California's e-commerce boom has triggered a warehouse construction surge — and the health consequences for nearby communities are only beginning to come into focus.

How California's Warehouse Boom May Be Worsening Air Quality

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 square feet), 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.

Who Is Most at Risk: Children and Communities of Color

Children are especially vulnerable to the health impacts of the warehouse boom. In California, over 300 warehouses are 1,000 feet or less from 139 schools, and an additional 600 warehouses are located within 1,500 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 California Is Doing to Protect Communities from Warehouse Pollution

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 square feet of warehouse space operating, with 170 million square feet 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.

Angelina Angelo is EHSC's communications student assistant, and an undergraduate at UC Davis studying Human Development. She is an aspiring writer with a focus on science communication.

Julianne Ng is EHSC's communications student assistant.