Perception, culture, and science: A framework to identify in-home heating options to improve indoor air quality in the Navajo Nation.

A 2010 study identified higher than average incidence of respiratory disease in Shiprock, NM, the largest city in the Navajo Nation. That study suggested that the potential cause was the combustion of solid fuels in in-home heating stoves and that respiratory disease could be greatly reduced by changing indoor heating behaviors and improving heating stove quality. Since the Navajo people are deeply embedded in culture and traditions that strongly influence their daily lives, a new framework was needed to identify feasible heating alternatives that could reduce the negative environmental and health impacts related to solid fuel use while respecting the culture of the Navajo people. The resulting Navajo framework included perception, cultural, and technical assessments to evaluate seven heating alternatives perceived viable by Navajo stakeholders. Cultural experts at the Diné Policy Institute identified potential cultural limitations and motivating factors for each alternative. A limited technical assessment of the health benefits of these options was conducted and integrated into the process. A parallel convergent mixed-methods approach was employed to integrate qualitative and quantitative results. The results and framework developed and presented here may be useful for decision makers in communities heavily reliant on solid fuels for heat, especially Native Nations, where culture plays an important role in the success of any intervention.

Development and evaluation of a continuous coarse (PM10-PM2.5) particle monitor.

In this paper, we describe the development and laboratory and field evaluation of a continuous coarse (2.5-10 microm) particle mass (PM) monitor that can provide reliable measurements of the coarse mass (CM) concentrations in time intervals as short as 5-10 min. The operating principle of the monitor is based on enriching CM concentrations by a factor of approximately 25 by means of a 2.5-microm cut point round nozzle virtual impactor while maintaining fine mass (FM)--that is, the mass of PM2.5 at ambient concentrations. The aerosol mixture is subsequently drawn through a standard tapered element oscillating microbalance (TEOM), the response of which is dominated by the contributions of the CM, due to concentration enrichment. Findings from the field study ascertain that a TEOM coupled with a PM10 inlet followed by a 2.5-microm cut point round nozzle virtual impactor can be used successfully for continuous CM concentration measurements. The average concentration-enriched CM concentrations measured by the TEOM were 26-27 times higher than those measured by the time-integrated PM10 samplers [the micro-orifice uniform deposit impactor (MOUDI) and the Partisol] and were highly correlated. CM concentrations measured by the concentration-enriched TEOM were independent of the ambient FM-to-CM concentration ratio, due to the decrease in ambient coarse particle mass median diameter with an increasing FM-to-CM concentration ratio. Finally, our results illustrate one of the main problems associated with the use of real impactors to sample particles at relative humidity (RH) values less than 40%. While PM10 concentrations obtained by means of the MOUDI and Partisol were in excellent agreement, CM concentrations measured by the MOUDI were low by 20%, and FM concentrations were high by a factor of 5, together suggesting particle bounce at low RH.

Trends in fine particle concentration and chemical composition in southern California.

Airborne fine particle mass concentrations in Southern California have declined in recent years. Trends in sulfate and elemental carbon (EC) particle concentrations over the period 1982-1993 are consistent with this overall improvement in air quality and help to confirm some of the reasons for the changes that are seen. Fine particle sulfate concentrations have declined as a strict sulfur oxides (SOx) emission control program adopted in 1978 was implemented over time. Fine particle elemental (black) carbon concentrations have declined over a period when newer diesel engines and improved diesel fuels have been introduced into the vehicle fleet. Organic aerosol concentrations have not declined as rapidly as the EC particle concentrations, despite the fact that catalyst-equipped cars having lower particle emission rates were introduced into the vehicle fleet alongside the diesel engine improvements mentioned above. This situation is consistent with the growth in population and vehicle miles traveled in the air basin over time. Fine particle ammonium nitrate in the Los Angeles area atmosphere contributes more than half of the fine aerosol mass concentration on the highest concentration days of the year, emphasizing both the need for accurate aerosol nitrate measurements and the likely importance of deliberate control of aerosol nitrate as a part of any serious further fine particle control program for the Los Angeles area.

Preserving residents' rights in long-term care settings: a values-based approach to restraint reduction.

This article describes a knowledge transfer process that was developed by Catholic Health East (CHE), headquartered in Newtown Square, PA, and that focuses upon one indicator of care, physical restraint use, in the skilled nursing/long-term care setting. The values-based process focuses on preserving residents' rights and using comparative data sharing as the basis for identifying opportunities for improvement. Further, it builds upon a collaborative cyclical model employed by all the CHE System's freestanding and hospital-based long-term care facilities. The experiences of four of the system's facilities are described; each one demonstrates different aspects of implementing mission-oriented strategies to target restraint reduction.

Speciation of arsenic in ambient aerosols collected in Los Angeles.

First-time measurements of the potentially toxic inorganic species of arsenic (arsenite and arsenate) have been obtained in fine (less than 2.5 microns AD) and coarse (greater than 2.5 microns AD) atmospheric particles in the Los Angeles area. A recently developed method that includes procedures for sample collection, preparation, and analysis was used in this study. Size-fractionated aerosol samples were collected with a high-volume dichotomous virtual impactor that employed polytetrafluoroethylene filters. Results were obtained for the recovery of arsenic standards added to unexposed and collected filters. Data from this study, indicated that the recently developed speciation method can be used to determine concentrations of As(III) and As(V) in atmospheric particulate matter samples. Size-fractionated aerosol samples were collected in the city of Industry during January and February 1987. In most samples, As(III) and As(V) were above the detection limit (approximately 1 ng m-3 of either species) in both aerosol size fractions. A greater portion (about 75 percent) of the two species were observed in the fine particles. The As(III)/As(V) ratio for both particle sizes was close to 1 (i.e., an equal mixture of both species). Comparison of total suspended particulate arsenic measured by the speciation method to that measured by a routine California Air Resources Board-approved procedure showed good agreement (r = 0.94), indicating both methods were approximately equivalent for the collection and analysis of aerosol arsenic.