Early life PM2.5 exposure, childhood cognitive ability and mortality between age 11 and 86: A record-linkage life-course study from Scotland.

BACKGROUND: Living in areas with high air pollution concentrations is associated with all-cause and cause-specific mortality. Exposure in sensitive developmental periods might be long-lasting but studies with very long follow-up are rare, and mediating pathways between early life exposure and life-course mortality are not fully understood. METHODS: Data were drawn from the Scottish Longitudinal Study Birth Cohort of 1936, a representative record-linkage study comprising 5% of the Scottish population born in 1936. Participants had valid age 11 cognitive ability test scores along with linked mortality data until age 86. Fine particle (PM2.5) concentrations estimated with the EMEP4UK atmospheric chemistry transport model were linked to participants' residential address derived from the National Identity Register in 1939 (age 3). Confounder-adjusted Cox regression estimated associations between PM2.5 and mortality; regression-based causal mediation analysis explored mediation through childhood cognitive ability. RESULTS: The final sample consisted of 2734 individuals with 1608 deaths registered during the 1,833,517 person-months at risk follow-up time. Higher early life PM2.5 exposure increased the risk of all-cause mortality (HR = 1.03, 95% CI: 1.01-1.04 per 10 µg m-3 increment), associations were stronger for mortality between age 65 and 86. PM2.5 increased the risk of cancer-related mortality (HR = 1.05, 95% CI: 1.02-1.08), especially for lung cancer among females (HR = 1.11, 95% CI: 1.02-1.21), but not for cardiovascular and respiratory diseases. Higher PM2.5 in early life (≥50 µg m-3) was associated with lower childhood cognitive ability, which, in turn, increased the risk of all-cause mortality and mediated 25% of the total associations. CONCLUSIONS: In our life-course study with 75-year of continuous mortality records, we found that exposure to air pollution in early life was associated with higher mortality in late adulthood, and that childhood cognitive ability partly mediated this relationship. Findings suggest that past air pollution concentrations will likely impact health and longevity for decades to come.

Access to Effective Communication Aids and Services among American Sign Language Users across North Carolina: Disparities and Strategies to Address Them.

OBJECTIVE: To examine the extent to which communication aids and services used by American Sign Language (ASL) users and their healthcare providers aligns with preferences, satisfaction, and unmet needs; and to elicit from stakeholders strategies to address disparities. METHODS: A cross-sectional study was conducted of ASL users in North Carolina. Respondents completed an online survey presented in ASL and English (N = 189). McNemar's tests were used to compare rates of preferred and actual methods of communication. Logistic regression models explored relationships of accessible communication with dissatisfaction and unmet need. Qualitative interviews explored satisfaction with communication and reflections on what works, what does not, and outcomes (N = 54). RESULTS: While 45% of respondents used a professional sign language interpreter, 65% of respondents preferred to do so. Accessible communication was associated with lower odds of dissatisfaction with communication (OR = .19, p < .05). Dissatisfaction with communication was associated with greater odds of unmet need for healthcare (OR = 8.95, p < .05). Interview respondents emphasized their preference for on-site interpreters, explaining how video remote interpreting was subject to technical difficulties while writing back-and-forth led to important gaps in understanding. CONCLUSIONS: While ASL users prefer to use professional, on-site sign language interpreters to communicate with providers, most use some other form of communication instead. Findings emphasize the need for policy strategies to facilitate access to high quality, well-functioning professional interpreter services and to have those services delivered on-site to overcome disparities.

Socioeconomic disadvantage, fetal environment and child development: linked Scottish administrative records based study.

BACKGROUND: Cognitive development in childhood is negatively affected by socioeconomic disadvantage. This study examined whether differences in fetal environment might mediate the association between family socioeconomic position and child development. METHODS: Data were linked from the Scottish Longitudinal Study, maternity inpatient records and the Child Health Surveillance Programme - Pre School for 32,238 children. The outcome variables were based on health visitor assessment of gross motor, hearing and language, vision and fine motor, and social development. Socioeconomic position was measured using parental social class and highest qualification attained. Random-effects logistic regression models were estimated to account for multiple reviews and familial clustering. Mediation analysis was conducted using the Karlson-Holm-Breen method. RESULTS: Hearing and language, vision and fine motor, and social development were associated with lower parental social class and lower parental educational qualifications after adjustment for fetal environment. Fetal environment partially mediated the estimated effect of having parents without educational qualifications for hearing and language (ß = 0·15; 95% confidence interval (CI) = 0·07, 0·23), vision and fine motor (ß = 0·19; CI = 0·10, 0·28) and social development (ß = 0·14; CI = 0·03 to 0·25). CONCLUSIONS: Socioeconomic position predicted hearing and language, vision and fine motor, and social development but not gross motor development. For children of parents without educational qualifications, fetal environment appears to contribute to a part of the socioeconomic gradient in child development abnormalities but post-natal environment appears to still explain the majority of the gradient and for other children most of it.

'A confession of ignorance': deaths from old age and deciphering cause-of-death statistics in Scotland, 1855-1949.

A large amount of the research undertaken in an attempt to discover the reasons underlying the late nineteenth- and early twentieth-century mortality decline in Britain has relied on the statistics published by the Registrars General. The processes by which individual causes of death are recorded and then processed in order to create the statistics are not, however, well understood. In this article, the authors build on previous work to piece together a time series of causes of death for Scotland, which removes many of the discontinuities encountered in the published statistics that result from the Registrar General deciding to update the nosology, or classification system, which was being used to compile his figures. Having regrouped individual causes of death to 'smooth' the time series, the authors use the new groups to examine the changing causes of death in Scotland for selected age groups, before turning to undertake a detailed examination of mortality amongst those aged 55 or more. The authors find that when deaths from 'old age' in the latter age group are separated from other 'ill-defined' causes, it becomes obvious that there was a 'rebranding' of cause of death. The authors then use individual-level data from two Scottish communities to further dissect the roles played by 'informants' and 'doctors' in this rebranding, in order to see how these roles may have altered over time and what the consequences might be for one's view of how mortality changed in Scotland between 1855 and 1949. Finally, the authors argue that their findings have important implications for some of historical demography's most prominent theories: the McKeown thesis and the theory of epidemiological transition.

Higher air pollution exposure in early life is associated with worse health among older adults: A 72-year follow-up study from Scotland.

Air pollution increases the risk of mortality and morbidity. However, limited evidence exists on the very long-term associations between early life air pollution exposure and health, as well as on potential pathways. This study explored the relationship between fine particle (PM2.5) exposure at age 3 and limiting long-term illness (LLTI) at ages 55, 65 and 75 using data from the Scottish Longitudinal Study Birth Cohort 1936, a representative administrative cohort study. We found that early life PM2.5 exposure was associated with higher odds of LLTI in mid-to-late adulthood (OR = 1.10, 95% CI: 1.06, 1.14 per 10 µg m-3 increment) among the 2085 participants, with stronger associations among those growing up in disadvantaged families. Path analyses suggested that 15-21% of the association between early life PM2.5 concentrations and LLTI at age 65 (n = 1406) was mediated through childhood cognitive ability, educational qualifications, and adult social position. Future research should capitalise on linked administrative and health data, and explore causal mechanisms between environment and specific health conditions across the life course.

Does cycle commuting reduce the risk of mental ill-health? An instrumental variable analysis using distance to nearest cycle path.

BACKGROUND: Previous studies have linked cycling with improved mental wellbeing but these studies tend to use cross-sectional survey data that have small sample sizes and self-reported health measures, and are potentially susceptible to omitted-variable bias and reverse causation. We use an instrumental variable approach and an objective measure of mental ill-health taken from linked administrative data to ask: 'Does cycle commuting reduce the risk of mental ill-health?' METHODS: Our study links data on commuting in Edinburgh and Glasgow from the Scottish population census with mental health prescriptions from the National Health Service Prescribing Information System records. We use road distance from home to nearest cycle path as an instrumental variable for cycle commuting. RESULTS: In total, 378 253 people aged 16-74 years living and working in the City of Edinburgh and Glasgow City council areas at the 2011 census were included in our study; 1.85% of commuters in Glasgow and 4.8% of commuters in Edinburgh cycled to work. Amongst cyclists, 9% had a prescription for mental health compared with 14% amongst non-cyclists. Using a bivariate probit model, we estimate a mean average reduction in prescriptions for antidepressants and/or anxiolytics in the 5 years following the census of -15.1% (95% CI: -15.3% to -15.0%) amongst cycle commuters compared with those who use any other mode to commute. CONCLUSIONS: This work suggests that cycle commuting is causally related to reduced mental ill-health and provides further evidence in support of the promotion of active travel to encourage commuters travelling shorter distances to shift to cycle commutes.

Influences on food supply from elk abundance and precipitation early in the growing season.

Large grazing mammals should negatively affect forage biomass of their food supply, but documentation is lacking in free ranging populations. Furthermore, complications from factors such as weather patterns and spatial heterogeneity might obscure grazing effects on the food supply. We examined influences of Roosevelt elk (Cervus canadensis roosevelti (Merriam, 1897)) abundance and precipitation on forage biomass at two spatial scales; meadows that contained most of the food supply, and sectors nested in meadows. Spatial heterogeneity in forage biomass might also decline with increasing elk abundance. Elk abundance was estimated from population counts and varied 3.9-fold across the 15 years of study in northwestern California, USA. Each January, early in the growing season, we estimated forage biomass in the 50-ha meadow complex used by the elk population. Measures of palatable forage cover and height were taken in 270 » m2 plots dispersed throughout sectors. These measurements were then related to dried forage biomass. At both spatial scales, elk abundance was inversely, and precipitation was positively related to forage biomass. At the sector scale, analysis of a linear mixed effect model indicated heterogeneity. In some sectors both predictors were related to forage biomass and in other sectors they were not. Heterogeneity was not from uneven elk grazing as elk grazed sectors in proportion to forage biomass. The varied elk abundance-forage biomass relationships across sectors indicated that spatial heterogeneity declined with increasing elk abundance. Detecting relationships between free ranging ungulate populations and biomass of their food supply is not straightforward.

Characterization of aerosols generated by high-power electronic nicotine delivery systems (ENDS): Influence of atomizer, temperature and PG:VG ratios.

The aerosol characteristics of electronic nicotine delivery systems (ENDS) are important parameters in predicting health outcomes since parameters such as aerosol particle size correlate strongly to aerosol delivery and deposition efficiency. However, many studies to date do not account for aerosol aging, which may affect the measurement of ultra-fine particles that typically coagulate or agglomerate during puff development. To reduce aerosol aging, we herein present a unique instrumentation method that combines a) positive pressure ENDS activation and sample collection, b) minimization of both sample tubing length and dilution factors, and c) a high-resolution, electrical low-pressure impactor. This novel approach was applied to systematically investigate the effects of coil design, coil temperature, and propylene glycol to vegetable glycerol ratios on aerosol characteristics including aerosol mass generation, aerosol count generation, and the mass and count size distributions for a high-powered ENDS. Aerosol count measurements revealed high concentrations of ultra-fine particles compared to fine and coarse particles at 200°C, while aerosol mass measurements showed an increase in the overall aerosol mass of fine and coarse particles with increases in temperature and decreases in propylene glycol content. These results provide a better understanding on how various ENDS design parameters affect aerosol characteristics and highlight the need for further research to identify the design parameters that most impact ultra-fine particle generation.

Intergenerational replacement and migration in the countries and regions of the United Kingdom, 1971-2009.

This article uses a recently proposed measure, the overall replacement ratio or ORR, to assess the extent to which migration alters intergenerational replacement within the United Kingdom. The UK as a whole can be seen to experience 'replacement migration' as immigration compensates for fertility below the replacement level. However, the article shows that the impact of migration differs radically in the different regions of the country. South East England experiences very substantial immigration from both the rest of the UK and overseas, far more than is needed for intergenerational replacement, whereas most of the rest of the UK sees little or no net immigration and the ORR remains below the replacement level.

Pathways between Socioeconomic Disadvantage and Childhood Growth in the Scottish Longitudinal Study, 1991-2001.

Socioeconomically disadvantaged children are more likely to be of shorter stature and overweight, leading to greater risk of obesity in adulthood. Disentangling the mediatory pathways between socioeconomic disadvantage and childhood size may help in the development of appropriate policies aimed at reducing these health inequalities. We aimed to elucidate the putative mediatory role of birth weight using a representative sample of the Scottish population born 1991-2001 (n = 16,628). Estimated height and overweight/obesity at age 4.5 years were related to three measures of socioeconomic disadvantage (mother's education, Scottish Index of Multiple Deprivation, synthetic weekly income). Mediation was examined using two approaches: a 'traditional' mediation analysis and a counterfactual-based mediation analysis. Both analyses identified a negative effect of each measure of socioeconomic disadvantage on height, mediated to some extent by birth weight, and a positive 'direct effect' of mother's education and Scottish Index of Multiple Deprivation on overweight/obesity, which was partly counterbalanced by a negative 'indirect effect'. The extent of mediation estimated when adopting the traditional approach was greater than when adopting the counterfactual-based approach because of inappropriate handling of intermediate confounding in the former. Our findings suggest that higher birth weight in more disadvantaged groups is associated with reduced social inequalities in height but also with increased inequalities in overweight/obesity.

Is changing status through housing tenure associated with changes in mental health? Results from the British Household Panel Survey.

BACKGROUND: Actual or perceived status, such as housing tenure, may impact on health through stress-inducing social comparisons. Studies of how status change impacts mental health change are rare but important because they are less prone to confounding. METHODS: We used data from the British Household Panel Survey to compare psychological distress in local authority renters who opted to buy their home under the UK's Right to Buy (RTB) policy versus those who continued to rent the same (social non-mover (SNM)) or a different (social mover (SM)) local authority property or who bought privately (owner mover (OM)). General Health Questionnaire (GHQ-12) scores before and after any change in tenure and/or address were compared across groups using a difference-in-difference approach. RESULTS: Individuals who moved house (bought or rented) were younger while those who bought (the same or different house) were better off, more likely to be employed, and had higher educational qualifications. Individuals who bought their home (under RTB or privately) had lower distress scores from the outset. Individuals who moved house (bought or rented) experienced a rise in distress prior to moving that was no longer evident 1 year after the move. There was no evidence that changing tenure reduced psychological distress comparing (difference (95% CI)) average GHQ score 2 years preaddress and 1 year postaddress/tenure change in RTB vs SNM, SM, OM: -0.08 (-0.68 to 0.51), 0.16 (-0.70 to 1.01) and -0.17 (-1.28 to 0.94), respectively). CONCLUSIONS: Changing tenure under RTB did not, on average, impact psychological distress, suggesting that this status change did not change mental health.