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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.

Putative agents associated with cases of WRA are grouped using established Association of Occupational and Environmental Clinics (AOEC) exposure categories and sub-categories 1 or combined individual exposure codes. The combined individual exposure codes contain agents of similar use or chemical nature. The following table shows the AOEC exposure categories and corresponding exposure code prefixes presented in the work-related asthma tables.

AOEC Exposure Categories and Codes
Exposure Categories Exposure Code Prefix Year Posted (eWoRLD)
Mineral and inorganic dusts010–0122012, 2014, 2015
Metals and metalloids020–0242012, 2014, 2015
Halogens (inorganic)0302012, 2014, 2015
Miscellaneous inorganic compounds040–0422012, 2014, 2015
Acids, bases and oxidizing agents050–0522012, 2014, 2015
Aliphatic and alicyclic hydrocarbons060–0612012, 2014, 2015
Alcohols0702012, 2014, 2015
Glycols0802012, 2014, 2015
Glycol ethers090–0912012, 2014, 2015
Ethers1002012, 2014, 2015
Epoxy compounds1102012, 2014, 2015
Aldehydes and acetals1202012, 2015
Ketones1302012, 2014, 2015
Esters140–1422012, 2014, 2015
Aliphatic carboxylic acids150–1512012, 2014
Aliphatic carboxylic acids and anhydrides150–1512015
Aromatic hydrocarbons160–1612012, 2014
Hydrocarbons160–1682015
Hydrocarbons, n.o.s.1702012, 2014, 2015
Solvents, n.o.s.1712012, 2014, 2015
Phenols and phenolic compounds180–1812012, 2014, 2015
Halogenated aliphatic hydrocarbons190–1922012, 2014, 2015
Halogenated aromatic hydrocarbons200–2012012, 2014, 2015
Cyanides and nitriles210–2112012, 2014, 2015
Isocyanates220–2212012, 2014, 2015
Aliphatic and alicyclic amines230–2332012, 2014, 2015
Aromatic nitro and amino compounds250–2522012, 2014, 2015
Aliphatic and miscellaneous nitrogen compounds260–2612012
Polymers270–2712012, 2014, 2015
Organochlorine insecticides2802012
Organophosphate pesticides/Carbamate pesticides290–2922012, 2014, 2015
Organic sulfur compounds310–3112012, 2014, 2015
Indoor air pollutants320.01, 320.332012, 2014, 2015
Cleaning materials3222012, 2014, 2015
Miscellaneous chemicals and materials320.02–320.32, 320.34–321.99, 323–329.32012, 2014
Miscellaneous chemicals and materials320.02–320.32, 320.34–321.35, 323.00–327.032015
Pyrolysis products330–3312012, 2014, 2015
Physical factors350–3542012, 2014, 2015
Ergonomics360–3622012, 2014, 2015
Plant materials370–3732012, 2014
Plant/Tree materials370–3732015
Animal materials380–3822012, 2014
Animal/Insect materials380–3822015
Microorganisms, not including mold390.00, 390.02–390.16, 391.09–391.11, 390.132012, 2014
Microorganisms, not including mold390.00–390.16, 391.10–391.11, 390.132015
Mold390.01, 390.12, 391.01–391.082012, 2014
Mold391.01–391.091, 391.122015
Hazard not on file000.002012, 2014, 2015
n.o.s. - not otherwise specified

A single case of WRA may be associated with up to three putative agents and as a result may be counted in more than one category. The 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.

For each agent, an indication of whether the agent has a high or low molecular weight is presented. Based on the Environmental Protection Agency standards, high molecular weight is defined as a molecular weight greater than or equal to 10,000 Daltons, and low molecular weight is defined as a molecular weight less than 10,000 Daltons. High and low molecular weights were determined using the Toxicology Data Network for the National Library of Medicine (http://toxnet.nlm.nih.gov/); NIOSH Pocket Guide to Chemical Hazards (http://www.cdc.gov/niosh/npg/default.html); PubChem Substance (http://pubchem.ncbi.nlm.nih.gov/); and Asthma in the Workplace2.

Industry/Occupation Codes and Titles

The primary industries and occupations associated with state-based surveillance silicosis and work-related asthma case data prior to June 2008 updates are grouped by the 1987 Standard Industrial Classification (SIC) system for industries and the 1990 Census Occupation Codes (COC) for occupations. Current presentation of primary industries and occupations are grouped using the 2002 North American Industry Classification System (NAICS), the 2000 COC, and the 2000 Standard Occupational Classification (SOC). Industries and occupations associated with five or more silicosis cases are listed. Industries and occupations associated with 10 or more work-related asthma cases using 1993–2008 data and five or more work-related asthma cases using 2009–2011 data are listed. Industries and occupations associated with less than five silicosis cases or with less than 10 work-related asthma cases using 1993–2008 data and less than five work-related asthma cases using 2009–2011 data are aggregated in an "All other" category.


REFERENCES:

1 Hunting KL, McDonald SM. Development of a hierarchical coding system for clinic-based surveillance of occupational disease and industry. Appl Occup Environ Hyg 1995;10(4):317–322. (Return to text)

2 Bernstein, IL, Chan-Yeung, M, Malo, JL, Berstein, DI. Asthma in the workplace, 3rd, Taylor and Francis, New York 2006.
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