Investigating the impact of London's ultra low emission zone on children's health: children's health in London and Luton (CHILL) protocol for a prospective parallel cohort study.

BACKGROUND: Air pollution harms health across the life course. Children are at particular risk of adverse effects during development, which may impact on health in later life. Interventions that improve air quality are urgently needed both to improve public health now, and prevent longer-term increased vulnerability to chronic disease. Low Emission Zones are a public health policy intervention aimed at reducing traffic-derived contributions to urban air pollution, but evidence that they deliver health benefits is lacking. We describe a natural experiment study (CHILL: Children's Health in London and Luton) to evaluate the impacts of the introduction of London's Ultra Low Emission Zone (ULEZ) on children's health. METHODS: CHILL is a prospective two-arm parallel longitudinal cohort study recruiting children at age 6-9 years from primary schools in Central London (the focus of the first phase of the ULEZ) and Luton (a comparator site), with the primary outcome being the impact of changes in annual air pollutant exposures (nitrogen oxides [NOx], nitrogen dioxide [NO2], particulate matter with a diameter of less than 2.5micrograms [PM2.5], and less than 10 micrograms [PM10]) across the two sites on lung function growth, measured as post-bronchodilator forced expiratory volume in one second (FEV1) over five years. Secondary outcomes include physical activity, cognitive development, mental health, quality of life, health inequalities, and a range of respiratory and health economic data. DISCUSSION: CHILL's prospective parallel cohort design will enable robust conclusions to be drawn on the effectiveness of the ULEZ at improving air quality and delivering improvements in children's respiratory health. With increasing proportions of the world's population now living in large urban areas exceeding World Health Organisation air pollution limit guidelines, our study findings will have important implications for the design and implementation of Low Emission and Clean Air Zones in the UK, and worldwide. CLINICALTRIALS: GOV: NCT04695093 (05/01/2021).

Considering Exposure Assessment in Epidemiological Studies of Chronic Health in Military Populations.

Exposure assessment is an important factor in all epidemiological research seeking to identify, evaluate, and control health risks. In the military and veteran context, population health research to explore exposure-response links is complicated by the wide variety of environments and hazards encountered during active service, long latency periods, and a lack of information on exposures in potentially vulnerable subgroups. This paper summarizes some key considerations for exposure assessment in long-term health studies of military populations, including the identification of hazards related to military service, characterization of potentially exposed groups, exposure data collection, and assignment of exposures to estimate health risks. Opportunities and future directions for exposure assessment in this field are also discussed.

Effect of work schedule on prospective antidepressant prescriptions in Sweden: a 2-year sex-stratified analysis using national drug registry data.

INTRODUCTION: Depression-related mood disorders affect millions of people worldwide and contribute to substantial morbidity and disability, yet little is known about the effects of work scheduling on depression. This study used a large Swedish survey to prospectively examine the effects of work schedule on registry-based antidepressant prescriptions in females and males over a 2-year period. METHODS: The study was based on an approximately representative sample (n=3980 males, 4663 females) of gainfully employed participants in the Swedish Longitudinal Occupational Survey of Health. Sex-stratified analyses were conducted using logistic regression. For exposure, eight categories described work schedule in 2008: 'regular days' (three categories of night work history: none, ≤3 years, 4+ years), 'night shift work', 'regular shift work (no nights)', 'rostered work (no nights)', 'flexible/non-regulated hours' and 'other'. For the primary outcome measure, all prescriptions coded N06A according to the Anatomical Therapeutic Chemical System were obtained from the Swedish National Prescribed Drug Register and dichotomised into 'any' or 'no' prescriptions between 2008 and 2010. Estimates were adjusted for potential sociodemographic, health and work confounders, and for prior depressive symptoms. RESULTS: In 2008, 22% of females versus 19% of males worked outside of regular daytime schedule. Registered antidepressant prescription rates in the postsurvey period were 11.4% for females versus 5.8% for males. In fully adjusted models, females in 'flexible/non-regulated' schedules showed an increased OR for prospective antidepressant prescriptions (OR=2.01, 95% CI=1.08 to 3.76). In males, odds ratios were most increased in those working 'other' schedules (OR=1.72, 95% CI=0.75 to 3.94) and 'Regular days with four or more years' history of night work' (OR=1.54, 95% CI=0.93 to 2.56). CONCLUSIONS: This study's findings support a relationship between work schedule and prospective antidepressant prescriptions in the Swedish workforce. Future research should continue to assess sex-stratified relationships, using detailed shift work exposure categories and objective registry data where possible.

Examining Exposure Assessment in Shift Work Research: A Study on Depression Among Nurses.

Introduction: Coarse exposure assessment and assignment is a common issue facing epidemiological studies of shift work. Such measures ignore a number of exposure characteristics that may impact on health, increasing the likelihood of biased effect estimates and masked exposure-response relationships. To demonstrate the impacts of exposure assessment precision in shift work research, this study investigated relationships between work schedule and depression in a large survey of Canadian nurses. Methods: The Canadian 2005 National Survey of the Work and Health of Nurses provided the analytic sample (n = 11450). Relationships between work schedule and depression were assessed using logistic regression models with high, moderate, and low-precision exposure groupings. The high-precision grouping described shift timing and rotation frequency, the moderate-precision grouping described shift timing, and the low-precision grouping described the presence/absence of shift work. Final model estimates were adjusted for the potential confounding effects of demographic and work variables, and bootstrap weights were used to generate sampling variances that accounted for the survey sample design. Results: The high-precision exposure grouping model showed the strongest relationships between work schedule and depression, with increased odds ratios [ORs] for rapidly rotating (OR = 1.51, 95% confidence interval [CI] = 0.91-2.51) and undefined rotating (OR = 1.67, 95% CI = 0.92-3.02) shift workers, and a decreased OR for depression in slow rotating (OR = 0.79, 95% CI = 0.57-1.08) shift workers. For the low- and moderate-precision exposure grouping models, weak relationships were observed for all work schedule categories (OR range 0.95 to 0.99). Conclusions: Findings from this study support the need to consider and collect the data required for precise and conceptually driven exposure assessment and assignment in future studies of shift work and health. Further research into the effects of shift rotation frequency on depression is also recommended.

Correlates of bushmeat in markets and depletion of wildlife.

We used data on number of carcasses of wildlife species sold in 79 bushmeat markets in a region of Nigeria and Cameroon to assess whether species composition of a market could be explained by anthropogenic pressures and environmental variables around each market. More than 45 mammal species from 9 orders were traded across all markets; mostly ungulates and rodents. For each market, we determined median body mass, species diversity (game diversity), and taxa that were principal contributors to the total number of carcasses for sale (game dominance). Human population density in surrounding areas was significantly and negatively related to the percentage ungulates and primates sold in markets and significantly and positively related to the proportion of rodents. The proportion of carnivores sold was higher in markets with high human population densities. Proportion of small-bodied mammals (<1 kg) sold in markets increased as human population density increased, but proportion of large-bodied mammals (>10 kg) decreased as human population density increased. We calculated an index of game depletion (GDI) for each market from the sum of the total number of carcasses traded per annum and species, weighted by the intrinsic rate of natural increase (rmax ) of each species, divided by individuals traded in a market. The GDI of a market increased as the proportion of fast-reproducing species (highest rmax ) increased and as the representation of species with lowest rmax (slow-reproducing) decreased. The best explanatory factor for a market's GDI was anthropogenic pressure-road density, human settlements with >3000 inhabitants, and nonforest vegetation. High and low GDI were significantly differentiated by human density and human settlements with >3000 inhabitants. Our results provided empirical evidence that human activity is correlated with more depleted bushmeat faunas and can be used as a proxy to determine areas in need of conservation action.

Association of body mass with price of bushmeat in Nigeria and Cameroon.

Spatially extensive patterns of bushmeat extraction (and the processes underlying these patterns) have not been explored. We used data from a large sample (n= 87) of bushmeat trading points in urban and rural localities in Nigeria and Cameroon to explore extraction patterns at a regional level. In 7,594 sample days, we observed 61,267 transactions involving whole carcasses. Rural and urban trading points differed in species for sale and in meat condition (fresh or smoked). Carcass price was principally associated with body mass, with little evidence that taxonomic group (primate, rodent, ungulate, or mammalian carnivore) affected price. Moreover, meat condition was not consistently associated with price. However, some individual species were more expensive throughout the region than would be expected for their size. Prices were weakly positively correlated with human settlement size and were highest in urban areas. Supply did not increase proportionally as human settlement size increased, such that per capita supply was significantly lower in urban centers than in rural areas. Policy options, including banning hunting of more vulnerable species (those that have low reproductive rates), may help to conserve some species consumed as bushmeat because carcass prices indicate that faster breeding, and therefore the more sustainable species, may be substituted and readily accepted by consumers.

Resumen: Los patrones espacialmente extensivos de extracción de carne silvestre (y los procesos relacionados con esos patrones) no han sido explorados. Utilizamos datos de una muestra grande (n =87) de puntos de venta de carne silvestre en localidades urbanas y rurales en Nigeria y Camerún para explorar los patrones de extracción a nivel regional. En 7,594 días de muestreo observamos 61,267 transacciones involucrando cuerpos completos. Los puntos de venta rurales y urbanos difirieron en especies en venta y condición de la carne (fresca o ahumada). El precio del cuerpo se asoció principalmente con la masa corporal, con poca evidencia de que el grupo taxonómico (primate, roedor, ungulado o mamífero carnívoro) afectara el precio. Mas aun, la condición de la carne no se asoció consistentemente con el precio. Sin embargo, algunas especies individuales en la región fueron más caras de lo esperado por su tamaño. Los precios se correlacionaron positiva y débilmente con el tamaño del asentamiento humano y fueron más altos en áreas urbanas. La oferta no incrementó proporcionalmente a medida que incrementó el tamaño del asentamiento, tanto que la oferta per cápita fue significativamente menor en centros urbanos que en áreas urbanas. Opciones de políticas, incluyendo la prohibición de la caza de especies más vulnerables (aquellas que tienen bajas tasas reproductivas), pueden ayudar a conservar algunas especies consumidas como carne silvestre porque los precios indican que especies de reproducción más rápida, y por lo tanto más sustentables, pueden ser sustituidas y aceptadas de buena gana por los consumidores.

Whose progress? The language of global health.

The barrier to global health most often noted in Western discourse is the enduring disparity of access to medical technologies. This assessment of the circumstances in global health fits well within a bioethic centered on the equitable distribution of access to medical goods. Yet through an interrogative consideration of two episodes in the marketing of progress, namely the Century of Progress Exposition in Chicago (1933-1934) and one post-war spin on atomic development in the National Geographic, I suggest that the language of medical advancement continues to trade on a division between civilized, rational, scientifically developed peoples and the atavism of peoples by whom Western science gauges its progress. I recommend unremittingly self-critical attention to the dynamics of language and legitimization used within the Western academy by those who seek ostensibly to be of use in regions (powerfully) labeled as "developing."