Modeling the resiliency of energy-efficient retrofits in low-income multifamily housing.

Residential energy efficiency and ventilation retrofits (eg, building weatherization, local exhaust ventilation, HVAC filtration) can influence indoor air quality (IAQ) and occupant health, but these measures' impact varies by occupant activity. In this study, we used the multizone airflow and IAQ analysis program CONTAM to simulate the impacts of energy retrofits on indoor concentrations of PM2.5 and NO2 in a low-income multifamily housing complex in Boston, Massachusetts (USA). We evaluated the differential impact of residential activities, such as low- and high-emission cooking, cigarette smoking, and window opening, on IAQ across two seasons. We found that a comprehensive package of energy and ventilation retrofits was resilient to a range of occupant activities, while less holistic approaches without ventilation improvements led to increases in indoor PM2.5 or NO2 for some populations. In general, homes with simulated concentration increases included those with heavy cooking and no local exhaust ventilation, and smoking homes without HVAC filtration. Our analytical framework can be used to identify energy-efficient home interventions with indoor retrofit resiliency (ie, those that provide IAQ benefits regardless of occupant activity), as well as less resilient retrofits that can be coupled with behavioral interventions (eg, smoking cessation) to provide cost-effective, widespread benefits.

Epizootics in Industrial Livestock Production: Preventable Gaps in Biosecurity and Biocontainment.

While technological advances in animal husbandry have facilitated increases in global meat production, the high density and geographic concentration of food animal production facilities pose risks of infectious disease transmission. The scale of the 2014-2015 highly pathogenic avian influenza H5N2 outbreak in the United States demonstrates the challenges in achieving pathogen control within and around industrial animal facilities using existing technologies. We discuss gaps in current practice in two specific systems within these facilities - ventilation and waste management - which are under-recognized as important drivers of microbial porosity. The development of innovative ventilation systems to reduce influx and efflux of pathogens is critically needed, and cross-sectoral partnerships should be incentivized to do so. Adapting current human biosolid treatment technologies for farm applications, reducing animal stocking density and shifting waste management responsibility from farmer to corporation would reduce risk from current manure management systems. While innovative approaches to functionally altering the industrial food animal production system remain important priorities to promote sustainability, our intention here is to identify gaps within the current system that allow for pathogen emergence and transmission and address specific areas in which technological, administrative or policy changes are necessary to mitigate these risks.