Although the built environment (BE) is important for children’s health, there is little consensus about which features are most important due to differences in measurement and outcomes across disciplines. This meta-narrative review was undertaken by a multi-disciplinary team of researchers to summarise ways in which the BE is measured, and how this links to children’s health. A structured search of four databases across the relevant disciplines retrieved 108 relevant references. The most commonly addressed health-related outcomes were active travel, physical activity and play, and obesity. Many studies used objective (GIS and street audits) or standardised subjective (perceived) measurements of the BE. However, there was a wide variety, and sometimes inconsistency, in their definition and use. There were clear associations between the BE and children’s health. Objective physical activity and self-reported active travel, or obesity, were positively associated with higher street connectivity or walkability measures, while self-reported physical activity and play had the strongest association with reduced street connectivity, indicated by quieter, one-way streets. Despite the high heterogeneity found in BE measures and health outcomes, the meta-narrative approach enabled us to identify ten BE categories that are likely to support children’s health and be protective against some non-communicable disease risk factors. Future research should implement consistent BE measures to ensure key features are explored. A systems approach will be particularly relevant for addressing place-based health inequalities, given potential unintended health consequences of making changes to the BE.

Air pollution is the environmental public health problem of our time. The United Nations Convention on the Rights of the Child sets out clear guidance to protecting the rights of children and young people, including a child's right to the best possible health (Article 24) and the right to a good standard of living. Unicef also consider that clean air is a right for all children. The UK Royal Medical Colleges vigorously advocate for a healthy environment at the population level and in local communities, especially where socio-economic circumstances limit the choice of where people can live, and which school children attend. Despite substantial progress in understanding outdoor air pollution, the potential risk to health, especially that of children and young people, from the indoor air has been largely overlooked, yet in modern times, the indoor environment has never been more important as lockdown with the Covi-19 virus pandemic has shown us. Here we provide an abridged version of the RCPCH/RCP Report The inside story: Health effects of indoor air quality on children and young people but without the section on recommendations. The full Report along with Issues in Environmental Science and Technology No.

Carbon monoxide (CO) poisoning is a major public health issue worldwide. People are exposed to CO in their daily lives, with one of the common sources of CO being cigarette smoking. Inhalation of CO leads to elevated carboxyhaemoglobin (COHb) levels in the blood and also in exhaled CO concentration. Several factors have been shown to affect COHb concentration and COHb half-life. However, factors affecting exhaled CO concentration and exhaled CO half-life are not well understood. The present study aimed to investigate the potential factors related to baseline exhaled CO concentration and exhaled CO half-life among smokers. A cross-sectional study was conducted between 26 January and 30 June 2019, and young adults were recruited into the study. A total of 74 participants (mean age: 27.1 years, 71.6% males and 28.4% females) attended the study. They were invited to complete a questionnaire, including demographic, physiological, and behavioural factors. Then, exhaled CO measurements were taken. These measurements were taken before and after smoking a single cigarette for smokers and only once for non-smokers. The average baseline exhaled CO concentration was 6.9 ± 4.9 ppm for smokers and 1.9 ± 0.5 ppm for non-smokers. The mean of exhaled CO half-life was around 273.3 min (4.6 h) for smokers. No difference was seen in exhaled CO half-life between light smokers and heavy smokers in the smoking group. Gender and cigarettes smoked weekly affected baseline exhaled CO in smokers. Even though height seemed to positively associate with exhaled CO half-life, the relationship disappeared when adjusting by gender and weight. Therefore, exhaled CO could be used as a marker of CO exposure, but we cannot ignore the factors mentioned in the study. For future study, considering factors related to smoking habits and smoking style are recommended as these may affect total inhaled CO.

This paper discusses the capabilities and the application of an innovative combined hygrothermal and population model to assess the impact of building design and occupant behaviour on house dust mite populations in a mattress. The combined model is the first of its kind able to predict the impact of hourly transient hygrothermal conditions within a 3-dimensional mattress on a population of 'wild' Dermatophagoides pteronyssinus mites. The modelling shows that the current drive for energy efficiency in buildings might lead to an increase in house dust mite infestations in UK dwellings. Further research is needed to accurately determine the size of these effects and to adequately evaluate any trade-offs between energy efficiency measures and health outcomes.

Life histories of "wild" house dust mites, Dermatophagoides pteronyssinus (Trouessart) (Acari: Pyroglyphidae), were compared with laboratory cultures by using a diet consisting of skin and dust or a laboratory diet consisting of dried liver and yeast. Under constant conditions of 25ЊC and 75% RH, fecundity and rate of reproduction were higher in laboratory cultures on both diets compared with wild mites. There were also trends for a shorter prereproductive period and more rapid egg development of laboratory mites compared with wild mites. Overall, there was little effect of diet on either strain of mites at 75% RH. At low RH (64%), fecundity was signiÞcantly lower (for both strains on both diets), and there were also trends for longer prereproductive period, reduced rate of reproduction, reduced adult survival, prolonged egg and juvenile development, or a combination compared with 75% RH. Additionally egg and juvenile mortality were signiÞcantly higher on the liver and yeast diet. Overall, the skin and dust diet favored both strains of mites at 64% RH. On the liver and yeast diet at 64% RH, wild mite adults performed signiÞcantly better than laboratory mites, and egg mortality was lower. These results suggest that laboratory mites have stronger reproduction and development than wild mites, except when under environmental stress and that diet is a signiÞcant factor, particularly in suboptimal conditions. This could have important implications for predictive models of house dust mite populations in their natural habitat. Ideally, such models should be developed using data from wild dust mite populations reared on a natural diet. KEY WORDS Dermatophagoides pteronyssinus, wild populations, life historyPopulation models to predict house dust mite, Dermatophagoides pteronyssinus (Trouessart) (Acari: Pyroglyphidae), populations in the home are currently under development (Pretlove et al. 2001(Pretlove et al. , 2005 Crowther et al. 2006, Biddulph et al. 2007). Their aim is to assist in the effective control of mites by manipulating the temperature and relative humidity in their habitats, psychrometric conditions known to play a crucial role in their survival (Cunningham 1999, Pretlove et al. 2002. The models set out to simulate, Þrst, psychrometric conditions in mite habitats (given climate and building characteristics), and, second, the effect of these conditions on house dust mite populations. In this way the most successful and feasible strategies for achieving psychrometric control can be determined, whether by improving ventilation or by a combination of modiÞcations to building design, building operation, and occupant behavior (e.g., with respect to moisture production, window opening habits). However, the population models upon which these simulations depend require mite physiology data inputs that relate to the house dust ecosystem.Data on house dust mite reproduction and development have, until now, predominantly been obtained from mite cultures that have been reared for many years under laboratory co...