Sludge Watch ==> Wastewater pollutants impacting humans and aquatic life

[Maureen Reilly]

http://www.sciencedaily.com/releases/2008/02/080216095740.htm


Chemicals in our waters impacting humans and aquatic life in unanticipated 
ways

ScienceDaily (Feb. 21, 2008) — American and Canadian scientists are finding 
that out of sight, out of mind can no longer be the approach we take to the 
chemicals in our waters. Substances that we use everyday are turning up in 
our lakes, rivers and ocean, where they can impact aquatic life and possibly 
ourselves.  Now these contaminants are affecting aquatic environments and 
may be coming back to haunt us in unanticipated ways.



Derek Muir of Environment Canada and colleagues have determined that of the 
30,000 or so chemicals used commercially in the United States and Canada, 
about 400 resist breaking down in the environment and can accumulate in fish 
and wildlife. These researchers estimate that of this 400, only 4 percent 
are routinely analyzed and about 75 percent have not been studied. These 
"emerging chemical contaminants," or ECCs, are not necessarily all new 
substances. But with improved detection technologies, their unexpected 
potential impacts on the environment and human health are just now coming to 
light.

John Incardona and Nathaniel Scholz at National Oceanic and Atmospheric 
Administration's Northwest Fisheries Science Center and the West Coast 
Center for Oceans and Human Health found that polycyclic aromatic 
hydrocarbons (PAHs) left in Pacific waters after the Exxon Valdez oil spill 
caused heart defects in herring and pink salmon embryos. PAHs from various 
sources, including oil spills and urban runoff, remain a threat to fish in 
coastal areas.

The scientists think these chemicals can cause the hearts of fish embryos to 
beat slower and slower, resulting in heart deformities and a buildup of 
fluid around the hearts. During the last six years, they tested the effects 
of PAHs on zebrafish, which medical researchers have determined to have 
systems comparable to those of humans. The zebrafish embryos' hearts were 
severely malformed after absorbing PAHs through their skin.

"What isn't good for them, isn't good for us," Incardona says. Given the 
amount of PAH emissions that come out car tailpipes daily, especially in 
dense, urban areas, "basically, we are breathing an aerosolized oil spill." 
He says PAHs should be considered as "prime suspects for cardiovascular 
impacts related to air pollution."

Combining Chemicals can be Dangerous

Scholz is also finding that although the effects of a single chemical may 
not be deadly, combinations of chemicals in our environment can be more 
potent. Pesticides are regulated one by one, but in the environment they can 
mix with other pesticides and such mixtures are not regulated.

Water quality monitoring of rivers and streams has shown that threatened and 
endangered coho salmon and steelhead habitats throughout the Northwest are 
widely contaminated with pesticides that have run off from urban areas and 
agricultural land. The researchers looked at mixtures of five common 
insecticides and found that some combinations were much more toxic to the 
juvenile salmon than any one of the chemicals acting alone. The researchers 
say the enhanced toxicity of pesticide mixtures could be a more important 
factor in salmon population declines than previously realized.

"Current risk assessments based on a single chemical will likely 
underestimate impacts on wildlife in situations where that chemical 
interacts with other chemicals in the environment," says Scholz. The current 
findings may have implications for human health because these insecticides 
act on the nervous systems of salmon and humans in a similar way. Also, 
mixtures of pesticide residues can be common in the human food supply.

Turtles Show Toxic Chemicals Persist in the Marine Environment

Stain repellents for carpets and nonstick coatings on food packaging derived 
from compounds known as perfluorinated compounds, or PFCs, are tough. But 
the same toughness that helps PFCs resist spills and grease also makes them 
resistant to breaking down in the environment. This means that PFCs can 
easily contaminate bodies of water and be ingested by wildlife.

Jennifer Keller of the National Institute of Standards and Technology (NIST) 
and the Hollings Marine Laboratory in Charleston, S.C., and her colleagues 
have monitored PFCs in loggerhead sea turtles along the U.S. East Coast to 
study the effects of the pollutants on these marine animals. Loggerhead 
turtles accumulate PFCs in their tissues because they eat filter feeders 
such as mussels that remove contaminants from the water.

Keller's team found that turtles with high concentrations of PFCs showed 
signs of liver damage and were immunocompromised. Keller says, "Endangered 
sea turtles run a gauntlet of stresses in the oceans, and chronic exposure 
to contaminants may impair their defenses against disease or their ability 
to reproduce." Because reptiles and humans have similar immune systems, 
Keller says that we also may be at risk for the same health problems as the 
loggerheads from exposure to PFCs.

Gender Bending can Impact Aquatic Food Webs

Chemicals are ending up in aquatic ecosystems in part because many municipal 
wastewater treatment plants do not filter out chemicals completely, 
including the estrogen women excrete in their urine after taking birth 
control medications. Karen Kidd of the University of New Brunswick is 
testing the effects of estrogen on aquatic life in a laboratory a bit larger 
than usual--a lake in northwestern Ontario.

After Kidd and her colleagues with Fisheries and Oceans Canada added 
estrogen to the lake in 2001, male fish in this lake started producing eggs 
or egg proteins and female fish produced up to 115 times more estrogen than 
normal. During the next summer, the fathead minnow, the shortest-lived fish 
species in the lake, stopped reproducing until more than 99 percent of its 
population was lost. This has impacts all through the food chain, ultimately 
hitting top predators and the entire lake ecosystem. In the next two years, 
she saw depletions in longer-lived species: the pearl dace declined 86 
percent and trout, 30 percent.

But Kidd also has some good news: "Once you take the estrogen out of the 
system, given enough time, the fish return to their original abundance." By 
2006, three years after the scientists ceased adding estrogen to the water, 
the fathead minnow began to repopulate the lake. This suggests that if 
treatment plants could remove such chemicals from municipal wastewaters 
before they enter the environment, affected ecosystems could rebound.

Dilution Not the Solution

Steven Bay at the Southern California Coastal Water Research Project in 
Costa Mesa, Calif., has seen evidence of altered hormone levels in marine 
fish. The hornyhead turbot, a common flatfish in the coastal waters of 
Southern California, hangs out on the seafloor where it can be exposed to a 
chemical cocktail discharged from nearby wastewater pipes. These chemicals 
range from industrial compounds to pharmaceuticals, some of which could 
contain substances that interfere with the fish's hormone system.

Bay found that up to 90 percent of the male hornyhead turbot tested at some 
locations had produced egg yolk proteins. They also had estrogen levels as 
high as females and low thyroid hormone and cortisol levels. Thyroid hormone 
manages growth, so development of the fish embryos could be impaired. And as 
cortisol is produced in response to stress, the low levels could actually 
mean the fish might be overstressed and "worn out," leaving them vulnerable 
to disease. Most of these responses in the fish were widespread and not 
confined to the areas around the discharge pipes, so their precise cause and 
source remain a mystery.

While you might think that the vast ocean could dissipate these chemicals, 
Bay says dilution is not the solution: "More than a billion gallons of 
treated municipal wastewater are discharged into Southern California coastal 
waters every day. Our study shows that some of these contaminants can be 
detected in sediments and water, even though the effluent is immediately 
diluted at least one hundredfold upon discharge."

Because most municipal treatment plants do not completely remove chemicals 
from wastewater, this study could have implications for groundwater and 
surface water. Treated wastewater effluent is sometimes discharged into 
rivers and used to replenish groundwater or to irrigate landscapes. If these 
chemicals are not filtered out through natural processes, they could end up 
in our drinking water supplies.

Carolyn Sotka, a contractor who is a senior science policy analyst at NOAA's 
Oceans and Human Health Initiative, says, "It's ironic that although we use 
drugs and products to benefit our health and well-being, we can sometimes in 
turn hurt our environment and ourselves. Studies such as these force us to 
see the whole picture, to make the connection not only between land and sea, 
but also how what we put in or on our bodies or use in our homes can affect 
our world." Sotka says a better understanding of the impacts of emerging 
contaminants will lead to improved management decisions for the environment, 
especially coastal ecosystems that are already battling such a multitude of 
stresses.

A panel of researchers discussed these findings  the AAAS annual meeting in 
Boston February 16, 2008.

Adapted from materials provided by SeaWeb, via EurekAlert!, a service of 
AAAS.

Need to cite this story in your essay, paper, or report? Use one of the 
following formats:
APA

MLA SeaWeb (2008, February 21). Chemicals In Our Waters Are Affecting Humans 
And Aquatic Life In Unanticipated Ways. ScienceDaily. Retrieved February 24, 
2008, from http://www.sciencedaily.com­ /releases/2008/02/080216095740.htm

--------------------------------------------------------------------------------

Pesticides In The Nation's Streams And Ground Water (Mar. 3, 2006) — US 
Geological Survey has released a report that concludes that pesticides are 
typically present throughout the year in most streams in urban and 
agricultural areas. The report also concludes ...  > read more
Toxicity Of Industrial Water Pollution Underestimated (Nov. 18, 2007) — A 
new study suggests that a holistic approach is needed in assessing the 
potential environmental and health effects of toxic effluent from industry. 
Studies of industrial effluent toxicity usually ...  > read more
If We Are What We Eat, Some Lake Fish Are Made Of Maple Leaves (Jan. 15, 
2004) — Aquatic plants form the base of the food web. The energy they create 
supports aquatic life, from invertebrates to the largest sport fish. Now, a 
study shows that aquatic plants are receiving a little ...  > read more
Pesticides And Schools: A 'Tragic' Health Hazard (Jul. 26, 2007) — 
Pesticides in schools are a pervasive, unnecessary health hazard, according 
to an entomologist at Indiana University's School of Public and 
Environmental Affairs. The most widely used insecticides ...  > read more
Medicated Ecosystems: Human Drugs Alter Key Aquatic Organism (Aug. 9, 2002) 
— The overuse of antibiotics not only leads to more resistant strains of 
infection, but, according to new research from the University of 
Wisconsin-Madison, antibiotics also may be adversely affecting ...  > read 
more
Fixed Assets: Aquatic Plants Sequester Toxic Compounds In Cell Tissue, 
Removing Contaminants From Wetlands (Aug. 27, 2004) — Researchers have found 
that a common aquatic plant removes many persistent organic compounds that 
are discharged into natural waters and engineered ...  > read more
Medicines, Caffeine And Antibacterial Soap Among Contaminants Found In 
American Streams (Mar. 13, 2002) — A national survey of U.S. streams across 
30 states has revealed a list of compounds that looks like a sample from our 
national medicine cabinet. Among them are the painkillers acetaminophen and 
...  > read more
USGS To Map Richness Of Aquatic Life In The Great Lakes (Sep. 10, 2002) — 
The U.S. Geological Survey (USGS) and its cooperators are launching a 5-year 
study in the Great Lakes basin to identify and map unprotected areas of 
substantial richness in aquatic animal species, ...  > read moreSearch 
ScienceDailyNumber of stories in archives: 44,032