Pesticides

Pesticides are chemical compounds that kill unwanted organisms, typically insects, fungi, plants, and other pests that harm humans or organisms valued by humans, such as crops and domesticated animals. Pesticides are agrochemicals, a category that includes synthetic fertilizers, which are derived from petroleum and other fossil fuels. Pesticide classification systems include those arranged by the target organisms (insecticide, fungicide, herbicide, acaricides, rodenticide, etc.), by chemical origin (“inorganic” pesticides are derived from basic chemical elements such as copper, “organic” or “synthetic” pesticides from fossil fuels, and “biological” pesticide from organisms), by chemical class (organochlorines, organo-phosphates, etc.), and by their effects on nontarget organisms.

Farmers producing horticultural crops began widely using inorganic pesticides for pest management in the late 1800s, while synthetic pesticides were widely adopted in many agricultural systems, especially in industrialized agriculture, starting in the 1940s. Today, more than 600 different pesticide active ingredients exist, although [Page 2158]national regulations on these chemicals vary substantially.

Rachel Carson's 1962 famous book Silent Spring helped popularize an ecological consciousness through an understanding of the environmental and health effects of chlorinated hydrocarbon pesticides, such as DDT, and the acute toxicity of organophosphate pesticides. The book also inspired the modern environmental movement and the creation of the U.S. Environmental Protection Agency in 1970. Concerns over pesticides and other environmental impacts of agriculture remain an important impetus for promoting organic agriculture. Pesticides are unique in that they are biologically active agents intended to cause harm that are released intentionally into the environment, and as such, their effects are considered externalities of agro-food systems.

Numerous disciplines and fields have become involved in research related to pesticides. Epide-miological and toxicological work has shown pesticides to harm many organisms, including humans. Some pesticides cause acute poisoning, often with long-term effects, while others are carcinogens. Impairment and disruption of the endocrine, immune, and neurological systems has been shown among lab animals at doses near levels currently found in groundwater. Neurological impairment has been demonstrated among pesticide applicators and children in intensive production areas.

Two bodies of geographical work contribute to pesticide research: environmental justice and political ecology. Environmental justice has revealed the unequal distribution of risks and harms in catastrophes such as the Bhopal disaster in 1984 in India; that agribusiness interests strongly shape pesticide regulation, including risk analysis and assessment; and that farm workers as a marginalized population have had less power to influence pesticide regulation except when organized, as the United Farm Workers in California in the 1960s and 1970s. Political ecological approaches to pesticide use involve putting land users’ decision making in a broader political economic context by emphasizing agricultural development policies, agrochemical marketing, and regulations, in addition to paying attention to smaller-scale variations such as farmer experiences, land ownership, agroecology, and management and geographical strategies. Similarly, scholars researching lawn pesticide use in First World contexts have taken a political-ecological approach to show how the chemical industry's need to increase sales shapes land user decision making by promoting a mono-cultural lawn aesthetic.