Environmental chemistry is thescientific study of the chemical andbiochemical phenomena that occur in natural places. It should not be confused withgreen chemistry, which seeks to reduce potential pollution at its source. It can be defined as the study of the sources, reactions, transport, effects, and fates of chemical species in theair,soil, andwater environments; and the effect of human activity andbiological activity on these. Environmental chemistry is aninterdisciplinary science that includesatmospheric,aquatic andsoil chemistry, as well as heavily relying onanalytical chemistry and being related toenvironmental and other areas of science.
Environmental chemistry involves first understanding how theuncontaminated environment works, which chemicals in what concentrations are present naturally, and with what effects. Without this it would be impossible to accurately study the effects humans have on theenvironment through the release ofchemicals.
Environmentalchemists draw on a range of concepts from chemistry and various environmental sciences to assist in their study of what is happening to a chemical species in theenvironment. Important general concepts from chemistry include understandingchemical reactions andequations,solutions,units,sampling, andanalytical techniques.[1]
Acontaminant is asubstance present in nature at a level higher than fixed levels or that would not otherwise be there.[2][3] This may be due to human activity and bioactivity. The term contaminant is often used interchangeably withpollutant, which is a substance that detrimentally impacts the surrounding environment.[4][5] While a contaminant is sometimes a substance in the environment as a result of human activity, but without harmful effects, it sometimes the case that toxic or harmful effects from contamination only become apparent at a later date.[6]
The "medium" such as soil or organism such as fish affected by the pollutant or contaminant is called areceptor, whilst asink is a chemical medium or species that retains and interacts with the pollutant such ascarbon sink and its effects by microbes.
Chemical measures ofwater quality includedissolved oxygen (DO),chemical oxygen demand (COD),biochemical oxygen demand (BOD),total dissolved solids (TDS),pH, nutrients (nitrates andphosphorus),heavy metals, soil chemicals (includingcopper,zinc,cadmium,lead andmercury), andpesticides.
Environmental chemistry is used by theEnvironment Agency inEngland,Natural Resources Wales, theUnited States Environmental Protection Agency, the Association ofPublic Analysts, and otherenvironmental agencies and research bodies around the world to detect and identify the nature and source of pollutants. These can include:
Quantitative chemicalanalysis is a key part of environmental chemistry, since it provides the data that frame most environmental studies.[11]
Common analytical techniques used for quantitative determinations in environmental chemistry include classical wet chemistry, such asgravimetric,titrimetric andelectrochemical methods. More sophisticated approaches are used in the determination of trace metals and organic compounds. Metals are commonly measured by atomic spectroscopy andmass spectrometry:Atomic Absorption Spectrophotometry (AAS) andInductively Coupled Plasma Atomic Emission (ICP-AES) orInductively Coupled Plasma Mass Spectrometric (ICP-MS) techniques. Organic compounds, includingPAHs, are commonly measured also using mass spectrometric methods, such asGas chromatography-mass spectrometry (GC/MS) andLiquid chromatography-mass spectrometry (LC/MS). Tandem Mass spectrometryMS/MS and High Resolution/Accurate Mass spectrometryHR/AM offer sub part per trillion detection. Non-MS methods using GCs and LCs having universal or specific detectors are still staples in the arsenal of available analytical tools.
Other parameters often measured in environmental chemistry areradiochemicals. These are pollutants which emit radioactive materials, such as alpha and beta particles, posing danger to human health and the environment. Particle counters and Scintillation counters are most commonly used for these measurements.Bioassays andimmunoassays are utilized for toxicity evaluations of chemical effects on various organisms. Polymerase Chain ReactionPCR is able to identify species of bacteria and other organisms through specific DNA and RNA gene isolation and amplification and is showing promise as a valuable technique for identifying environmental microbial contamination.
Peer-reviewed test methods have been published by government agencies[12][13] and private research organizations.[14] Approved published methods must be used when testing to demonstrate compliance withregulatory requirements.
Joan Berkowitz
Paul Crutzen (Nobel Prize in Chemistry, 1995)
Philip Gschwend
Alice Hamilton
John M. Hayes
Charles David Keeling
Ralph Keeling
Mario Molina (Nobel Prize in Chemistry, 1995)
James J. Morgan
Clair Patterson
Roger Revelle
Sherry Roland (Nobel Prize in Chemistry, 1995)
Robert Angus Smith
Susan Solomon
Werner Stumm
Ellen Swallow Richards
Hans Suess
John Tyndall
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