Pesticides and Cancer: Is there a link?
癌症代写 Research Question: Among children exposed to indoor or outdoor residential pesticides, what is the risk of developing childhood cancer?
癌症代写The last few decades, many environmental concerns have aroused divergent debates and multi-activism of the public…
The last few decades, many environmental concerns have aroused divergent debates and multi-activism of the public as much as pesticides, the main concern being the health of children. There are overlying deep controversies surrounding the issue of pesticides and the impact on human health, regardless of many publications of studies on the subject. This assessment paper will elucidate how the pesticide use has contributed immensely to the rates of cancer in children. It will also draw a true environmental health and risk assessment of the pesticides.
Looking back at the history of pesticide development and use will help us understand the controversies surrounding the environmental concerns of pesticides. Pesticides gained prominence use in World War II during warfare. In fact, those they were not referred to as pesticides but rather chemicals weapons because their sole purpose was used during the war.
Some pesticides used today were developed those days.
For instance, the organophosphate insecticides were developed as nerve gases, and the phenoxy herbicides were developed to eliminate Japanese rice crops and later applied to defoliate large areas in jungle warfare. The chemicals were later used by farmers in agricultural production, mosquito eradication, and backyard gardens.
In the late 1960s and early 1970s, the epidemiologists noted a rise in the incidences of non-Hodgkin’s lymphoma (NHL). (1) The incidences were more concentrated around agricultural areas. (2) The increase in the use of pesticides in agricultural areas paralleled with the NHL incidences. This prompted multi-agency interests into the study of the trend where they theorized the existence of a causal relationship between chemicals uses in the farms with NHL disease. Many scientific theories and works of literature developed around the world trying to explain the relationship between pesticide use and environmental health risk factors.
Literature review 癌症代写
Today, the main concerns about the use of the pesticide are the children and the unborn. A survey conducted by 20th Australian Total Diet Survey found residues of pesticide chemicals in infant foods, which it was regarded as insignificant because it was very low.
Considering the body size of children, they face the greatest biocide exposure. According to the 20th Australian Total Diet Survey, “in general, the dietary exposure to pesticides was highest for the toddler age group. This is due to the high food consumption relative to body weight.” (3)
A the University of Wisconsin-Madison, researchers established that children and developing fetus are affected by the amounts of agricultural chemicals found in foods regardless of the levels considered safe by the authorities. The study found that there were diminishing learning ability and aggression in children and newborn due to the influence of the low dosage mixture on developing neurological, endocrine and immune systems.
An independent research was conducted on the exposures, where it was established that exposure of fetus and juveniles to amounts more than 1000 times lower than previously regarded as safe caused serious developmental problems. (4, 5)
At the Dukes University Medical Center, (6)
and the Department of Pharmacology and Cancer Biology, explained how the far lower than currently permitted quantities of agricultural chemicals by most regulatory agencies around the world, affect the developing fetus and the newborn. They established that due to the lower concentration of protective serum proteins in the fetus than adults, the fetus and the newborns are more vulnerable to chemical effects. (6) As results of exposure to those chemicals, the fetus and newborns have developmental neurotoxicity which damages the developing nervous system. (7)
A study conducted to analyze incidences in the US found that cancer incidences were high in1992-2001 for children below 15 years. It was also noted that a county with agricultural activities has elevated cancer incidences of malignant bone tumors. These areas were also linked to a higher number of Ewing’s sarcoma and HL incidences. (2) Pesticides代写
在1960年代末和1970年代初，流行病学家注意到非霍奇金淋巴瘤（NHL）的发病率有所上升。 （1）发病率更多地集中在农业地区。 （2）与非霍奇金淋巴瘤发病率同时出现的是在农业地区使用杀虫剂的增加。这促使多机构的利益共同参与了对趋势的研究，在理论上他们对NHL疾病农场中化学品使用之间存在因果关系进行了理论分析。世界各地开发了许多科学理论和文献，试图解释农药使用与环境健康危险因素之间的关系。
如今，有关农药使用的主要问题是儿童和未出生的婴儿。澳大利亚第20次全面饮食调查（Total Diet Survey）进行的一项调查发现，婴儿食品中的农药残留物被认为是微不足道的，因为其含量非常低。
在杜克斯大学医学中心（6）以及药理学和癌症生物学系，解释了世界上大多数监管机构所使用的农药远远低于目前允许的数量如何对发育中的胎儿和新生儿产生了怎样的影响。他们确定，由于胎儿中保护性血清蛋白的浓度低于成人，因此胎儿和新生儿更容易受到化学作用的影响。 （6）由于暴露于这些化学物质，胎儿和新生儿具有发育性神经毒性，会损害发育中的神经系统。 （7）
Research has established a link between pregnant mother exposure to pesticides and the elevated risk of childhood brain tumors (CBT). A case study was conducted in Australia to investigate the link between the pregnant mother exposure and development of CBT. The odds ratio (ORs) for professional pest control treatments at homes in the period before pregnancy, during pregnancy, and after the child’s birth were 1.54 and 1.04. The odds ratio for treatments exclusively before pregnancy and during pregnancy were 1.90 and 1.02. The OR was found to be 1.79 if the father was at home during treatment.
The OR of 1.36 was observed as a result of parental occupational exposure.
The prenatal home pesticides exposure elevated the low and high-grade gliomas. The findings concluded that preconception and during pregnancy exposure to pesticides was associated with higher rates of children CBT. (8)
Retinoblastoma risk factors remain largely unknown. A researcher studied the relationships that exist between the parental occupational exposures for 10 years and one year before the conception and the development of children sporadic bilateral retinoblastoma. From 198 incidents of bilateral retinoblastoma, parental data on occupation were obtained from 1998 to 2006. The findings were that there exist correlations between parental pesticides exposure 10years before conception and one year to conception. The cases for childhood sporadic bilateral retinoblastoma were found to be higher in those of prior parental exposure. (9)
The Rationale for the risk assessment of pesticides 癌症代写
The environmental risk assessments of pesticides are well documented in the literature, mainly the organophosphate poisoning. However, the assessment of pesticide exposure and the chronic effect thereof is more difficult. A lot of researchers have tried to explain whether chronic exposure to pesticides has adverse effects. Over time the reviews of pesticides health effects have prompted lobby groups and activists to action. These groups have complained of the adverse effects of the considered safe levels of chemicals and the continued use of pesticides regardless of the impacts to the human health and other environmental impacts.
Conducting the risk assessment as part of protecting the human health is at the heart of this paper. The market evaluation of the pesticides products is vested in the environmental protection agencies. These evaluations are based on the specific standards for registration and studies required by the legislation. Risk assessment is important in identifying potential hazards posed by the active ingredients, the dosage levels of the pesticides exposure, and data evaluation of potential risks of agricultural activities.
This risk assessment paper will also establish the relationship between the exposures to environmental hazards to the health of the people. In this regard, the focus will be on the link between pesticides emission to the environment and the increasing number of cancer incidences among children.
Most studies on non-Hodgkin lymphoma and leukemia have established a relationship with agricultural chemicals. The studies have shown the dosage-response to the pesticides exposure and how specific pesticides have resulted in developmental and health issues to children and unborn. The development of cancers to children has been strongly linked to the pregnant mothers (1) and children exposed to pesticides (10). The studies have also established a link between pesticide exposure and solid tumors, (10) and brain cancer. (11) Parent’s pesticides exposure at work was linked to children kidney cancer.
In the industrialized countries 1 child out of 500 has cancer before attaining the age of 15 years. In European countries, childhood cancer cases have increased to 1%. (12) The consistency in the association is high in prolonged exposure. There are specific weaknesses and inherent limitations in epidemiology studies around especially around ascertaining whether and how much exposure had taken place.
Children’s Vulnerability 癌症代写
Because of children developmental, physiologic, and dietary factors, they are exceptionally vulnerable to uptake and effects of pesticides. The studies have shown that childhood exposure comes from ingestion, dermal contacts, and inhalations. The greater intake of food and fluids per their body size has contributed to higher dose through ingestion compared to adults. Children hand-to-mouth activities are also higher compared to adults, therefore increasing pesticides exposure. (13)
There are few cases of acute toxicity as a result of pesticide poisoning but sub-acute and chronic low-level exposures are common. The vulnerability is contributed to the use of insecticides and rodenticides in households. Also, exposure can come from insecticides and fungicides in home gardens. The use of indoor spray applications leave particles in the air and floors and also form part of the house specks dusts. (14) When children play around the house, they come into contact with specks of dust through inhalation, dermal and oral which increase their chances of exposure to the chemicals.
Continuous exposure happens and cumulatively has adverse effects on the children. Pesticides can also be brought home from the workplace, for instance, herbicides applied in home gardens can be traced in-house over time of build-up. (15) These traces are brought by pets and shoes from the farm fields. (14)
The residential related exposures are also found in the schools, child care centers, etc. This depends on the proximity of these areas to where pesticides are used. The traces of pesticides from public areas can be traced in households over time after accumulation. (16)
Bio-monitoring data for exposure assessment
A population-based bio-monitoring program was conducted by the Centers for Disease Control and Prevention (CDC) associated with the NHANES. The program report on the OP, organochlorine, and carbamate insecticides; pyrethroid insecticides; herbicides etc. Test on the pesticides metabolites has revealed traces of pesticides in the system of people aged 6 to 59 years with OP and organochlorine insecticides being the most prevalent.
Children behaviors and metabolic rates position them at higher risk of absorption of pesticides compared to adults. From the bio-monitoring data, chlorpyrifos was one of the chemical evidence in the samples of young children which was higher than for young adults and adults. Others like DDT, dieldrin, and chlordane show lower concentration in the same population. However, the accumulations of these fat-soluble persist over the lifetime.
Exposure from the food supply 癌症代写
Food supply represents the main source of exposures to organochlorines and OPs. (17) Food residues and household pest control products sources of pyrethroids. Food and Drug Administration ensure adherence to standards of the legal and allowable pesticides residues. To lower exposure to farm chemicals, people are encouraged to consume organic foods. The study has established a drop in the urinary excretion of metabolites insecticides in the period of organic food consumption. (18)
Agriculturally related exposures
Residential near agricultural farms or a family member working in such a farm present chances of pesticides residuals in the house which increase exposure to the children. A study was conducted to establish the level of exposure in children near agricultural areas. It was found that pesticides on carpets dust and pesticides metabolites in urine of children increased with nearness to farm areas especially during periods of applications, (19) and. (20)The presence of farm workers in those farms increase the level of dust particles in homes thus higher exposure to children. Also, children living in those farms have higher chances of exposure to pesticides as the study has proven with pesticides metabolites in their urine. (21)
连续暴露会发生，并累积对儿童产生不利影响。农药也可以从工作场所带回家，例如，在家庭花园中使用的除草剂可以随着时间的推移在室内进行追溯。 （15）这些痕迹是由农场里的宠物和鞋子带走的。 （14）
食物供应是接触有机氯和OPs的主要来源。 （17）拟除虫菊酯的食物残渣和家庭害虫防治产品来源。美国食品药品监督管理局确保遵守合法和允许的农药残留标准。为了减少对农用化学品的接触，鼓励人们食用有机食品。该研究确定了在食用有机食品期间，代谢物杀虫剂的尿排泄量有所下降。 （18）
在农业农场附近居住的居民或在这样的农场工作的家庭成员，房屋中残留农药的机会增加了对儿童的接触。进行了一项研究来确定农业地区附近儿童的接触水平。研究发现，地毯上的农药和儿童尿液中的农药代谢产物随着靠近农田的增加而增加，特别是在施用期间（19）。 （20）那些农场中的农场工人的存在增加了房屋中灰尘颗粒的含量，从而增加了对儿童的暴露。而且，由于该研究证明尿液中的农药代谢物，居住在这些农场中的儿童有较高的机会接触农药。 （21）
Exposer form drinking water
Water contaminated with herbicides is another agent of children exposure. The US Geological Survey’s National Water-Quality Assessment program conducted a study that took 10 years, provided occurrence of pesticides in streams and groundwater. The traces were detected in more than 50% of shallow wells tapping water from agricultural farms and 33% deeper wells tapping water from aquifers. Herbicides, especially triazine class were the most frequent traces in agricultural areas, while diazinon and carbaryl were frequently detected in urban areas. (22)
Risk communication 癌症代写
The public and other stakeholders need to be made aware of the health risks associated with pesticide use. Despite many publications of the environmental pollution of many agricultural chemicals and banning their use especially in foods, some of these chemical ingredients are still in use in most modern pesticides. This has elicited continuous debates on the environmental impacts and health effects of these pesticides.
Today, communication has been mostly influenced by the emergence of digital media which has allowed easy information sharing through social media to the global audience. Communicating environmental health and risk issues also need to adopt an online strategy in risk communication so as to reach more people and diverse population. More than 2 billion online users are the target for this information. The method also elicit debate on the topic will help shed more light on the environmental health issues and insights are able to give experiences in the environmental health risk factors learning the process. 癌症代写
Communication of how pesticides have contributed exponentially to the increase in cancer incidences will be of help to the agricultural farms, workers, and children caretakers. They will be able to look for alternative pest control methods such as practicing organic farming which has proven to be more effective in reducing pesticides exposure to children. At homes, parents must have a way to protect their children and unborn from pesticides exposures. To reduce exposures, pregnant mothers have to avoid environments which make her vulnerable to pesticide chemical.
From this environmental risk assessment, we can conclude that pesticide use poses higher risks to children than adults which results in developmental and malignant diseases. The higher exposure rate is attributed to their small body size, high rate of metabolism and being active both indoors and outdoors. These make them vulnerable to chronic pesticide exposures.
The studies have also established that, regardless of the levels of the pesticides residuals to the acceptable levels, cumulatively, they have developmental effects to children and newborn. Environmental pollution from the use of pesticides has more effects than benefits to the human and animals. Thus, strict control measures are necessary to regulate their use or ban. Alternative pesticides and herbicides controls need to be explored, and in this case, use of organic farming practices should be encouraged to reduce the environmental risks posed by pesticides.
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