Pesticides are used all over the world to manage agricultural pests and weed. They are believed to repel and kill unwanted pests but are also the reason for many human deaths. Pesticides include herbicides, insecticide, sanitizer, insect growth regulator, nematicide, mollucide, avicide, insect repellant, animal repellant and so on. Herbicide accounts for almost 80% of all pesticide use. Generally, pesticide is a chemical or biological agent that kills, deters, incapacitates or discourage pests. It is believed to target pests that include insects, plant pathogens, mollusks, weed, nematodes and microbes that destroy the plants and causes wide spread nuisance or diseases. Being a chemical compound, pesticides can be harmful for human beings.
Types of Pesticides:
They are grouped into categories depending on the type of pests they kill.
1. Insecticides- They kill insects.
2. Herbicides- They kill unwanted herbs or weeds.
3. Rodenticides- They kill rodents.
4. Bactericides- They kill harmful bacteria.
5. Fungicides- They kill unwanted fungi.
6. Larvicides- They kill larvae.
Pesticides can be both biodegradable and non-biodegradable or persistent. The biodegradable ones are broken down into harmless compounds by microbes. The non-biodegradable or the persistent ones takes months and often years to break down.
Advantages of Pesticides:
The advantages of pesticides are:
• Increase in food production: There has been a considerable increase in food production due to the use of pesticides. It is because a large number of crops are not damaged due to various pest attacks. By producing more crops, farmers have more products to sell.
• Labor Costs: Pesticides also help the farmers to make more money on labor costs. It is because they would not have to physically remove the pests and unwanted weeds. Thus, reducing time spent on the field and physical labor.
• Human Health: Apart from saving crops and livestock, pesticides have proven to be beneficial for human health. In the year 1945, it was estimated that the use of pesticides has prevented deaths of over seven million people all across the world by killing pests that either carry or transmit various kind of diseases. Malaria, one of the commonly known and deadly diseases, has decreases due to the use of pesticides. It does not let the female anopheles mosquito breed. Other diseases that showed a considerable amount of decrease include the bubonic plague which was carried by rat fleas and typhus which is carried by body lice and fleas.
• Protection of public property: Chemical pesticides are used to protect the parks, the gardens and the lakes from various pesticides. There are various Aflatoxins in these areas. Aflatoxin, a carcinogen, can cause liver cancer in humans. Thus, pesticides is very necessary to control and prevent its passage from the insect to the plants.
Disadvantages of Pesticides:
The various disadvantages of pesticides are:
• Human health: The chemicals used in pesticides increases the productivity of the crops but they are believed to affect human health and safety. It can cause various types of cancer in the human beings which include leukemia or blood cancer, brain cancer, breast cancer, ovarian cancer, prostate cancer, liver cancer and testicular cancer. The farmers’ children are twice as likely to develop throat cancer versus those children who live in residences where pesticides are not used.
• Bioaccumulation and biomagnifications: Bioaccumulation is when a substance builds up in our body when there is no proper way to remove it. Many synthetic or non-biodegradable pesticides enter in our body and are permanently stored in our body tissue as there is no proper way to break these compounds down.
Biological magnification or bio-magnification is the term used to describe the increase in the concentration of pesticides or other harmful chemicals in every level of the food chain. DDT is a very famous example of biomagnifications.
The pesticides that are accumulated in our body can cause us harm or it may be passed on to a predator. The concentration of pesticide in the body of an individual will increase with the increase in consumption of pesticide infected items.
• Disruption in the balance of the ecosystem: When a pesticide is used, it kills both pests and non-pest germs. This can drastically change the ecosystem by changing it in the favor of the pests. Exposure to pesticides has also caused the death of around 20,000 to 40,000 people worldwide.
There is no permanent solution to this problem. It is advised by the scientists to use biodegradable pesticides in small amounts and to avoid non-biodegradable or persistent pesticides.