Archives for posts with tag: PCBs

From Environmental Health News (by Lindsey Konkel):

When Deidre Ramos moved with her infant son to the Parker Street section of New Bedford, Mass., little did she know that her new neighborhood was toxic.

Today, a decade later, Ramos is worried about the health of her two sons growing up in a community still contaminated by an old burn dump containing polychlorinated biphenyls (PCBs).

“What will be the long-term effects on my children?” asked Ramos.

Now new research conducted in New Bedford suggests that these industrial chemicals, which were first linked to learning problems in children more than two decades ago, may play a role in attention-deficit hyperactivity disorder (ADHD), too.

Boys who were exposed to higher levels of PCBs in the womb scored lower on focus and concentration tests, which indicates they are more likely to have attention problems often related to ADHD, according to a newly published study of New Bedford area children.

All of the children studied were born to mothers who lived near the contaminated harbor and dumpsites in these low-income communities, where twice as many people live below the poverty line than the Massachusetts average. But experts say that their exposures were fairly low, comparable to children’s levels throughout much of the United States, which means that a connection between PCBs and attention problems in boys could exist in other communities, too.

Banned in the United States more than 30 years ago, PCBs are long-lived industrial chemicals that accumulate in food chains. Nearly every U.S. resident still has detectable levels in his or her blood. PCBs have the ability to disrupt hormones, which can alter how the brain develops.

“These findings contribute to a growing literature showing associations between PCBs and ADHD-related behavior,” the scientists from Boston University, Harvard University and two other institutions wrote in the study, which was published in late February.

In the study, umbilical cord was collected from 788 newborns from four towns near New Bedford Harbor to see what they were exposed to in the womb. They were born between 1993 and 1998.

Blood from the umbilical cord “is one of the best measures of contaminants being transferred from mother to fetus,” said Sharon Sagiv, lead author of the study and an epidemiologist who now works at Boston University.

Roughly eight years after they were born, almost 600 of these children underwent two tests. One measured their ability to zero in on and react to a specific target  – in this case, the image of a cat on a computer screen — and to inhibit their response to another animal’s image. The other exam included parts of an IQ test that measured their processing speed and distractability, which tests whether they can maintain attention over time.

“It’s like playing whack-a-mole versus watching a radar monitor,” said Paul Eubig, a neuroscientist at the University of Illinois at Urbana-Champaign. Eubig, who studies effects in lab animals, was not involved in the study but co-authored a published report linking  PCBs with changes related to ADHD.

Boys exposed to the highest levels of PCBs during their mother’s pregnancy failed to press a button for the on-screen cat 12 percent more often than children exposed to the lowest levels, according to the study published in the journal Environmental Health Perspectives. Those same boys also scored slightly lower in the other test.

The same link was not found in girls. Animal data suggest that hormone-disrupting chemicals including PCBs affect each gender differently, but the connection in humans remains unclear.

“It’s possible that these compounds can impact brain development by altering the hormonal balance of a developing fetus,” said Joe Braun, an epidemiologist at the Harvard School of Public Health who did not participate in the research. “Boys and girls have different hormonal patterns,” he said.

Boys are two to three times as likely as girls to develop ADHD, the most common learning disorder reported in children worldwide. In 2007, U.S. parents reported that nearly 10 percent of children between the ages of 4 and 17 had been diagnosed with ADHD, according to the Centers for Disease Control and Prevention.

The researchers in their report called the effect of PCBs on attention skills “modest.” But they noted that the links were strongest for the children’s errors of omission and variability in reaction times, which they called “indicators of inattention.”

In their findings, the scientists took into account other factors that may contribute to ADHD-related behaviors, such as whether the mother smoked during pregnancy. However, they cannot rule out that chance – or some other factor – did not contribute to the results.

In the study, 31 percent of the children were non-white, 24 percent of the fathers did not finish high school and 20 percent had an annual household income of less than $20,000 per year.

The authors reported that PCB levels in the New Bedford area infants “were low relative to other population-based studies, given maternal residence adjacent to the PCB-contaminated New Bedford harbor.”

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From NJ.com:

Piles Creek is an offshoot of the Arthur Kill — a dead-end waterway that stops in an industrial no-man’s-land in Linden.

To the west is the rumbling New Jersey Turnpike and a cluster of puffing smokestacks. To the north a horizon of power lines and refineries. To the east and south factories and a brownfield.

And what lives here is not quite normal — a strange ecosystem of creatures large and small that seem cast from a bad toxic apocalypse movie.

Grass shrimp and fiddler crabs are larger, and tend to thrive — even though they eat less. In fact, they are not eaten as much themselves.

Their predators, like killifish and bluefish, are smaller, more sluggish and can’t hunt as well — perhaps because their thyroid glands and neurotransmitters are abnormal.

The blue crabs are sluggish and feeding on easily-available food like algae and sediments. But they are also hardier when exposed to toxicity and more savvy at avoiding predators — even becoming nasty and aggressive when provoked.

“It’s a tough neighborhood to grow up in — that’s the way we thought of it in the lab,” said Rutgers University marine biologist Judith Weis, a 70-year-old grandmother of three who has spent the past two decades documenting the creek’s slow recovery since the beginnings of the environmental movement.

For most of the 20th century, wildlife at Piles Creek had no chance to survive. Weis once saw no life in the brackish water, which is still contaminated by mercury, other metals and a whole mess of acronyms, including PAHs and PCBs. Even now, a bridge of gas and oil pipelines runs over the water, marked with neon stakes. A sign warns trespassers of danger.

Over time, though, the Clean Water Act and other environmental protections since the 1960s have slowly brought life back to Piles Creek. But the recovery has left a toxic legacy — a strange process caused by heavy industry, according to Weis.

Her team from Rutgers meticulously documented five species’ transformations. The food chain was in disarray. She said pollution has created its own variety of unnatural effects on the creatures in Linden and Newark Bay, compared with their counterparts in the cleaner waters of Tuckerton some 80 miles to the south.

The team found healthy creatures introduced into the tainted environment were immediately affected. Blue crabs and killifish from Tuckerton lost their innate hunting abilities when they were put into the polluted water.

“If a predator is worse off than you are, it’s an advantage,” Weis noted.

Despite the slow comeback of Piles Creek, it remains an ecological war zone. Lauren Bergey, a student of Weis’s who is now an assistant biology professor at Centenary College, said she once saw a male fiddler crab waving his huge claw atop a Thermos bottle, trying to attract a mate. He had made his burrow inside the container, she said.

“I still do work out there, and when I come back, I smell like an oil refinery,” Bergey said.

The Rutgers study is unique in that pollution-effects studies most often just examine the effects of poisons by dosing specimens in the laboratory, the researchers said.

“I’m hoping this leads to more research out in the field, instead of just exposing species to the contaminants in the lab,” said Weis, who wrapped up decades of observations of the return of life to the polluted water in a study published last month in BioScience.

Weis — who is chair of the science advisory board of the New Jersey Department of Environmental Protection, has served on committees for the Environmental Protection Agency, and is currently writing about water for the United Nations — believes the Clean Water Act and other environmental protections since the 1960s have brought life back to Piles Creek and other places. Yet she said the environmental threats remain.

“The current regulations are allowing really dreadful places like Piles Creek become better,” she said. “However, it will take a lot more effort, money and stronger regulations — and a lot of years — for them to really become healthy environments.”

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