Pesticide Control

Have you ever bought veg that is labelled “organic”? Organic produce is all the craze nowadays, mostly due to the perceived lack of pesticides used in their production (though certain “organic” pesticides can still be used). Despite this, pesticides have their place and play an important role in protecting important crops from pest species and, thus, protecting the agricultural industry from severe losses. However, it's important to ensure that pesticide use poses no harm to humans, animals, or the environment.

Ready to learn more about pesticide control? Take a look at this article!

Pesticide Control: Meaning and Importance

Before we discuss and define pesticide control, we need to briefly review what pesticides are.

Pesticides come in a wide variety of forms, which we'll explore in detail.

Classifying Pesticides

Pesticides can be classified according to their target:

Or by their chemical makeup, eg.:

• Organophosphates
• Carbamates
• Organochlorides
• Pyrethoids
• Arsenicals
• Sulfonylurea herbicides
• Biopesticides

Or by their elemental composition:

Pesticides can be chemicals or even living agents.

Figure 1: A plane dusts a crop with pesticides. Source: Wiki Commons, Public Domain

Benefits of Pesticides

Let's recap the positives of pesticides.

• Increased crop yields due to protection from diseases and parasites, enhancing food security

• Reduced food waste, as less food is spoiled or destroyed

• Decreased incidence of diseases, thus conserving health and saving the lives of millions of humans and domestic animals

Drawbacks of Pesticides

While pesticides bring many benefits to humans (especially controlling populations of pests organisms), most also come with notable drawbacks. Pesticides can be potentially harmful to human health – even being associated with the development of certain cancers, such as non-Hodgkin lymphoma and leukaemia. Animals can also be negatively affected by pesticides, often experiencing poisoning. For these reasons, it's important to control pesticide use.

Pesticide control involves the regulation of pesticides in order to ensure their safe and responsible use. There are many different ways in which pesticides are controlled, depending on the country and the pesticides in question. Pesticide control is of vital importance to public safety and the protection of the environment. Without effectively enforced pesticide control, potentially dangerous and even carcinogenic pesticides could be commonly used, resulting in higher rates of cancer, the death of wildlife, and environmental damage.

Types of Pesticide Control

Let's outline the types of pesticide control before we learn about the methods in detail.

• Regulation: ensuring that all pesticides are properly regulated and peer-reviewed before commercial production.

• Banning: prohibiting further production and commercial use of pesticides identified as harmful.

• Alternatives: instead of risking human health and environmental stability, alternative methods of pest control are encouraged.

Pesticide Control Methods

Different countries have different methods of pesticide control, though most are similar due to the nature of the subject. In the following, we will go over pesticide control in the European Union (EU) and the United Kingdom (UK), as well as in the United States (US). We will also go over two notable classes of synthetic pesticides- organochlorines and organophosphates.

EU and UK

In the EU, pesticides are known as Plant Protection Products (PPPs). They are defined by Regulation (EC) No. 1107/2009, which states that pesticides must be used to defend plants from pests and disease, through the increased ability of plants to defend themselves or by terminating the pest organism.

This regulation requires evaluation of pesticides to ensure that they pose no dangers to human health or the environment. The evaluations are backed up by peer-reviewed studies looking into toxicity and ecotoxicity.

US

In the US, the Environmental Protection Agency (EPA) regulates the use of pesticides. Prior to the 1950s, pesticide use in the US was not controlled. This changed following concerns over public safety and the Food Additives Amendment of 1958 (known as the “Delaney Clause”), which made it illegal for carcinogenic pesticides to be present in any foods. Like in the EU, in the US testing and peer-reviewed studies must be conducted before a pesticide is deemed safe for use.

Organochlorines (DDT)

The most well-known and notorious organochlorine pesticide is dichlorodiphenyltrichloroethane, known as DDT. While DDT was created during the late 19th Century, it was not used as a pesticide (specifically, an insecticide) until 1939, when a scientist from Switzerland named Paul Herman Muller discovered that it was insecticidal. It was prominently used during the latter half of World War II (Fig. 2) in an effort to combat insect-bourne diseases (e.g., malaria) that were problematic among both soldiers and civilians, particularly in tropical areas. By the mid-1940s DDT was being used domestically in Europe and the United States. In the 1950s, DDT was used in an attempt to eradicate malaria from many parts of the world and was successful in Europe, the US, Russia, Australia, and some other regions, though it often reoccurred due to increased tolerance of mosquitoes.

Figure 2: A person is sprayed with DDT during World War II. Source: Wiki Commons, Public Domain

There were concerns over human health and environmental damage regarding DDT use from the beginning. Initially, entomologists were concerned over the effect of DDT on non-target species, including beneficial insects. DDT can have a number of detrimental impacts on the environment and wildlife. It was found to be the cause of the thinning of raptor eggs in Europe and the US, causing declines in raptor populations and possibly even contributing to the decline of the California condor (Gymnogyps californianus). It is also toxic to many marine and freshwater species, including crustaceans and fish. In humans, DDT is considered to be a “probable” carcinogen and has been associated with various cancers, including pancreatic, liver, and breast.

It's also an endocrine disruptor; meaning that it interferes with hormonal production and regulation, leading to development issues, mental issues, birth defects, and cancer.

Countries began banning DDT use during the late 1960s, starting with Hungary in 1968 and two Nordic countries, Norway and Sweden, in 1970. By 1972 its use was mostly banned in the US, and it was banned in the UK in 1984. It is still being used in India, where it is utilised to eliminate mosquitoes from human habitation.

Organophosphates

Around half of all current chemical-based pesticides are OPPs, but their use comes with drawbacks.

OPPs inhibit acetylcholinesterase (AChE) in insects and other animals, including humans.

They'e been associated with various cancers, as well as cardiovascular and respiratory diseases, brain damage, and birth defects.

Organophosphates degrade much faster than organochlorines, so they're less likely to be found in human food and water. However, farmworkers still face significant exposure. OPPs have been largely banned for residential use, they are still widely used in many other sectors, including agriculture and pest control.

Pesticide Control Examples

Rodenticides are pesticides used to kill rodents, such as rats, rabbits, and squirrels. Unfortunately, anticoagulant rodenticides are potentially lethal to other animals that may prey upon the rodents that consume them.

^{1. Malaria Consortium, Malaria Prevention: Insecticides, 2010}