Another reason for natural soaps

[Guest guest]

Threat Seen From

Antibacterial Soap Chemicals

The compounds end up in sewage sludge that is

spread on farm fields across the country.

By Marla Cone

L.A. Times Staff Writer

5-11-06

 

 

 

 

Tons of chemicals in antibacterial soaps used in the bathrooms and kitchens

of virtually every home are being released into the environment, yet no

government agency is monitoring or regulating them in water supplies or

food.

 

 

 

About 75% of a potent bacteria-killing chemical that people flush down their

drains survives treatment at sewage plants, and most of that ends up in

sludge spread on farm fields, according to Johns Hopkins University

research. Every year, it says, an estimated 200 tons of two compounds --

triclocarban and triclosan -- are applied to agricultural lands nationwide.

 

 

 

The findings, in a study published last week in Environmental Science &

Technology, add to the growing concerns of many scientists that the

Environmental Protection Agency needs to address thousands of

pharmaceuticals and consumer product chemicals that wind up in the

environment when they are flushed into sewers.

 

 

 

> From dishwashing soaps to cutting boards, about 1,500 new antibacterial

consumer products containing the two chemicals have been introduced into the

marketplace since 2000. Some experts worry that widespread use of such

products may be helping turn some dangerous germs into " superbugs " resistant

to antibiotics.

 

 

 

Triclocarban, an ingredient of antibacterial bar soaps and toothpaste, is

" potentially problematic " because it breaks down slowly, which means it is

accumulating in soil and perhaps water, said Rolf Halden, an assistant

professor at Johns Hopkins' Department of Environmental Health Sciences, who

led the study.

 

 

 

" What we are finding is this chemical is building up in the environment, "

Halden said. " This is an example of an emerging contaminant. It has been in

the environment for almost five decades, and we manufacture large volumes of

it, but we don't know what happens to it. "

 

 

 

The scientists calculated that a large, modern East Coast sewage treatment

plant spreads sludge containing more than 1 ton of triclocarban onto farm

fields every year. The plant was not identified by the researchers, but data

in the study indicated that it was in Baltimore.

 

 

 

Southern California's sludge has not been analyzed for antibacterial

chemicals. But households in the Los Angeles region are likely to be a major

source, because sewage plants in the area produce hundreds of thousands of

tons of sludge every year.

 

 

 

Sludge is the solid waste that is left when sewage is processed in treatment

plants. Billions of pounds are produced annually in the United States -- 47

pounds per person -- and two-thirds is hauled to agricultural fields for

disposal. Federal regulations limit metals and pathogens in sludge, but not

other chemicals.

 

 

 

Triclocarban is used in bar soaps, deodorants, toothpaste, kitchen supplies

such as cutting boards and countertops, and baby toys. Triclosan, which is

more abundant because it is used in liquid soaps, has been detected in human

breast milk and fish in streams in Europe.

 

 

 

Toxicological tests have shown that the chemicals seem safe for human

exposure, even in the high doses applied to skin. However, in water,

triclosan can react with chlorine and turn into chloroform and dioxins

linked to cancer. The chemicals also might kill microbes beneficial to

ecosystems or promote new pathogens that resist antibiotics.

 

 

 

Allison E. Aiello, an assistant professor of epidemiology at the University

of Michigan's School of Public Health who has studied antibacterial soaps,

calls the new report an important finding that " suggests these types of

chemicals are persistent and prevalent in the environment. "

 

 

 

" From these findings, it seems likely that microorganisms in the environment

are often exposed to these chemicals at various concentrations, " Aiello

said. The next step, she said, is to assess whether these microbes show

reduced resistance to antibiotics.

 

 

 

Previous research by Halden suggested that triclocarban was among the top 10

contaminants in waterways, while triclosan was among the most prevalent in a

national analysis of streams by the U.S. Geological Survey.

 

 

 

Yet no one knows whether the chemicals are contaminating crops or

groundwater. Drinking water also is not monitored for them. The EPA is

exploring the prevalence of pharmaceuticals and personal care products in

the environment, but it has nowhere near enough data to consider regulations

for sludge.

 

 

 

Rick Stevens, national biosolids coordinator at the EPA's Office of Science

and Technology, said the discovery of triclocarban in the plant's sludge was

" of interest " to the EPA, but " at this time, the agency cannot determine

what significance [the concentrations found] may represent to humans or the

environment due to the limitations in the database. "

 

 

 

Stevens said there were no national data -- not even an accepted,

standardized technique for measuring the chemicals. " One facility is not a

nationally representative sample, " he said.

 

 

 

Triclocarban in the plant's sludge averaged 51 parts per million, considered

a high concentration for an environmental contaminant. But Stevens said

people regularly rubbed triclocarban into their hands at levels 100 times

higher. Also, the chemicals would be degraded and diluted on farm fields, he

said.

 

 

 

Hans Sanderson, director of environmental safety at the Soap and Detergent

Assn., which represents manufacturers, said the new research was " important

and analytically sound " and was helping address what happens to the

chemicals in soaps and other household products.

 

 

 

But Sanderson said it was wrong to assume that the presence of them in the

sludge meant that they were posing risks. Most sludge is applied to fields

and forests that do not produce food crops, he said.

 

 

 

" It is clear that the majority of exposure to triclocarban is direct

exposure, when you actually use these materials in hand soap or toothpaste

or whatever, " Sanderson said. But, he said, laboratory tests have shown that

even those exposures have no effects on animals, are not toxic to aquatic

life and pose no known threat to people.

 

 

 

Ann Heil, a senior engineer at the Sanitation Districts of Los Angeles

County, said many environmental precautions were required on lands where

sludge was applied. The material is plowed into soil within 24 hours and no

runoff is allowed.

 

 

 

Heil said it probably was better that treatment plants removed the

antibacterial chemicals from wastewater and concentrated them in the sludge,

because otherwise the chemicals would be discharged into streams where they

could harm wildlife.

 

 

 

Farm disposal of sludge is controversial in California. On June 6, residents

of Kern County, which takes in one-third of the state's sludge, will vote on

whether to ban its use on farms. If the measure passes, as expected,

Southern California will have to ship more sludge to Arizona at an extra

cost of millions of dollars a year in Los Angeles alone.

 

 

 

About 37% of the 160,000 tons produced last year by the Sanitation Districts

of Los Angeles County was applied on land. The county's sludge is subjected

to an extra process called thermal treatment, which Heil said probably

removed more antibacterial chemicals than the East Coast plant studied in

the report.

 

 

 

But, Halden said, even newer tests, yet to be published, showed that the

heat treatment was " not very effective " in eliminating antibacterial

chemicals. So this " Type A " sludge, the type used on food crops, still could

contain high amounts.

 

 

 

In October, an advisory panel of the Food and Drug Administration reported

that there was no evidence that the household products protected people any

better than regular soap. The panel urged the agency to study their risks

and benefits. The American Medical Assn. has opposed routine use of

antibacterial soaps since 2002.

 

 

 

" The bottom line, " Halden said, " is [that] we are mass-producing chemicals

in the environment that are not helpful and potentially are harmful. "

 

 

 

But Sanderson of the Soap and Detergent Assn. said it would be foolish to

eliminate products that could stem the spread of diseases when there was no

evidence they posed a threat.

 

 

 

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Semper in fæcibus sumus, sole profundum variat.

 

 

 

 

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