New Study Finds Air Pollution Varies Block to Block

Featured Faculty: Joshua Apte

The amount of pollution in the air we breathe depends largely on the prevalence and proximity of emission sources, like factories, power plants, and cars. A group of researchers led by Professor Joshua Apte has taken our understanding on air quality monitoring a step further, showing that the amount of air pollution in a community varies not only by region, such as between urban and rural areas, but by city block.

The team’s results, published in the Proceedings of the National Academy of Sciences (PNAS), expanded on the authors’ previous findings by detailing the racial and ethnic disparities in air pollution exposure. The study shows that areas with high levels of air pollution tend to be populated by people of color.

In contrast to other air quality studies, where only a few measurements were taken per city, the researchers used Google Street View cars equipped with air monitoring decides to measure air pollutants street by street. Over 32 months, the cars covered every street of 13 cities, towns and urban districts in four San Francisco Bay Area counties. This allowed them to detect fine-scale variation in air quality at the hyperlocal level and create highly detailed maps of the differences.

The researchers found that most variation occurs at the hyperlocal level — from one city block to the next. They also shed more light on how the variation in air pollution corresponds with segregated communities in these urban areas, finding that white populations have 9–14% less exposure to pollutants than the population average, while Black and Hispanic populations have 8–30% higher exposure than the average.

For instance, the study found that West Oakland, a historically Black neighborhood in Oakland, has an elevated concentration of pollutants. This neighborhood is surrounded by highways and has a railyard, shipping port and factories located near homes and schools. Apte and his colleagues have worked closely with a local environmental justice organization, the West Oakland Environmental Indicators Project (WOEIP), to develop strategies to overcome these environmental burdens.

According to Apte, expanding hyperlocal mobile air pollution monitoring would be affordable compared to the high costs of traditional fixed measurements. He hopes this will soon become a reality, allowing researchers to monitor these locations for longer periods of time and evaluate how air pollution mitigation efforts play out several years down the road.

Published 09/20/2021