Filtering by
- Creators: Barrett, The Honors College
- Creators: Cohn, S.
- Creators: Fraser, M.P.
To investigate the impacts of an energy efficiency retrofit, indoor air quality and resident health were evaluated at a low‐income senior housing apartment complex in Phoenix, Arizona, before and after a green energy building renovation. Indoor and outdoor air quality sampling was carried out simultaneously with a questionnaire to characterize personal habits and general health of residents. Measured indoor formaldehyde levels before the building retrofit routinely exceeded reference exposure limits, but in the long‐term follow‐up sampling, indoor formaldehyde decreased for the entire study population by a statistically significant margin. Indoor PM levels were dominated by fine particles and showed a statistically significant decrease in the long‐term follow‐up sampling within certain resident subpopulations (i.e. residents who report smoking and residents who had lived longer at the apartment complex).
Quantifying halogen presence and speciation in particulate matter is crucial given the role atmospheric particulates play in transport and cycling. While some halogens (fluorine and chlorine) are often included in aerosol studies, iodine and bromine have rarely been examined, especially outside of a marine environment. Focus on this environment is, in part, due to the existence of biogenic marine sources for both halogens. However, examining iodine and bromine in an urban environment has the potential to provide key insights into the transport and processing of these species in the atmosphere. As Tempe is set within a desert environment, bromine concentration is expected to be relatively high due to its presence in Earth’s crust, while iodine is expected to exist in higher concentrations near the coast. To detect presence and concentration, ICP-MS analysis was performed on samples taken in Tempe, AZ as well as sites in Bakersfield, CA and Davis, CA, which yielded preliminary results in line with these expectations. A secondary set of samples were taken in Tempe, AZ during dust storms, haboobs, and winter holidays. CIC was used to determine the organic fraction. In doing so, this study aims to identify species present in an urban environment as well as potential transportation pathways.
-see the additional "abstract.pdf" document for formatting
In arid environments like Phoenix, many professional and residential outdoor spaces are cooled by the use of misting systems. These systems spray a fine mist of water droplets that cool down the surrounding air through the endothermic evaporation process. When the water droplets evaporate, they leave behind dissolved material that is present in the water, generating ambient particulate matter (PM). Thus, misting systems are a point source of PM. Currently there is no information on their impact on air quality in close proximity to these systems, or on the chemical composition of the particulate matter generated by the evaporating mist.
In this project, PM concentrations are found to increase on average by a factor of 8 from ambient levels in the vicinity of a residential misting system in controlled experiments. PM concentrations in public places that use misting systems are also investigated. The PM10 concentrations in public places ranged from 0.102 ± 0.010 mg m-3 to 1.47 ± 0.15 mg m-3, and PM2.5 ranged from 0.095 ± 0.010 mg m-3 to 0.99 ± 0.10 mg m-3. Air quality index (AQI) values based on these concentrations indicate that these levels of PM range from unhealthy to hazardous in most cases. PM concentrations tend to decrease after remaining relatively constant with increasing distance from misting systems. Chemical data reveal that chloride and magnesium ions may be used as tracers of aerosolized water from misting systems. The average chloride concentration was 71 µg m-3 in misting samples and below the detection limit for Cl- (< 8.2 µg m-3) in ambient samples. The average magnesium concentration was 11.7 µg m-3 in misting samples and 0.23 µg m-3 in ambient samples.