The intensive use of pesticides and insecticides, mainly in agriculture, has resulted in dispersal and persistence of pollutants and residuals not only in our food but in the environment too. It has put our eco-system at stake as it has severely and adversely effected the balance naturally held by the eco-system of the planet. Pesticides, which were developed and used to increase the production of food to meet the ever increasing demand for food for alarmingly increasing population of world, have now proven to be a menace in disguise. Pesticides have polluted the water we drink, food we eat, air we breathe, and environment we live in.
　　Ecology is "the state of living" in harmony with nature and guarantees the continued existence of our species along with all the others on the planet. It has been threatened. Many aspects have played key roles in the degradation of our environment, climate and habitats which collectively form the eco-system of different parts of world and collectively as a whole ecological system of the planet Earth. Pesticides are one of those human induced interferences with the nature whose excessive use has created an imbalance which threatens ecological balance and our harmonious existence in peace with the nature.
　　Pesticides, as bio-historians claim, have been in use far before the industrial revolution since more than a century and a half ago. But, of course, their use was not as huge, planned and systematic, as it has got since 1950s. As we all know, pesticides are mostly used in agriculture both on soil and on water where agricultural food products are produced in aqua-culture and also on fertile terrains. Insecticides, on the other hand, are used both in agriculture and domestically at home to kill unwanted species of animals like ants, lizards, and cockroaches etcetera and governments have also not only supported the use of such chemicals but have actually initiated programs for urban areas for fumigation and spray to get rid of unwanted creatures mentioned above. You might remember the spray and fumigation teams to fumigate your house and spray those insecticides to kill lizards, ants, cockroaches, bugs and worms.
　　The reporter has personal experience about the initial relationship with pesticides and insecticides. When the reporter was a kid, spraying teams used to visit every now and then and spray on walls and every nook and corner of the house. Being a kid then, the reporter was never able to understand the purpose apart from being heard that this was good and kills all those ants, worms and bugs which used to disturb my sleep. People were not permitted to enter our rooms for a couple hours or so whenever the teams visited and sprayed the chemicals, which the reporter now understand, those sprayed chemicals were poisonous and it was not good to breathe in toxic air inside the rooms. The reporter later saw some pesticides used and sprayed on the crops. This spraying was good for the crops and would increase the yield per acre. Researches have proved that residues from pesticides can even affect the food, water sources, environment, and creatures on which those were not directly used. Researches and scholarship on the topic agree that data on pesticides effects remains scattered and one of the biggest challenges is to link results from those widely scattered cellular studies to many levels of increasing complexity and to eco-systems. 　　As science advanced, we have come to know the hazards such chemicals can cause to our bodies, food, economies, environment, and eco-systems. Historically, arrival of human being in certain area brings a human impact or footprint to the ecological order of the eco-system there. Patches of land are cleared in order to cultivate more favorable food producing cultivable plants instead of wild plants of the area desire to introduce those cultivars causes a larger scale impacts such as reducing biodiversity by reducing food availability for the native species. Use of pesticides and chemicals in order to get more yields in already disturbed ecological equilibrium of such area causes to increase that footprint by manifolds. You might have heard the names like DDT, DDE, Triazine, Organophosphates, Carbamate, Nicotinoid, etc., all of these pesticides widely used once and some of those now banned in most of the countries around the world have proven health and environmental dangerous impacts which were either overlooked or not known in the beginning. Each pesticide or class of pesticides comes with certain unwanted side effects and environmental concerns which affect our environment adversely it has caused abandoning and banning of many of such pesticides by governments. Some developed countries like United States, United Kingdom, France, Germany, Switzerland, Denmark and many other European Union nations have specific authorities to control and monitor use of such pesticides and prohibited chemicals in their countries. As a result of these efforts and general awareness of the public about hazardous effects of pesticides on their health and environment, the use of pesticides has generally become less persistent and in certain cases has declined by 99% minimizing their environmental and ecological footprint. But in other parts of the world, especially third world or underdeveloped countries, there are no effective mechanisms to control so those prohibited pesticides and chemicals are even used due to lack of implementation of the law and also ignorance of the hazardous impacts of insecticides on crops and environment.
　　Pesticides and air pollution
　　Pesticides contribute to air pollution a lot directly and indirectly. Pesticides and insecticides are sprayed using various methods of spray ranging from manually spraying on crops to the aerial spray on crops and even cities to control mosquitoes and pests. Researches have proven that these pesticides can move to other areas through wind. In hot weather conditions they evaporates and become more volatile and travel not only to other areas causing hazards for the wild life and human population in those areas by contaminating the air they breathe in but also getting into troposphere of Earth's atmosphere causing formation of tropospheric ozone. Scientists have believed that at least 6% of atmospheric tropospheric ozone is caused by the pesticide use and thus it not only adds to the environmental pollution but also health problems of populations on the planet. Air pollution and turning it into unsafe for breathing for living beings in the areas where pesticides are sprayed is one of the demanding problems in countries with huge agricultural base. It also brings health related problems ranging from simple respiratory problems to the extent of lung cancer and heart diseases. 　　Water resources are polluted everywhere and soil quality declines
　　Water pollution is one of the biggest problems around the world due to use of pesticides. Studies have shown that pesticides can travel down streams to the areas where pesticides have never been used and residues can cause problems even in those communities which never experienced use of pesticides. A study by Geological Survey of United States found that 90 % of the wells sampled in the study were polluted by the pesticide residues. They have also been found in rain, stream, and groundwater. Similarly studies in some European countries also showed that levels of pesticides residues exceeded the allowable and safe levels in the drinking waters in most parts of the countries. There are four major ways how pesticides residues can enter the water resources, a) drifting outside the intended area where sprayed, b) leaching through the soil, c) carried to water reservoirs as run off and d) it may be spilled accidentally or due to neglect. Pesticides' solubility with water, distance from water, and weather also influence their ability to pollute water severely or mildly. Developed nations have their environmental protection agencies which decide and set standards for allowable maximum limits for the waters. Although third world's developing countries also have such agencies and institutions but loose and inefficient mechanisms of implementation cause, in most of the cases, to let lose any violators.
　　Water pollution by pesticides carries health and environmental hazards as the infected water is used for variety of purposes from using for agriculture to cleaning and drinking so it causes multidimensional impacts too from health hazards to human population to toxic food production and also affecting any area's ecological balance by affecting certain organisms in an ecosystem which serve as food for many other living beings necessary and important for the food chain of that ecosystem. Water pollution also affects life in rivers and streams by killing or intoxicating the species there which are later used a food by the human beings indirectly affecting them. But that is the only impact it makes, it also causes genetic, physical, and behavioral changes in those organisms causing a threat of extinction or making them easy prey for predators and thus fueling the speed of their extinction from the habitat. One such example has been found in toads where thinning of egg layers has been noted by researchers due to their being exposed to pesticide residues and thus affecting their reproduction cycle and also bringing behavioral change in them by slowing their responses to their predators' attacks and making them easy prey. 　　Many of the chemicals used in pesticides are persistent soil contaminators. Higher use of fertilizers, pesticides, and other chemicals damages biodiversity of the soil and affects soil conservation. Many scientific researches have also proven that no use of chemicals in soil results in better soil quality and fertile lands. Degradation and sorption are two very important factors in determining the quality of soil and also they are very important to help in transportation inside soil. Pesticides particles, depending on their chemical type and nature, affect transportation processes of soil and thus end up adversely affecting the soil quality by hindering the decomposition processes of the soil.
　　Pesticides cause health hazards for humans
　　Hazards caused by pesticides for humans are manifold and numerous. Human beings get exposed to pesticides in many ways. Oral exposure or direct exposure by consuming food, inhaling the air containing pesticide particles, drinking or cleaning with water contaminated with pesticides, and in case of farmers their direct contact while using pesticides exposes humans to pesticides. Aerial fumigation and spraying campaigns by authorities in tropical regions have even exacerbated conflicts among countries and communities. There have been thousands of people infected by such fumigation campaigns including children, pregnant women, elderly and young. As there are many ways to get exposed to pesticides, there are as many ways of getting contaminated by these pesticides, mainly being the health hazards but they also have started causing losses to economy and biodiversity.
　　Estimates from governmental organizations in United States claim that US farmers now lose annually worth of 200 million dollars because of adverse effects of pesticides use. Health hazards caused by the pesticide residues are huge in number and as mentioned range from simple respiratory problems to lung cancer and heart diseases thus also causing the family incomes going into getting the treatments for those unexpected diseases. People in developed societies have started opting for buying foods grown without or less pesticides and there is growing amount of concern among populations across the globe towards the hazards of pesticides.
　　Pesticides cause less produce in crops and eliminate food sources for animals
　　In some parts of the world governments had to come up with biodiversity action plans after their countries were adversely hit by negative impacts of use of pesticides. As pesticides cause food to be toxic especially when they are freshly sprayed or applied on crops and when those plants are consumed by animals in the vicinity, the intake of the poisonous food causes their deaths and elimination from the vicinity they lived in. Another huge and undesired impact of pesticides is non-target populations of organisms where these pesticides are sprayed. As pesticides also kill non-targeted certain kinds of animals and organisms which serve as food base for many other living beings in the eco-system, they eliminate food base for those organisms and thus cause starvation and elimination of both non-target organisms and those dependent on them. Pesticides' residues travel through food chain from lowest level to top and from top to down. Certain residues which might not be harmful for third level organisms in a food chain could be extremely dangerous and harmful for the upper or lower level in the same food chain and as they travel through they disturb food chain balances and eventually cause an allover disturbance of some ecosystems. This explanation of the food chain situation also illustrates that food chains are sensitive and minor disturbances at any level of those food chains can result in catastrophe for the whole food chain and may disturb ecological balance of organism in the vicinity where the disturbance happened. 　　Case with plants is even worse as these pesticides kill unwanted targeted along with non-targeted organisms from the eco-system where they are sprayed or applied, thus, they eliminate those organism which are extremely necessary for plant to bear fruit and reproduce. One example in such case is killing of honey bees and ants which are vital for pollination of plant species and fertility of soil respectively. With the extinction or decline in number of ants and honey bees, pollination process gets slower or at extreme points of time it even stops resulting in loss in grains and plants not being able to bear fruit. Us agencies USDA and USFWS estimate that farmers in US only lose USD200 million annually due to decline in number of pollinator honey bees. Pesticides sprayed on crops when they are in blossom, cause catastrophic and large scale deaths of honey bees and other nectar loving species causing colony collapse disorder and leaving very small number of pollinators to perform the task. On the other hand, pesticides also cause direct adverse impacts on plants growth like poor root hair development, shoot yellowing, and reduced plat growth and so on.
　　Millions of birds are killed globally and fish are deprived of food sources
　　Australian broadcaster ABC reported in March this year that almost 700 native birds were killed due to use a pesticide in New South Wales State in Australia. It further reported that use of the pesticide causing the deaths is common in area and is widely used in the region. Exactly a year ago, in March 2013, an organization called American Bird Conservancy (ABC) published a report on use of one of the widely used insecticides in US and it impacts on birds. The report found the following,
　　"A single corn kernel coated with a neonicotinoid can kill a songbird," Palmer said. "Even a tiny grain of wheat or canola treated with the oldest neonicotinoid -- called imidacloprid -- can fatally poison a bird. And as little as 1/10th of a neonicotinoid-coated corn seed per day during egg-laying season is all that is needed to affect reproduction."
　　US fish and wildlife services department estimates that around 72 million birds are killed every year due to the use of pesticides in United States of America. DDE induced egg shell thinning has caused in sharp decline of bird populations across Europe and North America. Birds play as important role in eco-system as any other specie on ground or underneath water and many of the bird species are facing extinction due the poisons we have fed. 　　Fisheries and aquatic resources (ponds, lakes, rivers, streams, and oceans) are exceptionally valuable natural assets enjoyed by us all and provide countless benefits including commercial, recreational and societal. Pesticides and insecticides are also used on aquatic resources. Pesticides used on soil also arrive to streams and rivers as result of run off and poor management and have been causing damages to the marine life. In extreme cases pesticides have caused killing of whole population of fish in ponds streams and rivers. For a long time, Pesticides have been considered beneficial and are used all over the world but there benefits are now overshadowed by the negative impacts they have caused.
　　Aquatic resources particularly fish are the worst affected by the pesticides. Researches have shown that insecticides prove more lethal to aquatic life as compared to other pesticides and weedicides. Weedicides used to get rid of unwanted weeds for corporate and commercial farming in lakes and seashores but these weedicides, pesticides, and insecticides have proven to be lethal in many ways. They target non-targeted weeds and species and ultimately creating a shortage of weeds and species used by fish as food. In most of the cases shortage of food makes fish travel more to seek food in the sea and thus exposing them to predators and puts them at risk. Then they also contaminate water and fisheries itself resulting in poisonous food products.
　　Overall speaking, one of the challenges faced by pesticides is that the targeted pests develop resistance to pesticides and get no more efficiently wiped out by the use of pesticides while non-target species continue to suffer the brunt of these chemicals. Some of the main drawbacks of using pesticides can be summed up as: threats to biodiversity of eco-systems, deforestation, desertification, erosion of fertile lands, coral reef damages, fresh water contamination, Habitat destruction, Holocene extinction, global warming and climate change exacerbation, land degradation, acidification, and Ozone depletion. All these negative impacts and many others emanating from use of pesticides, worsen already meager and low lingering living standards of most of the poor population across the globe.
　　Alternatives to pesticides are at initial stage of development but possible
　　Recently, people are looking for the alternatives to pesticides. There are organic alternatives being developed by research labs in different parts of the world but such solutions are still on early and experimental stages. Some companies in China have tried introducing organic alternatives and have setup large experimental farms but the procedures for acknowledgment by governments around the world to adapt to such solutions are slow and time taking. But on smaller scale farming methods like manual removal, applying heat, covering weeds with plastic, placing traps and lures, removing pest breeding sites, maintaining healthy soils which breed healthy plants, more resistant plant plantation, cropping native species of the plants that are naturally more resistant to pests and predators, and supporting the bio control agents like native birds and predators are being implemented by farmers. Results from such actions and alternatives adapted by farmers are very encouraging as knowledgeable public is opting to buy food free of pesticide residues which guarantees their health and ultimately not only keeps them healthy but saves a lot of money and trouble from getting treated in hospitals. It can also ensure better food quality free of chemicals and diseases ensuring better health and immunization for common human beings especially for women, children and elderly.
　　Some of the main drawbacks of using pesticides can be summed up as: threats to biodiversity of eco-system, deforestation, desertification, erosion of fertile lands, coral reef damages, fresh water contamination, Habitat destruction, Holocene extinction, global warming and climate change exacerbation, land degradation, acidification, and Ozone depletion. All these negative impacts and many others emanating from use of pesticides, worsen already meager and low lingering living standards of most of the poor population across the globe.