Characterizing occupational exposure to asbestos in Ontario An Evaluation of the Ontario Asbestos Workers Registry from 1986 to 2011

Transcription

1 Characterizing occupational exposure to asbestos in Ontario An Evaluation of the Ontario Asbestos Workers Registry from 1986 to 2011 Anna Koné, Kris Moore, Ann Del Bianco, Desre Kramer, Leon Genesove, Paul A. Demers

2 Background Asbestos is a known human carcinogen Highly present in workplaces in Canada, particularly in Ontario The relevance of surveillance of occupational exposure and hazards has been demonstrated Administrative databases can be useful but data need to be accurate and valid 2

3 Background In Ontario, the Ministry of Labour (MoL) filed a regulation in 1985 from which the Asbestos Workers Registry originated aims to collect and store data on those exposed to asbestos in construction and repair operations includes: demographic and other personal data; employer and physician details; medical information; and the number of hours of occupational exposure to asbestos as a result of Type 2 or Type 3 operations o including but not limited to removal, enclosure, breaking, cleaning or application of asbestos containing material 3

4 Objectives To describe the characteristics of workers reporting an exposure to asbestos in the Ontario Asbestos Workers Registry Analyze the proportion of workers registered and the hours of exposure reported Describe the demographics of the workers and their industries. Report on and discuss the spatial and temporal trends in the reporting of asbestos exposure To evaluate the validity of data contained in the registry and explore the usefulness 4

5 Data Sources and Study Population 1) All entries of the Ontario Asbestos Workers Registry; Access obtained through the MoL via the Freedom of Information Act, filed in 2012 Original sample comprised more than 87,000 entries for a total of 33,011 workers with working dates from Jan 1934 to June 2012 Exclusion criteria: final sample included 30,829 workers ages <15 or >84 Invalid number of hours (=0 or >16 hours per day) Postal codes outside of Ontario excluded from geographic variations 2) The Statistics Canada census database (population data) 3) Labor force survey estimates (workers population) 5

6 Analyses Data elements - Employers operating name, legal name, business number, mailing address and industry sector; employee s name, date of birth, start and end date of report period, hours in asbestos-related work Statistics - Proportion of workers registered and hours of exposure reported - SR of workers, hours by demographics and industry - Spatial and temporal trends in the number of workers 6

7 Results: Data Validity Assigned sex based on names (6% missing) Determined accuracy of dates (birthdate, employment starting and end date) of and hours (vs work duration) Assigned regions Postal code of the employers not the workers (multiple postal codes, missing) could be address of head offices, not necessarily the place of work 7

8 Data Validity, con t Organizations names Multiple or missing names (discordances between individual and organization files) Changes over time Assigned industries Multiple industries for a given employer, but no indication of worker s occupation Primary industry assigned o Google search of organization names to confirm/modify classification Approximately 10% of all entries had work dates before 1986 (when the registry started) 27,515 workers registered between 1986 and June

9 Results: Age and sex Characteristics Number of workers (%) Hours (n=27,199) Total Number Median (Q1; Q3) Mean (SD) All ,776, (20; 427) 543(1,315) Sex Female Male 1,002 (4.0) 23,966 (96.0) 1,035,730 12,493, (26; 2000) 86 (20; 398) 1,039 (1,550) 525 (1,312) Age at first exposure ,876 (21.5) 8,061 (29.4) 6,608 (24.1) 4,494 (16.4) 2,334 (8.5) 3,184,988 4,769,890 3,284,405 2,032,612 1,483, (40; 460) 112 (27; 463) 71 (16; 358) 50 (10; 280) 60 (10; 1,767) 246(1,264) 596 (1,554) 499 (1,268) 456 (1,092) 642 (1,013) 9

10 number of workers exposed First and current date of employment in the registry Incidence Ongoing exposure

11 Workers per 100,000 Standardized rates of ongoing exposure (current date of employment) per 100,000 workers, by year Hours per 100, SR of hours exposed per 100,000 SR of exposure per 100,000 70,000 60, , , , ,000 10,

12 Organizations Example of data inconsistency # of people # of people # of # of people # of # of people (valid hours) Hours people (valid hours) Hours people (valid hours) AXA INSURANCE CANADA ,463 LAIDLAW ENERGY TECHNOLOGIES LTD ,386 CANADIAN ASBESTOS SERVICES LTD , , ,908 LE CONSEIL DES ECOLES SEPAREES D'OTTAWA ,000 OTTAWA BOARD OF EDUCATION CASEY-HEWSON CONSTRUCTION LIMITED , , ,569 TORONTO DISTRICT SCHOOL BOARD , , ,664 TORONTO HYDRO 6 6 2, UNIVERSITY OF TORONTO ,745 CORPORATION OF THE CITY OF OSHAWA, THE ,000 ONTARIO GYPSUM CO LTD ,588 CROSSBY INSULATIONS (LONDON) LTD , ,880 QUINTE INSULATORS LTD ,128 INTERPROVINCIAL INSULATION INC 3 3 6, ,928 CANADIAN INDUSTRIAL SPECIALTIES LIMITED , ,941 DOW CHEMICAL CANADA INC , ,289 LAMBTON COUNTY BOARD OF EDUCATION ,370,000 BOARD OF GOVERNORS OF UNIVERSITY OF WESTERN ONTARIO, THE , BEST ASBESTOS REMOVAL LTD ,977 PEEL BOARD OF EDUCATION, THE , PERTH COUNTY BOARD OF EDUCATION ,000 CENTRAL CONTRACTING COMPANY ,872 I & I CONSTRUCTION SERVICES LTD , ,399 Grand Total 3,563 3, ,639 4,860 4, ,282 6,000 5,926 2,491,571 Hours 12

13 Example of data inconsistency, con t Organizations # of people # of people (valid hours) Hours # of people # of people (valid hours) Hours # of people # of people (valid hours) Hours Schools 2.8% 2.9% 5.0% 2.1% 2.1% 11.9% 19.9% 20.1% 70.2% 14 companies (excluding schools) 25.8% 25.2% 25.3% 2.0% 2.1% 2.4% 18.4% 18.2% 4.5% Grand Total 3,563 3, ,639 4,860 4, ,282 6,000 5,926 2,491,571 13

14 Number of registrants per 100,000 Average annual rate of exposure per 100,000 workers, by industry Hours exposed per 100, , Hours N 35,000 30,000 25,000 20, ,000 10, ,000 0,0 14

15 # of registrants per 100,000 Rate of exposure by industry, 5-year categories Construction only Agricultural and Related Service Industries Logging and Forestry Industries Mining (including Milling), Quarrying and Oil Well Manufacturing Industries Construction Industries

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17 Age-standardized rates of ongoing exposure per 100,000 capita by LHU, Lambton City of Hamilton Timiskaming Halton Regional Thunder Bay District Peel Regional Niagara Regional Area York Regional Middlesex-London City of Toronto Ontario Kingston, Frontenac, and Lennox Haldimand-Norfolk Waterloo Huron County North Bay Parry Sound District City of Ottawa Windsor-Essex County Hastings and Prince Edward Porcupine Brant County The District of Algoma Oxford County Durham Regional Grey Bruce The Eastern Ontario Perth District Peterborough County-City Sudbury and District Simcoe Muskoka District Haliburton, Kawartha, Pine Ridge Chatham-Kent Renfrew County and District Elgin-St. Thomas Northwestern Wellington-Dufferin-Guelph Leeds, Grenville and Lanark ,0,500 1,000 1,500 2,000 2,500 3,000 3,500 # of workers registered per 100,000 17

18 # of workers registered per 100,000 Distribution by LHU and 5-year categories Thunder Bay District Halton Regional Niagara Regional Area York Regional Lambton Timiskaming City of Hamilton Peel Regional City of Toronto Middlesex-London

19 Discussion The Asbestos Registry is a useful source of information on asbestos, providing insights but also challenges for the interpretation of levels of exposure in Ontario. Despite the closure of major asbestos sites, there are operations and workplaces where exposure to asbestos still occurs. Exposure can only be evaluated if the Registry remains active in collecting information and improves the data quality. This research initiates conversations on whether or not the trends and geographic variations depicted are meaningful. Further work needs to be done to ascertain the temporal and spatial trends in asbestos exposure as well as distribution by industry, using this data source. 19

20 Thank you! Questions/ Comments? 20