Pesticides: Are They as Harmful as We Think?
by Sadaf Atayee
Atrazine: Human Health Risk or Harmless
by Katherine Fite
Ever since post- World War II, the use of herbicides and pesticides has been widespread and abundant. These chemicals agents have ranged from highly toxic compounds to synthetic organic compounds and almost all share the same concerns. Are they toxic and harmful to human health? In what concentrations do these pesticides prove unsafe? Should their use be limited or even banned? From DDT to Chlorpyrifos, all pesticides and herbicides have been put to question about their potential human health risk.
One such herbicide is Atrazine. Discovered in the 1950’s, it is today one of the most common herbicides in the United States. Every year, almost 76 million pounds of this herbicide is used on various crops. In fact, over 50% of all corn crops, 76% of sugar can and 59% of grain sorghum are sprayed with Atrazine and these crops are primarily concentrated in the Midwest.
As is the nature of pesticides and herbicides, Atrazine poses a considerable threat to groundwater and surface water contamination. It’s slow hydrolysis (a process that is essential for chemical removal) and ability to stay in the soil for a prolonged period means there’s a greater chance of water contamination. For one, Atrazine can leach into groundwater and contaminate well water and belowground drinking water supplies. In addition, agricultural runoff from heavy rains can seriously pollute watersheds and other surface waters with the herbicide. Therefore; the thought of Atrazine contaminating our drinking water supply has become a concern.
Over the past two decades, numerous scientific studies have illuminated the serious potential human health and wildlife risks Atrazine poses. In 1990, the Environmental Protection Agency (EPA) formally classified Atrazine as a Restricted Use Pesticide. In addition the EPA reduced and put restrictions on the amount of Atrazine applied for agricultural use and industrial weed control. However, Atrazine was available to consumers in over-the-counter lawn care products, which meant residential use was unlimited and unsupervised. So Atrazine was still a common and heavily used herbicide.
In 2000, EPA issued a statement saying that Atrazine is unlikely to be carcinogen, a statement they still support today. In the early 2000’s, biologists and wildlife scientists began noticing that amphibians and fish in areas of high Atrazine use were having endocrine issues. EPA did agree at that time that there was enough evidence to conduct a study further exploring amphibian exposure to Atrazine. In 2002, researches gave male frogs >0.1 parts per billion (ppb) of Atrazine. They found that in a significant number of frogs, Atrazine severely weakened the immune system, making them susceptible to infection and deformities. Many frogs developed female sex traits and had delayed gonad growth. In 2007, EPA concluded that, because of study design flaws and uncertainties in the data, the findings in the amphibian study could not be conclusively disproved or confirmed.
In another study, female lab rats exposed to Atrazine developed cancer in mammary glands. The EPA dismissed these cancerous tumors found in rats on the grounds that the difference in the physiology of rats and humans is too significant and therefore cancerous mammary tumors are not expected to develop in humans.
After these results in mammals and amphibians were made public, studies on human health effects began. In late 2002, the National Lymphoma Foundation of American saw an increase in non-Hodgkin’s lymphoma in populations exposed to herbicides. In addition, other researchers found that women exposed to high levels of Atrazine were three times more likely to develop ovarian cancer. Another study done on men found that high exposure led to poor semen quality. The EPA also dismissed these all of these results, citing that there is no significant relationship between Atrazine exposure and prostate cancer and lymphoma.
Yet despite these findings, the EPA struck a deal with the herbicide industry, particularly with Syngenta (one of the United State’s largest producers of Atrazine) in late 2003. EPA promised to put no more restrictions on Atrazine use, partly because the economic loss of the ban of Atrazine would be in the billions. This deal also gave Syngenta total responsibility in monitoring Atrazine contamination in US waterways. Yet from 1998 to 2003, the USDA estimated 7 million people were exposed to Atrazine in their drinking water and 94% of all drinking water contained some level of Atrazine.
From 2004 to 2011, Syngenta and the EPA conducted a large-scale watershed monitoring program that focuses on surface waters most susceptible to Atrazine contamination, especially in the Midwest. They originally tested 40 watersheds for at least two years, but their findings prompted them to test an additional 25 sites. In every single water samples, Atrazine was detected. More than 27% of the samples exceeded the EPA maximum contamination level and were classified as level of concerns. Sites that contained water contamination at levels of concern were closely monitored by Syngenta; however, four sites are still at levels of concern to this day.
In 2006, EPA concluded that the level of exposure to herbicides in food and drinking water was safe and met the health standards put forth by the EPA. Today, the EPA along with Syngenta continue to monitor more than 100 community water systems and ensure that drinking water does not reach more than the 3 ppb level of contamination standard. The EPA maintains the promise that they will not let Atrazine reach levels in drinking water that could possibly affect hormone levels. Since 2003, they have reviewed more than 150 scientific studies on potential health concerns and continue to do so. They also state that if new data on Atrazine health risks surfaces, they will modify their standards.
The EPA has made great strides in monitoring Atrazine levels in surface and drinking water and ensuring the levels are safe for human consumption and exposure. However, more can be done. Appointing one of the leading producers of Atrazine to monitor levels of their own product in waterways seems to be a conflict of interest. In addition, scientific studies are still being published warning of the adverse health effects of Atrazine. One of the most recent studies looked at women who drank water with low levels of Atrazine. These women were more likely to develop menstrual irregularities and hormone imbalance and those not exposed to Atrazine. A USGS study also found that 75% of stream water and 40% of groundwater samples taken in the US had traces of Atrazine. It is apparent there is still a lot of work to be done, research conducted, and policies put in place to ensure our good health and reduce Atrazine prevalence.
Pesticides and their Effects on the Endocrine System
By Maddelene Karlsson
by Brigitte Keen
Historically, pesticides have proven to be useful
agents in preventing the spread of disease, deterring invasive species from
destroying crops, and increasing farming production. Despite the range of
benefits that pesticides offer, the use and abuse of these chemicals come at a
are used to kill or repel insects, fungi, slugs, and rodents, but can cause
detrimental health effects to humans and the environment. Depending on the type
of pesticide and its concentration, some may be carcinogenic to
humans or alter the endocrine or nervous systems. Correlations have been made which
suggest that even “acceptable”
levels of insecticides contribute to 30 percent of the decline found in
freshwater biodiversity. In a recent review of more than 800 studies, it was found that
insecticides were detected in 2.6 percent of areas studied, and that over half
of those areas contained concentrations exceeding
regulatory limits. The studies were conducted in 2,500 waterways,
across 73 countries, spanning over 50 years. The Institute for Environmental Sciences
at the University
Koblenz-Landau formed this collection of studies, researching 28 kinds of
insecticides, ranging in toxicity. At regulated levels, these insecticides do not necessarily
pose a risk
to humans and the environment. However over half of the areas found with
pesticides exceeded the set regulations. Furthermore, predicting the “full
array” of damage could prove difficult because of the lag time that exists
between chemical application and contamination of ground water. This issue is
of great concern to public health in the United States due to the fact that
half of the nation’s drinking water derives from ground water. Additionally,
the U.S. is now the world’s
largest food producer with demands that require increased usage of
pesticides. Currently there is a lack
of monitoring and reporting on the level of insecticides in waterways
adjacent to farmlands. This must be amended in order to reduce agrochemical
abuse, especially as pesticide
application increases due to rising demand of exports.
World Without Atrazine
Atrazine is produced by the
Swiss agrochemical company Syngenta, was
first registered for use in the United States in 1959. Atrazine is considered
as an agricultural
herbicide that used by famers to control broadleaf weeds and grasses
that interfere with the growth of corn, sugar cane, sorghum, lupins, pine and
other crops. The herbicide is also used as a weed killing agent on golf courses
and on commercial and residential lawns. The herbicide has been banned in the
European Union in 2004—some countries in Europe banned Atrazine as early as
1991—but almost 80
million pounds of this agent is used annually in the United
States. It can be difficult for the
United States to adopt a different herbicide because the primary reason why
farmers like atrazine because it is relatively cheap. Atrazine
is one of the most affordable, effective, and trusted agricultural herbicide
that has been used for over 50 years by farmers. From a study, farmers that
grew corn and used atrazine over a 20 year
period (1986-2005) yield 5.7 bushel more per acre, an increase of
more than 5%. The study continues on that atrazine greatly increased the
incomes of farmers. The lowered cost for atrazine and higher yields, estimated
$25.74 per acre to farmers’ income in 2005, which generated a total income of $1.39
billion to U.S. farmers. The EPA conducted another study stating
that the increase of income of $28 per acre, has a total benefit of more than $1.5
billion to U.S. farmers. In 2006 the United States
Environmental Protection Agency re-registered
atrazine and arrived to a conclusion that it [atrazine] posed “no harm that
would result to the general U.S. population, infants, children or
other…consumers”. However, other studies have suggested that atrazine is a
human carcinogen and can also lead other human health issues. Researchers found a connection
between atrazine and poor
birth outcomes in humans. In a study in 2009, there was a
finding of that prenatal atrazine exposure, which is primarily from the
drinking water consumed by pregnant women, leads to unhealthy body weight of
newborns. Low birth weight is associated with increased risk of illness in
infants and leading to cardiovascular disease and diabetes. Atrazine is most
commonly detected in American groundwater. The United States Geological Survey
conducted a study in 2009, which
garnered surprising results. Approximately 75% of stream water and about 40% of
groundwater samples in the agricultural lands were tested. Atrazine is also
present in drinking water, which from the 153 samples that were taken from
public water systems, 80% of the
water had atrazine present. Current views shows that
farmers are conservatively supporting the usage of atrazine regardless of how
harmful it can be. The reasoning behind this is that previous generations of
farmers have been using atrazine religiously to
produce a mass profit, it would be a no-brainer on abandoning this idea if the
EPA already approved atrazine as a “no harm” herbicide.
However, it can be said that it
if atrazine was banned, it would not hurt famers and their farm productivity.
This idea will be assessed in the following paragraphs, accompanied with
domestic and international examples that will support the cause of banning
An economist from Tufts
University, Dr. Frank Ackerman concluded that the estimates for higher corn
losses were flawed due to problems in
methodology. Ackerman found that despite the 1991
on atrazine in both Italy and Germany (both corn producing countries), neither
country has recorded significant adverse economic effects. In his report,
Ackerman wrote that there was “no sign of yields dropping in Germany or Italy
after 1991, relative to the U.S. yield—as would be the case if atrazine were
essential. Far from showing and slowdown after 1991, both Italy and
(especially) German show faster growth in harvested areas after banning
atrazine than before”. Based on Ackerman’s analysis, he
concluded that if “the yield impact is on the order of 1%, as USDA estimated,
or close to zero, as suggested by the new evidence discussed her, then the
economic consequences [of phasing out atrazine] become minimal”. Controversially, the economic
cost of continuing to use atrazine—both in water treatment and public health
cost—could be significant when compared to the relatively small economic losses
of banning the chemical. An example can be Mt.
water system in Ohio. Mt. Orab produces 372,000 gallons of drinking water per
day for 3,600 people. With its experience with high atrazine levels, the village
of Mr. Orab installed a granular activated carbon filters to treat the water.
Each carbon filter has the life of a year and they cost approximately $50,000 to replace
annually. The primary purpose of this system is to reduce the total organic
carbon level and prevent formations in treated water. The secondary purpose is
to remove pesticides and also filters have proved to be successful in removing
atrazine level in drinking waters. Syngenta, the manufacturer of
atrazine faced a class-action
lawsuit in 2012 concerning with the levels of atrazine in human
water supplies. The company agreed to pay $105 million to reimburse more than
one thousand water systems “the cost of filtering atrazine from drinking
water”. Syngenta denies all wrongdoings. In the recent year of 2014, New Yorker writer Rachel
reported that Syngenta have sought out to attack “scientific credibility” of
not just Tyrone
Hayes (lead critic of atrazine), but other scientists as well.
The studies that were carried out by these scientists, have shown atrazine
having an adverse effects on the environment, human and/or animal health, but
Syngenta is doing all it can to keep people quiet. |