California has experienced an unprecedented surge in the expansion of e-commerce and, subsequently, a dramatic boom in warehouse construction.  The warehouse boom, while contributing to economic growth, has also raised significant concerns over the long-term environmental justice and health equity repercussions. 

Environmental Concerns

The boom in warehouses has raised significant health concerns, especially in already overburdened communities. The exponential growth of warehouses in the Inland Empire is intrinsically tied to its critical location in the nation’s goods movement system. In 1980, the Inland Empire hosted 234 large warehouses (over 10,000 sq ft), by January 2023, this had skyrocketed to over 4,000. This growth will have massive impacts on air quality here with similar impacts elsewhere in the state, including the Central Valley.

California’s dependence on diesel-powered vehicles has produced large increases in nitrogen oxide (NOx) emissions, creating ozone, a significant health concern. Ozone is a hazardous compound that forms in the atmosphere when nitrogen oxide (NOx) and volatile organic compounds (VOCs) react in the presence of sunlight. According to the EPA, in 2009, California had the highest levels of ozone concentration in the country; since then, this has only increased. In June of 2023, six California counties, San Bernardino, Riverside, Los Angeles, Tulare, Kern, and Fresno, ranked the highest for most polluted due to ozone and particle pollution, according to the American Lung Association and CalEnviroScreen 4.0.

Diesel engines emit a mixture of harmful air pollutants, including NOx. In addition to ozone, Diesel Particulate matter (DPM) is responsible for a staggering 70% of the total cancer risk attributable to air pollution. According to the EPA, prolonged exposure to high levels of DPM poses dangerous health risks, such as exacerbating respiratory conditions like asthma, and can worsen pre-existing conditions like lung or heart disease. However, it's the long-term health effects that are of increasing concern for scientists, health practitioners, and communities.

Populations of Concern

Children are especially vulnerable to the health impacts of the warehouse boom. In California, over 300 warehouses are 1000 feet or less from 139 schools, and an additional 600 warehouses are located within 1500 feet, according to a recent report. This toxic geography places thousands of children in the crosshairs. Children, with their still-developing respiratory systems and outdoor play, are at heightened risk for long-lasting health issues resulting from exposure to air pollution. Read more about concerns for children’s environmental health here.

Underrepresented communities are also of concern. According to CalMatters, the adverse effects of warehouse pollution and related traffic congestion are overwhelmingly concentrated in neighborhoods inhabited primarily by Latino communities and low-income communities. Other new research shows the population living within half a mile of a warehouse is 64% people of color in California. 

What Next?

The emergence of air pollution and its associated health risks, particularly for children and the region's residents, demands immediate attention and proactive measures. The warehouse expansion plans in California show no signs of slowing; the Inland Empire alone currently has one billion sq feet of warehouse space operating, with 170 million sq ft of warehouse space currently approved or pending, according to a CalMatters State of Emergency Public Health Request. 

In response to these health concerns, lawmakers are actively pushing for the implementation of a buffer zone between warehouses and “sensitive receptors” such as daycare centers, schools, and hospitals to reduce exposure to air pollution. Assembly Bill 2840, which would provide a buffer zone of 1,000 feet between diesel truck traffic emissions generated by any new warehouse facilities and defined these sensitive receptors, has passed the Assembly and is currently in the Senate. Assembly Bill 1000, a similar policy that bans land permits within 1,000 feet of sensitive receptors, did not pass earlier this year. Many California residents, educators, and local officials are beginning to protest new warehouse builds, according to CalMatters. 

As the long-term effects of the warehouse boom on both environmental and health effects continue to be unknown, it becomes increasingly crucial to put more effort into bridging the gaps between science and policy to protect overburdened California communities.

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The author would like to acknowledge and thank Dr. Jonathan London for his contribution of expertise and editing of this blog post. 

Angelina Angelo produced this article with support from Julianne Ng, EHSC student assistant in communications & media. 

Angelina is an EHSC editorial assistant & undergraduate writer for the communications department and an undergraduate student at UC Davis studying Human Development. She is an aspiring writer with a focus on science communication.