Mark Cherrie

Land cover and air pollution are associated with asthma hospitalisations: A cross-sectional study

BACKGROUND There is increasing policy interest in the potential for vegetation in urban areas to mitigate harmful effects of air pollution on respiratory health. We aimed to quantify relationships between tree and green space density and asthma-related hospitalisations, and explore how these varied with exposure to background air pollution concentrations. METHODS Population standardised asthma hospitalisation rates (1997-2012) for 26,455 urban residential areas of England were merged with area-level data on vegetation and background air pollutant concentrations. We fitted negative binomial regression models using maximum likelihood estimation to obtain estimates of asthma-vegetation relationships at different levels of pollutant exposure. RESULTS Green space and gardens were associated with reductions in asthma hospitalisation when pollutant exposures were lower but had no significant association when pollutant exposures were higher. In contrast, tree density was associated with reduced asthma hospitalisation when pollutant exposures were higher but had no significant association when pollutant exposures were lower. CONCLUSIONS We found differential effects of natural environments at high and low background pollutant concentrations. These findings can provide evidence for urban planning decisions which aim to leverage health co-benefits from environmental improvements.

Coastal climate is associated with elevated solar irradiance and higher 25(OH)D level.

INTRODUCTION There is evidence that populations living close to the coast have improved health and wellbeing. Coastal environments are linked to promotion of physical activity through provision of safe, opportune, aesthetic and accessible spaces for recreation. Exposure to coastal environments may also reduce stress and induce positive mood. We hypothesised that coastal climate may influence the vitamin D status of residents and thus partly explain benefits to health. MATERIALS AND METHODS Ecological and cross-sectional analyses were designed to elucidate the connection between coastal residence and vitamin D status. We divided residential data, from developed land use areas and the Lower Super Output Areas or Data Zones (Scotland) of the 1958 Birth Cohort participants, into the following coastal bands: <1 km, 1-5 km, 5-20 km, 20-50 km and over 50 km. In the ecological analysis we used a multiple regression model to describe the relationship between UV vitd and coastal proximity adjusted for latitude. Subsequently, using the residential information of the participants of the 1958 Birth Cohort we developed a multiple regression model to understand the relationship between serum 25(OH)D (a marker of vitamin D status) and coastal proximity adjusted for several factors related to vitamin D status (e.g. diet, outdoor activity). RESULTS We found that coastal proximity was associated with solar irradiance; on average a 99.6 (96.1-103.3)J/m(2)/day regression coefficient was recorded for settlements <1 km from the coast compared with those at >50 km. This relationship was modified by latitude with settlements at a lower latitude exhibiting a greater effect. Individuals living closer to the coast in England had higher vitamin D levels than those inland, particularly in autumn. CONCLUSION Geographic location may influence biochemistry and health outcomes due to environmental factors. This can provide benefits in terms of vitamin D status but may also pose a risk due to higher skin cancer risk. We provide further evidence in support of the claim that coastal environments can provide opportunities for health and wellbeing.

P6 Varying mental health in the population across scotland during the recent recession

Background This research focusses on geographical variation in population mental health over the period 2007–2011 (during the onset of the economic recession). We report preliminary results from a project recently funded under the ESRC SDAI programme, seeking to explore variability in mental illness in Scotland during this period. Our methods combine information on individual lifecourse changes, as well as change over time in areas where the individuals are living. This research contributes to a growing field concerned with the relationships between population health and changes in wider determinants of health, operating over time for both individual people and places where they live. Methods We are making innovative use of a variety of data sources including individual data from the Scottish Longitudinal Study (SLS), a large (5%) sample from the Scottish population; drawn from the population census made available under secure conditions at the Longitudinal Studies Centre Scotland, with help and supervision of SLS staff. (SLS is supported by the ESRC/JISC, the Scottish Funding Council, the Scientists Office and the Scottish Government.) We report on work which has linked these data to information on prescriptions likely to be used to treat mental illness (provided by the Electronic Data Research & Innovation Service (eDRIS) and information on area socio-economic conditions publicly available via Scottish National Government and NOMIS (Durham University) a service provided by the Office for National Statistics, ONS. Results We report preliminary results from a dataset for more than 1 20 000 people. Most of those reporting mental illness were taking antidepressants. There is a significant statistical association between risk of reporting mental illness in 2011 and employment trajectory of local authority of residence by 2011, (after controlling for individual risk factors and for neighbourhood deprivation in 2001, before the onset of the recession). Conclusion Various personal, family and neighbourhood factors are associated with self-reported mental illness. Allowing for individual/family factors and local deprivation, people in local authorities where employment rates remained higher during the recession had lower risk of reporting mental illness, especially in the highlands and Islands of Scotland. Further research is being carried out to explore these relationships (eg controlling for migration and other possible area level determinants of mental health). The research underlines the importance of maintaining mental health services across Scotland during the recession to protect mental health and control inequality.

Association between Serum 25-Hydroxy Vitamin D Levels and the Prevalence of Adult-Onset Asthma

The major circulating metabolite of vitamin D (25(OH)D) has been implicated in the pathogenesis for atopic dermatitis, asthma and other allergic diseases due to downstream immunomodulatory effects. However, a consistent association between 25(OH)D and asthma during adulthood has yet to be found in observational studies. We aimed to test the association between 25(OH)D and asthma during adulthood and hypothesised that this association would be stronger in non-atopic participants. Using information collected on the participants of the 1958 birth cohort, we developed a novel measure of atopic status using total and specific IgE values and reported history of eczema and allergic rhinitis. We designed a nested case-control analysis, stratified by atopic status, and using logistic regression models investigated the association between 25(OH)D measured at age 46 years with the prevalence of asthma and wheezy bronchitis at age 50 years, excluding participants who reported ever having asthma or wheezy bronchitis before the age of 42. In the fully adjusted models, a 10 nmol/L increase in serum 25(OH)D prevalence had a significant association with asthma (aOR 0.94; 95% CI 0.88–1.00). There was some evidence of an atopic dependent trend in the association between 25(OH)D levels and asthma. Further analytical work on the operationalisation of atopy status would prove useful to uncover whether there is a role for 25(OH)D and other risk factors for asthma.