Long-term air pollution exposure can have detrimental effects on respiratory, cardiovascular, and cerebrovascular health, increasing mortality risk. Ultrafine particles (UFPs) are nanoscale air pollution particles with aerodynamic diameters under 100 nm. Growing evidence suggests that UFPs can deteriorate brain health by crossing the blood-brain barrier that protects the brain from toxins and pathogens. Historically, people of color and low income communities have been more likely to be exposed to higher concentrations of air pollution, but disparities in UFP exposure specifically have not been studied. This study used linear regression modeling to estimate the association of UFP exposure with race-ethnicity and income in the greater Seattle area. We observed that 83% of the census block groups in the study area were predominantly non-Hispanic white, and household incomes ranged from $9,000 to $250,000 with a median income of $71,000. Estimates of annual average UFP concentrations were modeled from mobile monitoring measurements during the year 2019. UFP concentrations ranged from 2,000 to 14,000 pt/cm3 with a mean of 6,000 pt/cm3. We found that UFP concentration decreased by 177 pt/cm3 (95%CI: 160, 194) for every 10% increase in household income. For every 10 percentage point increase in non-Hispanic white population, UFP concentration decreased by 449 pt/cm3 (95%CI: 410, 488). These results indicate disparities in UFP exposure due to both race-ethnicity and income in the Seattle area. Further analyses investigated this relationship in detail, by specific income and racial-ethnic groups, and compared the relative effects of race-ethnicity and income on UFP exposure. This study can help inform future studies on UFPs and public policies that promote healthier, more equitable communities.

Understanding the major patterns of phenotypic variation is a central goal of evolutionary biology. In vertebrates, body shape is one of the most prominent features of trait variation. Body shape diversity can be influenced by the locomotor modes required by different niches, which is what we explored within the Sciuridae (squirrel) family. Squirrels can be sorted into three distinct ecotypes—ground, tree, and gliding—that invite many questions about the adaptive significance of different body shapes for these different niches. We hypothesized that there is a relationship between the morphology of the axial skeleton (the spinal column) and the appendicular skeleton (the limbs) that may then correspond to ecological and functional adaptations. To quantify squirrel body shape, we took measurements of osteological specimens held at the Burke Museum and conducted phylogenetic comparative methods on these data. Our findings include how the axial and appendicular components of the different squirrel ecotypes contribute to their overall body shape. Our results also indicate whether any of the measured squirrel species can be considered elongate—having a high ratio of body length to body depth. This research marks the first time the axial skeleton of Sciuridae has been explicitly measured and aims to help advance the field by elucidating the trends in convergent evolution of elongate body shape across vertebrates. Future research could include investigating the relationship between the axial and appendicular skeletal components of different clades to diversify the data collected. Additionally, to explore the effect of dietary ecology in addition to locomotion, measurements of the jaw, forefoot, and hindfoot could be collected and analyzed.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic emerged in the United States in January 2020, altering how most individuals interact in public spaces. Many familiar indoor spaces such as restaurants, planes, and classrooms suddenly posed a significant risk of exposure to SARS-CoV-2. Most transmission of SARS-CoV-2 is airborne through contagious aerosols exhaled with carbon dioxide (CO₂) by infected individuals in indoor and outdoor spaces. Indoor CO₂ levels are impacted by factors including: size of the space, air changes per hour, number of individuals present, the activities of the individuals, humidity, and temperature. Vigorous activities — such as speaking or exercising — increase CO₂ levels just as they increase aerosol production. Thus, CO₂ levels provided a good approximation of the transmission risk of SARS-CoV-2 in a specific location. We investigated how available ventilation impacts the transmission risk of SARS-CoV-2 in different indoor settings. An indoor air quality monitoring system that utilized CO₂ levels was developed to evaluate risk of transmission. CO₂ levels were measured using CO₂ sensors in Seattle, WA from March 2021 to April 2021. This data was collected in a variety of public indoor spaces including public transit, educational buildings, restaurants, gyms, and grocery stores. CO₂ levels were analyzed with a COVID-19 Aerosol Transmission Estimator based on the Wells-Riley equation. This information is critical to understanding the comparative risk of contracting SARS-CoV-2 in various indoor public spaces and highlighting where improvements can be made to mitigate such risk.

Every Spring, a small group of gray whales, nicknamed the “Sounders,” come to Possession Sound and the surrounding waters to feed. Many of these individuals have been documented in this region consistently since the 1990s. Although this group of less than twenty individuals has been the subject of several research studies, little is known about their movement patterns in Possession Sound. Over the past few years, gray whales along the West Coast have been experiencing a mass mortality event. Gray whale research is essential in identifying potential contributing factors. The Sounders are benthic feeders and primarily consume ghost shrimp that live in the sediment throughout the intertidal zone. These gray whales access a handful of shallow areas for feeding which are only accessible during high tides, such as the Snohomish River delta. This research evaluates and combines fifteen years of sighting data from Ocean Research College Academy (ORCA) and thirty years of sighting data from Cascadia Research Collective (CRC) with the intent of identifying spatial patterns and possible correlations with the tides. I am creating ORCA’s sighting catalog with photographs taken during ORCA’s sightings and identifying the individuals present using reference photographs from CRC and compiling any additional available data. In this catalog, sighting data is evaluated on individual whale identification, date, time, location, and additional observational notes such as whale interactions. I am plotting this data and additional data from CRC’s sighting catalog in ArcGIS to create a map of spatial distributions. Preliminary results from ORCA’s sightings suggest that gray whales are most often sighted in Possession Sound between Hat Island and the south end of Jetty Island. Any spatial trends that I identify may lead to a better understanding of gray whale behavior, possibly including gray whale intercommunication, social structure, individual behavior, and local feeding practices.

Heat stress is a preventable exposure that can lead to heat-related illness and death. Agricultural workers are disproportionately exposed to heat from heavy work in hot environments. Though there have been efforts to prevent heat-related illness, few studies have rigorously evaluated multi-level prevention approaches. This study investigates the effects of a Heat Education and Awareness Tools (HEAT) educational intervention on outdoor agricultural workers’ knowledge using a parallel, comparison, group intervention design. We used convenience sampling to recruit 83 workers from six work crews from four different companies in Eastern Washington State. Crews of participating workers were randomized to receive HEAT training versus not receive HEAT training. All workers completed a baseline survey and knowledge assessment. Directly after the HEAT training, workers in the intervention group completed a post-training knowledge assessment. At the end of the season, which was approximately three months for most participants, workers in both groups completed a post-season knowledge assessment. We evaluated the change over time (pre, post-training, post-season) in heat knowledge in workers who were in the intervention group, and we evaluated the change in pre and post-season knowledge scores in the intervention versus comparison group. There were statistically significant differences between pre and post-training and pre and post-season assessments in the intervention group, with higher mean scores at the post-training and post-season time points (p<0.001). This improvement appeared to be driven specifically by improvement in knowledge about the treatment and risk factors for heat-related illness. The difference between pre and post-season scores was greater in the intervention group than in the control group, with greater improvement in the intervention group (p=0.03). This study suggests that HEAT training was effective in improving Washington farmworker heat-related illness knowledge over a summer season. Results of this study will be used to guide heat illness prevention efforts for farmworkers.

Thirteen months after the first confirmed case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the United States (U.S.), over 500,000 people have died. However, the pandemic in the U.S. has not affected all populations equally; there are vast differences in morbidity and mortality in areas of differing population densities. We hypothesized that the number of SARS-CoV-2 mutations would be higher in densely populated areas due to closer proximity among inhabitants, which would lead to increased viral spread from person to person, and thus a greater number of mutations. These mutations can impact and reduce vaccine efficacy, as well as morbidity and mortality, depending on where they occur in the virus’s genome. The complete genomes of SARS-CoV-2 cases from March 1^st, 2020 to March 1^st, 2021 were collected from the Global Initiative on Sharing Avian Influenza Data (GISAID) for counties of varying population density. These genomes were analyzed to identify geographic areas where problematic mutations had the potential to occur. Demographic data was collected at the county level from Integrated Public Use Microdata Series (IPUMS) for additional analysis. Mapping the incidence of mutations in the SARS-CoV-2 genome and the correlation of these mutations with population density and other demographic indicators may help decrease disease spread and ensure the vaccines will remain effective.