Use of official municipal demographics for the estimation of mortality in cities suffering from heavy environmental pollution: Results of the first study on all the neighborhoods of Taranto from 2011 to 2020

Background In cities suffering from heavy environmental pressure or pollution, it is extremely important to rapidly access municipal demographics that can be used as indicators of population health status. Among those, mortality rates represent the most reliable data as they are officially retained and available to municipality with high level of details, thus allowing epidemiological comparison between different neighborhoods of the city across several years. Our study was aimed at validating and propose as universally applicable approach the use of municipal demographics as first-line tool to rapidly assess population health and drive health policies or urban planning in cities characterized by heavy environmental pressure. The case study of Taranto has been chosen due to the presence of the biggest European steel plant since 1960s resulting in heavy burden on environment and population health. Methods We have performed an ecological study on general mortality data due to all causes, specific by gender, age groups and disaggregated at sub-municipal level (highest data granularity) into neighborhoods from 2011 to 2020 by using official demographics related to all people living in Taranto available at General Registry Office of the municipality. A preliminary analysis comparing data available at Municipality and those provided by the Italian National Institute of Statistics (ISTAT) was performed and confirmed the high level of reliability of the municipal source of data. For comparative analyses, we used Regional demographics and mortality from ISTAT. Indirect age-standardized mortality ratios (SMR; CI 90% and 95%), specific for gender and neighborhoods, were calculated in reference to the city of Taranto and Apulia Region; direct age-standardized and neighborhoods mortality rates were computed on city population. Results The city of Taranto shows relevant inequalities in terms of mortality between the northern neighborhoods, closest to the industrial area (Paolo VI, Tamburi and Città Vecchia-Borgo), with excess mortality highlighted across 10 years described by SMRs always higher than those of the entire Apulia region, with peaks exceeding 50% between 2015 and 2017 both in women and men. The significant excesses of mortality have increased from 2011 to 2020 and progressively extended across several neighborhoods of Taranto city. Compared to the Apulia regional, we recorded a 68% mortality excess for men living in Paolo VI district during the year 2019. In the 3 Northern neighborhoods of the city were recorded 1020 excess deaths with confirmed statistical significance. Conclusion The use of official mortality data allows a timely, reliable and costless assessment of population health in cities heavily impacted by environmental pollution like Taranto.