By Steven DiJoseph

Although the amounts vary and often do not reach levels that are believed to be dangerous to humans, pesticides now taint practically all of America’s rivers and streams as well as the fish that live in them.

While contamination is a relative term, there is no doubt that the toxic chemicals involved have been linked to a wide range of medical problems ranging from various cancers and neurological impairment to birth defects.

Environmentalists as well as many scientists are concerned about potential long-term and cumulative effects on marine life, animals that rely on fish and other aquatic organisms for food, overall water quality, and the environment as a whole. Clearly, the ecosystems affected are fragile and can be easily disrupted or even destroyed by chemical pollutants.

Thus, the U.S. Geological Survey’s (USGS) study of data between 1992 and 2001, which found pesticides in many urban and agricultural area waterways at concentrations that could affect marine life and fish-eating wildlife, has prompted a call for careful monitoring of and limitations on the use of these chemicals.

According to an article in USA Today (by way of the Associated Press), USGS associate director for water, Robert Hirsch, said that “while the use of pesticides has resulted in a wide range of benefits to control weeds, insects, and other pests, including increased food production and reduction of insect-borne disease, their use also raises questions about possible effects on the environment, including water quality.”

Of the 100 pesticides that were studied, about 40 accounted for the majority of the findings in water, fish, and sediment. Three herbicides in particular, atrazine, metolachlor, and cyanazine, which are used mainly for farming, were the detected most frequently in agricultural-area streams.

In urban-area streams, simazine, prometon, and tebuthiuron, three herbicides used commonly in cities were most frequently found.

Since fish live directly in the contaminated water as does everything they feed on, it was not surprising that the pesticides showed up in more than 90% of the fish from “agricultural, urban and mixed land-use areas.”

The pervasiveness of the contamination is evident from the fact that the scientists detected the presence of at least one pesticide in water from each of the streams tested. Moreover, the chemicals were found almost year-round in about 95% of the streams tested regardless of their location (agricultural, urban or mixed land-use watersheds).

Pesticides were most commonly found in shallow ground water under urban and agricultural areas, where more than 50% of the wells tested positive for one or more pesticides.

According to the AP article, the U.S. currently relies on some 1 billion pounds of pesticides each. This “shows an urgent need to strengthen policies at all levels of government and curtail pesticide use,” says Jay Feldman, executive director of Beyond Pesticides, a national research and advocacy group.

The USGS analyzed data from 51 major river basins and aquifer systems around the country as well as a study of an aquifer system running through eight states “from South Dakota to Texas east of the Rocky Mountains.” (AP)

While the report found the prevalence of insecticide residue to be widespread, it also noted that, in most cases, the concentrations of individual pesticides were within Environmental Protection Agency drinking-water standards.

The EPA has the responsibility of analyzing the results of pesticide testing that is done by manufacturers before their products are approved for marketing. According to industry figures, it “typically takes up to a decade to study each one [pesticide] before it can reach the marketplace.” (AP)

The pesticide industry points out that the mere presence of pesticides, in and of itself, is not a reason for concern or a sign of danger since the use of pesticides by farmers, ranchers, and others is strictly regulated by federal and state laws.

“Water quality is of paramount importance to us. And the USGS report correctly recognizes that the large majority of pesticide detections in streams and groundwater were trace amounts, far below scientifically based minimum levels set for protecting human health and the environment,” stated Jay Vroom, president of CropLife America, which represents pesticide developers and manufacturers.

One of the problems seen by environmentalists and a number of scientists, however, is that no one is certain of the true long-term health effects of low-dose pesticide exposure.

While government agencies and organizations such as WHO set what they believe to be safe limits on these chemicals, data simply does not exist to rule out any harmful effects small amounts of these toxins may cause over a lifetime. This is especially so when one considers the fact that, in higher amounts, these toxins are unquestionably linked to cancers, neurological injuries, and birth defects.

There is no longer any doubt that chemicals and other toxins find their way into every ecosystem and organism on earth to one extent or another.

As we have previously reported, for the past two years, there has been a growing concern over the safety of the manmade chemical known as C-8 or PFOA which can be found in everything from bread to birds, green beans to ground beef, dolphins to drinking water, and in the blood of up to 96% of the population of the United States.

The acid is used to manufacture Teflon coating for cookware and hundreds of other products like telephone cables, carpets, clothing, computer chips, chemical piping, and automobile fuel systems.

Because there are no known “natural” sources of C-8, scientists are curious as to how the chemical enters the environment. C-8 has also contaminated the groundwater in areas where Teflon is manufactured.

In addition, on July 14, 2005, the Environmental Working Group (EWG) published its “benchmark investigation of industrial chemicals, pollutants and pesticides in umbilical cord blood.” (http://www.ewg.org/reports/bodyburden2/execsumm.php). That massive report was summarized by EWG as follows:

“Summary. In the month leading up to a baby’s birth, the umbilical cord pulses with the equivalent of at least 300 quarts of blood each day, pumped back and forth from the nutrient- and oxygen-rich placenta to the rapidly growing child cradled in a sac of amniotic fluid. This cord is a lifeline between mother and baby, bearing nutrients that sustain life and propel growth.

Not long ago scientists thought that the placenta shielded cord blood — and the developing baby — from most chemicals and pollutants in the environment. But now we know that at this critical time when organs, vessels, membranes and systems are knit together from single cells to finished form in a span of weeks, the umbilical cord carries not only the building blocks of life, but also a steady stream of industrial chemicals, pollutants and pesticides that cross the placenta as readily as residues from cigarettes and alcohol. This is the human “body burden” — the pollution in people that permeates everyone in the world, including babies in the womb.

In a study spearheaded by the Environmental Working Group (EWG) in collaboration with Commonweal, researchers at two major laboratories found an average of 200 industrial chemicals and pollutants in umbilical cord blood from 10 babies born in August and September of 2004 in U.S. hospitals. Tests revealed a total of 287 chemicals in the group. The umbilical cord blood of these 10 children, collected by Red Cross after the cord was cut, harbored pesticides, consumer product ingredients, and wastes from burning coal, gasoline, and garbage.

This study represents the first reported cord blood tests for 261 of the targeted chemicals and the first reported detections in cord blood for 209 compounds. Among them are eight perfluorochemicals used as stain and oil repellants in fast food packaging, clothes and textiles — including the Teflon chemical PFOA, recently characterized as a likely human carcinogen by the EPA’s Science Advisory Board — dozens of widely used brominated flame retardants and their toxic by-products; and numerous pesticides.

Of the 287 chemicals we detected in umbilical cord blood, we know that 180 cause cancer in humans or animals, 217 are toxic to the brain and nervous system, and 208 cause birth defects or abnormal development in animal tests. The dangers of pre- or post-natal exposure to this complex mixture of carcinogens, developmental toxins and neurotoxins have never been studied.”

Clearly, as the emerging research in this area demonstrates, the potential long-term effects of exposure to low levels of environmental chemicals and toxins is a topic worthy of further scientific investigation and public concern.

This entry was posted on Saturday, March 4th, 2006 at 6:19 am and is filed under Health Concerns, Legal News, Toxic Substances.