 0.60, 0.56 and 0.41 micrometers, respectively. The four slag samples were found to be chemically similar. The rats received a single intratracheal instillation of 40 milligrams of test material. Sterile water was instilled in the vehicle control group. Lung function decrements were determined by intubation of anesthetized rats and measurements of pulmonary function parameters such as flow, volume, transpulmonary pressures, and ventilatory performance. The rats were killed at 2 days, 3, 6, or 12 months for the determination of treatment related histopathological lesions in various tissues. The Minusil group had significantly lower body weights at 1 to 12 months than the Slag-I, Slag-II, and Slag-IV group, and at 2 to 5 months than the Slag-III group. The Minusil group had significantly greater average lung weight and hydroxyproline content than the slag treated groups. The mean weights of Slag-II and Slag-III groups were significantly greater than the vehicle control group. Statistical analyses showed that the average lung and tracheobronchial lymph nodes (TBLN) dust burden and dust retention were significantly greater for the Minusil group than all slag groups. The average TBLN dust burden and dust retention were significantly greater for Slag-IV than for Slag II- and-III groups. No significant differences were seen in pulmonary function analyses between the slag groups and vehicle control group. The Minusil group had significantly lower lung volumes and flow rates. Histopathological examination found mild to moderate interstitial fibrosis in the slag treated groups, which increased in severity with time. Differences between slag groups were minor in comparison to the Minusil treated group. The authors conclude that coal slags have reduced toxicity in comparison to Minusil.
Lloyd E. Stettler, PhD, Applied Biology Branch (C-26), Division of Biomedical and Behavioral Science, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, OH 45226, USA
Links with this icon indicate that you are leaving the CDC website.
The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website.
Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
You will be subject to the destination website's privacy policy when you follow the link.
CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website.
For more information on CDC's web notification policies, see Website Disclaimers.
CDC.gov Privacy Settings
We take your privacy seriously. You can review and change the way we collect information below.
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.
Cookies used to make website functionality more relevant to you. These cookies perform functions like remembering presentation options or choices and, in some cases, delivery of web content that based on self-identified area of interests.
Cookies used to track the effectiveness of CDC public health campaigns through clickthrough data.
Cookies used to enable you to share pages and content that you find interesting on CDC.gov through third party social networking and other websites. These cookies may also be used for advertising purposes by these third parties.
Thank you for taking the time to confirm your preferences. If you need to go back and make any changes, you can always do so by going to our Privacy Policy page.