Background: In Italy, healthcare workers (HCWs) were among the first to receive COVID-19 vaccination. Aim of the present study is to evaluate frequency and severity of adverse events (AEs) following the second dose of BNT162b2 vaccine among HCWs of a large university hospital in Milan, Italy. Methods: One month after having received the second dose of vaccine, HCWs filled-in a form about type, severity, and duration of post-vaccination local and systemic symptoms. We calculated the overall frequency of AEs and used multivariable Poisson regression models (adjusted for sex, age, BMI, smoking, allergy history, previous SARS-CoV-2 infection, anti-hypertensive therapy, and occupation) to calculate risk ratios (RR) and 95% confidence intervals (CI) of AEs according to selected variables. Results: We included 3659 HCWs. Overall, 2801 (76.6%) experienced at least one local event, with pain at injection site being the most frequent (2788, 76.2%). Systemic events were reported by 2080 (56.8%) HCWs, with fatigue (52.3%), muscle pain (42.2%), headache (37.7%), joint pain (31.9%), and fever (26.2%) being the most frequent. Risks of systemic events were associated with female gender (RR=1.14, CI: 1.06-1.23), age (strong decrease with increasing age, p-trend<0.001), allergy history (RR=1.13, CI: 1.05-1.20), and current smoking (RR=0.90, CI: 0.84-0.97). HCWs with previous SARS-CoV-2 infection (even if symptomatic) were not at increased risk. Conclusions: Both local and systemic acute effects after second dose of BNT162b2 vaccine were frequently reported. However, symptoms were mostly light/mild and of short duration. Thus, our findings support the safety of COVID-19 vaccination in adults in relatively good health.

Background: The aim of the present study was to summarise the available data about the link between air pollution exposure and the new-onset and severity of psychiatric disorders in pregnant women during the perinatal period. Materials and methods: We selected articles published until June 2022 on PubMed and the Web of Science. Pollutants included were PM_2.5 (particulate matter 2.5 micrometres and smaller), PM₁₀ (particulate matter 10 micrometres and smaller), NO₂ (nitrogen dioxide), O₃ (ozone), SO₂ (sulphur dioxide), CO (carbon monoxide), PBDEs (polybrominated diphenyl ethers), PFAS (per- and polyfluoroalkyl substances), lead, and cadmium. The perinatal period was considered as the time of pregnancy until one year after childbirth. Results: Nine studies were included; most of them evaluated the association between exposure to air pollutants and the onset of Postpartum Depression (PPD). Two studies showed an association between, respectively, only PM_2.5 and both PM_2.5 and NO₂ exposure and PPD onset 12 months after childbirth, while another study found a significant association between NO₂ exposure and PPD occurrence 6 months after childbirth. PBDE blood levels were associated with more severe depressive symptoms. Lastly, one study observed a link between stressful symptoms and exposure to PM_2.5, PM₁₀ during pregnancy. Conclusion: More comprehensive and uniform studies are required to make a roadmap for future interventions, given the growing relevance of issues such pollution and mental health, particularly during the perinatal period.

Major depressive disorder (MDD) is a serious and disabling condition, whose etiological mechanisms are not fully understood. The aim of the DeprAir study is to verify the hypothesis that air pollution exposure may exacerbate neuroinflammation with consequent alterations in DNA methylation of genes involved in circadian rhythms and hormonal dysregulation, resulting in the worsening of depressive symptoms. The study population consists of 420 depressed patients accessing the psychiatry unit of the Policlinico Hospital (Milan, Italy), from September 2020 to December 2022. Data collection is still ongoing for about 100 subjects. For each participant demographic and lifestyle information, depression history and characteristics, as well as blood samples, were collected. MDD severity was assessed through five rating scales commonly used in clinical practice to assess the severity of affective symptoms. Exposure to particulate and gaseous air pollutants is assigned to each subject using both air pollution monitoring station measurements and estimates derived from a chemical transport model. DeprAir is the first study investigating in a comprehensive picture whether air pollution exposure could be an important modifiable environmental factor associated with MDD severity and which biological mechanisms mediate the negative effect of air pollution on mental health. Its results will represent an opportunity for preventive strategies, thus entailing a tremendous impact on public health.

Reduced telomere length (TL) has been associated with increased risk of age-related diseases, most likely through oxidative stress and inflammation, which have also been claimed as mechanisms underlying health effects of air pollution exposure. We aimed to verify whether exposure to particulate matter with diameter ≤10 µm (PM₁₀) affects TL. We recruited 1792 participants with overweight/obesity in Milan (Italy) in 2010–2015 who completed a structured questionnaire on sociodemographic data, gave a blood sample for TL measurement by real-time PCR, and were assigned air pollution and meteorological data of their residential address. In multivariate mixed-effects linear models (with a random intercept on PCR plate), we observed a −0.51% change in TL (95% confidence interval (CI): −0.98; −0.05)) per 10 µg/m³ increase in PM₁₀ at the day of recruitment. A similar decreasing trend in TL was observed up to two weeks before withdrawal, with percentage changes as low as −1.53% (average exposure of the 12 days before recruitment). Mean annual exposure to PM₁₀ was associated with −2.57% TL reduction (95%CI: −5.06; −0.08). By showing consistent associations between short- and long-term PM₁₀ exposures and reduced TL, our findings shed light on the potential mechanisms responsible for the excess of age-related diseases associated with air pollution exposure.

Major Depressive Disorder (MDD) is a psychiatric condition whose onset and progression may be influenced by environmental factors. Our study investigates the association between greenness exposure and MDD severity, while also exploring the role of air pollutants and temperature. Three hundred ninety-six MDD patients were included. MDD severity was assessed using five rating scales. Two- and three-dimensional indicators of urban space were estimated around participants' houses: Normalized Difference Vegetation Index (NDVI), Green Volume, Grey Volume, and Normalized Difference Green-Grey Volume Index (NDGG). Annual exposure estimates of air pollutants and temperature were assigned to the participants' residential addresses. Multivariate linear and ordinal regression models were applied to assess associations between exposure variables and MDD severity, adjusting for and stratifying by air pollutants and temperature. Increasing levels of all urban space indicators (within a 100 m radius), except for Grey Volume, were associated with decreased MDD severity. The strongest effect was observed for Green Volume (e.g., Hamilton Depression Rating Scale [HAMD]: β = -2.67, 95 % confidence interval [CI]: -4.57; -0.76, for an interquartile range [IQR] increase in the exposure variable). The inverse associations between greenness and MDD severity were confirmed only when values of particulate matter ≤2.5 μm (PM2.5) were below the median (e.g. β = -5.32, 95 %CI: -8.28; -2.36 for an IQR increase in Green Volume). The same occurred with temperature levels below the median. Green spaces are associated with lower severity of depression, especially when PM2.5 and temperature levels are low.