ABSTRACT
Despite SARS-CoV-2 transmission being a complex phenomenon, greater population density seems to be a risk factor. The aim of this study was to analyze through an epidemiologic urban health approach the relationship between population density and SARS-CoV-2 incidence using data which are comparable with regard to testing strategies. All 10,300 SARS-CoV-2 confirmed cases between October and December 2020 were included. We conducted separate analysis by gender standardizing and stratifying by age and month. In the Province Capital (p.d.=765 inhabitants/km2), standardized SARS-CoV-2 incidence rate was higher than the expected, both in men (SIR=1.17, 95%CI=1.12;1.22, p<0.0001) and women (SIR=1.20, 95%CI=1.15;1.25, p<0.0001). In municipalities with p.d. >200 inhabitants/km2, standardized SARS-CoV-2 incidence rate was similar to the expected (p>0.05). In municipalities with p.d. <200 inhabitants/km2, standardized SARS-CoV-2 incidence rate was lower than the expected, both in men (SIR=0.85, 95%CI=0.81;0.90, p<0.0001) and women (SIR=0.84, 95%CI=0.80;0.88, p<0.0001). Stratified analysis by months with likelihood ratio test showed heterogeneity of the p.d. effect in men and women (p<0.05). SARS-CoV-2 incidence rate seemed to be higher in most densely populated areas, both in men and women. Our results confirmed the great importance of restrictive measures as well as the importance of limiting the epidemic wave in the initial stages and could help guide pandemic management strategies according to urban context and population density.
ABSTRACT
OBJECTIVE: to summarize the main updated evidence about the health effects of air pollution and to focus on Italian epidemiological experiences on the respiratory effects. RESULTS: the recent literature indicates that there is strong evidence for causal relationships between PM2.5 air pollution exposure and all-cause mortality as well as mortality from acute lower respiratory infections, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lung cancer. A growing body of evidence also suggests causal relationships with type II diabetes and impacts on neonatal mortality from low birth weight and short gestation as well as neurologic effects in both children and adults. Italy, a Southern European country, faces a more threatening air pollution challenge because of the effects of both anthropogenic pollutants and natural dust (particulate matter, PM). The 2020 Report of the European Environment Agency highlighted the number of premature deaths in Italy attributable to main pollutants: 52,300 for PM2.5, 10,400 for NO2 and 3,000 for O3 in 2018. In Italy, original time series and analytical epidemiological studies showed increased cardio-respiratory hospital admissions and mortality and increased risk of respiratory diseases in people living in urban areas. CONCLUSIONS: adverse health effects of air pollutants, even at low levels, have been confirmed by recent epidemiological studies. Further studies should focus on the potential link between air pollution exposure and respiratory infections. This topic has become particularly important in the current SARS-COV-2 pandemic. Based on strong scientific evidence, the Italian government, which hosts the Global Alliance against Chronic Respiratory Diseases (GARD)-Italy at the Ministry of Health, the scientific respiratory societies and the patients' associations, as well as others in the health sector and civil society, must increase their engagement in advocacy for clean air policies, especially in light of the new Air Quality Guidelines of the World Health Organization.