This study evaluates the use of Glyphosate, Altrazine and Chlorpyrifos to control weeds and pests in a wetland area. The report identifies that the three compounds should not be allowed for agricultural, domestic or any other use in a wetland area. However, if the chemicals have to be used, their concentration should be monitored to ensure they do not have serious effects on the environment. Conclusions are based on the toxicity of the three elements with a specific emphasis on amphibians and aquatic life.
Glyphosate, though approved by some authorities as safe, has a chemical called roundup that has adverse effects on the environment, aquatic life and humans respectively. Reproductive deformities, neurological disorders in wildlife and death of aquatic life are some of the greatest effects to the use of glyphosate. The use of Altrazine has been controversially debated over the last decade with speculative conclusions that it can change the genetic composition of amphibians. This is as a result of research studies done on frogs. More studies have identified that it causes death to aquatic animals but its impact on wildlife and terrestrial animals are not yet conclusive. This herbicide is probably the most controversial in this study but with conclusive effects on fish and other aquatic forms of life, its use should be prohibited in a wetland area.
The effects of Chlorpyrifos are also evaluated with specific conclusions based on its lethal effects on aquatic life. The insecticide has been observed to cause endocrine and ChE inhibitions in humans. Other studies also point out that it leads to reproductive deformities in humans and animals respectively. Conclusions have been based on the fact that it leads to the birth of underweight children who later develop neurological disorders. More studies found in this report affirm that the three compounds should not be used in a wetland.
Glyphosate and Altrazine are common herbicides used to eliminate perennial weeds, especially in large-scale farming. Altrazine is organic and consists of an s-triazine ring which is very effective for weed management (Wackett, 2002, pp. 39-42). Altrazine is therefore widely used in prevention of pre and post emergence broad leaf and growth of grass weeds because of its effectiveness and relative inexpensive nature (Bichat, 1999, p. 100-102). Production systems with dismal profit margins such as conservation systems to prevent soil erosion and other tillage systems are therefore better placed in production and use of the herbicide. These systems have been majorly observed in maize plantations (Shipitalo, 2008, pp. 401-402). Because of these factors, Altrazine has been widely used in America with its utilization approximated at about seventy there million pounds annually (Crawford, 1998, p. 618).
The effect Altrazine has on total crop yield is estimated at 1% and 6%, but scientific research has settled on an average of 3%-4% (Arnold, 2002). In other studies, the effectiveness of the herbicide has received outstanding rankings because it is deemed the most effective of all herbicides of its category. These conclusions were derived from a comprehensive study done in more than 200 universities on corn fields that showed the herbicide yielded more than 5.7 bushels in each acre examined (Ackerman, 2007, p. 17). These studies were undertaken between the periods of 1985 to 2005. Altrazine has therefore been identified to be quite useful in many aspects but it is sometimes quite toxic to untargeted species (Caviness, 1971, pp. 83-84). Such species may include amphibians and fish but its toxicity is much widespread than previously thought.
Glyphosate is no different because it has also been evidenced to have some detrimental effects on the environment. The use of glyphosate can be traced back to the 70s when it was widely used on lawns and yards as well as a herbicide for most agricultural practices (Muller, 2000, p. 541). In the USA alone, approximately five to eight million kilotonnes of glyphosate are used on lawns and gardens while approximately eighty to ninety million pounds of the substance are used for agricultural activities (Watts, 2010). Glyphosate normally works by inhibiting enzyme function in the synthesis of aromatic amino acids (Walsh, 2000, p. 769). Components of glyphosate settle at the growth points of unwanted plants after being absorbed through foliage points which makes it quite effective for prevention of weed growth. It can however not be used to prevent pre-growth of weeds.
Glyphosate has been used in the US to control growth of illegal crops or drug plants, as evidenced in Columbian coca fields. Nonetheless, the effectiveness of the herbicide to control legal crops and more especially the fight against drugs has been a huge ground for debate (Heck, 2005, p. 329). The use of the herbicide has been criticized because it leads to the development of herbicide resistant crops such as the Boliviana Negra for the Columbian Coca plants. Its effects are also extended to the general environmental make up (Giesy, 2000, p. 35).
Chlorpyrifos is also a chemical byproduct majorly used as an insecticide. It however has adverse effects on the environment. Its functions are majorly focused on the prevention of acetylcholinesterase as an organophosphate insecticide for many crops such as cotton, corns and many fruit plant species (National Pesticide Information Centre, 2009). Its use has been generally assumed to have moderate toxicity but its advantages have also been outstanding.
This report provides a categorically detailed recommendation of the above discussed insecticide (Chlorpyrifos) and the two previously discussed herbicides (Glyphosate and Altrazine) for approval as acceptable chemicals to prevent insect pests and weeds respectively. Focus will be made on the effects of the ingredient chemicals in all the three products with regards to the environment and more so, the surrounding wetlands they are to be used. The wetland is considered home to several animal species including amphibians, crustaceans and fish and because of this reason; their use on any wetland, ecosystem and native fauna should be extensively discouraged.
Essentially, the functioning of glyphosate is through interference with amino acids (Watts, 2010). It succeeds in doing so by inhibiting many enzyme functions in plants; effectively making it a reliable weed killer (Watts, 2010). However, the same function has the same impact on animals as well. Considering the herbicide is to be used in a wetland that is home to amphibians, fish and other animal species, the infiltration of the chemical into the wetland endangers the general environment of the animals when they eat the plants (because animals obtain their amino acids from plants). This will lead to enzyme dysfunction in their bodies and probably cause death.
Considering the glyphosate is going to be largely used in a wetland, the chances of ecological support of human activity are probably high. The wetland may therefore support many human functions like providing water for domestic consumption, agricultural purposes and such like activities. The wetland is also likely to be home to many rivers and tributaries which if left to flow downstream, may be used for many activities other than domestic use. In this respect, it is essential that the wetland be free from any deadly chemical to minimize the risk of human reliance on the environment.
The toxicity of glyphosate has been empirically evidenced to be the lowest among its organochlorine family group (Watts, 2010). In fact, the United States Protection Agency has categorized the herbicide at level three of toxicity where toxicity levels are categorized from level one to four and the fourth level is the least toxic (David, 1998, 12- 14). In addition, the herbicide is organic and breaks quite rapidly. However, the reduced toxicity only applies when inhalation occurs.
There is enough scientific evidence to point out that if an individual consumes a lifetime supply of food obtained from glyphosate sprayed fields, it may have future detrimental effects. These developments have further prompted the United States Environmental Protection Agency to carry out further studies on the endocrinal disruptor effects of glyphosate (Chensheng, 2008, p. 537). These events have led to further reestablishment that the chemicals used to make glyphosate are probably more harmful than the herbicide itself. For instance, studies carried out to determine the toxicity of roundup, (a component in glyphosate) established that the chemical had a greater level of toxicity on aromatase when compared to glyphosate in isolation (Duke, 2007, p. 36). Further studies have established that roundup has a devastating effect on human embryonic, placental and umbilical effect; also a stronger effect than glyphosate has in isolation (regardless of the concentration level associated with it) (Richard, 2005, p. 716). Despite the fact that the effects of roundup are disproportional to that of glyphosate, it should be noted that the level of toxicity depends on the concentration of adjuvant used to develop the formula (Hassan, 1991. p. 55).
Glyphosate has been observed to be the number one cause of human complications as compared to other herbicides (Bradberry, 2004, p. 159). However, these statistics dont show other facts related to the number of people whove been exposed to the chemicals and who exhibit symptoms not fully blown into a serious complication. For instance, if hospitalizations were used as a method to determine the effects of glyphosate, the herbicide would be assumed to have a relatively safe degree of usage because out of the over 500 cases of hospitalization noted, none can be directly attributed to the herbicide (Benachour, & Gilles-Eric, 2008, p. 97).
Collectively, there have been a number of studies (more than 58) which establish the diverse effects glyphosate has on many organisms. These studies established that when the herbicide is used for terrestrial organisms, the effects were minimally acute. Additionally, chronic risks attributed to organisms which were not targeted in the initial project increased (Watts, 2010). Additionally, it was confirmed that there was a high degree of dangerous exposure for aquatic animals that live under shallow water. Interestingly, the same research concluded that roundup had adverse effects on the functional development of rats at a fetus stage (with respect to the development of limbs). The same also goes for pregnant rats (Watts, 2010). In close relation, the chemical has been established to have a negative effect on the stabilization of testosterone level in mice. Further mammalian studies have established that with regard to human effects, the chemical has a detrimental effect on the estrogen biosynthesis of enzymes for placental cells in human beings.
Systematic sequelae and reported fatalities of human beings have been directly traced to the ingestion of the roundup chemical over long periods of time. In fact, the proportionality has been established that with the ingestion of more than 85 milliliters of the chemical, serious toxic implication for adult human beings will be noted (Watts, 2010).
Glyphosate is also preserved with a chemical called proxel which can cause serious effects of photo contact dermatitis and serious skin burns (though rarely observed) if strong concentrations of proxel are ingested (Watts, 2010). Instances of dermal exposure (which is often known to cause irritation of the skin) have been increased due to the use of glyphosate if it comes in contact with water sources over extensive periods of time. When a person inhales the chemicals found in the herbicide, nasal irritation may be experienced. In addition, there are often tingling and irritation sensations on the throat as well as a sour taste in the mouth. Extensive exposure of the eyes to the chemical components of glyphosate may also cause conjunctivitis (though mild) (Watts, 2010).
Effects on other Animal Species
Glyphosate does not necessarily affect mammals and bird species in an adverse manner. The acute effect of the herbicide that results in complications arises from dosages in excess of 5,000 mg/kg (Daruich, 2001, pp. 226-228). The reason for its low level of toxicity to mammals is based on research that shows if glyphosate is administered to mammals for two years or less, there were no serious effects (except for the reproductive system). This study was done on rodents and dogs. Apart from the chemical components of the herbicide showing low absorption rate in the digestive tract of the animals, there is little evidence to show that the herbicide increases cancer. In the same regard, glyphosate has a very small likelihood of accumulating in animal tissues (Watts, 2010).
Despite these findings, recent research studies published in 2010 have established that the formula can cause neural and craniofacial malformations on frogs which are very common in wetland areas. Among the most likely possible effects on the animals would be the diminution of the body size and a change in the size of the brain (the cephalic area) (Watts, 2010). Converse to other result studies that showed a high level of toxicity on the chemicals that constitute glyphosate, the 2010 studies have identified that the herbicide has the same level of effects as its components.
The level of toxicity of the herbicide has also been observed on earthworms and other insects that may be of benefit to the general environment (Springett, 1992, p. 1739). However, the effects of the herbicide on earthworms are still in contention. Previous studies cited that the herbicide has no effect on nematodes, motes and springtails after they were administered with about two kilograms of roundup (Watts, 2010). The conclusion to these findings are therefore still in contention but other studies have affirmed that glyphosate undoubtedly has a negative effect on the nitrogen fixing bacteria found in soil (Santos, 1995, pp. 349-352). This has consequently led to increased susceptibility of plants to various types of diseases.
Studies done in 2005 have also shown that constant use of glyphosate may have a profound effect on amphibians and specific surfactants may also have a negative effect on fish and some animals of the invertebrate family. This is the leading reason why the substance has been abolished in an aquatic environment. Such types of banned products include Bianctive and Aqua master (Watts, 2010). Interestingly, some conservation groups have adopted the use of glyphosate in the eradication and prevention of the growth of weeds when the intention of use is in an aquatic environment. This is due to its relative low toxicity levels in wildlife (Watts, 2010).
Normally, glyphosate is used with five types of salts but samples of the substance can be found with traces of surfactants which have varying degrees of toxicity (brought about by varying concentrations). This exposes the fact that human and animal poisoning should never be blanketly attributed to glyphosate in totality. Their concentrations and formulas for mixture are therefore the leading cause of poisoning (Watts, 2010).
When analyzed with regard to toxicity of the herbicide in the productivity of soil; findings have been inconclusive because certain components of the herbicide usually attach themselves to soil particles which later make them inactive (Alibhai & Stallings, 2001, p. 2944). Additionally, an element of the herbicide that doesnt bind itself to the soil particles is usually degraded by bacteria. This shows that the herbicide has a low effect on soil nutrients. As a result, most environmental bodies like the United States and the United Nations Environmental program (UNEP) have concluded that pure glyphosate is in no way carcinogenic (Goldstein, 2002, p. 885). However, strong critics of the herbicide have identified the strong effects of roundup in its chemical composition as disastrous.
Effects on Aquatic Life
Glyphosate has been generally confirmed to be detrimental to amphibians. Fish and general invertebrates have especially been identified to be very sensitive to chemical components from the herbicide (and most especially the roundup component) (Richard, 2005, p. 716). Conversely, terrestrial animals arent that sensitive. The European Union (EU) has affirmed these concerns and established that the herbicide is highly lethal to aquatic life. Roundup in isolation has been discouraged for aquatic use and studies done on the chemical with regard to amphibians have established that the chemical should not be used on amphibians. However, other components found in glyphosate have been established to have a minimal effect on amphibians (even on the sensitive ones) (Alejandra, 2010, p. 2). Though studies have shown that elements of glyphosate attach themselves to soil and become inactive, there is enough scientific research to show that the herbicide has negative effects on the environment (Funke, 2006, p. 13010).
Altrazine has been noted to have serious detrimental effects on rats, hamsters and rabbits. The lethal dose however varies, but doses as little as 750mg/kg if ingested for a long time may cause the death of some animals (Hayes, 2003). Altrazine has also been observed to contaminate ground water which is not only used by plants but by animals and humans as well (Cai, 2003, pp. 272- 275). This has eventually led to its banning in Europe. However, in the US, Altrazine is widely used as a reliable herbicide with large quantities of consumption recorded each year in spite of existent regulations on its applicability. Nonetheless, its extensive use is not only limited to America alone because Altrazine has been termed the most widely used herbicide globally with a record use in more than eighty countries (Ralebitso, 2002, p. 11).
Its however noteworthy to realize that its use in the US has not been free from controversies. Scientists have attributed low sperm counts in men, endocrine disruptor, carcinogenic and epidemiological effects to the use of the herbicide (these reasons are the cause for its banning in Europe) (Mizota, 2006, p. 362). Its use is also deeply contested because some quarters have noted that even within the legal concentrations of the herbicide; it can potentially cause birth defects, menstrual problems and consequently lead to the birth of underweight children (Hayes, 2004, p. 1138). Moreover, recent findings released in 2010 have affirmed that even legal concentrations of the herbicides may have potential, far reaching effects on the health of human beings. This has consequently prompted further studies on the effects of the herbicide with regards to its safety standards. These developments are still witnessed despite assurances from researchers that the herbicide does not have any health implications for American infants, children or any other age group. The assurances were made in 2006.In addition, in 2007; researchers affirmed that amphibians are not affected through genodal development (allegedly worsened by the use of the herbicide). However, there have been studies which have further investigated the effects of the herbicide on amphibians.
Effects on Amphibians
Studies have affirmed that even small doses of Altrazine have a teratogen effect on amphibians because they make them less masculine with a 75% proof that it has the potential of making male amphibians sterile (University of California, 2010). These studies have been done on frogs. In the same regard, the herbicide has been known to be an estrogen disruptor with interesting findings of its ability to turn male frogs into females. The probability of its occurrence is 1 out of 10 (University of California, 2010).
In close relation, research studies done in 2002 identified that the herbicide can potentially change the gender of frogs or make them posses both male and female sexual characteristics. Interestingly subsequent studies done by Syngeta failed to verify these conclusions. Controversy has therefore surfaced with claims that Syngeta produces the chemical (Altrazine) and therefore the counter studies done were bound to be doctored by the company; or there was a possibility the experiments were not done in ideal conditions (University of California, 2010). However, the United States Environmental Protection Agency have undertaken impartial research and arrived at the conclusion that there is no sufficient evidence to support either of the claims.
Other independent studies affirmed that the herbicide had potential capability of turning male frogs into females when exposed to the herbicide for a long time. However, when frog larvae were exposed to concentration levels of 0.01 to 100 microg/l of the herbicide, no effect was observed (University of California, 2010). Larval development and sexual differentiation was also noted to be dismally affected by the herbicide. However, these conclusions have further spurred a flurry of other experiments to determine the role the herbicide plays on the decline associated with larval development. Consequently, some Japan researchers in 2008 undertook the same studies and identified that there were no hermaphrodite frogs, no increase in aromatase and consequently no evidence of frog feminization after exposure to the herbicide (University of California, 2010).
These studies were further followed by research done by the US Environmental protection agency which established that the herbicide does not affect the gonadal development of amphibians after careful field and laboratory studies done with the consideration of research material published in many scientific journals in the past (which suggested otherwise). The institutions website further went ahead to note that there was no need for any additional experiments on the matter.
Predictably, more studies were done which advanced the opinion that tadpoles developed acute cardiovascular problems and impaired kidneys in their first years of existence, after being exposed to the herbicide (University of California, 2010). The studies further established that most of these effects further led to tissue malformation which was directly linked to cell death through ectopic means. However, the mechanism to which these observations were based wasnt established. Complimentary research studies have identified that if Altrazine is combined with other herbicides such as mesotrione, the potential effects were surprisingly positive because it was noted to increase plant yields and more especially that of the corn. The study especially identified that the herbicide mixture improved the carotenoid biosynthetic pathway of the plant to produce a . With regard to the quality of human life, the herbicide was observed to exhibit high quantities of lutein and zeaxanthin which is beneficial in the suppression of symptoms related to ageing eye complications which affect more than a million citizens in America alone.
The positive effects of the herbicide and more especially its safety have been affirmed by the Australian Pesticide and Veterinary authority. The institution further established that the herbicide has a very limited possibility of having any adverse effects on frogs. The same findings have been resonated by the American equivalent of the institution, American Environmental Protection Authority. The Australian authorities have also rubbished previous reports claiming that the herbicide has a potential effect of changing the gender of frogs by identifying that their findings were not based on a which is required for the affirmation of such like claims. Contention therefore exists on the use of the chemicals especially in light of the fact that Altrazine has a potential bad effect on fish.
Though Chlorpyrifos is widely used in many households and agricultural farms, its safety has been a huge matter of concern. At one time (since its inception in 1965), the insecticide was widely used in most US households for home and garden use (National Pesticide Information Centre, 2009). United States environmental agency however raised some safety concerns in relation to increased adoption, forcing its ban in household use and other places where children were exposed to it. In the same way, its use on crops was highly regulated. These effects took place as recent as 2001.
However, Chlorpyrifos is still widely used for agricultural purposes and is still being marketed as a home product out of America (in third world countries) (National Pesticide Information Centre, 2009). In Iran for example, Chlorpyrifos has been given a clean bill of health for domestic and agricultural use. Authorities have also not detected any safety concerns with regard to human life and pest control.
However, generally speaking, Chlorpyrifos has severe detrimental effects (though the extent is still widely in dispute). In 1995 for example, the company that manufactures the insecticide failed to produce reports detailing cases of poisoning (caused by the insecticide). In 2003, the company also agreed to pay damages of up to two million shillings to the state of New York for advertising the product as safe for domestic and agricultural use (National Pesticide Information Centre, 2009). Evidently, this assumption was untrue. Its use has also been widely discouraged in some other countries like India where the company manufacturing the product had to bribe Indian officials to allow its sale in the country (National Pesticide Information Centre, 2009). This incident was noted in 2007. In the same regard, the National Maritime Fisheries authority has imposed a ban in the use of the insecticide at least within a 1000 feet buffer zone around water that supports aquatic life to protect the Salmon and Steal head species (National Pesticide Information Centre, 2009). Aerial application of the insecticides around the prohibited zones is also banned.
Implications on Health
Scientists have observed that the mode of action in which Chlorpyrifos acts for target organisms and non target organisms is the same. More especially, the human have been noted to be highly affected by the components of the chemical (National Pesticide Information Centre, 2009). ChE levels have therefore been affected at different levels throughout the human mammalian system. Not only is the insecticide bound to cause ChE inhibition in the red blood cells, recent research studies have shown that the brain and plasma is equally affected by the insecticide (Jack, 2002, p. 181). However, it takes higher levels of the insecticide concentration to affect the brain (Gupta, 2006, p. 296).
Humans have therefore been observed over the years to be more susceptible to the effects of Chlorpyrifos more than other animals with specific studies done on dogs and rats. These conclusions were based on dermal exposure, poor eyesight and plasma red blood cell inhibition (National Pesticide Information Centre, 2009). There was however significant differences of its effects on dogs, rats and humans which was attributed to the fact that rats contain higher levels of acetylcholinesterase while humans and dogs contained higher levels of Butyrylcholinesterase which increased the sensitivity of the red blood cells to the chemicals and ChE inhibitors found in the insecticide (National Pesticide Information Centre, 2009).
Research has also affirmed that neonates and children are more susceptible to the effects of Chlorpyrifos with regard to ChE inhibitions because they have been noted to be adversely affected, even below levels thought to be out of ChE inhibition. In rats, neuronal cell development has been inhibited as well as neurobehavioral effects in young rats. The sensitivity level in young rats is noted to be at least nine times more than older rats (National Pesticide Information Centre, 2009). Female rats have also been known to exhibit the same level of sensitivity but with regard to bulls and cows; bulls are more sensitive (National Pesticide Information Centre, 2009).
Chlorpyrifos has been observed over the years to disrupt the endocrine system from its neurotoxin nature; eventually causing its victims to develop asthma complications (National Pesticide Information Centre, 2009). Acute levels of toxicity also lead to reproductive deformities as well as developmental complications which often occur during pregnancy. According to the American Environmental Protection Agency, Chlorpyrifos is ranked number 2 on a scale of 1-4 of increasing toxicity National Pesticide Information Centre, 2009). The insecticide is therefore moderately toxic.