Agricultural pesticides are an integral part of most agricultural systems, and they continuously play a vital role in meeting the challenge of feeding the world’s rising population. Annually 2 million tonnes of pesticides are used worldwide. Pesticides are beneficial to crops, but they have a major negative effect on the climate. The threats of agricultural pesticides to public health have gotten more coverage in both developing and developed countries.
Excessive pesticide use can destroy biodiversity. The survival of many birds, marine species, and livestock is threatened by toxic pesticides. Various pesticides have poisoned the air, water, soil, and overall environment, posing a significant health risk to living beings. In modern agriculture use of pesticides is a must, but proper and efficient use has to be done. To save current and future generations, ecology; judicious use of chemicals is recommended.
Introduction to Pesticides
A substance or mixture of substances used or represented as a means for preventing, destroying, repelling, mitigating or controlling directly or indirectly any insect, fungus, bacteria, nematode, virus, weed, rodent or other plant or animal pest, but does not include a substance which is a drug within the meaning of Drug Act of Pakistan 1940. Pesticides can be used for a variety of purposes all over the world without understanding the consequences. They have been used to protect crops since before the year 2000 BC.
Pesticides of various types have been used to protect crops for decades. Synthetic insecticides, such as organophosphate, carbamates, and pyrethroids, as well as herbicides and fungicides, greatly aided pest control and agricultural production. They are proved to be very helpful for controlling pests and increasing production. Almost 20-40% of agricultural products can be lost every year just because of insects, diseases and weeds which is a major threat to the increasing population.
Pesticides have the potential to contaminate soil, water, turf, and other plant life. Pesticides can be harmful to a variety of species, including birds, fish, beneficial insects, and non-target plants, in addition to killing insects and weeds. The book “Silent Spring” written by Rachel Carson in 1962 also indicates the harmfulness of pesticides. Insecticides are the most acutely toxic form of pesticide, herbicides may also damage non-target species. Human health and environmental issues increase day by day.
Types of Pesticides Use in Agriculture
- Insecticides (used to kill insects)
- Herbicides (used to kill weeds)
- Rodenticides (to kill rodents)
- Bactericides (to kill bacteria)
- Fungicides (to kill fungus)
Effect of Pesticides
Pesticides are used for crop protection-the primary goal of using pesticides. The crop can also be protected by mechanical, physical, biological and cultural methods, but these methods are slow as compared to pesticides which are quick in their action. Pesticides have more damaging effects as compared to valuable effects.
Beneficial effects of Pesticides
- Farmers can save money by using pesticides to avoid crop losses due to insects and other pests.
- By protecting crops from pests, they help farmers grow more food on less land.
- Improved crop yields
Harmful effects of Pesticides
Everyone in the world can take exposed to pesticides, whether are farmers, pesticide workers, rural or urban residents, birds, or animals. Pesticides have a lot of harmful effects which are described below.
- Residual effects of pesticides in soil enter the food chain and cause biomagnification.
- Pesticides not only kill target pests but also non-target pests.
- The persistence of pesticides is also a major reason.
- Related to humans, acute and chronic effects are listed.
- Pesticide application can reduce the quality of drinking water.
Pesticides’ Effect on Soil
Pesticide treatment of soil can lead to a decline in beneficial soil microorganism populations. “If all microorganisms and fungi vanish, the soil deteriorates,” according to Dr Elaine Ingham a soil scientist Pesticides are hydrophobic, persistent and bio-accumulable that are strongly bound to the soil. The organochlorine DDT, endosulfan, endrin, and heptachlor are examples of pesticides that exploit this modesty. Glyphosate inhibits the growth and activity of soil bacteria that fix nitrogen.
Overall, Long-term pesticide use can interrupt nutrient cycle metabolic pathways.
Pesticides’ Effect on Humans
Pesticide exposure can have a wide range of negative health effects, from basic skin and eye irritation to more serious effects including affecting the nervous system, reproductive issues, and even cancer. About 1 million deaths occur from pesticide poisoning all around the world every year. The diseases caused by exposure to pesticides are Carcinogenicity, Oncogenicity, Mutagenicity, Teratogenicity, Neurotoxicity, and Reproductive disorders respectively. Pesticide residues on fruits and vegetables cause serious health issues.
Effect on the Environment
The use of pesticides poses a host of environmental issues. More than 98% sprayed insecticide and 95% herbicide can disperse in the environment, involving non-target species, soil, air and water. Each pesticide or pesticide class is associated with a specific set of environmental issues. Many pesticides have been banned as a result of their negative effects.
Effect on Water
Via runoff from treated plants, pesticides may enter surface water. Pesticides contain sulfur, chlorine, nitrogen, phosphorus, bromine and heavy metals. These harmful chemicals contaminate groundwater, and by this, the aquatic flora and fauna are unable to breathe. They have also caused a serious threat to the biological integrity of marine and aquatic ecosystems. It can take years for the impurity to be cleaned up.
Effect on Beneficial Insects
Beneficial insects like honeybees, butterflies and many other types of predators and pollinators can be affected badly by exposure to pesticides. Their population will decrease with time.
Pesticides have proven to be a blessing to farmers and people all over the world by rising agricultural yield and offering various indirect benefits to society. However, the risks that pesticides pose to human health and the environment have put into question their effectiveness. Although we cannot eliminate the use of pesticides, we can minimize their usage by other methods, we have to keep check and balance while using pesticides.
The increasing use of pesticides creates a greater threat to the environment and human health. There is a need to manage all these circumstances by producing maximum without diminishing natural resources. Alternative cropping methods, IPM, use of biopesticides, biocontrol agents, and cultural, mechanical, and physical methods will use as an alternative instead of pesticides.