Study reveals air exposure and high concentration of carcinogen in Guánica residents

A University of Miami research found a carcinogenic contaminant in the blood samples of 86% of the people who participated in the study. It is also the first confirmation that the chemical substance is also in the air.

May 16, 2024

Photo by José Miguel Morales, photographer, and community resident.

Guánica residents discuss the findings after the presentation, held in the town’s Municipal Legislature.

Two years after the Environmental Protection Agency (EPA) included an area in Guánica on its Superfund program priority list, for being a highly contaminated area, an independent public health study revealed that town residents have blood levels of 2,651% polychlorinated biphenyls (PCBs) higher than the average found by federal health agencies in people in the United States.

The study, which was released to the community by public health researcher at the University of Miami, Naresh Kumar, also found that there are concentrations of the chemical in the air, which leads to a route of exposure to the contaminant that had not yet been confirmed.

86% of blood samples taken from 150 residents of Guánica showed detectable levels of PCBs. People over 60 had the highest concentrations, confirming the cumulative nature of the contaminant in the body, according to Kumar’s study. The scientist announced the findings to the community last week at a meeting, accompanied by professors from the University of Puerto Rico’s Medical Sciences Campus.

Guánica residents showed as much as 27,510 picograms per milliliter (pg/mL) of the carcinogen in their blood, while, according to the Centers for Disease Control and Prevention (CDC), normal concentrations in the body usually do not exceed 1,000 pg/mL.

“I’m trying hard not to cry. We’ve heard for a long time about PCB contamination, but never in all the meetings we’ve been to, which have been many, has anyone ever explained to us how harmful they are,” said Benjamín Toro, who grew up facing the Guánica Bay and is a skin cancer survivor. “The people here don’t represent [in quantity] the population of the town of Guánica, and so we’re all contaminated, but what have the Puerto Rico  and federal governments done to warn  people to take care of themselves? We have a situation that I’m realizing today is bigger than I thought,” he added.

Benjamín Toro, pictured, during the meeting to present findings with researcher Naresh Kumar on May 6, 2024.
Photo by José Miguel Morales, photographer, and community resident.

PCBs are persistent organic pollutants (POPs): They remain in the environment because they are resistant to deterioration. They were used in electrical transformers, but the EPA prohibited their manufacture in 1977. After discontinuing their production, the concentration of the chemical in the US population has decreased, however it has been detected in populations near industries that used it, places that have been declared as Superfund.

More than a year after the area of the former Ochoa Fertilizer company in Guánica was declared a Superfund, neither the government of Puerto Rico nor the federal government have organized effective risk communication to inform the affected communities about the real level of contamination and state if there is a potential health risk to visitors of the bay, a Centro de Periodismo Investigativo (CPI) investigation revealed. The contamination in the area is not limited to the former factory’s location, but the contaminant has moved to the bay through run-off rainwater, representing the main source of exposure as several University of Miami investigations revealed, of which the EPA and the Puerto Rico Environmental Quality Board has been aware of since 2000.

After his visit to Puerto Rico, the scientist met with the EPA’s Caribbean Division, which coordinates the long-term cleanup of the affected area, to provide them with the details of his study.

“EPA staff assigned to the project are evaluating this data while we await the rest of the data from Dr. Kumar. Some of Dr. Kumar’s findings reinforce EPA’s data and support EPA’s recommendation to exercise caution in the use of Guánica Bay,” the agency said in writing to CPI.

The EPA states that “PCB mixtures changes following their release into the environment. The types of PCBs that tend to bioaccumulate in fish and other animals and bind to sediments happen to be the most carcinogenic components of PCB mixtures. As a result, people who ingest PCB-contaminated fish or other animal products and contact PCB-contaminated sediment may be exposed to PCB mixtures that are even more toxic than the PCB mixtures contacted by workers and released into the environment,” the agency states on its website.

Participants in the University of Miami research study were asked about the chronic health conditions they suffered from — options included cancer, cardiovascular disease, and diabetes, among others.

Kumar identified a connection between the concentration of the carcinogen in the blood of those who suffered from chronic conditions: Those with one to three conditions had the highest levels of PCBs in their blood.

“High concentrations of the chemical exacerbate the effects of these diseases,” Kumar said. He described this as a biomagnification effect.

According to the National Institute of Environmental Health (NIH), “exposure to PCBs has been linked to chronic inflammatory diseases, such as cardiovascular disease, type 2 diabetes, obesity, as well as hepatic disorders, endocrine dysfunction, neurological deficits and many others.”

Concentration of PCBs in Guánica Bay residents according to samples collected in 2018 and 2019.

Concentration of PCBs in Guánica Bay residents by number of chronic health conditions.

“When I saw the data, I was shocked,” said the also air quality specialist when he initially saw the results of the first 50 blood samples he took in 2018. In 2019 he went back to Guánica and took 100 more samples for a total of 150 participants.

A total of 33 Barrio Ensenada residents and 97 Barrio Pueblo residents participated in the University of Miami study; 20 people did not specify their address. The scientist and his team collected the data with the support of the Protectores de Cuencas (Basin Protectors) organization between 2018 and 2019, without the EPA’s support.

The National Institutes of Health’s Superfund research program and the University of Miami  funded the study, which is based on research carried out since 2013, so that the EPA would include Guánica on the list of priorities to be decontaminated in the United States after the world’s second-highest concentration of PCBs in sediment was found — after St. Lawrence River, Canada — contaminating the food chain and air.

“All [participants] were asked if they consumed fish and those who only consumed the filet [of the fish] showed lower levels [of PCBs] versus those who consumed all its parts, including its organs,” Kumar explained, although the finding was not significant statistically.

Kumar recommended that Guánica residents ensure that the fish they consume have been caught outside of Guánica Bay, which showed concentrations of less than 0.5 parts per million (ppm), lower than the safe limit established by the Food and Drug Administration (FDA) — 2ppm.

The EPA has been waiting for more than a year for the Agency for Toxic Substances and Disease Registry (ATSDR) to identify the routes of exposure of the chemical that affects the population in Guánica.

ATSDR has documented that PCBs “public health concern because they persist in the environment, bioaccumulate in human and animal tissues, and potentially can cause chronic or delayed toxicity.”

It is up to the EPA to carry out the emergency removal, which should have started in January, but has not yet begun.

“The work includes soil removal and additional investigation of PCBs in the soil of residential and commercial properties west of PR-333 [which borders the community], as well as the evaluation of any rain runoff from the property,” the EPA explained in written statements.

PCBs Concentrations in the Air are Eight Times Higher than in Nearby Yauco

In addition to being in the blood, Kumar confirmed that the contaminant was found in the air.

“PCB concentrations in the air on the bay coast were eight times higher than the concentration monitored in Yauco, about 11 kilometers inland,” Kumar said. This happens, he explained, because this contaminant can also evaporate.

Air sampling stations he placed on the roofs of three bayfront properties in the boardwalk area recorded 792, 883 and 1,146 picograms per cubic meter per day. It was observed that houses that are receiving easterly winds — where the most contaminated area is — are hit with more PCBs in the air, but it is unknown how much reaches the Ensenada neighborhood on the west coast of the bay since the area was not part of the study.

PCBs concentration in sediments and air according to data collected between 2013 and 2019.

The EPA does not establish safe exposure limits for PCBs in outdoor air, but it does establish safe exposure limits for indoor air with a maximum of 500,000 picograms per cubic meter. That is, the chemical concentration in the air does not seem to be so significant on a daily basis. Still, people exposed in the long term could see their health affected since the PCBs also accumulate in the body, the researcher warned.

However, the scenario is different when considering events related to climate change such as hurricanes, storm surges, and environmental conditions such as heat and humidity, “which could result in seasonal volatilization/deposition and long-range air transport,” according to the EPA. In relation to these conditions, Kumar found in 2018 that after Hurricane María, which hit Puerto Rico in 2017, the concentration of the chemical in the environment increased tenfold after the contaminated sediment was agitated.

Kumar’s work began in 2013 with one goal: To decipher what the presence of PCBs in Guánica Bay was about. After finding the second highest concentration of this carcinogen in the world there, he dedicated his work to helping the site be investigated and included in the priority list of the EPA’s Superfund program.

Since 2020, Kumar has been waiting for the NIH to extend funding to investigate concentrations of the chemical in the air around the entire bay.

For more information on this topic:

Parte 1: Local, federal governments remain mum about substance posing carcinogenic threat in Guánica Bay

Part 2: Cleanup of Guánica Land Polluted with chemical substances is yet to begin


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