Environmental and socio-economic determinants of infant mortality in Poland: an ecological study

BACKGROUND Health status of infants is related to the general state of health of women of child-bearing age; however, women's occupational environment and socio-economic conditions also seem to play an important role. The aim of the present ecological study was to assess the relationship between occupational environment, industrial pollution, socio-economic status and infant mortality in Poland. METHODS Data on infant mortality and environmental and socio-economic characteristics for the 66 sub-regions of Poland for the years 2005-2011 were used in the analysis. Factor analysis was used to extract the most important factors explaining total variance among the 23 studied exposures. Generalized Estimating Equations model was used to evaluate the link between infant mortality and the studied extracted factors. RESULTS Marked variation for infant mortality and the characteristics of industrialization was observed among the 66 sub-regions of Poland. Four extracted factors: "poor working environment", "urbanization and employment in the service sector", "industrial pollution", "economic wealth" accounted for 77.3% of cumulative variance between the studied exposures. In the multivariate regression analysis, an increase in factor "poor working environment" of 1 SD was related to an increase in infant mortality of 40 (95% CI: 28-53) per 100,000 live births. Additionally, an increase in factor "industrial pollution" of 1 SD was associated with an increase in infant mortality of 16 (95% CI: 2-30) per 100,000 live births. The factors "urbanization and employment in the service sector" and "economic wealth" were not significantly related to infant mortality. CONCLUSION The study findings suggested that, at the population level, infant mortality was associated with an industrial environment. Strategies to improve working conditions and reduce industrial pollution might contribute to a reduction in infant mortality in Poland.