The impact of the COVID-19 vaccination programme on symptomatic and severe SARS-CoV-2 infection during a period of Omicron variant dominance in Ireland, December 2021 to March 2023.

BackgroundAs Ireland prepared for an autumn 2023 COVID-19 vaccination booster campaign, there was concern that vaccine fatigue would affect uptake, which has been abating.AimThis study aimed to quantify the direct impact of the COVID-19 vaccination programme in Ireland on averted COVID-19-related outcomes including symptomatic presentations to primary care/community testing centres, emergency department (ED) presentations, hospitalisations, intensive care unit (ICU) admissions and deaths, in individuals aged ≥ 50 years, during Omicron dominance.MethodsWe conducted a retrospective observational COVID-19 vaccine impact study in December 2021-March 2023 in Ireland. We used national data on notified outcomes and vaccine coverage, as well as vaccine effectiveness (VE) estimates, sourced from the World Health Organization's live systematic review of VE, to estimate the count and prevented fraction of outcomes in ≥ 50-year-olds averted by the COVID-19 vaccination programme in this age group.ResultsThe COVID-19 vaccination programme averted 48,551 symptomatic COVID-19 presentations to primary care/community testing centres (36% of cases expected in the absence of vaccination), 9,517 ED presentations (53% of expected), 102,160 hospitalisations (81% of expected), 3,303 ICU admissions (89% of expected) and 15,985 deaths (87% of expected).ConclusionsWhen Omicron predominated, the COVID-19 vaccination programme averted symptomatic and severe COVID-19 cases, including deaths due to COVID-19. In line with other international vaccine impact studies, these findings emphasise the benefits of COVID-19 vaccination for population health and the healthcare system and are relevant for informing COVID-19 booster vaccination programmes, pandemic preparedness and communicating the reason for and importance of COVID-19 vaccination in Ireland and internationally.

The impact of hospital presentation time on stroke outcomes: A nationally representative Irish cohort study.

OBJECTIVES: There is conflicting evidence regarding the outcomes of acute stroke patients who present to hospital within normal working hours ('in-hours') compared with the 'out-of-hours' period. This study aimed to assess the effect of time of stroke presentation on outcomes within the Irish context, to inform national stroke service delivery. MATERIALS AND METHODS: A secondary analysis of data from the Irish National Audit of Stroke (INAS) from Jan 2016 to Dec 2019 was carried out. Patient and process outcomes were assessed for patients presenting 'in-hours' (8:00-17:00 Monday-Friday) compared with 'out-of-hours' (all other times). RESULTS: Data on arrival time were available for 13,996 patients (male 56.2%; mean age 72.5 years), of which 55.7% presented 'out-of-hours'. In hospital mortality was significantly lower among those admitted 'in-hours' (11.3%, n = 534) compared with 'out-of-hours' (12.8%, n = 749); (adjusted Odds Ratio (OR) 0.82; 95% Confidence Interval CI [95% CI] 0.72-0.89). Poor functional outcome at discharge (Modified Rankin Scale ≥ 3) was also significantly lower in those presenting 'in-hours' (adjusted OR 0.79; 95% CI 0.68-0.91). In patients receiving thrombolysis, mean door to needle time was shorter for 'in-hours' presentation at 55.8 mins (n = 562; SD 35.43 mins), compared with 'out-of-hours' presentation at 80.5 mins (n = 736; SD 38.55 mins, p < .001). CONCLUSION: More than half of stroke patients in Ireland present 'out-of-hours' and these presentations are associated with a higher mortality and a lower odds of functional independence at discharge. It is imperative that stroke pathways consider the 24 hour period to ensure the delivery of effective stroke care, and modification of 'out-of-hours' stroke care is required to improve overall outcomes.

All hands on deck during the COVID-19 pandemic. Maintaining face-to-face medical education and clinical placements.

Medical students must have robust educational experiences, graduate and commence timely employment. Here, we describe how the Royal College of Surgeons in Ireland (RCSI) delivered clinical placements in medical programmes over the first three waves of the COVID-19 pandemic in Ireland, including a student-centred, holistic approach to students' educational, social and health needs with strong student involvement, re-organising the university's primary care team, developing COVID-19 PCR testing on site and re-focusing communications and student services. This resulted in re-arranging the students into learning communities, and students and staff electronically recorded their COVID-19 symptom status daily. In-person observed structured clinical examination and other clinical exams progressed. No lockdown of any campus occurred. Over the two senior years, 693 students completed 15,000 weeks of clinical and experiential learning across 104 sites, similar to previous years, including anatomy practicals, procedural skills training, simulated ward rounds and patient encounters, case-based presentations and small group tutorials. The compliance rate with the daily symptom tracker was 91%. The percentage response rate and the number of students providing feedback from October 2020 to April 2021 was as high as 50%. The overall response rate was 33%. By mid-May, 93-95% of students in the two senior years had had at least one dose of the SARS-CoV-2 vaccine, with 99% fully vaccinated by the start of the next academic year in autumn 2021. Over the period of testing for SARS-CoV-2, just over 22,000 samples were processed, of which 0.79% were positive; no medical student acquired COVID-19 or was associated with nosocomial transmission. The total investment by the RCSI in Dublin, was €9.3m (€1.2 in capital expenditure and €8.1 in operational expenses). Continuing face-to-face clinical placements during a pandemic was possible through a multi-model approach that prioritised two-way communication, compliance with national public health advice and student screening.

Understanding sexual health service access for gay, bisexual and other men who have sex with men in Ireland during the COVID-19 crisis: Findings from the EMERGE survey.

BACKGROUND: In the Republic of Ireland, the COVID-19 crisis led to sexual health service closures while clinical staff were redeployed to the pandemic response. Gay, bisexual and other men who have sex with men (gbMSM) face pre-existing sexual health inequalities which may have been exacerbated. The aim of this study is to understand sexual health service accessibility for gbMSM in Ireland during the COVID-19 crisis. METHODS: EMERGE recruited 980 gbMSM in Ireland (June-July 2021) to an anonymous online survey investigating well-being and service access through geo-location sexual networking apps (Grindr/Growlr), social media (Facebook/Instagram/Twitter) and collaborators. We fit multiple regression models reporting odds ratios (ORs) to understand how demographic and behavioural characteristics (age, sexual orientation, HIV testing history/status, region of residence, region of birth and education) were associated with ability to access services. RESULTS: Of the respondents, 410 gbMSM accessed sexual health services with some or no difficulty and 176 attempted but were unable to access services during the COVID-19 crisis. A further 382 gbMSM did not attempt to access services and were excluded from this sample and analysis. Baseline: mean age 35.4 years, 88% gay, 83% previously tested for HIV, 69% Dublin-based, 71% born in Ireland and 74% with high level of education. In multiple regression, gbMSM aged 56+ years (aOR = 0.38, 95%CI:0.16, 0.88), not previously tested for HIV (aOR = 0.46, 95%CI:0.23, 0.93) and with medium and low education (aOR = 0.55 95%CI:0.35, 0.85) had lowest odds of successfully accessing services. GbMSM with HIV were most likely to be able to access services successfully (aOR = 2.68 95%CI:1.83, 6.08). Most disrupted services were: STI testing, HIV testing and PrEP. CONCLUSIONS: Service access difficulties were found to largely map onto pre-existing sexual health inequalities for gbMSM. Future service development efforts should prioritise (re)engaging older gbMSM, those who have not previously tested for HIV and those without high levels of education.

Evaluating the Impact of Low-Pathogenicity Avian Influenza H6N1 Outbreaks in United Kingdom and Republic of Ireland Poultry Farms during 2020.

In January 2020, increased mortality was reported in a small broiler breeder flock in County Fermanagh, Northern Ireland. Gross pathological findings included coelomitis, oophoritis, salpingitis, visceral gout, splenomegaly, and renomegaly. Clinical presentation included inappetence, pronounced diarrhoea, and increased egg deformation. These signs, in combination with increased mortality, triggered a notifiable avian disease investigation. High pathogenicity avian influenza virus (HPAIV) was not suspected, as mortality levels and clinical signs were not consistent with HPAIV. Laboratory investigation demonstrated the causative agent to be a low-pathogenicity avian influenza virus (LPAIV), subtype H6N1, resulting in an outbreak that affected 15 premises in Northern Ireland. The H6N1 virus was also associated with infection on 13 premises in the Republic of Ireland and six in Great Britain. The close genetic relationship between the viruses in Ireland and Northern Ireland suggested a direct causal link whereas those in Great Britain were associated with exposure to a common ancestral virus. Overall, this rapidly spreading outbreak required the culling of over 2 million birds across the United Kingdom and the Republic of Ireland to stamp out the incursion. This report demonstrates the importance of investigating LPAIV outbreaks promptly, given their substantial economic impacts.

An investigation of inequalities in exposure to PM2.5 air pollution across small areas in Ireland.

The link between exposure to air pollution and adverse effects on human health is well documented. Yet, in a European context, research on the spatial distribution of air pollution and the characteristics of areas is relatively scarce, and there is a need for research using different spatial scales, a wider variety of socioeconomic indicators (such as ethnicity) and new methodologies to assess these relationships. This study uses comprehensive data on a wide range of demographic and socioeconomic indicators, matched to data on PM2.5 concentrations for small areas in Ireland, to assess the relationship between social vulnerability and PM2.5 air pollution. Examining a wide range of socioeconomic indicators revealed some differentials in PM2.5 concentration levels by measure and by rural and urban classification. However, statistical modelling using concentration curves and concentration indices did not present substantial evidence of inequalities in PM2.5 concentrations across small areas. In common with other western European countries, an overall decline in the levels of PM2.5 between 2011 and 2016 was observed in Ireland, though the data indicates that almost all small areas in Ireland were found to have exceeded the World Health Organization (WHO)'s PM2.5 annual guideline (of 5 µg/m3), calling for greater policy efforts to reduce air pollution in Ireland. The recent Clean Air Strategy contains a commitment to achieve the WHO guideline limits for PM2.5 by 2040, with interim targets at various points over the next two decades. Achieving these targets will require policy measures to decarbonise home heating, promote active travel and the transition to electric vehicles, and further regulations on burning fossil fuels and enforcing environmental regulations more tightly. From a research and information-gathering perspective, installing more monitoring stations at key points could improve the quality and spatial dimension of the data collected and facilitate the assessment of the implementation of the measures in the Clean Air Strategy.

SARS-CoV-2 Seropositivity in Urban Population of Wild Fallow Deer, Dublin, Ireland, 2020-2022.

SARS-CoV-2 can infect wildlife, and SARS-CoV-2 variants of concern might expand into novel animal reservoirs, potentially by reverse zoonosis. White-tailed deer and mule deer of North America are the only deer species in which SARS-CoV-2 has been documented, raising the question of whether other reservoir species exist. We report cases of SARS-CoV-2 seropositivity in a fallow deer population located in Dublin, Ireland. Sampled deer were seronegative in 2020 when the Alpha variant was circulating in humans, 1 deer was seropositive for the Delta variant in 2021, and 12/21 (57%) sampled deer were seropositive for the Omicron variant in 2022, suggesting host tropism expansion as new variants emerged in humans. Omicron BA.1 was capable of infecting fallow deer lung type-2 pneumocytes and type-1-like pneumocytes or endothelial cells ex vivo. Ongoing surveillance to identify novel SARS-CoV-2 reservoirs is needed to prevent public health risks during human-animal interactions in periurban settings.

Clinical Impact of Serious Respiratory Disease in Children Under the Age of 2 Years During the 2021-2022 Bronchiolitis Season in England, Scotland, and Ireland.

BACKGROUND: Interventions introduced to reduce the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to a widespread reduction in childhood infections. However, from spring 2021 onwards the United Kingdom and Ireland experienced an unusual out-of-season epidemic of respiratory disease. METHODS: We conducted a prospective observational study (BronchStart), enrolling children 0-23 months of age presenting with bronchiolitis, lower respiratory tract infection, or first episode of wheeze to 59 emergency departments across England, Scotland, and Ireland from May 2021 to April 2022. We combined testing data with national admissions datasets to infer the impact of respiratory syncytial virus (RSV) disease. RESULTS: The BronchStart study collected data on 17 899 presentations for 17 164 children. Risk factors for admission and escalation of care included prematurity and congenital heart disease, but most admissions were for previously healthy term-born children. Of those aged 0-11 months who were admitted and tested for RSV, 1907 of 3912 (48.7%) tested positive. We estimate that every year in England and Scotland 28 561 (95% confidence interval, 27 637-29 486) infants are admitted with RSV infection. CONCLUSIONS: RSV infection was the main cause of hospitalizations in this cohort, but 51.3% of admissions in infants were not associated with the virus. The majority of admissions were in previously healthy term-born infants.

Use of wastewater from passenger ships to assess the movement of COVID-19 and other pathogenic viruses across maritime international boundaries.

Objective: The worldwide spread of SARS-CoV-2 and the resulting COVID-19 pandemic has been driven by international travel. This has led to the desire to develop surveillance approaches which can estimate the rate of import of pathogenic organisms across international borders. The aim of this study was to investigate the use of wastewater-based approaches for the surveillance of viral pathogens on commercial short-haul (3.5 h transit time) roll-on/roll-off passenger/freight ferries operating between the UK and the Republic of Ireland. Methods: Samples of toilet-derived wastewater (blackwater) were collected from two commercial ships over a 4-week period and analysed for SARS-CoV-2, influenza, enterovirus, norovirus, the faecal-marker virus crAssphage and a range of physical and chemical indicators of wastewater quality. Results: A small proportion of the wastewater samples were positive for SARS-CoV-2 (8% of the total), consistent with theoretical predictions of detection frequency (4%-15% of the total) based on the national COVID-19 Infection Survey and defecation behaviour. In addition, norovirus was detected in wastewater at low frequency. No influenza A/B viruses, enterovirus or enterovirus D68 were detected throughout the study period. Conclusion: We conclude that testing of wastewater from ships that cross international maritime boundaries may provide a cost-effective and relatively unbiased method to estimate the flow of infected individuals between countries. The approach is also readily applicable for the surveillance of other disease-causing agents.

Drug-Drug Interactions and Their Association with Adverse Health Outcomes in the Older Community-Dwelling Population: A Prospective Cohort Study.

BACKGROUND: Evidence on associations between drug-drug interactions (DDIs) and health outcomes in the older community-dwelling population is limited. OBJECTIVE: We estimate potentially clinically important DDI prevalence and examine the association between DDIs and (1) adverse drug events (ADEs), (2) emergency hospital attendance and (3) health-related quality of life (HRQoL) in an older community-dwelling population in Ireland. METHODS: This is a prospective cohort study of community-dwelling older adults (N = 904) aged ≥ 70 years from 15 general practices in Ireland recruited in 2010 (wave-1) and followed-up over 2 years (wave-2; 2012-2013), with linked national pharmacy claims data. Individuals dispensed two or more drugs (wave-1: N = 842; wave-2: N = 763) were included. DDI prevalence at baseline, follow-up and 6 months prior to each health outcome was estimated. Multi-level regression was used to model the association between DDI-exposure and health outcomes at follow-up. DDI prevalence, adjusted incidence-rate ratios (aIRR), adjusted odds ratios (aOR), ß coefficients and robust standard error (RSE) from multi-level regression analyses, and 95% confidence intervals (CIs) are reported. RESULTS: At wave-1, n = 196 (23.3% [95% CI 20.5-26.3]), individuals were potentially exposed to ≥ 1 DDI, increasing to n = 345 (45.2% [41.7-48.9]) at wave-2. At 2-year follow-up, the median number of ADEs was 3 (interquartile range [IQR 2-5]); 229 (30.1%) had ≥ 1 emergency hospital attendance, and the mean EQ-5D was 0.74 (± 0.23). Evidence for the association between DDI-exposure and emergency hospital attendance at follow-up was lacking (aOR = 1.38 [0.42-4.53]). DDI-exposure was associated with an increasing number of ADEs (aIRR = 1.26 [1.03-1.55]), and decreasing EQ-5D utility (ß = - 0.07, [-0.11 to -0.04], RSE = 0.02). Aspirin-warfarin, clarithromycin-prednisolone, amiodarone-furosemide, clarithromycin-salbutamol, rosuvastatin-warfarin, amiodarone-bisoprolol, and aspirin-nicorandil were common DDIs 6 months preceding these health outcomes. CONCLUSIONS: We found a two-fold increase in DDI prevalence between wave 1 and 2. DDI exposure was associated with increasing ADEs and declining HRQoL at 2-year follow-up. Common DDIs involved anticoagulants, cardiovascular and antimicrobial drugs, which should be targeted for medicine optimisation.

Cardiovascular Autonomic Function and Progression of Age-Related Macular Degeneration in The Irish Longitudinal Study of Ageing (TILDA).

Purpose: To examine if changes in hemodynamic measures during an orthostatic challenge were associated with progression of age-related macular degeneration (AMD) over a 4-year period in The Irish Longitudinal Study on Ageing. Methods: Participants with AMD who underwent an active stand (AS) test at wave 1 (2009/2010) and retinal photographs at both wave 1 and wave 3 (2014/2015) were included (N = 159: 121 with no AMD progression and 38 with progression). Beat-to-beat hemodynamic data were non-invasively collected using a Finometer MIDI device during the AS at wave 1, recording systolic blood pressure (sBP), diastolic blood pressure (dBP), mean arterial pressure (MAP), and heart rate. Cardiac output, stroke volume, and total peripheral resistance (TPR) were derived from these measures. Baseline characteristics were compared between groups with and without AMD progression. Mixed-effects linear regression models were used to assess the association between changes in hemodynamic parameters during the AS and AMD progression, controlling for known AMD-associated risk factors. Results: At baseline, increasing age and lower dBP were significantly associated with AMD progression. Mixed-effects models for the period between standing and 10 seconds post-stand revealed significant associations with AMD progression with a steeper drop in dBP and a slower drop in TPR. Between 10 and 20 seconds post-stand, AMD progression was significantly associated with less pronounced reduction in heart rate. Conclusions: These observational data suggest that impaired hemodynamic responses within the first 20 seconds of orthostasis may be associated with the progression of AMD.

Perspectives of primary school teachers on the capacity of schools to support post-pandemic health needs emerging among school-age children.

BACKGROUND: This study aimed to explore the impact of the COVID-19 pandemic on capacity building for health promotion in primary schools from the perspectives of primary school teachers. METHODS: A cross-sectional observational study was conducted via an anonymous online survey between February and May 2022. Three-quarters (n2460) of all schools in the Republic of Ireland were invited to participate. Demographics such as gender, teaching experience, school type and delivering equality of opportunity in schools (DEIS) designation were collected. Perceived capacity for health promotion was measured on a 10-point Likert scale. Facilitators and barriers related to health promotion and aspects of child health prioritised for health promotion in the 2 years after restrictions eased were explored via closed- and open-ended questions. RESULTS: Of the 595 responses, 493 were eligible for analysis. Participants were based in schools in every county in the Republic of Ireland, with most (85.4%, n421) being female. Almost a third (30.5%, n150) were 11-20 years post-qualification, and a quarter (25.2%, n124) had over 30 years' teaching experience. Mean capacity for school-based health promotion pre-pandemic was moderate, at 6.6 ± 2.2 on a 10-point scale. Mean capacity in spring 2022 decreased significantly (p < 0.001) to 4.1 ± 2.4, indicating poor capacity. Capacity ratings did not significantly differ by school type (p = 0.31), socioeconomic designation (p = 0.27) or years post-qualification (p = 0.08). Capacity decrements were most frequently (49.7%, n245) attributed to organisational factors, while individual and community-level factors were cited by 27.6% (n136) and 21.5% (n106) of respondents, respectively. Healthy eating significantly (p < 0.001) decreased as a priority for health promotion between pre-pandemic times (76.3%, n376) and spring 2022 (23.1%, n114). Mental health significantly (p < 0.01) increased as a priority, being listed by 38.1% (n188) as a priority pre-pandemic and doubling to 72.6% (n358) in spring 2022. CONCLUSIONS: Fostering a holistic approach to health promotion in schools remains a challenge. Further efforts are needed to support schools to implement sustainable and balanced systems of health promotion.

Investigation and management of young-onset hypertension: British and Irish hypertension society position statement.

National and international hypertension guidelines recommend that adults with young-onset hypertension (aged <40 years at diagnosis) are reviewed by a hypertension specialist to exclude secondary causes of hypertension and optimise therapeutic regimens. A recent survey among UK secondary care hypertension specialist physicians highlighted variations in the investigation of such patients. In this position statement, the British and Irish Hypertension Society seek to provide clinicians with a practical approach to the investigation and management of adults with young-onset hypertension. We aim to ensure that individuals receive consistent and high-quality care across the UK and Ireland, to highlight gaps in the current evidence, and to identify important future research questions.

Comparing times of self-harm presentations to hospital emergency departments in children, adolescents, young adults and adults: a national registry study 2007-2019.

PURPOSE: The few studies that have explored self-harm presentation times at hospital emergency departments (EDs) - an important factor that can determine if a patient receives a mental health assessment - primarily focus on adult samples. This study examined the times of self-harm presentations to EDs, self-harm methods used, mental health assessments, and admission data across different age-groups. METHODS: Using data from the National Self-Harm Registry Ireland over a 13-year timeframe (2007-2019), this study compared times, days, seasons, methods of self-harm, and admission data for children (8-12 years), adolescents (13-17 years), young adults (18-25 years) and adults (> 25 years). RESULTS: The majority of the 152,474 self-harm presentations (78.6%) for all ages occurred out-of-hours (outside the standard working hours or in-hours times of 09:00-17:00, Monday-Friday). The four hours before midnight had the highest proportions of self-harm presentations for adolescents (27.9%) and adults (23.1%), whereas the four hours after midnight had the highest proportion of self-harm presentations for young adults (22.9%). The 16:00-midnight timeframe had highest proportion of self-harm presentations in children (52.3%). Higher proportions of patients received a mental health assessment in-hours compared to out-of-hours among young adults (78.2% vs. 73.3%) and adults (76.1% vs. 72.0%). Self-harm presentations were lowest during summer months in children and adolescents. DISCUSSION: Hospitals should ensure that adequate resources are available for individuals presenting with self-harm, especially in the case of overcrowded EDs, and protocols need to be designed for those presenting with self-harm due to intoxication. In line with national policy, protocols for patients presenting during out-of-hours should be designed that can incorporate services from allied health multidisciplinary teams, social work, addiction services and counselling organisations. Given the lower rates of self-harm during school holidays for children and adolescents, the school environment must be considered in the context of mental health and self-harm public health prevention interventions.

Major trauma patients and their outcomes - A retrospective observational study of critical care trauma admissions to a trauma unit with special services.

INTRODUCTION: International data describes a changing pattern to trauma over the last decade, with an increasingly comorbid population presenting challenges to trauma management and resources. In Ireland, resource provision and management of trauma is being transformed to deliver a trauma network, in line with international best practice. Our hospital plays a crucial role within this network and is designated a Trauma Unit with Specialist Services (TUSS) to distinguish it from standard trauma units. METHODS: This study aims to describe the characteristics of patients and injuries and assess trends in mortality rates. It is a retrospective observational study of adult ICU trauma admissions from August 2010 to July 2021. Primary outcome was all-cause mortality at 30-days, 90-days, and 1 year. Secondary outcomes included length of stay, disposition, and complications. Patients were categorised by age, injury severity score (ISS), and mechanism of injury. RESULTS: In all, 709 patients were identified for final analysis. Annual admissions doubled since 2010/11, with a trough of 41 admissions, increasing to peak at 95 admissions in 2017/18. Blunt trauma accounted for 97.6% of cases. Falls <2 m (45.4%) and RTAs (29.2%) were the main mechanisms of injury. Polytrauma comprised 41.9% of admissions. Traumatic brain injury accounted for 30.2% of cases; 18.8% of these patients were transferred to a neurosurgical centre. The majority of patients, 58.1%, were severely injured (ISS ≥ 16). Patients ≥ 65 years of age accounted for 45.7% of admissions, with falls <2 m their primary mechanism of injury. The primary outcome of all-cause mortality reduced with an absolute risk reduction (ARR) of 8.0% (95% CI: -8.37%, 24.36%), 12.9% (95% CI: -4.19%, 29.94%) and 8.2% (95% CI: -9.64%, 26.09%) for 30-day, 90-day and 1-year respectively. Regression analysis demonstrated a significant reduction in mortality for 30-days and 90-days post presentation to hospital (P-values of 0.018, 0.033 and 0.152 for 30-day, 90-day and 1-year respectively). CONCLUSION: The burden of major trauma in our hospital is considerable and increasing over time. Substantial changes in demographics, injury mechanism and mortality were seen, with outcomes improving over time. This is consistent with international data where trauma systems have been adopted.

Long-term exposure to PM2.5 air pollution and mental health: a retrospective cohort study in Ireland.

BACKGROUND: Mental illness is the leading cause of years lived with disability, and the global disease burden of mental ill-health has increased substantially in the last number of decades. There is now increasing evidence that environmental conditions, and in particular poor air quality, may be associated with mental health and wellbeing. METHODS: This cross-sectional analysis uses data on mental health and wellbeing from The Irish Longitudinal Study on Ageing (TILDA), a nationally representative survey of the population aged 50+ in Ireland. Annual average PM2.5 concentrations at respondents' residential addresses over the period 1998-2014 are used to measure long-term exposure to ambient PM2.5. RESULTS: We find evidence of associations between long-term exposure to ambient PM2.5 and depression and anxiety. The measured associations are strong, and are comparable with effect sizes for variables such as sex. Effects are also evident at relatively low concentrations by international standards. However, we find no evidence of associations between long-term ambient particulate pollution and other indicators of mental health and well-being such as stress, worry and quality of life. CONCLUSIONS: The measured associations are strong, particularly considering the relatively low PM2.5 concentrations prevailing in Ireland compared to many other countries. While it is estimated that over 90 per cent of the world's population lives in areas with annual mean PM2.5 concentrations greater than 10 µg/m3, these results contribute to the increasing evidence that suggests that harmful effects can be detected at even low levels of air pollution.