It is extremely hard to imagine the modern agriculture without the pesticides but nonetheless using pesticides is very bad for our environment. This is mostly because it is practically impossible to limit the area on which pesticides have effect as 98% of sprayed insecticides and 95% of herbicides reach a destination other than just targeted pests. This destination does not only include different animal and plant species but also water and air often resulting in huge pesticide contamination.
Pesticides can easily become a main source of air and water pollution. The droplets of sprayed pesticides can travel a long distances carried by the wind, spreading air pollution through many areas. Water pollution is even bigger issue, for instance in United States pesticides were found to pollute every stream in the country. In many cases the concentration of pesticides in the water exceeded those allowable for drinking water in taken samples of river water and groundwater.
The pesticides also create a soil pollution because the large number of chemicals used in pesticides belong to the category of persistent soil contaminants whose negative impact on soil may last for couple of decades. More chemicals used means bigger degradation of soil quality.
Some scientists even believe that the use of pesticides is one of the biggest reasons behind the huge loss of bees around the globe. According to one of the latest studies the use of pesticides has eliminated about a fifth of honeybee colonies in the United States, and created damage for additional 15%. Bees are not the only animals affected by pesticides as they also have extremely negative impact on bird population such as bald eagles and chaffinches.
The pesticides can also have serious negative impact on human health. Once pesticides enter human body they can be quite harmful depending on the toxicity of the chemical and the length and magnitude of exposure to pesticides. The pesticides can cause not only cause skin irritation, blood and nerve disorders but also more serious health issues such as tumors.
The scientists still haven't fully assessed the environmental risk of pesticide use mostly because their current experiments have been done in experimental conditions which differ considerably from real-world conditions.
Many farmers believe that using pesticides is the only way to get rid of the pests but this is not true. Pests can be also eliminated by removing pest breeding sites, by keeping healthy soil which breed healthy plants that are resistant to pests, by planting native species that are naturally more resistant to native pests, and by using different pest eating organisms such as birds or even by manually removing weeds and pests from plants.