Welcome to Reciprocal Net!

Reciprocal Net  a distributed crystallography network for researchers, students and the general public

Reciprocal Net is funded by the U.S. National Science Foundation as part of the National Science Digital Library project.  NSDL Logo
You are here : Reciprocal Net > Learn About Molecules > Common Molecules > Environmental Molecules   

Common Molecules:
Environmental Molecules
spray of pesticides smoke

Agricultural Use

Molecules relevant to agriculture and food production are compiled here. Included are chemicals directly used on farms in the raising of animals or in crop production (e.g., pesticides that may improve crop yield by killing weeds, insects, or other "pests"). Also included are molecules used in the manufacture of these chemicals.
Fertilizers are chemicals or natural products (like lime, guano, manure, etc.) that may contain nitrogen, phosphorus, or potassium, or other nutrients and are used to promote plant survival and health.
Fumigation is the spraying of vapor to exterminate pests, disinfect, or to preserve perishables. Fumigants are highly and acutely toxic. They are used in agriculture to sterilize soil before planting and to kill pests in stored food before shipment. In urban settings, fumigants are used to treat dwellings against termite, ant, cockroach and other pest infestations. They are potentially harmful to humans.
These are pesticides used to eliminate harmful fungae without harming crops.
They are chemicals specifically used to destroy or retard the growth of unwanted vegetation (various types of weeds, grasses, and woody plants) without harming the desired crop.
They comprise chemicals used to kill insects that damage crops. Some insecticides specifically target insects and are not toxic to other animals. Others are not so specific but are rather highly toxic, accumulate in the environment, and pose a health risk to humans and insects alike.
Pesticides are chemicals used to kill pests, for example insects, fungae, weeds etc.


Pollution arises whenever a chemical is released or accumulates to an unnaturally high concentration in the environment. Chemicals known as pollutants may come from various sources (industry, agribusiness, urban areas). Many of them adversely affect the health and welfare of biota. Pollutants may migrate through and accumulate in various parts of the environment such as air, water, soils, and body tissue.
Listed are chemicals applied heavily to crops (including pesticides and fertilizers) or used in the raising of livestock (e.g., flee dips, insecticides, and antibiotics).
Chemical industrial pollutants are often the waste products of manufacturing. They may also be intended substances that are accidentally released during production, storage, transportation, or use.
Urban Areas
Pollution of one form or another inevitably arises when many people live within a small area (e.g., cities). Anthropogenic (human-derived) pollutants may include chemicals emitted into the air from heating devices, automobiles, power plants, or waste incineration. Pollutants may also enter streams from wastewater or storm water contaminated with, for instance, leaked motor oil, laundry detergents, fumigants, wood preservatives, solvents, and paints.
The 'Dirty Dozen'
These are chemicals identified by the United Nations' Convention on Persistent Organic Pollutants (POPs) as being the most toxic chemical pollutants. Countries that have signed this treaty have agreed to reduce and/or eliminate the production, use, and release of these chemicals. The list is updated as needed. The "dirty dozen" are highly toxic to humans and wildlife, biomagnify in the food chain, spread to remote regions of the planet, and do not breakdown easily in the environment.
Element and IonsMaterials and TechnologyBiological MoleculesMinerals and GemsEnvironmental Molecules
Copyright 2004, The Trustees of Indiana University