Cardiovascular mortality as it relates to the geographic distribution of employment in non-metropolitan Quebec

This exploratory analysis examines relationships between employment-specific cardiovascular mortality and certain spatially-based potential risk factors. Standard mortality ratios (SMRs) are mapped on the basis of non-metropolitan primary and secondary employment basins of Quebec. In order to control for geographical anomalies, the data are broken down into three spatial grids: employment basins with the employment poles, employment basins without the employment poles and the employment poles (municipalities) taken alone. This cartography suggests a certain number of cardiovascular disease-prone employment areas in Quebec. Linkage analysis and principal components analysis are used to simplify and clarify the complex relationships that exist among selected independent variables (potential risk factors) and multiple regression analysis is used to identify the functional relationships between these employment, geographic and demographic variables and the study's dependent variable (ischaemic heart disease and cerebrovascular mortality) in the form of standard mortality ratios (SMRs). Cardiovascular mortality (SMRs) are found to be related negatively to an employment age-factor and, in the case of women, negatively to agricultural employment, marginally and positively to pulp and paper employment. It would appear that outside the very large cities in areas of primary and industrial employment, men are at greater risk of cardiovascular mortality during their working lives than those who are over the age of 65. Although it was not possible to establish strong positive links between most employment sectors and cardiovascular mortality, it is possible to conclude that there is a negative association for men between textile employment and cerebrovascular mortality; that in the case of women, those who work in agriculture are less at risk than women who are working in industrial employment. There is also some statistical evidence that there is an association between women in the pulp and paper industry and cardiovascular risk levels. This research provides some clues as to the need to investigate certain areas of employment that may be creating unnecessary risks to health, especially in the case of female workers.