Methods: State-Based Surveillance
Silicosis
Cases of silicosis from state-based surveillance are confirmed based on the surveillance case definition for silicosis. The silicosis case definition includes 1) an occupational exposure history to airborne silica dust and 2) a positive chest radiograph or other imaging technique for silicosis and/or positive pathologic findings characteristics of silicosis. For more information, see Silicosis State Reporting Guidelines and Case Definition .
The year (time period) presented in the table is the year (time period) that the case was first reported to the state. This may or may not be the year of silicosis diagnosis, which may have been earlier.
State-based information is presented by case ascertainment source, duration of silica exposure, Workers' Compensation claim status, small and large opacity profusion categories, and by reported primary industries and occupations of the cases identified. See Industry/Occupation Codes and Titles section below for industry and occupation classifications.
Work-Related Asthma
Cases of work-related asthma (WRA) from state-based surveillance are grouped based on WRA classification criteria into two major types: 1) work-aggravated asthma (WAA) and 2) new-onset asthma (NOA). NOA is further classified as either reactive airways dysfunction syndrome (RADS) or occupational asthma (OA) and its sub-classifications. For more information, see Work-Related Asthma State Reporting Guidelines and Case Definition . In some instances WRA cases may meet the requirements of the surveillance case definition for a confirmed case of WRA without sufficient information for classification. These cases are noted as "Confirmed, but unclassified".
The year (time period) presented in the table is the year (time period) that the case was first reported to the state. This may or may not be the year of work-related asthma onset or diagnosis, which may have been earlier.
Information is also presented by Workers' Compensation claim status, and by reported primary industries and occupations. See Industry/Occupation Codes and Titles section below for industry and occupation classifications.
A single case of WRA may be associated with up to three putative agents. The Association of Occupational and Environmental Clinics (AOEC) designation of agents as occupational asthmagens on the exposure code list is made according to an AOEC protocol (see Revised Protocol: Criteria for Designating Substances as Occupational Asthmagens on the AOEC List of Exposure Codes at http://www.aoec.org/content/Asthmagen_Protocol_10-25-08.pdf.
Industry/Occupation Codes and Titles
The primary industries and occupations associated with state-based surveillance silicosis and work-related asthma case data are grouped by the 2002 North American Industry Classification System (NAICS), the 2000 Census Occupation Codes (COC), and the 2000 Standard Occupational Classification (SOC).