New Bedford Harbor Identified as Major Source of Airborne PCBs

Effects of long-term exposure still unknown

New Bedford Harbor is one of the largest PCB Superfund sites in the nation. Local industry used PCBs to produce electronic devices from 1940 until the late 1970s, when the EPA banned the chemicals.

Sediment contaminated with polychlorinated biphenyls, or PCBs, from the bottom of New Bedford Harbor is the number-one source of airborne PCBs in the neighborhoods surrounding the port, according to a new study by researchers from the Boston University School of Public Health (SPH) and the University of Iowa.

In fact, airborne PCB emissions are so high that researchers say the harbor is the single largest continuous source of airborne PCBs ever measured from natural waters in the US or Canada. The study appears in Environmental Science & Technology Letters.

The harbor is one of the largest PCB Superfund sites in the nation, currently undergoing cleanup. The US Environmental Protection Agency (EPA) has monitored airborne PCB levels near the harbor since 1999. The levels measured in the study are consistent with levels measured by the EPA, but this is the first time that researchers have focused on the harbor as a unique source of airborne PCBs.

Residents have been concerned with air quality since dredging to clean the port started in 1994. Industry in the area used PCBs to produce electronic devices from 1940 until the late 1970s, when the EPA banned the manufacture of PCBs due to health concerns.

“As our knowledge grew about the high levels of PCBs in the sediments and water, we began to question the air from this site,” says Karen Vilandry, president of the community-based group Hands Across the River Coalition (HARC).

Wendy Heiger-Bernays, BU associate professor of environmental health, says the New Bedford-area community requested the study and “played an integral role in its completion.”

Researchers used calculated emissions and atmospheric dispersion modeling to confirm New Bedford Harbor as the source of airborne PCBs. PCBs are released from the sludge at the bottom of the port and escape into the water and air.

The research team worked with residents affiliated with HARC to select air-sampling locations at 18 sites in New Bedford, Fairhaven, Dartmouth, and Acushnet. Air samples were taken during three consecutive periods from July to November 2015. The highest readings for airborne PCBs were from sampling locations closest to the harbor.

PCBs can cause a variety of adverse health effects, including an increased risk for cancer in humans. The effects of long-term inhalation of airborne PCBs are still unknown.

Keri Hornbuckle, professor of civil and environmental engineering at IIHR—Hydroscience & Engineering at the University of Iowa and core leader of the Iowa Superfund Research Program, says the study shows that PCBs are coming from the harbor and “not from a variety of sources.” Lead author Andres Martinez, a research scientist at IIHR—Hydroscience & Engineering, says there is more work to be done to pinpoint the sources of PCBs.

Community engagement in the study was assisted by Alternatives for Community & Environment and the Toxics Action Center (TAC).

“Every time we went to collect the monitors from residents’ homes, we were faced with the same question: ‘Should I be worried?'” says Claire Miller of TAC. “Exposure is a 24/7 reality for folks living near the harbor, and this study is an important step forward.”

Co-authors from SPH include Madeleine Scammell, assistant professor of environmental health, and Kathryn Tomsho and Komal Basra of the BU Superfund Research Program.

A version of this article was originally published in BU School of Public Health.


  1. And to think we have Trump trying to undo our EPA… as I commuted into Boston this very morning on the train I was passing by the Neponset river and its wetlands and remembered what a horrible experience I had kayaking on it. I didn’t see a single fish, all I saw was an emaciated otter climb out onto the river bank, it was very sickly looking, I could only imaging it found its way into this river accidentally and was not getting the food it needed. It may have become ill as a result of the contamination in the river. One of the main sources of contamination is in fact PCBs. I simply can’t understand putting profits for people over health and well being of our environment, something we are so closely tied to for long term survival and health. A republican recently stated “we need to put the life of people in front of the life of wildlife” in response to the debate about the undoing of the endangered species act, but what this really means is they want to put “quality of life” in front of wildlife, not our life. It shocks me people don’t understand this after all of our advancements.

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