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Natural infiltration in residential buildings has two major drivers: indoor-outdoor temperature differences (stack effect) and wind effect. While residential infiltration models are long established, their validity has not been evaluated with measurements, and they have rarely been deployed to explain time-resolved indoor-outdoor exchange. Pressure differentials (ΔP) across building envelopes are an intermediate step in modeling; if they cannot be well predicted from the driving forces, then neither can infiltration. We report nearly 16,000 h of environmental and ΔP data, in nine homes, at one-minute resolution that reflects the transient nature of air exchange. Under conditions of low wind (less than 0.25 m/s) and heating (outdoor temperature below indoor), stack pressure is predicted exceptionally well. Biases between observed and predicted values average 0.11 Pa or less across all sites. Biases increase by about a factor of two under cooling conditions, but observations under these conditions were of insufficient length to diagnose the causes. Wind influence on pressure, and hence on infiltration, is not well predicted even with practical, site-based measurements. Airport and site wind speeds, and site wind and envelope pressure, are correlated only modestly, even accounting for wind direction. Simple terrain and shielding classifications cannot reproduce intersite variation. Infiltration models overestimate the influence of wind on pressure even when the most extreme shielding and terrain classes are used in scaling airport data. In addition to evaluating infiltration drivers, this study establishes the difference between time-resolved, cross-envelope pressure differentials at separate points in a single zone (Δ−ΔP) as a building diagnostic. 

Despite significant evidence that housing quality plays a key role in the overall health of the population, health risks that originate at home have failed to garner direct policy attention or intervention commensurate with their impact. Drawing on the sociology of social problems, we identify how causal and political responsibility for risks in the United States context is complicated when these environmental health risks are embedded in private homes. We argue that changing how home health is addressed by health and building practitioners requires a reconceptualization of home health whereby the multiple responsible parties and sources of exposure become leverage points for future research and interventions. This reframing includes identifying housing as an arena of health, representing a class of risks tied to place. We also contend that health is an essential element of homes as systems and must be embedded in how those in building science, construction, property management, and code design approach housing. Finally, we suggest the need for specialists to navigate home health issues, drawing on the hospitalist model of health provision. These proposals illustrate multiple points at which residents, researchers, and health and building professionals may intervene and home health risks can be addressed. 

Abstract Iron emissions from human activities, such as oil combustion and smelting, affect the Earth's climate and marine ecosystems. These emissions are difficult to quantify accurately due to a lack of observations, particularly in remote ocean regions. In this study, we used long‐term, near‐source observations in areas with a dominance of anthropogenic iron emissions in various parts of the world to better estimate the total amount of anthropogenic iron emissions. We also used a statistical source apportionment method to identify the anthropogenic components and their sub‐sources from bulk aerosol observations in the United States. We find that the estimates of anthropogenic iron emissions are within a factor of 3 in most regions compared to previous inventory estimates. Under‐ or overestimation varied by region and depended on the number of sites, interannual variability, and the statistical filter choice. Smelting‐related iron emissions are overestimated by a factor of 1.5 in East Asia compared to previous estimates. More long‐term iron observations and the consideration of the influence of dust and wildfires could help reduce the uncertainty in anthropogenic iron emissions estimates. 

Abstract. Emission of organic aerosol (OA) from wood combustion is not well constrained;understanding the governing factors of OA emissions would aid in explainingthe reported variability. Pyrolysis of the wood during combustion is theprocess that produces and releases OA precursors. We performed controlledpyrolysis experiments at representative combustion conditions. The conditionschanged were the temperature, wood length, wood moisture content, and woodtype. The mass loss of the wood, the particle concentrations, and light-gasconcentrations were measured continuously. The experiments were repeatable asshown by a single experiment, performed nine times, in which the real-timeparticle concentration varied by a maximum of 20 %. Highertemperatures increased the mass loss rate and the released concentration ofgases and particles. Large wood size had a lower yield of particles than thesmall size because of higher mass transfer resistance. Reactions outside thewood became important between 500 and 600 ∘C. Elevatedmoisture content reduced product formation because heat received was sharedbetween pyrolysis reactions and moisture evaporation. The thermophysicalproperties, especially the thermal diffusivity, of wood controlled thedifference in the mass loss rate and emission among seven wood types. Thiswork demonstrates that OA emission from wood pyrolysis is a deterministicprocess that depends on transport phenomena. 

Abstract The iron cycle is a key component of the Earth system. Yet how variable the atmospheric flux of soluble (bioaccessible) iron into oceans is, and how this variability is modulated by human activity and a changing climate, is not well known. For the first time, we characterize Satellite Era (1980 to 2015) daily‐to‐interannual modeled soluble iron emission and deposition variability from both pyrogenic (fires and anthropogenic combustion) and dust sources. Statistically significant emission trends exist: dust iron decreases, fire iron slightly increases, and anthropogenic iron increases. A strong temporal variability in deposition to ocean basins is found, and, for most regions, dust iron dominates the absolute deposition magnitude, fire iron is an important contributor to temporal variability, and anthropogenic iron imposes a significant increasing trend. Quantifying soluble iron daily‐to‐interannual deposition variability from all major iron sources, not only dust, will advance quantification of changes in marine biogeochemistry in response to the continuing human perturbation to the Earth System.