The Use of Chemical Pesticides: A Balancing Act Between Benefits and Risks

Chemical pesticides are like “infants born with congenital defects”: as bioactive chemicals deliberately introduced into the environment by humans, they inevitably exert some degree of adverse impact on ecosystems and on human and animal health. In 1962, Rachel Carson published Silent Spring, the first work to bring chemical pesticides and environmental protection into the global spotlight. A literary masterpiece as well as a monumental scientific exposition grounded in extensive research, it sparked worldwide awareness and heightened concern over the environmental pollution caused by pesticide use. Today, as “ecological conservation” and “green development” have become defining themes of our era, revisiting this book reveals that its insights on the safe use of pesticides and their future direction remain far from outdated—worthy of reflection and emulation. Nearly six decades after its publication, pesticides continue to be widely employed around the globe, yet the bleak scenarios described in the book have not materialized. This vividly demonstrates a fundamental ecological principle: “intensive agricultural production cannot do without pesticides, and their use entails a constant balancing act between benefits and risks.” It also underscores humanity’s success in mastering the dual challenge of harnessing the advantages of pesticides while mitigating their harms. We should avoid blindly demonizing the perceived drawbacks of pesticides; instead, we ought to adopt a scientifically informed perspective, recognizing both the tangible benefits they bring to human society and the ongoing advances and transformations in their safety profile, thereby leveraging strengths while minimizing weaknesses.

01 Scientifically Understanding the Pros and Cons of Pesticides

Pesticides are widely used worldwide to control agricultural pests and diseases, helping to boost both yield and quality and playing a crucial role in meeting global food demand. However, they are often scapegoated as the primary culprits behind food safety concerns and environmental pollution, repeatedly thrust into the spotlight, yet they continue to lack scientific, objective, and impartial evaluation and treatment. Knutson et al. have illustrated that, without pesticides, U.S. agriculture would see reduced production, higher food prices, diminished competitiveness in the global market, declining agricultural exports, and, consequently, substantial job losses.

1.1 The Hazards of Pesticides

Pesticides are toxic substances released into the environment to control harmful organisms—such as plant pathogens, pests, weeds, and rodents—and can be applied through methods like spraying, soil treatment, or seed coating. However, only a small fraction of these chemicals is actually utilized (reaches the target), while the remainder may contaminate agricultural fields and harm beneficial insects, soil microorganisms, and other non‑target organisms. They can also enter surface water bodies, volatilize into the atmosphere, or exert effects on non‑target species via ingestion, leading to the death of honeybees, natural enemy insects, frogs, and other beneficial organisms. Moreover, some pesticides can bioaccumulate across different trophic levels in food webs, resulting in long‑term chronic toxicity.

Furthermore, pesticides that enter drinking water or food can also pose risks to human health, contributing to a range of cancers and diseases. Children, in particular, are more vulnerable because their immune systems, nervous systems, and detoxification mechanisms are not yet fully developed. According to the literature, paraquat can cause damage to the lung, liver, and kidney tissues; the metabolite ethylene thiourea (ETU) derived from dithiocarbamate compounds can induce thyroid cancer and modulate thyroid hormone levels; and organochlorine pesticides such as DDT (dichlorodiphenyltrichloroethane) have been linked to cancer, asthma, diabetes, and developmental disorders in children, while also exerting endocrine-disrupting effects.

1.2 The Benefits of Pesticides

The purpose of using pesticides is the benefits they bring to humanity; otherwise, their use would not come at the expense of the environment and human health. Pesticides are among the most critical plant protection technologies: without them, food production would decline, many fruits and vegetables would become scarce, and prices would rise. They can also be used to control termites, cockroaches, ants, rodents, and other pests, thereby creating a healthier living environment for people. Furthermore, they help safeguard public spaces such as gardens, parks, sports fields, lakes, and ponds. Pesticides play a vital role in managing disease‑carrying insects and curbing the spread of illnesses like malaria. They are also employed to combat both pathogenic and non‑pathogenic microorganisms, reducing contamination by microbial toxins—such as the highly carcinogenic aflatoxin—whose harm far outweighs that of the pesticides themselves. Thus, pesticides are an indispensable tool in humanity’s struggle with nature, delivering substantial benefits to humankind.

02 Pesticides have continuously evolved alongside the times.

Pesticides have continuously evolved with advances in science and technology, yet they are by no means a recent invention. As early as 2,500 BCE, the Sumerians were already using sulfur to control pests and mites; by 1,200 BCE, the Chinese employed mercury- and arsenic-based compounds to manage body lice; pyrethrum extracts have been used as insecticides for more than two millennia; and salt or seawater has long been utilized to suppress weeds. Inorganic substances such as sodium chlorate and sulfuric acid, as well as organic chemicals derived from natural sources, were widely employed for pest control prior to the 1940s.

The development of pesticides can broadly be divided into five stages: (1) the early stage, around 1,000 years ago; (2) 1,000–1850, characterized by the use of plant-, animal-, and mineral‑based compounds; (3) 1850–1940, marked by inorganic substances and industrial byproducts; (4) 1940–1970, dominated by organo‑synthetic compounds exemplified by DDT; and (5) from 1970 to the present, featuring low‑risk, organo‑synthetic formulations. Pesticides prior to 1940 are often referred to as “first‑generation pesticides,” typically relying on natural sources such as plants and minerals. These compounds were generally highly toxic, offered limited efficacy, readily accumulated in soils, and, after prolonged use, gave rise to resistance—leading to their widespread phaseout today. The period from 1940 to 1970 saw the emergence of “second‑generation pesticides,” with the introduction of DDT ushering in the era of chemically synthesized agents. Representative classes include organochlorines, organophosphates, and carbamates. These products exhibited strong efficacy but posed significant risks to mammals and beneficial organisms, with some persisting in the environment for extended periods. To address the high toxicity of second‑generation pesticides, post‑1970 developments introduced juvenile hormone analogs, ecdysone mimetics, insect pheromones, and chitin synthesis inhibitors—agents with markedly lower direct toxicity to humans and livestock. Many of these are environmentally friendly, though some may still exert adverse effects on non‑target organisms, leading them to be sometimes labeled as “third‑generation” or even “fourth‑generation” pesticides. Objectively speaking, due to factors such as efficacy, cost, and environmental persistence, these newer compounds have yet to fully supplant second‑generation products. Today, the dominant class comprises modern, chemically synthesized pesticides that are highly effective, highly selective, leave minimal residues, and pose low risks—examples include pyrethroids, neonicotinoids, and diamide insecticides; triazoles, methoxyacrylates, and succinate dehydrogenase inhibitors (SDHIs) among fungicides; and sulfonylureas, as well as inhibitors of hydroxyphenylpyruvate dioxygenase (HPPD), used as herbicides. Consequently, pesticide innovation has consistently advanced toward lower toxicity and higher efficiency. The “modern pesticide” is no longer the long‑residual, bioaccumulative “organochlorine” type of the 1950s.

03 Management of the Ecological and Environmental Safety of Pesticides

In the 1940s, particularly during World War II, chemically synthesized insecticides such as DDT, aldrin, dieldrin, endrin, 2,4‑D, and parathion were widely employed to boost food production and to develop potential chemical weapons. Their agricultural use was initially regarded as beneficial, with little concern about their environmental and human health impacts. In 1962, Rachel Carson’s book Silent Spring sparked widespread public attention to pesticide safety, and by the 1970s, the emergence of pest resistance had amassed substantial evidence of adverse effects. Consequently, the United States banned DDT in 1972. This also prompted the establishment of the U.S. Environmental Protection Agency (EPA) in 1970, which created a dedicated division to regulate the production and use of pesticides—making it the world’s first government agency specifically tasked with pesticide management. The primary goal was to strengthen safety oversight, and beginning in the 1980s, the EPA developed a technical framework for assessing the environmental risks of pesticides, providing a model for pesticide regulation in other countries.

In 1978, with the approval of the State Council, China reestablished the former Pesticide Inspection Institute under the Ministry of Agriculture and Forestry, thereby establishing a dedicated pesticide regulatory agency. Following the formal promulgation of the “Regulations on Pesticide Registration” in 1982 and the subsequent implementation of a pesticide registration system, although environmental safety concerns initially attracted attention, limitations in technical capabilities, human resources, and infrastructure meant that early registration assessments primarily focused on product quality and efficacy. Compared with developed countries such as Europe and the United States, China’s efforts to manage pesticide environmental safety lagged behind by at least three decades; its development can broadly be divided into three stages (Table 1). Today, China has achieved a remarkable leap forward in pesticide environmental safety management, transitioning from an early reliance on subjective judgments based solely on acute toxicity data to a scientifically grounded, quantitative risk‑management approach, which has garnered widespread international recognition. 6

Table 1: Stages of Development in China’s Management of Pesticide Environmental Safety

04 Reducing the Harm Caused by Chemical Pesticide Use

Pesticides are an inevitable product of scientific and technological progress and social development; they are critical agricultural inputs that directly affect national economic growth, public health, agricultural production safety, and social stability. However, as long as pesticides are used in production, it is difficult to avoid their adverse effects. The most effective approach is to minimize both the scope and the level of these risks. “Silent Spring” has provided valuable insights for our work, demonstrating that humanity can implement numerous measures to reduce pesticide use and mitigate their harmful impacts.

4.1 Phasing out highly toxic and high-risk pesticide varieties

In “Silent Spring,” Rachel Carson documented the harm inflicted on wildlife, fish, birds, and livestock in the United States following the widespread use of persistent, high‑risk pesticides such as DDT, aldrin, and dieldrin. Today, DDT has been banned in at least 86 countries worldwide. In China, the State Council issued a directive in 1983 to cease production of the organochlorine pesticides hexachlorocyclohexane (HCH) and DDT; in 1992, the former Ministry of Chemical Industry prohibited their agricultural use; and by 2002, they were listed in Announcement No. 199 of the former Ministry of Agriculture as pesticides explicitly banned within the country. Since then, China has comprehensively banned or restricted the use of 66 pesticide active ingredients—accounting for roughly 8.7% of all registered pesticides—particularly those with high toxicity to beneficial non‑target organisms, such as fipronil, carbofuran, and flufenoxuron. As a result, phenomena akin to “Silent Spring” have occurred only in limited areas and for brief periods, while fish and birds have begun to proliferate in farmland, and biodiversity is gradually recovering.

4.2 Strengthening the management of pesticide use to reduce hazard risks

The environmental harm caused by pesticides is, in most cases, the result of improper use. As depicted in Rachel Carson’s “Silent Spring,” the widespread aerial spraying of pesticides in the United States during the 1950s and 1960s clearly demonstrates that this method is a major contributor to adverse effects on non‑target organisms, with significant pesticide drift being a persistent issue. In China, manned aircraft are still employed for pesticide application, particularly in forestry and state‑owned agricultural areas; moreover, some pesticides used in forestry—such as imidacloprid, abamectin, and emamectin benzoate—are highly toxic to bees and birds. Meanwhile, drone‑based aerial spraying is experiencing explosive growth, with annual treated areas now reaching hundreds of millions of mu. The resulting environmental pollution from these practices warrants serious attention. Selecting safe and environmentally friendly formulations is another effective strategy for mitigating risks associated with pesticide use. In 2019, nanopesticides were ranked first among the IUPAC’s ten emerging technologies in chemistry; however, their environmental safety remains a critical concern, and the trade‑offs between increased risks and reduced application rates deserve careful consideration. Furthermore, in actual production settings, off‑label and overdosing are common occurrences. Without robust regulatory controls, the scientific data and evidence we rely on could quickly become meaningless.

4.3 Strengthen technical guidance and training on the safe use of pesticides

Carson did not advocate an outright ban on the use of chemical pesticides, but he firmly opposed allowing individuals with no understanding of pesticide toxicity to handle them. Moreover, the font size for critical information—such as toxicity warnings, application instructions, and safety precautions—on pesticide labels is often very small. Coupled with users’ tendency to pay insufficient attention to these labels and the issue of rural population aging, this undermines the practical guidance and effectiveness of pesticide labeling in real‑world application. To reduce the inappropriate use of pesticides, measures should be taken, including strengthening training on safe pesticide use, promoting professionalized, integrated pest management, and improving the qualifications of pesticide retailers.

4.4 Accelerate the promotion of biopesticides as substitutes for chemical pesticides

Even at the time, Carson outlined strategies such as radiation‑induced sterility, sonic pest control, the use of biopesticides derived from natural sources, biological control using microorganisms, and biological control through predatory insects, all aimed at reducing and replacing chemical pesticides. Yet, after more than six decades of development, these approaches have advanced only slowly. The primary reasons lie in economic incentives and persistent technological barriers that hinder the widespread adoption of biopesticides. Overcoming the disadvantages of biological control will require government intervention and support; future measures could include bolstering product R&D, establishing fast‑track registration pathways, providing usage subsidies, and offering tax incentives.

05 Existing Issues and Future Prospects

5.1 Existing Issues

Carson reviewed an extensive body of literature, conducted numerous investigations and studies, and engaged in in-depth exchanges with leading experts from multiple countries, identifying gaps in pesticide environmental safety management as well as issues warranting further consideration. Taking China’s national context into account, there remain several challenges in pesticide safety management that call for careful reflection and concerted efforts to address.

5.1.1 The Issue of Combined Pesticide Contamination

Carson pointed out that our safety‑assessment studies typically expose experimental animals to a single pesticide at a time to observe its toxic effects. However, in real‑world settings, we cannot know how many different pesticides we encounter across various times and contexts. Whether it concerns human and animal health or environmental health, the “cocktail effect” of pesticides has long remained an intractable challenge. Fortunately, the pesticides currently approved for registration no longer exhibit the strong bioaccumulation potential seen with DDT, and we are actively developing and prioritizing environmental risk‑assessment procedures and methodologies for pesticide mixtures. Moreover, given the countless compounds present in nature, it is difficult to determine whether pesticides might react with other substances to form even more toxic compounds; the most effective approach remains to avoid and minimize exposure to and contact with pesticides.

5.1.2 Issues in the Perception of Pesticide Toxicity

Risk assessment is, within the framework of current knowledge and technological capabilities, the most effective tool for predicting or evaluating the risks associated with pesticide use. It provides a standardized metric that enables us to select, under comparable conditions, pesticide formulations with relatively higher efficacy and lower safety risks. However, objectively speaking, we cannot guarantee that a pesticide assessed as posing low risk is necessarily safe, since the accuracy of such assessments depends on data regarding biological effects. Although relatively comprehensive ecotoxicological testing methods have been established, they predominantly focus on macroscopic, acute toxicological endpoints, while investigations into microscopic, chronic toxicological effects remain limited. Nevertheless, it is reasonable to expect that advances in molecular biology, metabolomics, and other emerging technologies will continually enhance our understanding of the toxicological impacts of pesticides.

5.1.3 How to Resolve the “Old Accounts” Issue

Prior to the implementation of stringent pesticide environmental risk assessments and safety management measures in China, certain active ingredients and application practices that have adverse impacts on the ecological environment had already been approved. While these products continue to meet the needs of agricultural production, they must be gradually phased out and discontinued to further mitigate the ecological consequences of pesticide use.

5.2 Future Prospects

China is home to 739 common agricultural pests, 775 plant diseases, 109 weed species, and 42 rodent pests; accordingly, pesticide use is indispensable for agricultural production. In 2019, the fall armyworm was introduced from abroad, and in 2020, the yellow-spined bamboo locust invaded Yunnan—both outbreaks were brought under effective control only through the application of chemical pesticides. To meet the growing food demands of an expanding population, humanity must continue to develop and produce pesticides that are efficient, safe, and environmentally friendly. At the same time, the ecological and environmental risks posed by pesticides are increasingly well understood and widely recognized. The revised Regulations on the Administration of Pesticides, promulgated in 2017, has raised the safety‑assessment standards for pesticide registration and underscored the principle of green development, thereby steering China’s pesticide industry toward higher‑quality, sustainable growth.

The guiding principles in the creation and development of pesticides have long been: (1) achieving high efficacy while minimizing application rates; (2) ensuring rapid degradation to reduce environmental persistence; and (3) maximizing selectivity to minimize harm to non-target organisms. In the early days, such as during the 1930s–1950s, pesticide application rates typically ranged from 1 to 10 kg per hectare; today, many novel compounds are applied at rates of 10 g per hectare or even lower, reflecting substantial progress toward greater efficiency. Moreover, as the costs of chemical‑pesticide R&D continue to rise and the likelihood of identifying effective compounds declines, pesticide innovation is increasingly shifting toward biopesticides, transgenic pest‑ and disease‑resistant technologies, disease‑resistant breeding, RNAi‑based approaches, and non‑chemical alternatives. Several multinational corporations and major domestic firms have begun investing in biopesticide research, and green pest‑management strategies are poised to play an ever more significant and far‑reaching role within integrated pest management (IPM) frameworks.