Environmental chemistry

Some people study how things work in nature. They look at the air, the water, and the soil.

They want to see how things change. They look for things that should not be there. These things can be bad for the world.

Sometimes, things from factories or farms get into the water. This can happen when it rains on roads.

These things can move from the land into the water. Then, plants and animals might take them in.

Scientists use special tools to find these things. This helps us understand our home better.

Environmental chemistry is a way to study our world. Scientists look at the air, soil, and water. They want to see how chemicals move and change. They also study how living things affect these places.

First, scientists learn how a clean place works. They find out which chemicals are there naturally. This helps them see when humans change things. They look for a contaminant. A contaminant is a substance that is not supposed to be there. Sometimes, a contaminant is also called a pollutant. A pollutant is a substance that harms the world around it.

Pollutants can come from many places. They might wash off roads during a rain storm. This is called urban runoff. They can also come from farms. Nutrients from farms can go into water. This can cause algal blooms. This means too much algae grows in the water. Scientists use many tools to find these things. They use mass spectrometry. This is a way to find tiny amounts of matter. They also use special tests to see if chemicals are toxic to living things.

Environmental chemistry is a special way of studying our world. It looks at the chemical things that happen in nature. Scientists study how these things move through the air, soil, and water. They also look at how living things and humans change these environments. This science is interdisciplinary, which means it uses many different types of science. It includes the study of water, soil, and the air around us.

To do this work, scientists must first understand a clean environment. They learn which chemicals are there naturally and in what amounts. This helps them see when human activity changes a place. They look for a contaminant, which is a substance found in higher levels than normal. Sometimes people call these pollutants if they harm the world around them. A receptor is the thing that is affected, like a fish in a river. A sink is a place where a chemical stays or interacts.

Pollutants can come from many different sources. Heavy metals from industry can soak into the land. These metals can then move into water and enter plants or animals. Oil spills can leave behind substances called PAHs in large bodies of water. These can be very toxic to living things. On farms, extra nutrients can wash into water paths. This can cause algal blooms, which is when too much algae grows.

Rainstorms also play a big part in moving chemicals. When rain hits roads or parking lots, it creates urban runoff. This water washes gasoline, motor oil, and metals into the environment. Scientists use many tools to find these tiny traces. They use mass spectrometry to find very small amounts of matter. They also use particle counters to find radioactive materials. Even DNA testing, called PCR, can help find tiny bacteria in the water.

Many famous scientists have helped us understand these complex ideas. Paul Crutzen and Mario Molina both won the Nobel Prize in Chemistry in 1995. Other important names include Sherry Roland and Hans Suess. These experts help us monitor the quality of our water and air. They look at things like pH levels and dissolved oxygen. By studying these things, we learn how to protect our planet.

Environmental chemistry is the scientific study of chemical and biochemical phenomena in natural places. It focuses on the sources, reactions, transport, effects, and fates of chemical species. These species move through the air, soil, and water environments. Scientists also examine how human activity and biological activity influence these systems. This field is interdisciplinary, meaning it combines many different scientific areas. It relies heavily on analytical chemistry and includes atmospheric, aquatic, and soil chemistry.

To study environmental changes, chemists must first understand a clean, uncontaminated environment. They determine which chemicals are present naturally and in what concentrations. This baseline knowledge is essential for measuring human impact. Without it, scientists could not accurately judge the effects of released chemicals. They use traditional chemical concepts alongside specialized sampling and analytical techniques. This allows them to distinguish between natural cycles and human-caused changes.

Chemists often look for substances called contaminants. A contaminant is a substance present at levels higher than fixed natural levels. It might also be a substance that would not otherwise be there. If a contaminant detrimentally impacts the surrounding environment, it is called a pollutant. Sometimes a contaminant is present due to human activity but does not cause immediate harm. However, toxic or harmful effects from such contamination may only become apparent much later.

In these studies, scientists use specific terms to describe how chemicals interact with the world. The medium or organism affected by a pollutant is called a receptor. For example, a fish in a river might act as a receptor. A sink is a chemical medium or species that retains and interacts with a pollutant. A common example is a carbon sink. Scientists also monitor environmental indicators to check quality. These include dissolved oxygen (DO), pH levels, and nutrients like nitrates and phosphorus. They also measure heavy metals, such as copper, zinc, cadmium, lead, and mercury.

Pollutants can enter the environment through many different pathways. Industrial activity can cause heavy metal contamination of land. These metals can then be transported into water bodies and taken up by plants and animals. Oil spills or leaks can introduce polycyclic aromatic hydrocarbons (PAHs) into large bodies of water. Many PAHs are carcinogens and are extremely toxic. Scientists regulate these by concentration, often measured in parts per billion (ppb). On farms, nutrients can leach from land into water courses. This process can lead to eutrophication, which causes algal blooms.

Urban environments also contribute to chemical changes through runoff. During rainstorms, water washes off impervious surfaces like roads, rooftops, and parking lots. This urban runoff carries gasoline, motor oil, hydrocarbons, metals, nutrients, and sediment into the environment. To detect these, chemists use quantitative chemical analysis. Classical wet chemistry methods include gravimetric, titrimetric, and electrochemical techniques. For more complex tasks, they use sophisticated tools to find trace metals and organic compounds.

Advanced laboratory technology allows for incredibly precise measurements. Metals are often measured using atomic spectroscopy or mass spectrometry. Specific techniques include Atomic Absorption Spectrophotometry (AAS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Organic compounds like PAHs are measured using Gas chromatography-mass spectrometry (GC/MS). Some methods, like Tandem Mass spectrometry (MS/MS), can detect substances at sub part per trillion levels. For radioactive materials, scientists use particle counters and scintillation counters. Even biology helps through Polymerase Chain Reaction (PCR), which identifies microbial contamination by isolating DNA and RNA genes.

Many notable scientists have shaped this field through their research. Paul Crutzen, Mario Molina, and Sherry Roland all received the Nobel Prize in Chemistry in 1995. Other important figures include researchers like Susan Solomon, Werner Stumm, and Ellen Swallow Richards. Their work helps us understand the complex connections between chemistry and the Earth's systems. By studying these chemical processes, we gain a better understanding of how to manage our global environment.