Early environmental quality and life-course mental health effects: The Equal-Life project.

BACKGROUND: There is increasing evidence that a complex interplay of factors within environments in which children grows up, contributes to children's suboptimal mental health and cognitive development. The concept of the life-course exposome helps to study the impact of the physical and social environment, including social inequities, on cognitive development and mental health over time. METHODS: Equal-Life develops and tests combined exposures and their effects on children's mental health and cognitive development. Data from eight birth-cohorts and three school studies (N = 240.000) linked to exposure data, will provide insights and policy guidance into aspects of physical and social exposures hitherto untapped, at different scale levels and timeframes, while accounting for social inequities. Reasoning from the outcome point of view, relevant stakeholders participate in the formulation and validation of research questions, and in the formulation of environmental hazards. Exposure assessment combines GIS-based environmental indicators with omics approaches and new data sources, forming the early-life exposome. Statistical tools integrate data at different spatial and temporal granularity and combine exploratory machine learning models with hypothesis-driven causal modeling. CONCLUSIONS: Equal-Life contributes to the development and utilization of the exposome concept by (1) integrating the internal, physical and social exposomes, (2) studying a distinct set of life-course effects on a child's development and mental health (3) characterizing the child's environment at different developmental stages and in different activity spaces, (4) looking at supportive environments for child development, rather than merely pollutants, and (5) combining physical, social indicators with novel effect markers and using new data sources describing child activity patterns and environments.

Head positioning and neck muscle activation during air combat.

INTRODUCTION: Specific mechanisms leading to acute neck injury in flight as a result of +Gz exposure remain unclear. In this study, head positions adopted by aircrew in air combat have been quantified, and the associated levels of cervical muscle activation have been determined. METHOD: Six fast jet aircrew subjects were instrumented with surface electromyography (EMG) electrodes, and activation potentials from neck erector spinae (ES) and sternocleidomastoid (SC) muscles were logged on a data recorder. EMG signal was normalized to preflight maximum voluntary contraction (MVC). All subjects flew a one-on-one air combat sortie in a Hawk T1 aircraft comprising at least four air combat engagements. In-cockpit video and +Gz acceleration were recorded. Time-synchronized analysis of video, EMG, and acceleration were conducted for head position and normalized muscle activation (%MVC). RESULTS: During air combat, the head was away from neutral for 68% of the time, predominantly in extension, or rotation plus extension. During neck extension under G, 40-80% MVC occurred in the ES: this was reduced by half when the canopy was used as a support. Similar activation occurred in the SC in neck extension plus rotation. The ES was activated at over 40% MVC for 25% of the engagement duration. Postsortie, 35% reduction in neck muscle strength occurred. CONCLUSIONS: Extreme neck extension +/- rotation is very common in air combat and is associated with high levels of muscle activation and fatigue. This information can be used to help devise targeted neck conditioning and positioning strategies in order to reduce injury risk.