Agreement between birthplace and self-reported ethnicity in a population-based mammography service.

BACKGROUND: Ethnicity is associated with genetic, environmental, lifestyle and social constructs. Difficult to define using a single variable, but strongly predictive of health outcomes and useful for planning healthcare services, it is often lacking in administrative databases, necessitating the use of a surrogate measure. A potential surrogate for ethnicity is birthplace. Our aim was to measure the agreement between birthplace and ethnicity among six major ethic groups as recorded at the population-based mammography service for British Columbia, Canada (BC). METHODS: We used records from the most-recent visits of women attending the Screening Mammography Program of British Columbia to cross-tabulate women's birthplaces and self-reported ethnicities, and separately considered results for the time periods 1990-1999 and 2000-2006. In general, we combined countries according to the system adopted by the United Nations, and defined ethnic groups that correspond to the nation groups. The analysis considered birthplaces and corresponding ethnicities for South Asia, East/Southeast Asia, North Europe, South Europe, East Europe, West Europe and all other nations combined. We used the kappa statistic to measure the concordance between self-reported ethnicity and birthplace. RESULTS: Except for the 'Other' category, the most-common birthplace was East/Southeast Asia and the most-common ethnicity was East/Southeast Asian. The agreement between birthplace and self-reported ethnicity was poor overall, as evidenced by kappa scores of 0.22 in both 1990-1999 and 2000-2006. There was substantial agreement between ethnicity and birthplace for South Asians, excellent agreement for East/Southeast Asians, but poor agreement for Europeans. CONCLUSION: Birthplace can be used as a surrogate for ethnicity amongst people with South Asian and East/Southeast Asian ethnicity in BC.

Effect of de-industrialisation on working conditions and self reported health in a sample of manufacturing workers.

STUDY OBJECTIVE: To explore the impact of de-industrialisation over a 20 year period on working conditions and health among sawmill workers, in the province of British Columbia (BC), Canada. DESIGN AND SETTING: This investigation is based on a sample of 3000 sawmill workers employed in 1979 (a year before the beginning de-industrialisation) and interviewed in 1998. The sample was obtained by random selection from an already gathered cohort of approximately 28 000 BC sawmill workers. Change in working conditions from 1979 to 1998 are described. Self reported health status, in 1998, was used as a dependent variable in logistic regression after controlling for confounders. MAIN RESULTS: Downsizing in BC sawmills eliminated 60% of workers between 1979 and 1998. Working conditions in 1998 were better for those who left the sawmill industry and obtained re-employment elsewhere. Workers who remained employed in restructuring sawmills were approximately 50% more likely to report poor health than those re-employed elsewhere. CONCLUSIONS: Working conditions and health status were better for workers who, under pressure of de-industrialisation, left the sawmill industry and obtained re-employment outside this sector.

Opportunities for a broader understanding of work and health: multiple uses of an occupational cohort database.

Occupational cohort studies conducted to study cancer incidence and mortality require extensive data gathering about workers' job histories, exposures, and health outcomes. Although this process is expensive, the database created can be looked upon as a resource for broad investigations of the relationship between work and health. This paper presents the example of a retrospective cohort study which began in the traditional way, examining the link between a specific pesticide exposure and mortality and cancer incidence. The cohort register has since been used to investigate whether infertility, adverse reproductive outcomes, and childhood cancers might be associated with this exposure. It is also being used as the basis for studying other sawmill exposures including noise and wood dust as well as socioeconomic factors including job strain, job mobility, unemployment, and retraining. This approach allows both the efficient use of occupational cohorts as well as providing the opportunity for investigators to develop a more comprehensive perspective on the determinants of the health status of workers and their families.

Unrecognized asbestos-induced disease.

It is being slowly recognized that there is serious under-reporting of cancers that are occupationally related, in the sense that they would not have occurred without the occupational exposure. Data from the Workers' Compensation Boards of New South Wales in Australia and British Columbia in Canada relating to disease attributable to asbestos exposure indicate that in both jurisdictions the ratio of lung cancer cases to mesothelioma cases is much lower than epidemiological studies indicate must be occurring. Over the period from 1980 to 1994, if both jurisdictions are considered together, about 1,207 cases of lung cancer that would not have occurred without asbestos exposure went unrecognized as occupationally related. The data also suggest that it is unlikely that radiological asbestosis should be regarded as a necessary condition for there to be an increased risk of lung cancer following asbestos exposure.

Electric and magnetic fields at three pulp and paper mills.

Extremely low frequency (60 Hz) electric and magnetic field levels were measured at three Canadian pulp and paper mills, using area point-in-time measurements. Most electric field levels were below the limit of detection of 1 V/m (92 of 132 measurements); the highest measured field was 47 V/m. Measured magnetic field strengths ranged from less than the limit of detection (0.125 mG, 2 of 132 measurements) to 706 mG, with a median of 1.6 mG. Magnetic field levels were higher in mills that consume more electric power, but worker exposures could not be predicted according to plant power consumption. Overall, electric and magnetic field levels in the three pulp and paper mills were similar to those experienced by the general population. However, maximum magnetic field intensities in some areas were as high as those experienced by electrical workers.

Occupational cancer in Canada: what do we know?

OBJECTIVE: To examine the reporting of cases of occupational cancer in Canada in order to determine reporting requirements, the availability of data, the characteristics of reported cancers and the completeness of reporting. DESIGN: Descriptive epidemiologic study based on data requested from workers' compensation boards (WCBs) and cancer registries in each province and territory from 1980 to 1989. OUTCOME MEASURES: The number of claims accepted and rejected by the WCBs; year of claim, cancer site, sex of claimant, age of claimant at diagnosis, occupation, industry, exposure agent and reasons for rejection of claims; and new primary cancers according to site, age and sex. RESULTS: Reporting of occupational cancer by physicians is required in Alberta, Saskatchewan and Newfoundland. Only British Columbia, Saskatchewan and Ontario were able to provide all the requested information about the claims. Of the 1026 claims in these three provinces almost all were by men, and about two-thirds were for cancers of the respiratory tract. Asbestos was listed as the etiologic agent in more than one-third of the cases. A comparison of the proportion of incident cancers accepted as occupational by the WCBs with the estimated proportion of cancers in the general population attributable to occupation (based on population-attributable risk percentages from epidemiologic data) suggests that less than 10% of occupational cancers [corrected] are compensated. The main source of the deficit is underreporting to WCBs rather than rejection of claims. CONCLUSIONS: The availability of data about occupational cancers in Canada is inconsistent from jurisdiction to jurisdiction, and reporting is incomplete. An active disease surveillance system and additional education of physicians and workers about work-related illnesses may be required to improve reporting.