Scope of Environmental Chemistry

Introduction 

Environmental Chemistry is the study of chemicals as they pass through our environment and the effects they cause on the air, water, soil, etc. It is an important field of study as it helps us to trace and control contaminants. 

Environmental chemistry is the study of chemical processes occurring in the environment which are impacted by humankind’s activities. Important general concepts from chemistry include understanding chemical reactions and equations, solutions, units, sampling and analytical techniques.

Environmental chemistry plays a major role in environment. Chemical species present in the environment are either naturally occurring or generated by human activities. Environmental pollution is the effect of undesirable changes in the surrounding that have harmful effects on plants, animals and human beings.

Environmental chemistry focuses on the presence and impact of chemicals in soil, surface water, and groundwater. Environmental chemists study how chemicals usually contaminants move through the environment. They also study the effects of these contaminants on ecosystems, animals and human health.

Chemicals measures of water quality include dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total dissolved solids (TDS), pH, nutrients nitrates and phosphorous, heavy metals (including copper, zinc, cadmium, lead, mercury) and pesticides.

Radionuclides in Environment

Radioactive elements are part of our ecosystem, part of the air we breathe, the water we drink and the food we eat.

• Radionuclides can occur naturally or can be man-made.
• Over half of the average annual radiation exposure of people comes from natural sources.

About Radionuclides in Environment

An ecosystem is a place with a one-of-a-kind combination of air. Water and land. An ecosystem has habitats that support plants and animals’ life. Ecosystem science focuses on all parts of the system, including the interaction among the water, air, land, plants, humans and other animals. Ecosystem science can tell us how minerals and other chemicals in natural including radionuclides) move through earth’s different natural systems.

Radionuclides enter an ecosystem in three ways:

1. As minerals present in earth’s origin crust.
2. As radionuclides created by cosmic rays hitting atoms in earth’s atmosphere.
3. From human activity.

Radionuclides in Earth’s Crust

Some radionuclides have been present in rocks since the formation of earth. Others are their decay product. Examples of these natural radionuclides include potassium-40, rubidium-87, uranium, etc.

These radionuclides end up naturally in soil, water and air. Rocks containing minerals broken down into soil by the weather, bacteria and fungi. When radionuclides are in soil particles they can be blown around by wind. Some will dissolve in water and end up in surface or ground water some radionuclides dissolve more easily than others. Also, the makeup of the water affects how much of the radionuclide will dissolve.

          More half of the average annual radiation exposure of people comes from natural sources. The natural radionuclide, radon, is the single biggest natural source of exposure. It comes from the breakdown of radium. Breathing indoor air containing radon is the most common route.

          Radon is one radionuclide that dissolves easily in water. Radon concentration in water is usually low enough that they are not a serious health threat.

Radiation from Space

          Cosmic rays come from stars, our sun, other stars and exploding stars. The rays continuously strike atoms in earth’s atmosphere. The atmosphere stops most of the cosmic rays, however, the collisions leave some atoms unstable (radioactive). These radioactive atoms are called Cosmo-Genic radionuclides. They are rare, but some of them do reach earth’s surface and settle on the soil and water.

Radionuclides from Human uses of Radio-active materials

          Nature is the major source or of radionuclides in an ecosystem. Much smaller amounts of radionuclides come from sources developed by humans. Examples include Uranium mines, nuclear power plants and research facilities that use radionuclides. However, for most people the annual exposure from these sources is very low. Only in certain areas where there are open uranium and other mineral mines, and mining wastes present is there a serious health hazard.

• Nuclear Weapons Testing: Nuclear weapons tests released large amounts of radionuclides that spread and remained in ecosystems until the radionuclides decayed away. Today, events include nuclear accidents and potentially terrorist’s acts.
• Nuclear Facility Releases: The small amounts of airborne radionuclides released from facilities that handle and process radioactive materials can get into the soil, water or air. The facilities operating permits allow only very small releases because they result in very small exposures.
• Radioactive Waste: Improper disposal of radioactive waste is another way radionuclides can enter an ecosystem. For example, water seeping through mining wastes can dissolve some radionuclides and carry them into the water system. Public water system is monitored carefully to make sure the drinking water in safe. This kind of waste accounts for less than a tenth of one percent of the average annual radiation exposure.