The number of asthma cases in children has increased significantly in the last couple of decades. Studies on links between outdoor air pollutants and asthma have had mixed results, suggesting the need for more focused studies. An increase in tree plantings for urban areas is now being called upon as a solution to the higher heat indexes and pollution rates for more densely populated areas. Green spaces and trees could further benefit some urban areas by providing an effective means to improve air conditions. The purpose of this study was to assess whether there is a relationship between levels of vegetation and reported rates of childhood asthma in Texas. Childhood asthma data were collected from the Center for Health Statistics and the Texas Department of State Health Services for the years 2005 and 2006. The asthma rates for each metropolitan statistical area (MSA) were mapped and inserted into a corresponding vegetation map using geographical mapping software. A comparison of vegetation rates and asthma rates in metropolitan areas was used to investigate whether vegetation and tree cover led to higher or lower incidences of childhood asthma rates. Asthma data, normalized difference vegetation index (NDVI), and canopy cover data were analyzed using statistical software. Regression analysis and correlations were calculated to analyze the data for the tree coverage/vegetation rates and asthma rates variable. No statistically significant relationships between NDVI, canopy cover, and asthma were found in this study.
The eriophyid mite, Phyllocoptes fructiphilus, vectors the causal agent, Rose rosette virus (RRV), that results in rose rosette disease. Parts of the southeastern United States have remained free of the disease, except for infected plant material introductions that were eradicated. A survey of sampling points through Alabama, Georgia, and Mississippi (n = 204) revealed the southeastern border of RRV. The presence of RRV in symptomatic plant tissue samples (n = 39) was confirmed by TaqMan-quantitative reverse transcription polymerase chain reaction (RT-qPCR). Samples were also collected at every plot for detection of eriophyid mites, specifically for P. fructiphilus. Three different species of eriophyid mites were found to be generally distributed throughout Alabama, Georgia, and Mississippi. Most of these sites (n = 60) contained P. fructiphilus, found further south than previously thought, but in low populations (<10 mites/gram of tissue) south of the RRV line of incidence. Latitude was found to be significantly correlated with the probability of detecting RRV-positive plants, but plant hardiness zones were not. Plot factors such as plant size, wind barriers, and sun exposure were found to have no effect on P. fructiphilus or the presence of RRV. The reason for the absence of RRV and low populations of P. fructiphilus in this southeast region of the United States are unclear.