Does the near-highway location of the house concern anyone else?
The correlation between near-highway air exposure and adverse health outcomes is well documented and I have not found a single study, article, etc that disputes the correlation. Below are three articles and snippets (emphasis mine) regarding the aforementioned correlation and how quickly the pollution levels drop over short distances from the freeway.
source: http://now.tufts.edu/articles/big-road-blues-pollution-highw...
"Throughout the 1980s and early ’90s, dozens of studies found links between fine particulate pollution and cardiovascular health. One of the largest and most influential of these, the Harvard Six Cities Study, followed more than 8,000 participants in six towns across the Midwest and New England. Over 15 years, the initial phase of the study tracked each person’s health and measured particulate levels in the air over their communities. Its findings, first released in 1993, showed that even a minuscule increase in fine particulates (just 10 micrograms per cubic meter of air), could cause up to an 18 percent bump in cardiovascular disease." ... there’s reason to think that ultrafine particles, which the EPA does not regulate, are even more insidious than their larger counterparts ... ultrafines can fluctuate dramatically over the course of a morning or afternoon, depending on the weather and how many cars and trucks are on the road. Ultrafines are also confined to a relatively small area ... close to major highways, often spiking dramatically within a few hundred meters of the source."
source: http://www.scpcs.ucla.edu/news/Freeway.pdf
"Studies conducted by SCPCS investigators here in LA show that carbon monoxide and ultrafine particles – the smallest portion of particulate matter emissions and potentially the most toxic – are extremely high on or near the freeway, dropping to about half that concentration 50-90 meters (~165-295 feet) from the freeway ..."
source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1971259/
"People living or otherwise spending substantial time within about 200 m of highways are exposed to these pollutants more so than persons living at a greater distance, even compared to living on busy urban streets. Evidence of the health hazards of these pollutants arises from studies that assess proximity to highways, actual exposure to the pollutants, or both. Taken as a whole, the health studies show elevated risk for development of asthma and reduced lung function in children who live near major highways. Studies of particulate matter (PM) that show associations with cardiac and pulmonary mortality also appear to indicate increasing risk as smaller geographic areas are studied, suggesting localized sources that likely include major highways. Although less work has tested the association between lung cancer and highways, the existing studies suggest an association as well. While the evidence is substantial for a link between near-highway exposures and adverse health outcomes, considerable work remains to understand the exact nature and magnitude of the risks."