Highest terrestrial 3He/4He credibly from the core.

The observation that many lavas associated with mantle plumes have higher 3He/4He ratios than the upper convecting mantle underpins geophysical, geodynamic and geochemical models of Earth's deep interior. High 3He/4He ratios are thought to derive from the solar nebula or from solar-wind-irradiated material that became incorporated into Earth during early planetary accretion. Traditionally, this high-3He/4He component has been considered intrinsic to the mantle, having avoided outgassing caused by giant impacts and billions of years of mantle convection1-4. Here we report the highest magmatic 3He/4He ratio(67.2 ± 1.8 times the atmospheric ratio) yet measured in terrestrial igneous rocks, in olivines from Baffin Island lavas. We argue that the extremely high-3He/4He helium in these lavas might derive from Earth's core5-9. The viability of the core hypothesis relaxes the long-standing constraint-based on noble gases in lavas associated with mantle plumes globally-that volatile elements from the solar nebula have survived in the mantle since the early stages of accretion.

Associations between health and different types of environmental incivility: a Scotland-wide study.

OBJECTIVES: Concern about the impact of the environment on health and well-being has tended to focus on the physical effects of exposure to toxic and infectious substances, and on the impact of large-scale infrastructures. Less attention has been paid to the possible psychosocial consequences of people's subjective perceptions of their everyday, street-level environment, such as the incidence of litter and graffiti. As little is known about the potential relative importance for health of perceptions of different types of environmental incivility, a module was developed for inclusion in the 2004 Scottish Social Attitudes survey in order to investigate this relationship. STUDY DESIGN: A random sample of 1637 adults living across a range of neighbourhoods throughout Scotland was interviewed. METHODS: Respondents were asked to rate their local area on a range of possible environmental incivilities. These incivilities were subsequently grouped into three domains: (i) street-level incivilities (e.g. litter, graffiti); (ii) large-scale infrastructural incivilities (e.g. telephone masts); and (iii) the absence of environmental goods (e.g. safe play areas for children). For each of the three domains, the authors examined the degree to which they were thought to pose a problem locally, and how far these perceptions varied between those living in deprived areas and those living in less-deprived areas. Subsequently, the relationships between these perceptions and self-assessed health and health behaviours were explored, after controlling for gender, age and social class. RESULTS: Respondents with the highest levels of perceived street-level incivilities were almost twice as likely as those who perceived the lowest levels of street-level incivilities to report frequent feelings of anxiety and depression. Perceived absence of environmental goods was associated with increased anxiety (2.5 times more likely) and depression (90% more likely), and a 50% increased likelihood of being a smoker. Few associations with health were observed for perceptions of large-scale infrastructural incivilities. CONCLUSIONS: Environmental policy needs to give more priority to reducing the incidence of street-level incivilities and the absence of environmental goods, both of which appear to be more important for health than perceptions of large-scale infrastructural incivilities.