Pesticides are compounds or combinations of substances mostly deployed in agriculture or public health prevention programs to protect vegetation from weeds, pests, or diseases. Furthermore, they are used to prevent people from vector-borne illnesses such as dengue fever, malaria, and schistosomiasis. Typical examples include insecticides, herbicides, fungicides, rodenticides, and plant growth, regulators. Other uses of pesticides include the upkeep and development of non-agricultural areas, including open-air urban green spaces and athletic fields. In addition, these chemicals are applicable in less well-known ways, such as in sailboat bottoms, construction materials, and pet shampoos, to eliminate or prevent undesirable species. Many pesticides have been linked to health and environmental problems, and certain pesticides are no longer used in agriculture. Pesticides can be ingested, inhaled, or applied directly to the skin. The type of pesticide, the amount and how it was exposed, and the person’s health status all affect the potential health result in a given circumstance. Pesticides may be digested, expelled, absorbed, or bio-accumulated in adipose tissue within an animal or human body. Therefore, they pose diverse impacts on the environment and its inclusions in different ways.
Impacts of Pesticides on the Environment
The broad range of negative impacts of applying pesticides is called the ‘environmental effects of pesticides.’ Therefore, one of the primary causes of the detrimental effects of modern industrialized agriculture on the environment is the careless use of pesticides. Pesticides can harm non-target species such as plants, animals, and people since they contain poisonous compounds designed to kill pest species. Since they are sprayed or distributed throughout entire agricultural areas, more than 98% of sprayed insecticides and 95% of sprayed herbicides end up somewhere other than their intended target species (Center for Food Safety and Applied Nutrition). Moreover, other agricultural chemicals, including fertilizers, may also harm the ecosystem. Environmental impacts of pesticides can be experienced in different areas, such as air, soil, and plants, among others, as discussed below.
The use of pesticides can increase air pollution as a result of ‘pesticide drift.’ That occurs when airborne pesticide particles are transported to neighboring locations by the wind and pollute them. After spraying pesticides on crops, they can volatilize and be carried by the wind into surrounding areas, perhaps endangering wildlife (Aktar et al. 6). The relative humidity and temperature at the moment of application, along with the weather, affect how widely the pesticide disperses in the air. Therefore, the exposure and drift of the spray increase with wind speed. More spray evaporates at high temperatures and low relative humidity; hence, the season frequently affects the number of inhalable herbicides in the surrounding area.
The population of microorganisms that live in the soil can be degraded and harmed by the heavy use of pesticides in agricultural output. That occurs especially when the compounds are abused or mishandled hence the chemical compounds accumulate in the soil. Many studies have found detrimental pesticide effects on soil microbes and biological pathways. In contrast, others have discovered that the residue of certain pesticides can be broken down and absorbed by microorganisms (Aktar et al. 3). However, pesticides’ full implications on soil organisms still need to be fully understood. The permanence, concentration, and cytotoxicity of the sprayed pesticide, in addition to several environmental conditions, affect the influence of pesticides on soil microbes (Aktar et al. 3). Therefore, the overall biodiversity of the soil is decreased by the usage of pesticides. Herbicides reduce soil quality, resulting in more water retention needed for plant growth.
Pesticides in the soil inhibit nitrification, which is essential for higher-growing plants. It has been demonstrated that the insecticides DDT, methyl parathion, and pentachlorophenol, in particular, obstruct the chemical transmission between legumes and rhizobium (Aktar et al. 4). Decreasing nitrogen fixation, and hence, lower crop yields arise from the reduced symbiotic chemical signaling. These plants’ ability to develop root nodules helps the global economy avoid spending billions annually on synthetic nitrogen fertilizer. However, pesticides also have some direct negative effects on plants, such as poor root hair formation, yellowing of the shoots, and decreased plant growth (Aktar et al. 4). In addition, when pesticides are sprayed on crops in bloom, bees, which act as pollinators, can be exterminated, decreasing crop reproduction and fertilization.
Pesticides can harm many different species of animals, which is why many nations have implemented Biodiversity Action Plans to control pesticide use. Pesticide residues on food can poison humans and other animals, for instance, when wild animals wander into sprayed fields or neighboring areas soon after spraying (Center for Food Safety and Applied Nutrition). Some animals’ primary food sources can be destroyed by pesticides, forcing them to move, alter their diet, or starve to death. As a result, since contaminants can go across the food chain, ingesting pesticide-contaminated flies and worms can harm birds.
There is proof that the usage of pesticides harms birds. The extinction of numerous bird species due to pesticide buildup in their tissues is covered by diverse researchers. Pesticides used in farming may affect worms, reducing the number of birds and animals that eat them. However, they are only mildly dangerous to birds and mammals (“Impacts of Pesticides on Wildlife”). The fact that some pesticides are accessible in granular form also increases the risk that birds and other animals would mistake the pellets for food grains and eat them. A few pesticide granules are sufficient to kill a little bird. By destroying their habitat, pesticides may put bird populations in peril.
Pesticide-contaminated waters may affect fish and other marine biotas. Surface runoff of pesticides into streams and rivers can be extremely deadly to aquatic life, occasionally obliterating all the fish in a specific stream. When herbicides are applied to bodies of water, the dead plants decompose and devour the water’s oxygen, drowning the fish. At quantities similar to those used to destroy the plants, aquatic herbicides such as copper sulfate are poisonous to fish and other aquatic species (“Impacts of Pesticides on Wildlife”). Sub-lethal dosages of various pesticides can be repeatedly exposed to frequently result in physiological and behavioral changes that lower fish populations, such as lowered disease resistance and decreased predatory avoidance.
Impacts of Pesticides on Water Supply
Rain and groundwater have both been shown to contain pesticide residues. Studies conducted by different researchers have revealed that some samples of ground and river water contain pesticide quantities above those permitted for drinking water (Aktar et al. 2). Therefore, a hydrology transport model is frequently used to examine the movement and destination of chemicals in streams and rivers to monitor the effects of pesticides on aquatic systems. Pesticide runoff was quantitatively analyzed as early as the 1970s to estimate the concentrations that would end up in surface waters (Aktar et al. 8).
Pesticides can get into the waters in one of four ways, including by being sprayed and landing somewhere other than where they were intended. Additionally, they may leak or infiltrate through the soil, enter the water via drainage or accidentally spill into water sources. Eroding soil can also carry them to the water streams or rivers. A pesticide’s water solubility, the proximity between an application site and a water source, weather, soil type, the existence of a growing crop, and the technique used to administer the chemical are all factors that can affect the pesticide’s potential to pollute water.
Health Issues as a Result of Digesting Pesticides
Pesticides can penetrate the body by inhalation of pesticide-containing aerosols, particles, and vapor; oral ingestion through food or drinks; and skin exposure via direct touch. Pesticides leak into the earth and soil, contaminating drinking water, and they might be sprayed into the air, polluting it. The potency of the chemical and the duration and intensity of exposure all affect how pesticides affect human health (Davies). The largest direct exposure to agrochemicals occurs among farm workers and their families.
Furthermore, children are more susceptible to pesticides since they are still growing and have a less developed immune system than adults. Due to their closeness to the ground and propensity to put strange objects in their mouths, children may also be more exposed. Like lead poisoning, hand-to-mouth contact depends on the child’s age (Davies). Breast milk exposure and tiny particle inhalation are more common in children younger than six months. Additionally, the risk of contact rises when family members bring pesticides into the house. A child’s exposure to toxins may be influenced by toxic residue in food. According to epidemiological studies, several pesticides negatively impact children’s cognitive growth at the present acquaintance levels (Davies).
Exposure impacts can range from minor skin irritation to birth deformities, genetic alterations, endocrine disturbance, blood and nerve diseases, unconsciousness, cancers, or death. Pesticides have also been linked to different children’s developmental impacts. As a result of pesticide toxins, somatic cell mutations may cause the recent rise in childhood cancers in North America, including leukemia (Davies). Moreover, insecticides used to eradicate insects may affect the neurological systems of mammals. After exposures, both acute and chronic changes have been noted. For instance, Breast cancer may result from the disruption of estrogenic action caused by DDT and the breakdown product DDE (Davies). Animals exposed to fetal DDT have smaller male penises and may have undescended testicles. Additionally, early developmental stages, in-utero exposure, and even prenatal exposure by a parent can impact fetuses. Chemical reactivity and structural alterations both can also impede reproduction.
When eliminating weeds and insect pests from urban landscapes, pesticides are frequently regarded as a quick, simple, and affordable answer; however, using pesticides is expensive. The ecosystem has been poisoned by pesticides in practically every area. Pesticide use in metropolitan areas contributes to the problem of pesticide residues in soil, air, surface, and underground aquifers worldwide. The ecosystem and non-target creatures, such as beneficial soil microbes, plants, insects, fish, and birds, are significantly in danger from pesticide pollution. Contrary to popular belief, even herbicides can harm the environment. In reality, weed killers can be particularly hazardous because they are applied in quite high quantities. Therefore, using safer, non-chemical pest management techniques is the best approach for everyone to contribute to reducing pesticide pollution in the environment.
“Impacts of Pesticides on Wildlife.” Beyond Pesticides, 2022. Web.
Aktar, Md Wasim, et al. “Impact of Pesticides Use in Agriculture: Their Benefits and Hazards.” Interdisciplinary toxicology, vol. 2, no.1, 2009, 1–12. Web.
Center for Food Safety and Applied Nutrition. “Pesticide Residue Monitoring Program Questions and Answers.” U.S. Food and Drug Administration, FDA, 2022. Web.
Davies, Erica. “Pesticide Drift: Causes and Adverse Health Effects.” Drugwatcher, 2021. Web.