TWO-PHASE PULMONARY CLEARANCE OF INSOLUBLE PARTICLES IN MAMMALIAN SPECIES

Existing experimental data on pulmonary clearance of low-toxicity, poorly soluble particles in several mammalian species including the rat, mouse, guinea pig, dog, monkey, and human have been analyzed using a two-exponential time-decay function with one exponential representing the fast clearance phase and the other for the slow clearance phase. Mass fractions of both clearance phases and the corresponding clearance rates were determined from the lung burden data for different specific initial lung burdens (initial lung burden/ lung weight). It was found that the slow clearance mass fraction increased with lung burden for all species, and it approached almost 100% when the specific initial lung burden exceeded 1 mg/ g lung. However, the slow clearance mass fraction at low lung burdens was found to be much higher for the slow-clearing species (guinea pig, dog, monkey, and human) than for the fast-clearing species (rat and mouse). It was also found that the fast clearance rate was nearly a constant, but the slow clearance rate decreased with lung burden. In addition, both clearance rates differed slightly between the fast-clearing and slow-clearing species. Based upon these data, a formula is proposed to calculate the clearance rate at any lung burden for humans.     

The contribution of self‐help/mutual aid groups to mental well‐being

This article explores the contribution of self‐help/mutual aid groups to mental well‐being. Self‐help/mutual aid groups are self‐organising groups where people come together to address a shared a health or social issue through mutual support. They are associated with a range of health and social benefits, but remain poorly understood. This article draws on data from stage one of ESTEEM, a project which runs from 2010 to 2013. Stage one ran from 2010 to 2011 and involved participatory, qualitative research carried out in two UK sites. Twenty‐one groups were purposively selected to include a range of focal issues, longevity, structures and ethnic backgrounds. Researchers carried out 21 interviews with group coordinators and twenty group discussions with members to explore the groups' purpose, nature and development. Preliminary analysis of the data suggested that mental well‐being was a common theme across the groups. Subsequently the data were re‐analysed to explore the groups' contribution to mental well‐being using a checklist of protective factors for mental well‐being as a coding framework. The findings showed that groups made a strong contribution to members' mental well‐being by enhancing a sense of control, increasing resilience and facilitating participation. Group members were uplifted by exchanging emotional and practical support; they gained self‐esteem, knowledge and confidence, thereby increasing their control over their situation. For some groups, socio‐economic factors limited their scope and threatened their future. The article provides an evidence‐base which illustrates how self‐help/mutual aid groups can enhance mental well‐being. If supported within a strategy for social justice, these groups enable people with varied concerns to develop a tailored response to their specific needs. The authors suggest that policy‐makers engage with local people, investing in support proportionate to the needs of different populations, enabling them to develop their own self‐help/mutual aid groups to enhance their sense of mental well‐being.