120 chest radiographs of dust exposed persons were classified twice by each of 39 physicians, and three times by 37 of them. All film readers use both the 22 standard films accompanying the current International Labour Office's (1980) Classification of Radiographs of Pneumoconiosis, and a modified set that reproduced selected parts from some of them as quadrants of full-size films. Variability within and between readers in small opacity profusion classifications was high, but similar when using the two sets of standards. Some readers recognized irregularly shaped small opacities more frequently higher on the scale when using the current standards. The effects found were small although the test films included a high proportion with some small opacities. It is concluded that use of the new quadrant standards is unlikely to introduce any important bias into results from occupational health surveys.
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.