Acute Effects of Particulate Matter on All-Cause Mortality in Urban, Rural, and Suburban Areas, Italy.

Matteo Renzi,Massimo Stafoggia,Marina Davoli,Matteo Scortichini,Stefano Marchetti,Francesca De' Donato,Marilena Pappagallo,Paola Michelozzi,Luisa Frova

doi:10.3390/ijerph182412895

Abstract

Background: Short-term exposure to particulate matter (PM) has been related to mortality worldwide. Most evidence comes from studies conducted in major cities, while little is known on the effects of low concentrations of PM and in less urbanized areas. We aim to investigate the relationship between PM and all-cause mortality at national level in Italy. Methods: Daily numbers of all-cause mortality were collected for all 8092 municipalities of Italy, from 2006 to 2015. A satellite-based spatiotemporal model was developed to estimate daily PM10 (inhalable particles) and PM2.5 (fine particles) concentrations at 1-km resolution. Multivariate Poisson regression models were fit to estimate the association between daily PM and mortality at province level, and then, results were pooled with a random-effects meta-analysis. Associations were estimated by combination of age and sex and degree of urbanization of the municipalities. Flexible functions were estimated to explore the shape of the associations at low PM concentrations. Results: We analyzed 5,884,900 deaths (40% among subjects older than 85 years, 60% occurring outside the main urban areas). National daily mean (interquartile range) PM10 and PM2.5 concentrations were 23 (14) μg/m3 and 15 (11) μg/m3, respectively. Relative increases of mortality per 10 μg/m3 variation in lag 0–5 (average of last six days since death) PM10 and PM2.5 were 1.47% (95% Confidence Intervals (CI): 1.15%, 1.79%) and 1.96% (1.33%, 2.59%), respectively. Associations were highest among elderly and women for PM10 only, similar between rural and urbanized areas, and were present even at low concentrations, e.g., below WHO guidelines. Conclusions: Air pollution was robustly associated with peaks in daily all-cause mortality in Italy, both in large cities and in less urbanized areas of Italy. Current WHO Air Quality Guidelines (2021) for PM10 and PM2.5 are not sufficient to protect public health.

Highlights

Ambient air pollution is one of the most important risk factors for the human health worldwide
In the last Global Burden of Diseases (GBD) [3] report, it has been observed that death rates related to outdoor air pollution are highest among the elderly [4]
As a sensitivity analysis, we considered as an index of urbanization provided by Institute of Statistics (ISTAT), which classifies each municipality by using socio-demographic characteristics, such as the average distance to local and health services, etc. (www.istat.it,)

Summary

Introduction

Ambient air pollution is one of the most important risk factors for the human health worldwide. In Italy, more than 20% of the population is aged over 65 years [5], making the health burden associated to air pollution a priority on the public health agenda. This implies the need for adequate measures to reduce air pollution levels. Many epidemiological studies have been conducted to assess the association between short-term exposure to outdoor air pollution and daily mortality [6,7,8]. Multivariate Poisson regression models were fit to estimate the association between daily PM and mortality at province level, and results were pooled with a random-effects meta-analysis.

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Methods

Results

Conclusion