Human communities benefit from technology. Inventions andhuman-engineered materials have improved human survivaland quality of life. Technology allows us to live comfortably inharsh habitats. It also helps us produce large quantities of foodand transport food, goods, and ourselves long distances.

Throughout each day and night, members of humancommunities consume oxygen, water, and food and producewaste. We use energy for transportation, heating and cooling,and to power businesses and industries. We interact with bioticand abiotic elements for survival, just as other living things do.

When we are developing new technologies to improve ourlives, we do not always stop to consider what impact they willhave on the other biotic elements in our ecosystem or theabiotic elements in the environment in general.

68 UNIT A Interactions in the Environment

The Environmental Impact of Humans3.2Here is a summary of what you will learn in this section:

Many modern human technologies have affected the quality of air and water for all living things.

Many human interactions with the environment have affected the habitat of other living things.

Many of the waste products of human technology cannot be cycled by decomposers.

A39 Starting Point

Untouched ecosystems are becoming rare. Oneway to maintain them is to close them off andprotect them from development and visitors.

Another idea is to show people the complexrelationships among the biotic and abiotic elementsin these special places by opening them to visitors.Ecotourism is a growing business in areas likeWabakimi Provincial Park near Thunder Bay, where ithelps to support the park financially.

These visitors need places to stay and eat, aswell as transportation. Roads and buildings must

be built. Power sources are required. Openingan unspoiled area to visitors could have somenegative costs for the ecosystem.

Consider This

With a partner or in class, debate the following:Visitors should be kept out of ecosystemsthat are fragile or unique.Choose your viewpoint and support yourargument.

Ecotourism

Skills A C

Figure 3.8 A water pump, whether it is small enough for a family or large enough for acity, is a technology that saves labour and improves the quality of life.

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Assessing Human ImpactWhile our activities and technologies improve our quality oflife, they also affect local ecosystems and Earths supply ofresources. Many of these technologies have damagedecosystems shared by all. Table 3.1 lists a few of the impactshuman activities have on ecosystems.

Housing, Transportation, and RecreationOutside of Ontarios big cities, communities are building onecosystems in order to add single-family homes, shoppingareas, businesses, and schools (Figure 3.9). These growingcommunities also need roads so the people who live there cantravel to work, get food, and get to other communities. Theroads cut through ecosystems, dividing or destroying habitat.

In 2005, it was estimated that Ontarios 8 million vehicleswere driven almost 125 billion kilometres. Those trips addedcarbon dioxide and other pollutants to the air. Shipping goodsby train takes cars and trucks off the roads, but accidents canresult in chemical and fuel spills that could poison water andsoil (Figure 3.10). Ecosystems may take a very long time torecover from the loss of these abiotic elements.

Popular recreational activities such as mountain biking andriding off-road vehicles are other human activities that cancause serious damage to ecosystems (Figure 3.11).

69We can change our actions and technologies to better protect the environment.

Figure 3.11 Popular outdooractivities with off-road vehicles cantear up the landscape and destroyplants and habitat.

Figure 3.10 Train accidents like thisone often result in poisonous leaksinto rivers and lakes.

Figure 3.9 New subdivisions ofsingle-family homes are sometimesdescribed as urban sprawl becausethey spread over land formerlyoccupied by ecosystems.

Element Impact

Air Burning fossil fuels for heating, transportation, and industry pollutes the air.

Water High water consumption by humans reduces the amount of

water available for other organisms. Development of human communities can disrupt the flow of

water through watersheds. Improper or casual disposal of chemicals can damage water

quality. Chemical spills occasionally poison rivers, lakes, and oceans.

Habitat Destruction of habitats means fewer producers are available to

anchor food chains. Destruction of habitats removes a basic support to all living things

in the ecosystem, possibly leading to extinction of some species.

Table 3.1 Selected Environmental Impacts of Human Activities

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These human activities can damage ecosystems, yet many ofthese activities are necessary for humans to live. Large farmsare needed to provide food. Roads are required to transportfood and goods to human consumers. Land is needed forhuman habitat.

Recycling vs. Waste Disposal Human activities produce large quantities of waste material.You have learned that some waste is organic and can bereturned to the soil through organic waste recycling programs.Other waste, such as paper, glass, metal, and some packaging,can be recycled. While these recycling activities remove somematerials from the piles of trash, communities in Ontario stillproduce thousands of tonnes of garbage that must be disposedof. Community garbage is often sent to landfill sites, where thematerial is buried (Figure 3.12). In 2007, the city of Torontosent about 441 350 tonnes of solid waste to landfill every day.

Early landfill sites leaked toxic substances and chemicalsinto the surrounding water and soil, poisoning abioticelements. Toxic substances can cause harm or death to livingthings. Modern landfills are monitored and sealed to preventtoxic leaks from garbage that could include discardedmedicines, home and industrial chemicals, and electronicequipment. We need landfill sites to store waste from ouractivities. No matter how carefully we manage them, landfillscover space once occupied by natural ecosystems.

70 UNIT A Interactions in the Environment

A40 During Writing

New homes, roads, and businesses are neededfor growing populations. However, they oftenharm local ecosystems. How can the needs ofhuman communities be met while stillprotecting the local environment and notdestroying the habitat of other living things?

Summarize the issue that this question aboveaddresses. Use what you read in this section andyour own thoughts to begin an organizer, such asa chart or web, to record ideas about this issue.Add more thoughts and facts as you continuereading. The ideas in this organizer will help youwrite a letter to the editor about the issue.

Gathering Ideas for Writing

Figure 3.12 Garbage, known assolid waste, is often disposed of inlandfill sites.

A growing number of people wantto buy organic foods. Find outwhat organic foods are and whysome people may be looking forthis type of food. Begin yourresearch at ScienceSource.

Take It Further

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A41 Decision-Making Analysis

71We can change our actions and technologies to better protect the environment.

Issue

Modern electronics are very popular. Thetechnologies used in these products are alwayschanging. New features are added. Products getsmaller and easier to use, and consumers wantto get the newest version. It has been estimatedthat Canadians throw out 1450 tonnes ofcellphones alone in a year. Computers, cameras,game systems, and music players add to thepile (Figure 3.13).

Electronic products contain plastic and metalssuch as aluminum, copper, gold, iron, lead,mercury, steel, and zinc. None of thesematerials can be broken down by decomposers.What should be done with all this waste?

Background Information

1. In order to evaluate the best way to dispose ofold electronic products, you need moreinformation. Working in a group of six, eachmember will choose one of the followingoptions for disposing of unwanted electronics.Not all of the options are available in Canada.Research will need to include options fromaround the world.

(a) donating the product to someone else

(b) sending the product to landfill

(c) incinerating the product

(d) recycling in a foreign country

(e) recycling in Canada for a fee

(f) requiring the manufacturer to take the oldproduct back

2. Use the guidelines below to focus yourresearch. Record the information and sourcesof your research in notes, charts, or tables.Use your judgement to choose the bestmethods for recording your data.

(a) Choose one electronic product you havediscarded in the last year. Try to find outthe estimated amount of this product thatis being discarded every year in Canada.

(b) Describe how your preferred disposaloption works.

(c) Describe the impact of your preferredoption on the environment, if any.

(d) Describe the impact of your preferredoption on human health, if any.

(e) Estimate whether or not your preferredoption could absorb all or most of theelectronic waste being generated inCanada.

Analyze and Evaluate

3. As a group, prepare a report recommendingthe best way or ways to handle electronicwaste in Canada. Include the reasons forchoosing the options the group isrecommending and the reasons for rejectingother options.

SKILLS YOU WILL USE Organizing information Reporting results

Taking Out the E-Trash

Toolkit 4

Figure 3.13

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72 UNIT A Interactions in the Environment

A42 Problem-Solving Activity

Cleaning Up an Oil Spill

Recognize a NeedOil is shipped long distances in large tankers. Fromtime to time, these tankers run aground and spilltheir contents along a shoreline. People livingnearby must move very quickly to clean up the oilbefore it damages local ecosystems.

ProblemHow can you clean up an oil spill in anecosystem?

Criteria for Success

Oil is completely cleaned out of the water andthe other abiotic and biotic materials.

Brainstorm Ideas1. Research the technologies used to clean up

spills from oil tankers. How effective werethese technologies?

2. What technologies could you use to clean upyour model oil spill?

Build a Model

3. Create a miniature shoreline ecosystem inyour container. Use the rocks to protect thesand. Add the water last, using just enough tocreate a model shoreline.

Test and Evaluate4. Take 2 tbsp of the oil and add it to the water.

Move the container from side to side tomodel gentle wave action.

5. Use the technology you researched to cleanup biotic and abiotic elements in your mini-ecosystem.

6. Share and compare your ideas and findingswith your classmates plans and findings. Didanyone have ideas exactly like yours? Similarto yours? Completely different from yours?How do your results compare with theirs?

Communicate7. Prepare a report or computer slide show

presentation on the success of your clean-upoperation. Or present your findings to theclass in a form suggested by your teacher.

SKILLS YOU WILL USE Identifying a problem Designing, building, and testing

Toolkit 3

Figure 3.14 Oil spills destroy the insulating qualities of thefeathers and fur of many shoreline birds and animals.

Materials & Equipment a square or rectangular shallow container

(minimum 1.2 L) 1 L of sand 4-5 small rocks 2 small plants water 2 tbsp (30 mL) motor oil materials of your choice for use in the

clean-up

Anchor Activity

DI

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73We can change our actions and technologies to better protect the environment.

In Chapter 2, you read about limiting factors onpopulations. These included predators and thesupply of resources such as water, food, andsuitable habitat.

In 1900, the worlds human population wasestimated to be 1.7 billion. In 2000, it wasestimated to be 6.1 billion.

What to Do

1. Use the Internet to find out what theestimated population of the world is nowand what the population is projected to be10 years from now.

Consider This

With a classmate or as a whole class, discussthe following questions.

1. Do you think limiting factors could affectthe worlds human population? Explainyour reasoning.

2. Which limiting factor do you think is mostlikely to have an impact on the worldspopulation? Explain your reasoning.

3. What do you think the worlds populationscould do to protect themselves from theimpact of limiting factors?

Limiting Factors and Human Communities

Key Concept Review

1. Describe two ways in which humanactivity has had an impact on abioticelements. How could these impacts affectthe environment?

2. How does recycling help solve some of theproblems caused by the amount of wasteproduced by human activities?

3. How could teens discard unwantedelectronic equipment without havingmuch or any impact on the environment?

4. Explain why some environmentalchanges caused by humans cannot bedealt with by the process of succession.

Connect Your Understanding

5. Describe three ways in which youractivities affect the environment. Arethese effects positive or negative?

Practise Your Skills6. Why is it important to consider opinions

from a variety of perspectives whenevaluating information to make adecision?

For more questions, go to ScienceSource.

3.2 CHECK and REFLECT

S TS EA43 Thinking about Science and the Environment

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