Holy Cross Collegiate

Environmental Chemistry

Student Notes Package

Mrs. Sample

Science 9

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Chemicals and Human Nutrition

Chemicals are essential for all life on earth.

Examples: _____________________________________________________________________

_____________________________________________________________________

Organic and Inorganic Substances

The human body requires 25 different chemicals for normal growth. These necessary nutrients can be classified as organic and inorganic o Organic compounds: _____________________________________________________o Inorganic compounds: ____________________________________________________

Essential Substances

Only green plants can form many of the organic compounds that our bodies require, while animals modify others.

The organic nutrients that are essential for health are classified into four major groups: Carbohydrates, proteins, lipids (fats), and vitamins.

Carbohydrates

Carbohydrates are organic molecules made up of atoms of carbon, hydrogen, and oxygen They are primarily used in the human body as an energy source Dietary sources of carbohydrates:

o _____________________________________________________________________

Proteins

Proteins are organic compounds made up of amino acidso Each protein has its own unique number, combination, and arrangement of amino acids

Functions of proteins include growth and repair of body tissues, as well as a source of energy Dietary sources of proteins:

o _____________________________________________________________________

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Lipids

Lipids are compounds composed of many carbon, hydrogen, and oxygen atoms Unused chemical energy is stored as lipids (fat). It is used as an energy source when no other

source is readily available. Dietary sources of lipids:

o _____________________________________________________________________

Canada’s Food Guide

Canada’s Food Guide was first introduced in 1942, to prevent nutritional deficiencies and improve the health of Canadians during wartime, due to food rationing.

Today, its continued purpose is to promote the health and well-being of Canadians Having the amount and type of food recommended an following the tips in Canada’s food

guide will help: o Meet your needs for vitamins, minerals and other nutrientso Reduce your risk of obesity, type 2 diabetes, heart disease, certain types of cancer and

osteoporosiso Contribute to your overall health and vitality

During the Apollo 15 mission, astronauts David Scott and James Irwin landed on the Moon. Although both astronauts were in excellent health before leaving Earth, both Scott and Irwin developed irregular heart rhythm during moments of high exertion and stress. NASA doctors, concerned that low gravity might have some negative effect on humans, tested both astronauts upon their return to Earth. The doctors found that Scott and Irwin had low potassium levels from eating the highly refined, prepared foods that were supplied to them. As a result of their findings, potassium enriched foods and snacks were added to the menu of subsequent space missions.

Essential Nutrients

Other nutrients, made up of elements and compounds, help living organisms survive. Plants obtain carbon, oxygen and hydrogen from the air, and nitrogen, phosphorus,

potassium, magnesium, calcium and sulfur from the soil. These macronutrients are essential for plants to grow. o Macronutrients: _______________________________________________________

There are other elements that are also needed, but not in large quantities. These elements are called trace elements.

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The body cannot manufacture macronutrients. It can only get them from food. 16 naturally occurring elements are present in all living organisms. Green plants require 18

elements for proper growth and functioning, while humans need 25 elements, which are used for growth and function.

Element Symbol

Nutrient Name

Importance of Element/Nutrient

MacronutrientsN - Composition of proteins and nucleic acids

- Growth and repair of tissue in plants and in humans

P

K - Helps regulate nerve signals and muscle activity- Involved in protein formation- Required to regulate acid/base balance

Mg

Ca

S - Not actually needed in element form, but sulfur in amino acids is the basis of all proteins

Na

Micronutrients (Trace Elements)Cl - Helps regulate water balance

- Plays a role in proper cell membrane function- Component of hydrochloric acid in the stomach

Fe

Zn - Essential component of enzymes regulating protein formation and carbohydrate metabolism

I

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Se - Component of an antioxidant enzyme that helps prevent decay of cell function

Cu

Mn

F

Cr Activates vitamin B3 to control use of blood sugar in energy production

Mo

Co

Think About It

Canada’s Food Guide recommends the balance of nutrients you should try to eat every day. Do you think you could get the same results by eating from only one food group each day, as long as you eat from all four food groups over the course of a week? Or from eating twice as much as normal in one day, then eating nothing the next day? Explain your reasoning.

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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Chemicals and Farming

Natural Fertilizers

Plants naturally obtain the nutrients necessary for survival from the soil surrounding their roots. These nutrients are returned to the soil during the process of ____________________.

Thus, compost (decomposed organic material) makes excellent natural fertilizer for plants.

Commercial Fertilizers

In order to facilitate more growth, larger growth, and faster growth, commercial fertilizers are often added to crops.

The three numbers on a bag of fertilizer refer to the percentage of nitrogen, phosphate, and potassium that is available to plants from that bag of fertilizer.

Nitrogen: promotes better growth for ________________ Phosphates: promotes better growth for ______________ Potassium: promotes better growth for _______________ The artificial production of fertilizers has increased the

amount of nitrogen in the environment by as much as 140 million tons per year.

Crop production has doubled worldwide due to the use of artificial fertilizers.

Pesticides

Pesticides are chemical agents used to protect crops by reducing the amount of damage caused by a variety of pests o Herbicides: _____________________________________________________________o Insecticides: ____________________________________________________________o Fungicides: _____________________________________________________________

Pesticides are often costly, and can have harmful effects on the environmento Ex. DDT (dichlorodiphenyltrichloroethane) is an example of a persistent pesticide that

can remain in the environment for long periods of time. It was widely used to control insects populations and a variety of human diseases in the 1950s and 1960s. It has since been banned globally for the numerous consequences it has on the health of both humans and on ecosystems.

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Uptake of Materials by Producers

All living organisms need a constant supply of raw materials and energy to produce new cells for growth, to repair damage and to maintain proper health. Plants take in inorganic compounds to make organic compounds.

Nutrients enter the roots by ______________________ - the movement of molecules from an area of high concentration to an area of low concentration. This action continues until the areas are equal concentrations.

Water moves through plants by a special type of diffusion, called _________________. In this process, water moves through the walls of the plant's roots from an area where there are more water molecules to an area where there are fewer water molecules. As the plant uses the water it draws more up from its roots.

Where organisms live affects how and when they can obtain the nutrients they need. o Some organisms get the nutrients they need often by restricting other organisms from

getting the same nutrients (__________________________________________). A substrate is a material on which an organism moves or lives. Some organisms attach

themselves to the substrate, while others obtain their nutrients from their substrate.

Uptake of Materials by Consumers

Consumers rely on the ingestion of other organisms in order to satisfy their energy and nutrient requirements. o Ingestion: ____________________________________________________________

The process of digestion breaks down the chemicals present in food. o Food is broken down into molecules that are small and soluble, which can then pass

through membranes into your blood. These chemicals (nutrients) are then carried throughout your body to the cells which need them for energy, growth, body building and cell repair.

Consumers use the organic compounds made by plants for their energy, growth and repair. When organisms take in these compounds, other substances are also taken. These substances may be harmless or harmful. By knowing how plants use each element, agriculturalists can diagnose deficiencies and excesses, and act accordingly, to alleviate the problem.

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Chemicals and the Ecosystem

Biological Monitoring

All wastes entering the environment are potentially harmful and must be broken down into nonpolluting compounds, or be treated to reduce the harmful effects these wastes can have.

________________________________________ wastes are naturally degraded. ____________________________ pollutants accumulate and take a long time to degrade. It is the ______________________________ of these wastes that can affect living

organisms. To determine the concentration scientists test wastes, persistent and non-persistent, to determine how to handle them and deal with their effects in the environment.

Chemicals and Biological Diversity

Most types of pollution adversely affect water quality and directly affect living organisms. Microscopic organisms (bacteria) can cause serious health problems if they are present in

sufficient numbers. Samples are taken to identify their presence to avoid contamination of the water supply.o Example: Health Canada requires that no E. coli bacteria be detectable in 100 mL of

water before it is deemed safe for human consumption.

Aquatic Environments are places where __________________________________ live depending on the pH level and the amount of _______________________________ present. o Macroinvertebrates: organisms with no backbone that are visible to the human eye

Worms, leeches and midge larva thrive in polluted water, as they require only small amounts of dissolved oxygen for survival

Water Quality

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Water quality is determined using chemical and biological indicators according to what the water is going to be used for.

Chemical indicators of water quality include: dissolved oxygen, acidity, heavy metals, nitrogen, phosphorus, pesticides, salts, and turbidity.

Chemical Concentrations in Water

A pollutant is any material, or form of energy, that can cause harm to living organisms. Pollution is _______________________________________________________________

that produces a condition which threatens living organisms. To determine if something is a pollutant or pollution, we must determine how much of it is

present. Concentrations are usually measured in parts per million (ppm)

o One part per million means that one unit of an element or chemical can be found in one million units of solution.

o Example: 1 ppm means there is one gram of chemical dissolved in 1000 L of water, or 1 mg of chemical dissolved in 1 L of water.

ppm= grams of solutegrams of solution

× 106=mg of soluteL solution

Some substances are measured in ppb (parts per billion) or even ppt (parts per trillion)

Allowable Concentrations of Chemicals in Canadian Drinking Water(Source: Health Canada)

Chemical Toxic Effects Allowable ConcentrationAluminum No adverse health effects in

humans0.1 – 0.2 ppm

Arsenic Cancer (lung, bladder, liver, skin)

0.010 ppm

Chromium VI Enlarged liver, irritation of the skin, respiratory and gastrointestinal tracts

0.05 ppm

Mercury Irreversible neurological symptoms

0.001 ppm

Nitrate Methaemoglobinaemia (blue baby syndrome), possible carcinogen

45 ppm

Toxicity Levels

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Toxicity is the ability of a chemical _____________________________________________. o _____________ toxicity: when serious symptoms occur after only one exposure to the

chemical o _____________ toxicity: when symptoms appear only after a chemical accumulates to a

specific level after many exposures over time A common measurement of the toxicity of a substance is by its Lethal Dose 50.

o LD50: the dose of a chemical that will kill 50 percent of the population to which it is applied.

The LD50 takes into account that some individuals within the target population may be more resistant to the toxic effects of the chemical.

Examples of LD50 Levels for Selected Chemicals

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Acidity and Alkalinity

Acids

Acids taste _________, are soluble in water, react with bases, and have a pH less than 7 Examples: __________________________________________________________________

Bases

Bases taste _________________, are soluble in water, feel slippery, react with acids, and have a pH greater than 7.

Examples: __________________________________________________________________

Neutral Substances

Substances that are neither acidic not basic are said to be neutral. Examples: __________________________________________________________________

pH Scale

pH means “power of hydrogen,” and is a measure of the concentration of hydrogen ions (hydrogen atoms that have lost an electron) in a solution.

The strength or concentration of an acid or base determines the extent to which it reacts with water. The reaction changes the electrical conductivity of the water, which can be measured with a sensitive conductivity test meter.

The pH scale is a way of comparing the relative acidity or alkalinity of a substance.

pH Indicators

To identify a substance as an acid, a base, or neutral, an indicator is used.

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A litmus paper test cannot provide a specific pH value, but is a useful tool for classifying a substance as either an acid or a base.

Meaning of Litmus Paper TestsThe following chart indicates the conclusions that can be drawn about a substance based on the results of testing it with litmus paper.

Red Litmus Paper turns blue Red Litmus Paper stays red

Blue Litmus Paper turns red

Blue Litmus Paper stays blue

pH paper will change to a colour that is characteristic of a specific pH. These colours are then matched against a chart that shows the range of colours for known pH values.

Red cabbage juice is a natural indicator that will also change colour for a variety of pH values.

Other chemical pH indicators include bromothymol blue, bromocresol green, cresol red, methyl orange, and phenolphthalein. o Each of these solutions will change in colour when exposed to substances within

particular pH ranges.

Neutralization

Acids and bases react together when they are mixed. This type of reaction is called neutralization. Both the acid and the base are used up in this type of reaction. o The products of neutralization reactions are _____________ and _________________.

Example: Acid in your stomach has a normal pH of 2. This acid helps in the digestion of food and kills off bacteria. If you eat too quickly, or are under stress, your stomach produces an excess amount of gastric acid, giving you heartburn. To neutralize the excess acid, an antacid tablet is swallowed. This antacid is a mild base.

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Acid Precipitation

Sulfur, nitrogen and carbon oxides emitted from industries combine with ________________ in the air to produce sulfuric, nitric and carbonic acid.

These pollutants then fall to the ground as acid precipitationo Acid precipitation has a pH lower than that of normal rain, which is about 5.6

Some effects of acid precipitation:

o Soil fertility is reducedo Kills organisms in lakes and

streamso Leaches toxic chemicals from the

soil

o Damages or destroys aquatic ecosystems

o Slows tree growtho Corrodes exposed metal surfaceso Breaks down stone and limestone

To neutralize acid precipitation, ____________ (calcium hydroxide, a base) is added to lakes. o This is not necessary in Alberta because the

mountains contain rich deposits of limestone, making the water naturally basic. When the acid rain falls, it is neutralized almost immediately.

Preventing Acid Precipitation

Acid precipitation is caused by sulfur, nitrogen and carbon oxides from industry reacting with water vapour in the air. Reducing these emissions at the source is a simple, economical method to prevent acid precipitation.

Modern cars come equipped with __________________________________, which ensures complete combustion of the hydrocarbon fuel, thus reducing the production of carbon monoxide and nitrous oxides produced by passenger vehicles.

Thermo-electric power plants that burn coal can be a major source of oxides, depending on the ______________________________________________ in the coal. These plants utilize ____________________ to reduce oxide emissions. Chemical reactions inside the scrubbers remove sulfur from the air before it is released into the environment.

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Think About It

1. According to the information in the graph, which of the species is most sensitive to changes in the pH of the lake? Why?

____________________________________________________________________________________________________

2. Which species has the fewest number of organisms present in lake water that has a neutral pH? How do you know?

____________________________________________________________________________________________________

3. If acid rain falls into the lake and changes the pH of the water from 6.3 to 5.0, which species will increase in concentration? How do you know?

____________________________________________________________________________________________________

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Chemicals and Industry

Transfer of Materials through Air

The source of a pollutant may be in one place, but it can show up in many other places around the world.

The direction and distance that airborne chemicals travel are determined by various factors, includingo The properties of the chemical pollutanto The wind speedo The direction of the prevailing winds

The distribution of particles may also be limited by lack of __________ or ______________ The source of most airborne particles now is primarily human activities (industries,

agriculture and manufacturing), whereas in the past natural sources (forest fires and volcanoes) were the main culprits.

Transfer of Materials through Water

Hazardous chemicals can enter surface water from the air, the groundwater, runoff from agricultural fields and industrial sites and outflow from storm sewers and sewage treatment plants.

A substance that dissolves in water easily may be carried by water a fair distance and dispersed over a wide area.

Substances that do not dissolve easily may sink to the bottom and be concentrated close to the source, affecting organisms in the immediate area.

Most surface water pollution is a result of washing clothes or watering lawns. o Nitrates and phosphates enter the water system through storm sewers, runoff or

untreated wastewater. Treatment of wastewater and sewage is necessary to reduce its harmful effects when it

reenters the water system from which it was taken. o Certain contaminants can remain collected in the groundwater for long periods of time

(because they are heavy metals), posing problems if the groundwater is used for drinking, agricultural purposes or industrial use.

A factor that affects the movement of contaminants in groundwater is the number and connection of pores (tiny spaces between soil grains) in the soil. o When the pores are packed together very tightly and are not connected, the soil is

considered impermeable. o If the pores are connected the soil is permeable and water can move through easily.

Permeable ground can create aquifers, which collect naturally filtered amounts of water that providing a good source of drinking water, accessible when a well is drilled.

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Transfer of Materials through Soil

Activities around a sanitary landfill often evoke a “not in MY backyard” response. There are so many negative impacts of landfills that the activities to make sure they are safe must be monitored daily. The problems that can be encountered include: wind dispersal, scavengers and disease, leaching into groundwater, as well as methane and carbon dioxide gas production.

To reduce these problems, a _______________________________ is designed to ensure that possible negative impacts are addressed and the landfill site is a secure and safe operation.

Biodegradation

Biodegradation occurs in the environment because living things (earthworms, bacteria and fungi) are actively breaking down organic substances, including many pollutants. Micro-organisms are especially important in the biodegradation of pollutants.

The existing organic molecules provide carbon atoms, which are used to build biological compounds, such as carbohydrates and proteins. This is a multi-step process in which the large organic molecules are broken down either inside or outside bacteria.

Some bacteria grow and reproduce only when oxygen is present. They use the oxygen for the process of ______________________ biodegradation.

When oxygen is not present – in an ________________________ environment (like deep in landfill sites) – some bacteria remove chlorine from harmful chlorine-containing compounds, such as PCB’s and replace them with hydrogen atoms, which can be used as food for the bacteria.

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During the winter biodegradation is slow, because temperature affects the rate of biodegradation. Other factors include soil moisture, pH, oxygen supply and nutrient availability.

When chemicals are released in the environment in an uncontrolled manner, the consequences can be devastating.

Environmental Effects of Exxon Valdez Spill Still Being FeltBy Sarah Graham | December 19, 2003

On March 24, 1989, the Exxon Valdez ran aground in northern Prince William Sound, spilling 42 million liters of crude oil and contaminating 1,990 kilometers of shoreline. Some 2,000 sea otters, 302 harbor seals and about 250,000 seabirds died in the days immediately following the spill. Now researchers writing in the journal Science caution that more than a decade later, a significant amount of oil still persists and the long-term impacts of oil spills may be more devastating than previously thought.Charles H. Peterson of the University of North Carolina at Chapel Hill and his colleagues compiled and analyzed the findings of dozens of previous studies. The results, Peterson says, "showed that oil has persisted in surprisingly large quantities for years after the Exxon Valdez spill in subsurface reservoirs under coarse intertidal sediments. This oil was sequestered in conditions where weathering by wave action, light and bacteria was inhibited, and toxicity remained for a decade or more." Exposure to this oil, in turn, caused additional animal deaths. Salmon, for example, had increased mortality for four years after the spill because incubating eggs had come into contact with it. Larger marine mammals and ducks, meanwhile, suffered ill effects because their prey was contaminated. The team estimates that shoreline habitats such as mussel beds affected by the spill will take up to 30 years to recover fully.The findings should inform the development of better ways to assess the ecological risks of large-scale oil spills, the scientists say. In addition, the work applies to other areas of environmental remediation. "Recognition that chronic exposures of fish eggs to oil concentrations as low as a few parts per billion lead indirectly to higher mortality shows the critical need to better control stormwater runoff of petroleum hydrocarbons and other toxins," Peterson remarks. "In a developed country like the U.S., an amount of petroleum equal to the Exxon Valdez oil spill is spilled annually for every 50 million people."

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Fracking wastes may be toxic, tests showChemicals in the wastes can fool the body by mimicking hormones or disrupting their actionsBY BETH MOLE  7:00AM, APRIL 5, 2015

This field of storage tanks (in yellow) holds fracking wastewater. At one point, an estimated 760,000 gallons of watery wastes were being stored at this Lamb's Farm Storage Facility, in Pennsylvania.DENVER, Colo. — Fracking is a procedure used to extract oil or gas from deep underground. The process uses lots of water and lots of chemicals. This

means it also produces lots of watery wastes. A series of new tests now show those wastes may be toxic.Scientists found the wastewater can contain chemicals that alter the action of the body’s hormones. In mice exposed in the womb, the heart and reproductive tissues did not develop normally.Many energy companies around the world use hydraulic fracturing — or fracking — to release oil, and especially gas. (That gas usually comes from deposits of shale, a type of rock.) But this process has been controversial. Oil and gas companies inject chemicals deep into wells to flush out the gas and oil. Those chemicals can contaminate groundwater, some studies have shown.For the new study, researchers worked with human cells and mice. First, they looked for signs in cells that the chemicals altered signaling by any of five different hormones. Hormones are natural chemicals produced by the body’s endocrine system. That system  produces hormones that tell various tissues when to turn on or off a particular important action.For instance, hormones help people process food, identify hunger and recognize when it’s time to sleep. Hormones also tell tissues when it’s time to grow. Puberty and reproduction, for instance, are controlled by a complex series of hormonal changes.

Signs of animal impacts

Christopher Kassotis works at the University of Missouri in Columbia. He’s also the study’s lead researcher and an endocrinologist (EN-doh-krin-OLL-uh-gizt), someone who studies hormone impacts. For the new study, his team combined 23 hormone-disrupting chemicals known to have been used by oil and gas companies for fracking.Hormone-like pollutants can do harm in one of two ways. Some may block a true hormone’s signal. Others may fake out the body, turning on some activity normally triggered by a real hormone.Energy companies seldom disclose the precise recipe of chemicals in their fracking fluids. But

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lists of some fracking chemicals have been published. (Such ingredients can include chemicals that kill microbes or that inhibit rust and other forms of corrosion.) Kassotis and his coworkers tried to mix these chemicals in amounts that might roughly match levels in real fracking wastewater.

For their new study, the researchers gave pregnant mice drinking water that contained a cocktail of these fracking chemicals. Male offspring of these mice grew up overweight. Those males also had heavier hearts compared to mice whose mothers hadn’t drunk water containing fracking chemicals. (The researchers are still analyzing the data from female offspring.)

Finally, male mice exposed in the womb to the fracking chemicals developed bigger testes. “This is not actually a good thing,” said Kassotis. Larger testes can lead to cysts and other health problems, he says.The effects seen in the male offspring echo health problems seen in people: Studies have linked other hormone disrupters to obesity. And epidemiologists have found an increased rate of heart defects in babies whose mothers live near natural gas wells, including fracking sites.It’s unlikely people would ever encounter doses of fracking chemicals as high as those given to the mice, Kassotis says. But some human exposures might not be too much lower, he adds. Fracking fluids and wastewaters often spill, he explains. This can taint soils and rivers. In January, for example, a leaking pipeline spewed more than 11 million liters (2.9 million gallons) of fracking wastewater. That pollution entered a stream near Williston, N.D.Earlier, Kassotis’s team collected samples of soil and water from areas where spills had occurred in Colorado. Hormone-disrupting chemicals showed up.How dangerous are these exposures to people? No one knows, says Karl Linden. He’s an environmental engineer at the University of Colorado Boulder. But he is developing ways to clean up fracking wastewater. He hopes these techniques will help remove hormone mimicking pollutants.Scientists don’t know all of the hormone-like chemicals in fracking fluid yet, Linden notes. But, he adds, they’re definitely there.

Record dolphin die-off linked to BP oil spillExposure to oil spill caused life-threatening adrenal and lung diseaseThomson Reuters Posted: May 20, 2015 2:31 PM ET Last Updated: May 20, 2015 2:31 PM ET

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A record dolphin die-off in the northern Gulf of Mexico was caused by the largest oil spill in U.S. history, researchers said on Wednesday, citing a new study that found many of the dolphins died with rare lesions linked to petroleum exposure.Scientists said the study of dead dolphins tissue rounded out the research into a spike of dolphin deaths in the region affected by BP Plc's oil spill that was caused by the 2010 Deepwater Horizon oil rig explosion.Millions of barrels of crude oil spewed into Gulf waters, and a dolphin die-off was subsequently seen around coastal Louisiana, Alabama and Mississippi, according to the National Oceanic and Atmospheric Administration (NOAA)."Dolphins were negatively impacted by exposure to petroleum compounds," from the spill, said Stephanie Venn-Watson, a veterinary epidemiologist at the National Marine Mammal Foundation and lead author of the study published in the scientific journal PLOS ONE."Exposure to these compounds caused life-threatening adrenal and lung disease that has contributed to the increase of dolphin deaths in the northern Gulf of Mexico," she added.More than 1,200 cetacean marine mammals, mostly bottlenose dolphins, have been found beached or stranded since the spill, according to NOAA, which has declared an ongoing "unusual mortality event" under 1972 Marine Mammal Protection Act.To understand the cause of death, researchers compared tissue samples from 46 dolphins in areas affected by the spill with 106 dolphins that were not exposed.Dead dolphins near the spill were more likely to have lung damage and pneumonia, researchers found, explaining the mammals would have inhaled contaminants coming up for air near the water's surface."These dolphins had some of the most severe lung lesions I have ever seen in wild dolphins throughout the United States," said Kathleen Colegrove, the University of Illinois-based lead veterinary pathologist for the study.